feat(patreon): ingester rate-limit resilience — #703 step 1

A single 429 mid-walk used to fail the run → RATE_LIMITED → platform-wide
cooldown → every Patreon source dark ("testing dead"). The native path also
ignored the operator's existing politeness setting. Fixed both:

- Pacing (avoid 429s): honor download_rate_limit_seconds (gallery-dl's
  `rate_limit`, read off self.gdl) as a pre-download sleep on real media
  downloads only (skips don't pace); pace /api/posts page fetches with the
  per-source sleep_request override, defaulting to max(0.5, rate_limit/4) —
  the same API-pacing default gallery-dl used for `sleep-request`.
- 429 backoff (ride out transient limits): PatreonClient._fetch retries a
  429 with backoff (honor Retry-After, else exponential 2·2^(n-1), capped
  30s, ≤3 tries); only a PERSISTENT 429 propagates as terminal
  RATE_LIMITED. Light 2-retry on a media-GET 429 too.

Threaded via PatreonIngester(rate_limit=, request_sleep=) →
PatreonClient/PatreonDownloader; download_service sources them. Injected
test client/downloader are unaffected (carry their own pacing).

Tests mock time.sleep (no real sleeping): retry-then-success, persistent
429 raises after N, Retry-After honored, request_sleep paces, media pacing
per real download, skips don't pace, media 429 retried.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

alembic/versions/0037_patreon_seen_media.py

@@ -0,0 +1,53 @@
+"""patreon_seen_media: per-source ledger of already-ingested Patreon media
+
+Revision ID: 0037
+Revises: 0036
+Create Date: 2026-06-05
+
+Native Patreon ingester (build step 2a). Replaces gallery-dl's
+archive.sqlite3 with our own queryable table. The downloader upserts one
+row per (source, media) so routine walks skip media we've already
+processed; a future "recovery" mode bypasses the ledger to re-walk.
+
+`filehash` is a 32-hex Patreon CDN MD5, OR a video sentinel of the form
+``video:<post_id>:<media_id>`` — hence String(128). The unique
+constraint on (source_id, filehash) is the dedup upsert key.
+"""
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "0037"
+down_revision: Union[str, None] = "0036"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "patreon_seen_media",
+        sa.Column("id", sa.Integer, primary_key=True),
+        sa.Column(
+            "source_id",
+            sa.Integer,
+            sa.ForeignKey("source.id", ondelete="CASCADE"),
+            nullable=False,
+            index=True,
+        ),
+        sa.Column("filehash", sa.String(128), nullable=False),
+        sa.Column("post_id", sa.String(64), nullable=True),
+        sa.Column(
+            "seen_at",
+            sa.DateTime(timezone=True),
+            nullable=False,
+            server_default=sa.text("NOW()"),
+        ),
+        sa.UniqueConstraint(
+            "source_id", "filehash", name="uq_patreon_seen_media_source_id"
+        ),
+    )
+
+
+def downgrade() -> None:
+    op.drop_table("patreon_seen_media")

backend/app/api/credentials.py

@@ -121,13 +121,15 @@ async def delete_credential(platform: str):
 
 @credentials_bp.route("/<platform>/verify", methods=["POST"])
 async def verify_credential(platform: str):
-    """Test the stored credential by running gallery-dl --simulate
-    against one of the platform's enabled sources. On success stamps
-    last_verified. Returns {valid: bool|null, reason, last_verified?}.
-    valid=null means "couldn't test" (no credential, or no enabled
-    source to point at)."""
+    """Test the stored credential against one of the platform's enabled sources,
+    WITHOUT downloading. Routes through the platform's backend
+    (download_backends.verify_credential) — native ingester for Patreon, an
+    authenticated API page; gallery-dl --simulate for the rest. On success
+    stamps last_verified. Returns {valid: bool|null, reason, last_verified?};
+    valid=null means "couldn't test" (no credential, no enabled source, or an
+    inconclusive network/drift result)."""
     from ..models import Artist, Source
-    from ..services.gallery_dl import GalleryDLService, SourceConfig
+    from ..services.download_backends import verify_source_credential
 
     async with get_session() as session:
         if not await _ext_key_ok(session):
@@ -154,14 +156,14 @@ async def verify_credential(platform: str):
         cookies_path = await svc.get_cookies_path(platform)
         auth_token = await svc.get_token(platform)
 
-    gdl = GalleryDLService(images_root=Path("/images"))
-    ok, message = await gdl.verify(
+    ok, message = await verify_source_credential(
+        platform=platform,
         url=source.url,
         artist_slug=artist.slug,
-        platform=platform,
-        source_config=SourceConfig.from_dict(source.config_overrides or {}),
+        config_overrides=source.config_overrides or {},
         cookies_path=str(cookies_path) if cookies_path else None,
         auth_token=auth_token,
+        images_root=Path("/images"),
     )
 
     last_verified = None

backend/app/api/sources.py

@@ -122,26 +122,32 @@ async def delete_source(source_id: int):
 
 @sources_bp.route("/<int:source_id>/backfill", methods=["POST"])
 async def set_backfill(source_id: int):
-    """Plan #544: arm a source for backfill mode for the next N download
-    runs. Body: `{"runs": int}` (1..10, default 3). Returns the updated
-    source dict. While backfill_runs_remaining > 0, downloads use
-    gallery-dl's full-walk config (skip: True + 30-min timeout) instead
-    of the catch-up default (skip: "exit:20" + 14.5-min timeout)."""
+    """Plan #693/#697: start/stop a run-until-done backfill, or start a recovery.
+    Body: `{"action": "start" | "stop" | "recover"}` (default "start"). 'start'
+    walks the full post history in time-boxed chunks until it reaches the bottom
+    (then the source shows 'complete'); 'recover' is the same walk but bypasses
+    the Patreon seen-ledger to re-fetch dropped-and-deleted near-dups under the
+    current pHash threshold; 'stop' cancels either back to tick mode. Returns the
+    updated source dict (incl. backfill_state / backfill_chunks /
+    backfill_bypass_seen)."""
     payload = await request.get_json(silent=True) or {}
-    runs = payload.get("runs", 3)
-    try:
-        runs = int(runs)
-    except (TypeError, ValueError):
-        return _bad("invalid_runs", detail="runs must be an integer")
+    action = payload.get("action", "start")
+    if action not in ("start", "stop", "recover"):
+        return _bad(
+            "invalid_action",
+            detail="action must be 'start', 'stop', or 'recover'",
+        )
     async with get_session() as session:
         try:
-            record = await SourceService(session).set_backfill_runs(
-                source_id, runs,
-            )
+            svc = SourceService(session)
+            if action == "start":
+                record = await svc.start_backfill(source_id)
+            elif action == "recover":
+                record = await svc.start_recovery(source_id)
+            else:
+                record = await svc.stop_backfill(source_id)
         except LookupError:
             return _bad("not_found", status=404)
-        except ValueError as exc:
-            return _bad("invalid_runs", detail=str(exc))
     return jsonify(record.to_dict())
 
 

backend/app/models/__init__.py

@@ -14,6 +14,7 @@ from .import_settings import ImportSettings
 from .import_task import ImportTask
 from .library_audit_run import LibraryAuditRun
 from .ml_settings import MLSettings
+from .patreon_seen_media import PatreonSeenMedia
 from .post import Post
 from .post_attachment import PostAttachment
 from .series_page import SeriesPage
@@ -33,6 +34,7 @@ __all__ = [
     "BackupRun",
     "Source",
     "Credential",
+    "PatreonSeenMedia",
     "Post",
     "PostAttachment",
     "SeriesPage",

backend/app/models/patreon_seen_media.py

@@ -0,0 +1,38 @@
+"""PatreonSeenMedia — per-source ledger of Patreon media already
+downloaded+processed.
+
+Replaces gallery-dl's archive.sqlite3 with our own queryable table so
+routine walks can skip media we've already ingested (and a future
+"recovery" mode can deliberately bypass the ledger to re-walk).
+
+`filehash` is normally a Patreon CDN MD5 (32 hex chars), but videos —
+which have no stable content hash at discovery time — use a sentinel of
+the form ``video:<post_id>:<media_id>``, hence String(128) rather than 32.
+"""
+
+from datetime import datetime
+
+from sqlalchemy import ForeignKey, Integer, String, UniqueConstraint, func
+from sqlalchemy.orm import Mapped, mapped_column
+from sqlalchemy.types import DateTime
+
+from .base import Base
+
+
+class PatreonSeenMedia(Base):
+    __tablename__ = "patreon_seen_media"
+    __table_args__ = (
+        # Dedup key the downloader upserts against: one ledger row per
+        # (source, media). A second sighting of the same media is a no-op.
+        UniqueConstraint("source_id", "filehash", name="uq_patreon_seen_media_source_id"),
+    )
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    source_id: Mapped[int] = mapped_column(
+        ForeignKey("source.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    filehash: Mapped[str] = mapped_column(String(128), nullable=False)
+    post_id: Mapped[str | None] = mapped_column(String(64), nullable=True)
+    seen_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now()
+    )

backend/app/services/download_backends.py

@@ -0,0 +1,71 @@
+"""Platform → download-backend dispatch (one place that knows which platforms
+are served by the native FC ingester vs. the gallery-dl subprocess).
+
+gallery-dl wasn't built to be driven by an automated scheduler — no native
+checkpoint/resume, no structured logs, per-file HEADs that dominate wall-clock.
+The native ingester (services/patreon_ingester.py, plan #697) replaces it for
+Patreon and is the path we grow as more platforms migrate. To keep that
+migration DRY, every caller that has to behave differently per backend —
+download routing, the credential-verify probe, cursor handling — asks THIS
+module instead of testing ``platform == "patreon"`` inline. When a platform gets
+a native ingester, it moves into ``NATIVE_INGESTER_PLATFORMS`` here and both the
+download path and verify switch over together.
+
+The backend surfaces share a UNIFORM signature so a caller invokes the same
+function regardless of platform:
+  - verify_credential(...)  → (ok: bool|None, message: str)
+  - (download stays in download_service for now; uses_native_ingester() is the
+    shared predicate it routes on, so the decision lives here too.)
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+# Platforms whose download + verify go through the native ingester rather than
+# gallery-dl. gallery-dl still serves every other platform (subscribestar,
+# hentaifoundry, discord, pixiv, deviantart) unchanged.
+NATIVE_INGESTER_PLATFORMS = frozenset({"patreon"})
+
+
+def uses_native_ingester(platform: str) -> bool:
+    """True when `platform` is served by the native ingester (not gallery-dl).
+    The single predicate the download path and verify both route on."""
+    return platform in NATIVE_INGESTER_PLATFORMS
+
+
+async def verify_source_credential(
+    *,
+    platform: str,
+    url: str,
+    artist_slug: str,
+    config_overrides: dict | None,
+    cookies_path: str | None,
+    auth_token: str | None,
+    images_root: Path,
+) -> tuple[bool | None, str]:
+    """Uniform credential probe across backends. Returns `(ok, message)`:
+    True = authenticated, False = rejected, None = inconclusive (drift /
+    network / nothing to test). Callers don't branch on platform — they call
+    this and render the result.
+    """
+    if uses_native_ingester(platform):
+        # Native ingester platforms verify via their own lightweight auth probe
+        # (resolve campaign id + one authenticated API page). Patreon today.
+        from .patreon_ingester import verify_patreon_credential
+
+        return await verify_patreon_credential(url, cookies_path, config_overrides)
+
+    # gallery-dl platforms: --simulate one item; the extractor errors before it
+    # can list if auth is bad.
+    from .gallery_dl import GalleryDLService, SourceConfig
+
+    gdl = GalleryDLService(images_root=images_root)
+    return await gdl.verify(
+        url=url,
+        artist_slug=artist_slug,
+        platform=platform,
+        source_config=SourceConfig.from_dict(config_overrides or {}),
+        cookies_path=cookies_path,
+        auth_token=auth_token,
+    )

backend/app/services/download_service.py

@@ -13,7 +13,6 @@ from __future__ import annotations
 
 import asyncio
 import logging
-import re
 from datetime import UTC, datetime
 from pathlib import Path
 from typing import Any
@@ -25,44 +24,26 @@ from sqlalchemy.orm import joinedload
 
 from ..models import Artist, DownloadEvent, Source
 from .credential_service import CredentialService
+from .download_backends import uses_native_ingester
 from .gallery_dl import (
+    BACKFILL_CHUNK_SECONDS,
     BACKFILL_SKIP_VALUE,
-    BACKFILL_TIMEOUT_SECONDS,
     TICK_SKIP_VALUE,
+    DownloadResult,
     ErrorType,
     GalleryDLService,
     SourceConfig,
+    parse_last_cursor,
 )
 from .importer import Importer
-from .patreon_resolver import resolve_campaign_id
+from .patreon_ingester import PatreonIngester
+from .patreon_resolver import resolve_campaign_id_for_source
 from .platforms import auth_type_for
 from .scheduler_service import set_platform_cooldown
 
 log = logging.getLogger(__name__)
 
 
-_PATREON_VANITY_RE = re.compile(
-    r"^https?://(?:www\.)?patreon\.com/(?:c/)?(?!id:)([^/?#]+)",
-    re.IGNORECASE,
-)
-_CAMPAIGN_ID_FAILURE_PATTERN = "failed to extract campaign id"
-
-
-def _extract_patreon_vanity(url: str) -> str | None:
-    m = _PATREON_VANITY_RE.match(url)
-    return m.group(1) if m else None
-
-
-def _looks_like_campaign_id_failure(stdout: str, stderr: str) -> bool:
-    return _CAMPAIGN_ID_FAILURE_PATTERN in f"{stdout}\n{stderr}".lower()
-
-
-def _effective_url(platform: str, source_url: str, overrides: dict) -> str:
-    if platform == "patreon" and overrides.get("patreon_campaign_id"):
-        return f"https://www.patreon.com/id:{overrides['patreon_campaign_id']}"
-    return source_url
-
-
 class DownloadService:
     """Async orchestrator. The Celery task runs `asyncio.run(svc.download_source(N))`.
 
@@ -77,12 +58,18 @@ class DownloadService:
         gdl: GalleryDLService,
         importer: Importer,
         cred_service: CredentialService,
+        sync_session_factory=None,
     ):
         self.async_session = async_session
         self.sync_session = sync_session
         self.gdl = gdl
         self.importer = importer
         self.cred_service = cred_service
+        # Sync sessionmaker the native Patreon ingester opens SHORT-LIVED
+        # sessions from for its seen-ledger reads/writes (never one held across
+        # the multi-minute walk — see PatreonIngester). Only the patreon branch
+        # of phase 2 uses it; gallery-dl sources leave it None.
+        self.sync_session_factory = sync_session_factory
 
     async def download_source(self, source_id: int) -> int:
         """Returns DownloadEvent.id. Idempotent: in-flight events are returned as-is."""
@@ -107,63 +94,155 @@ class DownloadService:
         self.sync_session.close()
 
         source_config = SourceConfig.from_dict(ctx["config_overrides"] or {})
-        # alembic 0031 / plan #544: derive skip_value + timeout from the
-        # source's backfill_runs_remaining counter. When > 0, walk the full
-        # post history (skip: True + 1170s); when 0, exit gallery-dl after
-        # 20 contiguous archived items (skip: "exit:20" + the default
-        # 870s). Operator sets backfill via POST /api/sources/{id}/backfill.
-        backfill_remaining = ctx.get("backfill_runs_remaining", 0) or 0
-        if backfill_remaining > 0:
+        # Backfill mode (plan #693): the source's `_backfill_state == "running"`
+        # selects a time-boxed deep-walk chunk — skip: True (walk full history)
+        # + the BACKFILL_CHUNK_SECONDS budget, resuming from the cursor
+        # checkpoint (plan #689). State is the single source of truth; it stays
+        # "running" across ticks until the walk reaches the bottom (phase 3
+        # flips it to "complete"). Otherwise tick mode: exit gallery-dl after
+        # 20 contiguous archived items (skip: "exit:20" + the default 870s).
+        # Operator drives this via POST /api/sources/{id}/backfill {action}.
+        overrides = ctx["config_overrides"] or {}
+        in_backfill = overrides.get("_backfill_state") == "running"
+        # Recovery (plan #697) reuses the entire #693 backfill state machine —
+        # cursor checkpoint, time-boxed chunks, complete/stall lifecycle — and
+        # differs only in bypassing the tier-1 seen-ledger so dropped-and-deleted
+        # near-dups get re-fetched and re-evaluated under the CURRENT pHash
+        # threshold (tier-2 disk still spares files we kept). The
+        # `_backfill_bypass_seen` flag rides alongside the running backfill state;
+        # download mode is "recovery" when both are set.
+        bypass_seen = bool(overrides.get("_backfill_bypass_seen"))
+        if in_backfill:
             skip_value: bool | str = BACKFILL_SKIP_VALUE
-            source_config.timeout = BACKFILL_TIMEOUT_SECONDS
+            source_config.timeout = BACKFILL_CHUNK_SECONDS
+            pending_cursor = overrides.get("_backfill_cursor")
+            if uses_native_ingester(ctx["platform"]) and pending_cursor:
+                source_config.resume_cursor = pending_cursor
         else:
             skip_value = TICK_SKIP_VALUE
 
-        effective_url = _effective_url(
-            ctx["platform"], ctx["url"], ctx["config_overrides"] or {}
-        )
-
-        dl_result = await self.gdl.download(
-            url=effective_url,
-            artist_slug=ctx["artist_slug"],
-            platform=ctx["platform"],
-            source_config=source_config,
-            cookies_path=ctx["cookies_path"],
-            auth_token=ctx["auth_token"],
-            skip_value=skip_value,
-        )
-
         resolved_campaign_id: str | None = None
-        if (
-            ctx["platform"] == "patreon"
-            and not dl_result.success
-            and "patreon_campaign_id" not in (ctx["config_overrides"] or {})
-            and _looks_like_campaign_id_failure(dl_result.stdout, dl_result.stderr)
-        ):
-            vanity = _extract_patreon_vanity(ctx["url"])
-            if vanity:
-                log.info(
-                    "Attempting campaign-ID resolution for %s (%s)",
-                    ctx["artist_slug"], vanity,
+        if uses_native_ingester(ctx["platform"]):
+            # Native ingester (plan #697) fully replaces gallery-dl for Patreon
+            # in phase 2 — zero per-file HEADs, native cursor/resume, loud drift
+            # detection. Returns a DownloadResult-shaped object so phase 3 is
+            # untouched. The gallery-dl Patreon path + its campaign-id retry are
+            # removed at the step-5 cutover.
+            if in_backfill and bypass_seen:
+                mode = "recovery"
+            elif in_backfill:
+                mode = "backfill"
+            else:
+                mode = "tick"
+            dl_result, resolved_campaign_id = await self._run_patreon_ingester(
+                ctx, source_config, mode,
+            )
+        else:
+            dl_result = await self.gdl.download(
+                url=ctx["url"],
+                artist_slug=ctx["artist_slug"],
+                platform=ctx["platform"],
+                source_config=source_config,
+                cookies_path=ctx["cookies_path"],
+                auth_token=ctx["auth_token"],
+                skip_value=skip_value,
+            )
+
+        # A backfill chunk that hit its time-box but made forward progress is
+        # NORMAL, not a failure — reclassify TIMEOUT → PARTIAL so it reads as
+        # "ok/progress" (PARTIAL maps to status "ok"), not a red error, and the
+        # next chunk just resumes from the new cursor (plan #693). A chunk that
+        # timed out with NO progress stays TIMEOUT and feeds phase 3's
+        # stall-guard. Leave RATE_LIMITED alone so the platform-cooldown fires.
+        if in_backfill and dl_result.error_type == ErrorType.TIMEOUT:
+            new_cursor = parse_last_cursor(dl_result.stdout, dl_result.stderr)
+            advanced = bool(
+                (new_cursor and new_cursor != overrides.get("_backfill_cursor"))
+                or dl_result.files_downloaded > 0
+            )
+            if advanced:
+                dl_result.error_type = ErrorType.PARTIAL
+                dl_result.error_message = (
+                    f"Backfill chunk: {dl_result.files_downloaded} file(s) — continuing"
                 )
-                resolved_campaign_id = await resolve_campaign_id(
-                    vanity, ctx["cookies_path"]
-                )
-                if resolved_campaign_id:
-                    dl_result = await self.gdl.download(
-                        url=f"https://www.patreon.com/id:{resolved_campaign_id}",
-                        artist_slug=ctx["artist_slug"],
-                        platform=ctx["platform"],
-                        source_config=source_config,
-                        cookies_path=ctx["cookies_path"],
-                        auth_token=ctx["auth_token"],
-                        skip_value=skip_value,
-                    )
 
         return await self._phase3_persist(
             ctx["event_id"], ctx, dl_result, resolved_campaign_id,
         )
 
+    async def _run_patreon_ingester(
+        self, ctx: dict, source_config, mode: str,
+    ) -> tuple[DownloadResult, str | None]:
+        """Phase-2 Patreon branch: resolve the campaign id, then run the native
+        ingester in a worker thread (it is sync requests/subprocess).
+
+        Returns (DownloadResult, resolved_campaign_id). `resolved_campaign_id` is
+        non-None only when we had to look it up from the vanity URL this run, so
+        phase 3 caches it on the source the same way the old gallery-dl retry did.
+        A campaign id we cannot resolve is a loud failure (NOT_FOUND) — never a
+        silent empty success.
+        """
+        overrides = ctx["config_overrides"] or {}
+        # Shared resolution path (override / id: URL / vanity lookup) — the same
+        # helper the credential-verify probe uses. resolved_campaign_id is
+        # non-None only when a vanity lookup ran, so phase 3 caches it.
+        campaign_id, resolved_campaign_id = await resolve_campaign_id_for_source(
+            ctx["url"], ctx["cookies_path"], overrides
+        )
+
+        if not campaign_id:
+            return (
+                DownloadResult(
+                    success=False,
+                    url=ctx["url"],
+                    artist_slug=ctx["artist_slug"],
+                    platform="patreon",
+                    error_type=ErrorType.NOT_FOUND,
+                    error_message=(
+                        "Could not resolve Patreon campaign id from the source "
+                        "URL (vanity lookup failed — cookies expired or creator "
+                        "moved?)"
+                    ),
+                ),
+                None,
+            )
+
+        # Honor the operator's existing rate-limit knobs on the native path
+        # (plan #703): the global download_rate_limit_seconds (gallery-dl's
+        # `rate_limit`, here on self.gdl) paces media downloads. Page fetches use
+        # the per-source sleep_request override, else `max(0.5, rate_limit/4)` —
+        # the SAME API-pacing default gallery-dl applied as its `sleep-request`
+        # (gallery_dl._get_default_config), so the rate-limited /api/posts
+        # endpoint stays politely paced without over-throttling.
+        rate_limit = self.gdl._rate_limit
+        request_sleep = (
+            source_config.sleep_request
+            if source_config.sleep_request is not None
+            else max(0.5, rate_limit / 4)
+        )
+        ingester = PatreonIngester(
+            images_root=self.gdl.images_root,
+            cookies_path=ctx["cookies_path"],
+            session_factory=self.sync_session_factory,
+            validate=self.gdl._validate_files,
+            rate_limit=rate_limit,
+            request_sleep=request_sleep,
+        )
+        loop = asyncio.get_running_loop()
+        dl_result = await loop.run_in_executor(
+            None,
+            lambda: ingester.run(
+                source_id=ctx["source_id"],
+                campaign_id=campaign_id,
+                artist_slug=ctx["artist_slug"],
+                url=ctx["url"],
+                mode=mode,
+                resume_cursor=source_config.resume_cursor,
+                time_budget_seconds=source_config.timeout,
+            ),
+        )
+        return dl_result, resolved_campaign_id
+
     async def _phase1_setup(self, source_id: int) -> dict[str, Any]:
         source = (await self.async_session.execute(
             select(Source).options(joinedload(Source.artist)).where(Source.id == source_id)
@@ -395,36 +474,91 @@ class DownloadService:
             source_id=ctx["source_id"], status=status, error_message=ev.error,
             error_type=dl_result.error_type.value if dl_result.error_type else None,
         )
-        # Plan #544: backfill lifecycle — auto-complete when a clean
-        # backfill run drained the queue (gallery-dl exited 0 + zero files
-        # downloaded means there was nothing to fetch); otherwise decrement
-        # the counter. Next tick falls back to tick mode once it hits 0.
-        #
-        # Audit 2026-06-02 gating: VALIDATION_FAILED also exits the
-        # subprocess with return_code=0 and files_downloaded=0 (every
-        # file was quarantined), which used to match the auto-complete
-        # predicate exactly — zeroing the operator's armed budget on
-        # the FIRST quarantine run instead of decrementing. Require
-        # dl_result.success + no error_type so only genuinely-empty
-        # successful runs drain the counter.
-        backfill_remaining = ctx.get("backfill_runs_remaining", 0) or 0
-        if backfill_remaining > 0:
-            src = (await self.async_session.execute(
-                select(Source).where(Source.id == ctx["source_id"])
-            )).scalar_one()
-            queue_drained = (
-                dl_result.success
-                and dl_result.error_type is None
-                and dl_result.return_code == 0
-                and dl_result.files_downloaded == 0
-            )
-            if queue_drained:
-                src.backfill_runs_remaining = 0
-            else:
-                src.backfill_runs_remaining = max(0, backfill_remaining - 1)
+        await self._apply_backfill_lifecycle(ctx, dl_result)
         await self.async_session.commit()
         return event_id
 
+    async def _apply_backfill_lifecycle(self, ctx: dict, dl_result) -> None:
+        """Backfill state machine (plan #693, building on the cursor of #689).
+
+        A backfill runs in time-boxed chunks while
+        `config_overrides["_backfill_state"] == "running"`. Each chunk:
+          - COMPLETES the walk → clean rc=0 (gallery-dl with skip:True exits 0
+            only after exhausting the newest→oldest walk; a chunk cut short by
+            its time-box returns success=False / rc<0 via TimeoutExpired). On
+            completion: state="complete", clear the cursor, return to tick mode.
+          - made PROGRESS (cursor advanced and/or files written) → stay
+            "running", checkpoint the new cursor, bump the chunk counter, and
+            spend one of the safety-cap chunks (backfill_runs_remaining). If the
+            cap is exhausted without finishing → state="stalled".
+          - made NO progress → increment the stall counter; two strikes →
+            state="stalled", clear the cursor (a wedged walk can't loop).
+
+        State is the single source of truth; the cursor lives only inside a
+        running backfill. config_overrides is reassigned (not mutated in place)
+        for SQLAlchemy JSON change detection.
+        """
+        overrides = ctx["config_overrides"] or {}
+        if overrides.get("_backfill_state") != "running":
+            return  # not backfilling — tick mode, nothing to do
+
+        old_cursor = overrides.get("_backfill_cursor")
+        cap_remaining = ctx.get("backfill_runs_remaining", 0) or 0
+
+        src = (await self.async_session.execute(
+            select(Source).where(Source.id == ctx["source_id"])
+        )).scalar_one()
+        new_overrides = dict(src.config_overrides or {})
+        chunks = int(new_overrides.get("_backfill_chunks", 0)) + 1
+        new_overrides["_backfill_chunks"] = chunks
+
+        completed = (
+            dl_result.success
+            and dl_result.error_type is None
+            and dl_result.return_code == 0
+        )
+        if completed:
+            new_overrides["_backfill_state"] = "complete"
+            new_overrides.pop("_backfill_cursor", None)
+            new_overrides.pop("_backfill_cursor_stalls", None)
+            # plan #697: a recovery walk shares this lifecycle; clear its bypass
+            # flag on completion so the next routine tick honors the seen-ledger.
+            new_overrides.pop("_backfill_bypass_seen", None)
+            src.config_overrides = new_overrides
+            src.backfill_runs_remaining = 0
+            return
+
+        # Did not finish. Patreon checkpoints + resumes via cursor; other
+        # platforms have no resumable cursor (every chunk re-walks from the
+        # top), so they advance only by the download archive growing.
+        new_cursor = (
+            parse_last_cursor(dl_result.stdout, dl_result.stderr)
+            if uses_native_ingester(ctx["platform"]) else None
+        )
+        advanced = bool(
+            (new_cursor and new_cursor != old_cursor)
+            or dl_result.files_downloaded > 0
+        )
+        if advanced:
+            if new_cursor:
+                new_overrides["_backfill_cursor"] = new_cursor
+            new_overrides.pop("_backfill_cursor_stalls", None)
+            cap_remaining = max(0, cap_remaining - 1)
+            src.backfill_runs_remaining = cap_remaining
+            if cap_remaining == 0:
+                # Safety cap hit before reaching the bottom — pause, don't loop.
+                new_overrides["_backfill_state"] = "stalled"
+        else:
+            stalls = int(new_overrides.get("_backfill_cursor_stalls", 0)) + 1
+            if stalls >= 2:
+                new_overrides["_backfill_state"] = "stalled"
+                new_overrides.pop("_backfill_cursor", None)
+                new_overrides.pop("_backfill_cursor_stalls", None)
+            else:
+                new_overrides["_backfill_cursor_stalls"] = stalls
+
+        src.config_overrides = new_overrides
+
     async def _update_source_health(
         self, *, source_id: int, status: str, error_message: str | None,
         error_type: str | None = None,

backend/app/services/extension_service.py

@@ -16,7 +16,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 
 from ..models import Artist, Source
 from ..utils.slug import slugify
-from .source_service import NEW_SOURCE_BACKFILL_RUNS
+from .source_service import BACKFILL_MAX_CHUNKS
 
 
 class UnknownPlatformError(Exception):
@@ -205,16 +205,17 @@ class ExtensionService:
             return existing, False
         sp = await self.session.begin_nested()
         try:
-            # New subscription sources arm a few backfill runs so the
-            # first ticks walk the full history (otherwise gallery-dl's
-            # exit:20 short-circuits before the archive is built).
-            # Mirrors SourceService.create — without it, Firefox quick-
-            # add on a creator with >20 unsynced posts would surface
-            # as "check failed" with no diagnosis. Audit 2026-06-02.
+            # New subscription sources arm run-until-done backfill (plan #693)
+            # so the first ticks walk the full history (otherwise gallery-dl's
+            # exit:20 short-circuits before the archive is built). Mirrors
+            # SourceService.create — without it, Firefox quick-add on a creator
+            # with >20 unsynced posts would surface as "check failed" with no
+            # diagnosis. Audit 2026-06-02.
             src = Source(
                 artist_id=artist_id, platform=platform,
                 url=url, enabled=True,
-                backfill_runs_remaining=NEW_SOURCE_BACKFILL_RUNS,
+                config_overrides={"_backfill_state": "running"},
+                backfill_runs_remaining=BACKFILL_MAX_CHUNKS,
             )
             self.session.add(src)
             await self.session.flush()

backend/app/services/gallery_dl.py

@@ -13,6 +13,7 @@ from __future__ import annotations
 import asyncio
 import json
 import logging
+import re
 import subprocess
 import sys
 import tempfile
@@ -39,6 +40,12 @@ class ErrorType(StrEnum):
     HTTP_ERROR = "http_error"
     UNSUPPORTED_URL = "unsupported_url"
     VALIDATION_FAILED = "validation_failed"
+    # Native Patreon ingester only (plan #697): a response parsed as JSON but
+    # didn't match the JSON:API shape the ingester depends on (missing `data`,
+    # media lacking `file_name`/`url`, etc.). Distinct from AUTH_ERROR — the fix
+    # is updating the ingester's field-set/parser, not rotating credentials. The
+    # contract test guards against silently shipping this.
+    API_DRIFT = "api_drift"
     # Run made real progress (downloaded ≥1 file) but did not finish in the
     # subprocess budget. Distinct from UNKNOWN_ERROR — the downstream status
     # mapping classifies this as "ok" because the next tick continues.
@@ -55,25 +62,24 @@ class ErrorType(StrEnum):
 # 20 contiguous HEADs is still negligible.
 TICK_SKIP_VALUE = "exit:20"
 
-# Backfill mode (operator-triggered deep scan): walk the full history.
-# Source.backfill_runs_remaining > 0 selects this mode; the longer
-# timeout below absorbs creators with thousands of posts.
+# Backfill mode (operator-triggered deep scan): walk the full history,
+# one TIME-BOXED CHUNK per run (plan #693). config_overrides["_backfill_state"]
+# == "running" selects this mode; the cursor checkpoint (plan #689) lets each
+# chunk resume where the last stopped, so the walk advances across chunks
+# until gallery-dl exits cleanly (= reached the bottom).
 #
-# Sits below download_source's Celery soft_time_limit
-# (DOWNLOAD_SOFT_TIME_LIMIT=1350, tasks/download.py) with ~180s of
-# headroom for phase-3 persist. subprocess.run MUST raise TimeoutExpired
-# before Celery raises SoftTimeLimitExceeded — that exception path
-# captures partial stdout/stderr and finalizes the event; the soft-limit
-# path (until the 2026-06-03 fix) did not. Audit history: 1800 guaranteed
-# SIGKILL against the old hard limit (Knuxy #38275); 1170 was then sized
-# "30s shy of the hard limit (1200)" but still EXCEEDED the soft limit
-# (900), so SoftTimeLimitExceeded preempted TimeoutExpired and every
-# backfill stranded empty (Anduo #39912). Raising the Celery soft/hard
-# limits to 1350/1500 (tasks/download.py) is what made 1170 safe.
-# backfill_runs_remaining=3 still gives ~58 minutes of cumulative walk
-# across three runs for prolific creators.
+# The chunk budget is deliberately FAR below download_source's Celery
+# soft_time_limit (DOWNLOAD_SOFT_TIME_LIMIT=1350, tasks/download.py), not
+# "just under" it. Hitting this budget is the NORMAL chunk boundary, not a
+# failure: subprocess.run raises TimeoutExpired (which captures partial
+# stdout/stderr + the last emitted cursor), and download_service reclassifies
+# a chunk that made progress as PARTIAL (status "ok"), not an error. The huge
+# headroom means a stuck file or a slow chunk can never let Celery's
+# SoftTimeLimitExceeded preempt TimeoutExpired (the failure mode behind Knuxy
+# #38275 / Anduo #39912/#40411). Earlier we ran one ~1170s run-to-the-wall
+# per arming; that died as a timeout error every time on large catalogs.
 BACKFILL_SKIP_VALUE = True
-BACKFILL_TIMEOUT_SECONDS = 1170
+BACKFILL_CHUNK_SECONDS = 600
 
 
 # Sits well below download_source's Celery soft_time_limit
@@ -98,6 +104,17 @@ class SourceConfig:
     Source.backfill_runs_remaining column at the download_service layer
     and is passed to _build_config_for_source as `skip_value`. Same for
     the per-run subprocess timeout.
+
+    `resume_cursor` is RUNTIME state, not persisted operator config: the
+    cursor-paged backfill checkpoint (see parse_last_cursor + the
+    download_service backfill lifecycle). It is consumed only by the native
+    Patreon ingester (the sole cursor-paged platform; gallery-dl's Patreon path
+    was removed at the #697 cutover): on a backfill/recovery run the ingester
+    resumes its newest→oldest walk from that pagination cursor instead of
+    restarting from the top. download_service threads it from
+    config_overrides["_backfill_cursor"]; SourceConfig deliberately does NOT read
+    it in from_dict (config_overrides also holds operator config, and
+    resume_cursor must only apply in backfill/recovery mode).
     """
     content_types: list[str] = field(default_factory=lambda: ["all"])
     sleep: float | None = None
@@ -106,6 +123,7 @@ class SourceConfig:
     filename_pattern: str | None = None
     save_metadata: bool = True
     timeout: int = _DEFAULT_GDL_TIMEOUT_SECONDS
+    resume_cursor: str | None = None
 
     @classmethod
     def from_dict(cls, data: dict) -> SourceConfig:
@@ -154,6 +172,22 @@ def _summarize_validation_failures(failures: list[dict]) -> str:
     return f"{n} files quarantined ({top_count}× {top_reason}, mixed)"
 
 
+# The native Patreon ingester emits its pagination cursor as `Cursor: <token>`
+# — one line per fetched page — into the DownloadResult stdout (mirroring the
+# convention gallery-dl used before the #697 cutover, so the backfill lifecycle
+# stayed unchanged). The LAST such line is the furthest-progressed page, i.e.
+# the resume point. We scan both streams (be defensive) and take the final
+# match; download_service checkpoints it as the next chunk's resume_cursor.
+# Survives a time-boxed chunk too: the ingester emits the cursor for a page when
+# it STARTS it, so an interrupted walk still yields its last cursor.
+_CURSOR_RE = re.compile(r"Cursor:\s*(\S+)")
+
+
+def parse_last_cursor(stdout: str, stderr: str) -> str | None:
+    matches = _CURSOR_RE.findall(f"{stdout or ''}\n{stderr or ''}")
+    return matches[-1] if matches else None
+
+
 class GalleryDLService:
     """Service for executing gallery-dl downloads."""
 
@@ -187,16 +221,10 @@ class GalleryDLService:
         "permission denied", "tier required", "pledge required",
     ]
 
-    # Per-platform defaults. Lifted from GS — same six platforms FC supports.
+    # Per-platform defaults for the gallery-dl-backed platforms. Patreon was
+    # removed at the plan-#697 cutover — it now uses the native ingester
+    # (services/patreon_ingester.py), not gallery-dl.
     PLATFORM_DEFAULTS = {
-        "patreon": {
-            "content_types": ["images", "image_large", "attachments", "postfile", "content"],
-            "directory": ["{date:%Y-%m-%d}_{id}_{title[:40]}"],
-            "filename": "{num:>02}_{filename}.{extension}",
-            "videos": True,
-            "embeds": True,
-            "cursor": True,
-        },
         "subscribestar": {
             "content_types": ["all"],
             "directory": ["{date:%Y-%m-%d}_{id}_{title[:40]}"],
@@ -255,7 +283,12 @@ class GalleryDLService:
                 "skip": True,
                 "sleep": self._rate_limit,
                 "sleep-request": max(0.5, self._rate_limit / 4),
-                "retries": 3,
+                # 2 (not 3) retries — a stuck CDN host shouldn't burn a whole
+                # backfill chunk on one file. Anduo #40838 spent ~600s on a
+                # single image (4 extractor HEAD retries × 30s + 4 downloader
+                # GET retries × 120s); halving retries + the downloader
+                # timeout below caps a wedged file at ~1-2 min instead.
+                "retries": 2,
                 "timeout": 30.0,
                 "verify": True,
                 "postprocessors": [
@@ -270,27 +303,17 @@ class GalleryDLService:
             "downloader": {
                 "part": True,
                 "part-directory": str(self._config_dir / "temp"),
-                "retries": 3,
-                "timeout": 120.0,
-                # Forward Patreon as Referer/Origin to yt-dlp when it
-                # fetches video manifests. Operator-flagged 2026-06-01
-                # (DaferQ patreon): video posts hosted on Mux carry a JWT
-                # playback restriction that checks Referer/Origin on every
-                # request — not just the token signature. gallery-dl's
-                # HEAD probe to stream.mux.com returns 200 (the token is
-                # valid), but yt-dlp's actual GET-with-Range to fetch the
-                # m3u8 manifest 403s because yt-dlp sends its own default
-                # Referer, which Mux's policy rejects. Forcing the right
-                # headers fixes the headers-only case; Mux IP-range
-                # restrictions are unfixable from here.
-                "ytdl": {
-                    "raw-options": {
-                        "http_headers": {
-                            "Referer": "https://www.patreon.com/",
-                            "Origin": "https://www.patreon.com",
-                        },
-                    },
-                },
+                # See the extractor retries note above (Anduo #40838): 2
+                # retries + a 60s read-timeout (was 120) so a stalled
+                # connection fails fast. 60s is a per-read timeout, not a
+                # transfer cap — large GIFs that keep streaming are unaffected.
+                "retries": 2,
+                "timeout": 60.0,
+                # NOTE: the Patreon/Mux yt-dlp Referer/Origin forwarding lived
+                # here until the plan-#697 cutover. It was Patreon-specific (and
+                # would have wrongly tagged the other platforms' yt-dlp fetches);
+                # Patreon video is now handled by the native ingester's
+                # downloader (patreon_downloader._VIDEO_HEADERS), so it's gone.
             },
             "output": {"progress": True},
         }
@@ -342,14 +365,7 @@ class GalleryDLService:
 
         platform_section = config["extractor"].setdefault(platform, {})
 
-        if platform == "patreon":
-            if "all" in source_config.content_types:
-                platform_section["files"] = [
-                    "images", "image_large", "attachments", "postfile", "content",
-                ]
-            else:
-                platform_section["files"] = source_config.content_types
-        elif platform == "hentaifoundry":
+        if platform == "hentaifoundry":
             if "pictures" in source_config.content_types or "all" in source_config.content_types:
                 platform_section["include"] = "all"
 

backend/app/services/patreon_client.py

@@ -0,0 +1,588 @@
+"""Native Patreon JSON:API client (build step 1 of the native ingester).
+
+Clean-room reimplementation of the Patreon `/api/posts` read path. This is a
+plain, synchronous client over `requests` — the orchestrator already wraps
+sync importer calls, so nothing here needs to be async (mirrors
+patreon_resolver.py, which wraps its sync lookup in run_in_executor at the
+call site).
+
+Scope (build step 1): fetch + page + parse only. This module is NOT wired into
+download_service yet — that is a later step. The public surface here exists so
+the later step can drive it:
+  - PatreonClient(cookies_path).iter_posts(campaign_id)
+        → (post, included_index, page_cursor)
+  - extract_media(post, included_index) → list[MediaItem]
+  - parse_cursor_from_url(url) → cursor
+
+Drift detection is loud on purpose: Patreon ships JSON:API and the shapes we
+depend on (top-level `data`, media resources carrying `file_name`/`url`) are
+the contract. If a response comes back as an HTML login page or a media
+resource is missing the fields we resolve against, we raise PatreonDriftError
+rather than silently yielding empty media — so the later import step surfaces
+"Patreon changed something" instead of "creator has no posts".
+
+FC runs on a plain-HTTP homelab; nothing here uses a secure-context Web API.
+"""
+
+from __future__ import annotations
+
+import http.cookiejar
+import logging
+import os
+import re
+import time
+from collections.abc import Iterator
+from dataclasses import dataclass
+from html import unescape
+from pathlib import Path
+from urllib.parse import parse_qs, urlsplit
+
+import requests
+
+log = logging.getLogger(__name__)
+
+_POSTS_URL = "https://www.patreon.com/api/posts"
+_USER_AGENT = (
+    "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 "
+    "(KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36"
+)
+_TIMEOUT_SECONDS = 30.0
+
+# 429 backoff (plan #703): ride out a transient API rate-limit instead of
+# failing the whole walk (which would stamp RATE_LIMITED → platform-wide
+# cooldown → every Patreon source dark). Honor the server's `Retry-After`;
+# otherwise exponential base·2^(n-1), capped. Only after the retries are
+# exhausted does the 429 propagate as terminal RATE_LIMITED.
+_MAX_429_RETRIES = 3
+_BACKOFF_BASE_SECONDS = 2.0
+_BACKOFF_CAP_SECONDS = 30.0
+
+
+def _retry_after_seconds(
+    resp: requests.Response,
+    attempt: int,
+    *,
+    base: float = _BACKOFF_BASE_SECONDS,
+    cap: float = _BACKOFF_CAP_SECONDS,
+) -> float:
+    """Backoff delay for a 429: the `Retry-After` seconds header if present and
+    numeric, else exponential `base·2^(attempt-1)`, both capped. (HTTP-date form
+    of Retry-After is rare here and falls through to exponential.)"""
+    header = resp.headers.get("Retry-After")
+    if header:
+        try:
+            return min(float(header), cap)
+        except (TypeError, ValueError):
+            pass
+    return min(base * (2 ** max(0, attempt - 1)), cap)
+
+# JSON:API request contract (observed from real traffic — see module plan).
+_INCLUDE = (
+    "campaign,access_rules,attachments,attachments_media,audio,images,media,"
+    "native_video_insights,user,user_defined_tags,ti_checks"
+)
+_FIELDS_POST = (
+    "content,post_file,image,post_type,published_at,title,url,patreon_url,"
+    "current_user_can_view"
+)
+_FIELDS_MEDIA = "id,image_urls,download_url,metadata,file_name"
+_FIELDS_CAMPAIGN = "name,url"
+
+# A CDN download URL embeds a 32-char hex (MD5) path segment; that segment is
+# Patreon's stable per-file identity and is what we dedup + ledger against.
+# Same role gallery-dl's _filehash plays. Match the FIRST 32-hex run anywhere
+# in the URL (path or query); real Patreon CDN URLs carry exactly one.
+_FILEHASH_RE = re.compile(r"([0-9a-fA-F]{32})")
+
+# Inline post `content` is HTML; images are emitted as <img ... src="...">.
+# Pull every src; downstream dedup collapses any that duplicate a gallery item
+# by filehash. Tolerant of attribute ordering and single/double quotes.
+_CONTENT_IMG_RE = re.compile(r"<img\b[^>]*?\bsrc=[\"']([^\"']+)[\"']", re.IGNORECASE)
+
+# A bounded, sane extension parse (see importer._safe_ext for the FC gotcha:
+# URL-encoded basenames make Path.suffix return base64-ish junk). We only ever
+# use this for a fallback filename, never a network call.
+_MAX_EXT_LEN = 16
+
+
+class PatreonAPIError(Exception):
+    """Base for native Patreon client failures.
+
+    `status_code` carries the HTTP status when the failure was an HTTP response
+    (None for transport-level / parse failures), so the ingester can map it to a
+    DownloadResult.error_type (429 → rate_limited, 404 → not_found, …).
+    """
+
+    def __init__(self, message: str, *, status_code: int | None = None):
+        super().__init__(message)
+        self.status_code = status_code
+
+
+class PatreonAuthError(PatreonAPIError):
+    """Authentication / authorization failure — missing or expired session
+    cookies, an insufficient pledge tier, or an HTML login/challenge page served
+    where JSON was expected. DISTINCT from drift: the fix is rotating the
+    credential, not updating the ingester. Maps to error_type 'auth_error'.
+    """
+
+
+class PatreonDriftError(PatreonAPIError):
+    """A JSON response did not match the JSON:API shape we depend on.
+
+    Raised for: a missing top-level `data` list, `data` not a list, or a media
+    resource lacking the `file_name`/`url` fields we resolve against. Fail loud
+    so the import step flags API drift (ingester needs update) instead of
+    silently importing nothing. An HTML-login / non-JSON body is auth, not
+    drift — that raises PatreonAuthError.
+    """
+
+
+@dataclass
+class MediaItem:
+    """One resolved downloadable item belonging to a post.
+
+    Fields:
+      url       — the CDN/download URL to fetch.
+      filename  — media `file_name` when present; otherwise the URL basename
+                  (NEVER a network call). Bounded/sane extension.
+      kind      — one of: "images", "image_large", "attachments", "postfile",
+                  "content". Mirrors gallery-dl's `files` content-type names so
+                  the later step can honor the same per-source content_types.
+      filehash  — the 32-char hex (MD5) segment from the CDN URL, or None if
+                  the URL carries no such segment. Used for in-post dedup and
+                  the cross-run seen-ledger.
+      post_id   — the owning post's id (so a flattened media list stays
+                  traceable to its post).
+    """
+
+    url: str
+    filename: str
+    kind: str
+    filehash: str | None
+    post_id: str
+
+
+def _load_session(cookies_path: str | Path | None) -> requests.Session:
+    session = requests.Session()
+    session.headers.update(
+        {
+            "User-Agent": _USER_AGENT,
+            "Accept": "application/vnd.api+json",
+        }
+    )
+    if cookies_path and os.path.isfile(str(cookies_path)):
+        try:
+            jar = http.cookiejar.MozillaCookieJar(str(cookies_path))
+            jar.load(ignore_discard=True, ignore_expires=True)
+            session.cookies = jar  # type: ignore[assignment]
+        except (OSError, http.cookiejar.LoadError) as exc:
+            log.warning("Could not load Patreon cookies from %s: %s", cookies_path, exc)
+    return session
+
+
+def _filehash(url: str) -> str | None:
+    if not url:
+        return None
+    match = _FILEHASH_RE.search(url)
+    return match.group(1).lower() if match else None
+
+
+def _safe_ext(name: str) -> str:
+    suffix = Path(name).suffix.lower()
+    if not suffix or len(suffix) > _MAX_EXT_LEN:
+        return ""
+    if not all(c.isalnum() for c in suffix[1:]):
+        return ""
+    return suffix
+
+
+def _basename_from_url(url: str) -> str:
+    """Derive a sane filename from a URL when the media has no file_name.
+
+    Strips query/fragment, takes the path basename, and drops a junk
+    extension (the importer._safe_ext gotcha) so we never write base64 noise
+    as a name. Falls back to the filehash, then to "file".
+    """
+    path = urlsplit(url).path
+    base = os.path.basename(path)
+    if base:
+        ext = _safe_ext(base)
+        stem = base[: -len(Path(base).suffix)] if Path(base).suffix else base
+        # Keep the stem bounded; URL-encoded stems can be enormous.
+        stem = stem[:120] or "file"
+        return f"{stem}{ext}"
+    fh = _filehash(url)
+    return fh or "file"
+
+
+def parse_cursor_from_url(url: str | None) -> str | None:
+    """Extract the `page[cursor]` query param from a links.next URL."""
+    if not url:
+        return None
+    query = urlsplit(url).query
+    values = parse_qs(query).get("page[cursor]")
+    if values and values[0]:
+        return values[0]
+    return None
+
+
+class PatreonClient:
+    """Synchronous Patreon JSON:API read client.
+
+    Construct with a path to a Netscape cookies.txt (the same file
+    CredentialService.get_cookies_path materializes). Cookies are loaded into a
+    requests.Session; no secure-context APIs are used.
+    """
+
+    def __init__(
+        self,
+        cookies_path: str | Path | None,
+        *,
+        request_sleep: float = 0.0,
+        max_retries: int = _MAX_429_RETRIES,
+    ):
+        self.cookies_path = str(cookies_path) if cookies_path else None
+        self._session = _load_session(cookies_path)
+        # Politeness: seconds to sleep before each /api/posts page fetch (paces
+        # the rate-limited API endpoint). 0 = no pacing. plan #703.
+        self._request_sleep = request_sleep or 0.0
+        self._max_retries = max_retries
+
+    # -- request -----------------------------------------------------------
+
+    def _params(self, campaign_id: str, cursor: str | None) -> dict[str, str]:
+        params = {
+            "include": _INCLUDE,
+            "fields[post]": _FIELDS_POST,
+            "fields[media]": _FIELDS_MEDIA,
+            "fields[campaign]": _FIELDS_CAMPAIGN,
+            "filter[campaign_id]": campaign_id,
+            "filter[contains_exclusive_posts]": "true",
+            "filter[is_draft]": "false",
+            "sort": "-published_at",
+            "json-api-version": "1.0",
+        }
+        if cursor:
+            params["page[cursor]"] = cursor
+        return params
+
+    def _fetch(self, campaign_id: str, cursor: str | None) -> dict:
+        if self._request_sleep > 0:
+            time.sleep(self._request_sleep)  # pace the API endpoint
+        attempt = 0
+        while True:
+            try:
+                resp = self._session.get(
+                    _POSTS_URL,
+                    params=self._params(campaign_id, cursor),
+                    timeout=_TIMEOUT_SECONDS,
+                )
+            except requests.RequestException as exc:
+                raise PatreonAPIError(
+                    f"Patreon posts request failed (campaign_id={campaign_id}): {exc}"
+                ) from exc
+
+            # Transient rate-limit: back off and retry rather than failing the
+            # whole walk. Only a PERSISTENT 429 (retries exhausted) falls
+            # through to the terminal RATE_LIMITED raise below.
+            if resp.status_code == 429 and attempt < self._max_retries:
+                attempt += 1
+                delay = _retry_after_seconds(resp, attempt)
+                log.warning(
+                    "Patreon 429 (campaign_id=%s) — backing off %.1fs (retry %d/%d)",
+                    campaign_id, delay, attempt, self._max_retries,
+                )
+                time.sleep(delay)
+                continue
+            break
+
+        if resp.status_code in (401, 403):
+            # Auth rejected — expired/missing cookies or an insufficient tier.
+            # Actionable as "rotate credentials", so it's auth, not drift/http.
+            raise PatreonAuthError(
+                f"Patreon posts API returned HTTP {resp.status_code} — auth "
+                f"rejected (cookies expired or tier insufficient; "
+                f"campaign_id={campaign_id})",
+                status_code=resp.status_code,
+            )
+        if resp.status_code != 200:
+            raise PatreonAPIError(
+                f"Patreon posts API returned HTTP {resp.status_code} "
+                f"(campaign_id={campaign_id})",
+                status_code=resp.status_code,
+            )
+        try:
+            payload = resp.json()
+        except ValueError as exc:
+            # A non-JSON body here is almost always the HTML login/challenge
+            # page served when cookies are missing/expired — that is an AUTH
+            # failure (rotate cookies), not API drift (update the ingester) and
+            # not a transient network error.
+            raise PatreonAuthError(
+                "Patreon posts API returned a non-JSON response (likely an "
+                f"HTML login/challenge page — session expired; "
+                f"campaign_id={campaign_id}): {exc}"
+            ) from exc
+        return payload
+
+    # -- parsing -----------------------------------------------------------
+
+    @staticmethod
+    def _transform(response: dict) -> dict:
+        """Flatten the JSON:API `included` array for relationship resolution.
+
+        Returns a dict keyed by `(type, id)` → that resource's `attributes`
+        (so a post's relationships can be resolved in O(1)). Missing/oddly
+        shaped `included` entries are skipped rather than fatal — drift
+        detection for the top-level shape lives in _validate_response.
+        """
+        index: dict[tuple[str, str], dict] = {}
+        for inc in response.get("included") or []:
+            if not isinstance(inc, dict):
+                continue
+            rtype = inc.get("type")
+            rid = inc.get("id")
+            if rtype is None or rid is None:
+                continue
+            index[(str(rtype), str(rid))] = inc.get("attributes") or {}
+        return index
+
+    @staticmethod
+    def _validate_response(response: dict) -> None:
+        if not isinstance(response, dict):
+            raise PatreonDriftError("Patreon response was not a JSON object")
+        if "data" not in response:
+            raise PatreonDriftError("Patreon response missing top-level 'data' key")
+        data = response.get("data")
+        if not isinstance(data, list):
+            raise PatreonDriftError("Patreon response 'data' was not a list")
+
+    def _related_ids(self, post: dict, rel_name: str) -> list[str]:
+        rels = post.get("relationships") or {}
+        rel = rels.get(rel_name) or {}
+        data = rel.get("data")
+        if isinstance(data, dict):  # to-one relationship
+            data = [data]
+        if not isinstance(data, list):
+            return []
+        ids: list[str] = []
+        for ref in data:
+            if isinstance(ref, dict) and ref.get("id") is not None:
+                ids.append(str(ref["id"]))
+        return ids
+
+    @staticmethod
+    def _media_url(attrs: dict) -> str | None:
+        """Pick the best fetchable URL for a media resource.
+
+        Prefer the full-size `download_url`; fall back to the largest
+        `image_urls` size. gallery-dl prefers download_url too, only dipping
+        into image_urls when a smaller configured size is requested — FC
+        always wants the original, so download_url first.
+        """
+        download_url = attrs.get("download_url")
+        if isinstance(download_url, str) and download_url:
+            return download_url
+        image_urls = attrs.get("image_urls")
+        if isinstance(image_urls, dict):
+            for key in ("original", "full", "large", "default"):
+                candidate = image_urls.get(key)
+                if isinstance(candidate, str) and candidate:
+                    return candidate
+            # Otherwise take any non-empty string value.
+            for candidate in image_urls.values():
+                if isinstance(candidate, str) and candidate:
+                    return candidate
+        return None
+
+    def _media_item(
+        self, attrs: dict, kind: str, post_id: str, *, require_file_name: bool
+    ) -> MediaItem:
+        url = self._media_url(attrs)
+        if not url:
+            raise PatreonDriftError(
+                f"Patreon media (post {post_id}, kind={kind}) had no resolvable URL "
+                f"(no download_url / image_urls)"
+            )
+        file_name = attrs.get("file_name")
+        if require_file_name and not (isinstance(file_name, str) and file_name):
+            raise PatreonDriftError(
+                f"Patreon media resource (post {post_id}, kind={kind}) missing "
+                f"'file_name'"
+            )
+        filename = file_name if isinstance(file_name, str) and file_name else _basename_from_url(url)
+        return MediaItem(
+            url=url,
+            filename=filename,
+            kind=kind,
+            filehash=_filehash(url),
+            post_id=post_id,
+        )
+
+    def extract_media(self, post: dict, included_index: dict) -> list[MediaItem]:
+        """Resolve all downloadable media for one post.
+
+        Walks the kinds in the same order gallery-dl does — images,
+        image_large (post cover), attachments, postfile, content (inline
+        <img>) — and dedups within the post by filehash (first wins). The
+        image_large cover commonly duplicates a gallery image; deduping by
+        filehash collapses them to the gallery item (encountered first).
+        """
+        post_id = str(post.get("id") or "")
+        attrs = post.get("attributes") or {}
+        items: list[MediaItem] = []
+
+        def _resolve_rel(rel_name: str, kind: str) -> None:
+            for mid in self._related_ids(post, rel_name):
+                media_attrs = included_index.get(("media", mid))
+                if media_attrs is None:
+                    # Referenced but not in `included`: a media id with no
+                    # resource is drift (we asked for include=media).
+                    raise PatreonDriftError(
+                        f"Patreon post {post_id} references media {mid} "
+                        f"({rel_name}) not present in 'included'"
+                    )
+                items.append(
+                    self._media_item(
+                        media_attrs, kind, post_id, require_file_name=True
+                    )
+                )
+
+        # 1. gallery images
+        _resolve_rel("images", "images")
+
+        # 2. image_large — the post-level cover (`image.large_url`). Not a
+        #    media relationship; it lives on the post attributes.
+        image = attrs.get("image")
+        if isinstance(image, dict):
+            large_url = image.get("large_url") or image.get("url")
+            if isinstance(large_url, str) and large_url:
+                items.append(
+                    MediaItem(
+                        url=large_url,
+                        filename=_basename_from_url(large_url),
+                        kind="image_large",
+                        filehash=_filehash(large_url),
+                        post_id=post_id,
+                    )
+                )
+
+        # 3. attachments
+        _resolve_rel("attachments_media", "attachments")
+
+        # 4. postfile — the post's primary attached file (`post_file`).
+        post_file = attrs.get("post_file")
+        if isinstance(post_file, dict):
+            pf_url = post_file.get("url") or post_file.get("download_url")
+            if isinstance(pf_url, str) and pf_url:
+                pf_name = post_file.get("name")
+                filename = (
+                    pf_name
+                    if isinstance(pf_name, str) and pf_name
+                    else _basename_from_url(pf_url)
+                )
+                items.append(
+                    MediaItem(
+                        url=pf_url,
+                        filename=filename,
+                        kind="postfile",
+                        filehash=_filehash(pf_url),
+                        post_id=post_id,
+                    )
+                )
+
+        # 5. content — inline <img> in the post HTML body.
+        content = attrs.get("content")
+        if isinstance(content, str) and content:
+            for raw_src in _CONTENT_IMG_RE.findall(content):
+                src = unescape(raw_src)
+                if not src:
+                    continue
+                items.append(
+                    MediaItem(
+                        url=src,
+                        filename=_basename_from_url(src),
+                        kind="content",
+                        filehash=_filehash(src),
+                        post_id=post_id,
+                    )
+                )
+
+        return _dedup_by_filehash(items)
+
+    # -- iteration ---------------------------------------------------------
+
+    def iter_posts(
+        self, campaign_id: str, cursor: str | None = None
+    ) -> Iterator[tuple[dict, dict, str | None]]:
+        """Yield (post, included_index, page_cursor) for every post in the feed.
+
+        Pages newest→oldest via `links.next`, validating each response for
+        drift before yielding. The triple gives a caller everything it needs to
+        resolve and checkpoint without re-fetching:
+          - post           — the raw post resource.
+          - included_index — the page's flattened `included` (the same object
+                             for every post on a page), to pass straight to
+                             extract_media(post, included_index).
+          - page_cursor    — the cursor that FETCHED this post's page (None for
+                             the first page). The caller checkpoints THIS value,
+                             matching the existing backfill cursor logic where
+                             the saved cursor re-fetches the page being
+                             processed (so a chunk cut mid-page resumes the page,
+                             not the one after it).
+        """
+        current_cursor = cursor
+        while True:
+            response = self._fetch(campaign_id, current_cursor)
+            self._validate_response(response)
+            page_cursor = current_cursor
+            included_index = self._transform(response)
+            for post in response.get("data") or []:
+                if isinstance(post, dict):
+                    yield post, included_index, page_cursor
+            next_url = (response.get("links") or {}).get("next")
+            next_cursor = parse_cursor_from_url(next_url)
+            if not next_cursor:
+                return
+            current_cursor = next_cursor
+
+    # -- verify ------------------------------------------------------------
+
+    def verify_auth(self, campaign_id: str) -> tuple[bool | None, str]:
+        """Cheap auth probe: fetch the first `/api/posts` page and report whether
+        the credential authenticated, WITHOUT downloading anything.
+
+        Returns `(ok, message)` matching the credential-verify contract:
+          - True  — authenticated (the feed returned a valid JSON:API page).
+          - False — the credential was rejected (PatreonAuthError: 401/403, or an
+                    HTML login page → cookies expired / tier insufficient).
+          - None  — inconclusive: API drift (our parser is stale, not a cred
+                    problem) or a transient network/HTTP error.
+        """
+        try:
+            response = self._fetch(campaign_id, None)
+            self._validate_response(response)
+        except PatreonAuthError as exc:
+            return False, f"Patreon rejected the credential — {exc}"
+        except PatreonDriftError as exc:
+            return None, f"Couldn't verify — Patreon's API shape changed: {exc}"
+        except PatreonAPIError as exc:
+            return None, f"Couldn't verify (network/HTTP issue): {exc}"
+        return True, "Credentials valid — the Patreon feed authenticated."
+
+
+def _dedup_by_filehash(items: list[MediaItem]) -> list[MediaItem]:
+    """Drop later items sharing a filehash with an earlier one (first wins).
+
+    Items with no filehash (None) are never deduped against each other — we
+    can't prove they're the same file, so keep them all.
+    """
+    seen: set[str] = set()
+    out: list[MediaItem] = []
+    for item in items:
+        if item.filehash is not None:
+            if item.filehash in seen:
+                continue
+            seen.add(item.filehash)
+        out.append(item)
+    return out

backend/app/services/patreon_downloader.py

@@ -0,0 +1,416 @@
+"""Native Patreon media downloader (build step 2b of the native ingester).
+
+Given a Patreon post and its already-resolved `MediaItem`s (from
+patreon_client.extract_media), download the media to the EXACT on-disk layout
+gallery-dl produces, write a sidecar JSON the existing importer consumes, and
+report per-media outcomes.
+
+This module is PURE: no DB. The cross-run seen-ledger and the iter_posts
+orchestration are a LATER step. The tier-1 (seen) skip is an INJECTED predicate
+(`is_seen`), so this module needs no DB and is unit-testable without network.
+
+On-disk layout (matches gallery-dl):
+  <images_root>/<artist_slug>/patreon/<DIR>/<NN>_<filename>
+  where <DIR> = "<YYYY-MM-DD>_<post_id>_<title40>" (date prefix omitted when the
+  post's published_at is unparseable), <NN> is the 1-based index of the item in
+  the post zero-padded to 2, and <filename> is MediaItem.filename. The sidecar
+  is written next to the media as <NN>_<stem>.json (media_path.with_suffix).
+
+Video: a MediaItem whose URL is a Mux/HLS stream (host stream.mux.com or path
+endswith .m3u8) is fetched with yt-dlp (subprocess), passing the same
+Referer/Origin headers gallery-dl forwards for Mux playback (see gallery_dl.py
+_get_default_config). yt-dlp may remux to a container of its own choosing, so we
+accept the actual output extension and record the real path.
+
+FC runs on a plain-HTTP homelab; nothing here uses a secure-context Web API.
+"""
+
+from __future__ import annotations
+
+import contextlib
+import json
+import logging
+import os
+import shutil
+import subprocess
+import time
+from collections.abc import Callable
+from dataclasses import dataclass
+from datetime import datetime
+from pathlib import Path
+from urllib.parse import urlsplit
+
+import requests
+
+from .file_validator import is_validatable, validate_file
+from .patreon_client import _load_session, _retry_after_seconds
+
+log = logging.getLogger(__name__)
+
+_TITLE_MAX = 40
+_TIMEOUT_SECONDS = 120.0
+_CHUNK = 1 << 16
+# A CDN media GET rarely 429s, but if it does, a couple of backoff retries keep
+# one throttled file from becoming a per-item error (plan #703).
+_MAX_MEDIA_429_RETRIES = 2
+
+# Referer/Origin yt-dlp must send for Mux-hosted Patreon video. Mux's JWT
+# playback policy checks Referer/Origin on every request, so yt-dlp must send
+# Patreon's, not its own default. (gallery-dl forwarded the same headers before
+# the #697 cutover removed its Patreon path; this is now the only place they
+# live.)
+_VIDEO_HEADERS = {
+    "Referer": "https://www.patreon.com/",
+    "Origin": "https://www.patreon.com",
+}
+
+# Characters Windows/gallery-dl path-restrict forbids, plus path separators.
+_FORBIDDEN = set('<>:"/\\|?*')
+
+
+def _sanitize(name: str) -> str:
+    """Make `name` safe for a single filesystem path segment.
+
+    Replaces path separators, the Windows-forbidden set <>:"/\\|?* and control
+    characters with `_`, then strips trailing dots/spaces (gallery-dl
+    path-restrict behavior). Never returns empty (falls back to "_").
+    """
+    out = []
+    for ch in name:
+        if ch in _FORBIDDEN or ord(ch) < 32:
+            out.append("_")
+        else:
+            out.append(ch)
+    cleaned = "".join(out).rstrip(". ")
+    return cleaned or "_"
+
+
+def _is_video_url(url: str) -> bool:
+    parts = urlsplit(url)
+    if parts.hostname and parts.hostname.lower() == "stream.mux.com":
+        return True
+    return parts.path.lower().endswith(".m3u8")
+
+
+def _post_dir_name(post: dict) -> str:
+    """Build the post directory name matching gallery-dl's layout."""
+    post_id = str(post.get("id") or "")
+    attrs = post.get("attributes") or {}
+    title = attrs.get("title")
+    title = title if isinstance(title, str) else ""
+    title40 = title[:_TITLE_MAX]
+
+    published = attrs.get("published_at")
+    date_prefix = None
+    if isinstance(published, str) and published:
+        s = published.strip()
+        if s.endswith("Z"):
+            s = s[:-1] + "+00:00"
+        try:
+            dt = datetime.fromisoformat(s)
+        except ValueError:
+            dt = None
+        if dt is not None:
+            date_prefix = f"{dt:%Y-%m-%d}"
+
+    if date_prefix:
+        raw = f"{date_prefix}_{post_id}_{title40}"
+    else:
+        raw = f"{post_id}_{title40}"
+    return _sanitize(raw)
+
+
+@dataclass
+class MediaOutcome:
+    """Per-media result of a download_post pass.
+
+    status is one of: "downloaded", "skipped_seen", "skipped_disk", "error".
+    `path` is the final on-disk path for "downloaded" (the actual yt-dlp output
+    for video), or the path that already existed for "skipped_disk"; None for
+    "skipped_seen" and (usually) "error". `error` carries the failure reason for
+    "error", else None.
+    """
+
+    media: object  # MediaItem (avoid importing the name for a bare annotation)
+    status: str
+    path: Path | None
+    error: str | None
+
+
+class PatreonDownloader:
+    """Download resolved Patreon media to gallery-dl's on-disk layout.
+
+    PURE: no DB. The HTTP session and the yt-dlp invocation are injectable seams
+    so tests run without network or a real subprocess:
+      - pass `session=` to stub `session.get`, or monkeypatch `_fetch_to_file`.
+      - monkeypatch `_run_ytdlp` to avoid spawning yt-dlp.
+    """
+
+    def __init__(
+        self,
+        images_root: Path,
+        cookies_path: str | None = None,
+        *,
+        validate: bool = True,
+        rate_limit: float = 0.0,
+        session: requests.Session | None = None,
+    ):
+        self.images_root = Path(images_root)
+        self.cookies_path = str(cookies_path) if cookies_path else None
+        self._validate = validate
+        # Politeness: seconds to sleep before each actual media download (paces
+        # the CDN; honors ImportSettings.download_rate_limit_seconds, the same
+        # value gallery-dl used as its between-downloads `sleep`). 0 = no pacing.
+        # Applied only to real downloads, not to seen/disk skips. plan #703.
+        self._rate_limit = rate_limit or 0.0
+        # Build a cookie-loaded session the same way patreon_client does, so the
+        # CDN GETs carry the creator's auth.
+        self.session = session if session is not None else _load_session(cookies_path)
+
+    # -- public ------------------------------------------------------------
+
+    def download_post(
+        self,
+        post: dict,
+        media_items: list,
+        artist_slug: str,
+        *,
+        is_seen: Callable[[object], bool] = lambda m: False,
+    ) -> list[MediaOutcome]:
+        """Download every media item of one post; return per-item outcomes.
+
+        Builds the post directory, iterates media (1-based NN), applies the
+        two-tier skip (injected is_seen, then disk), downloads (plain GET or
+        yt-dlp for video), writes the sidecar for each freshly-downloaded item,
+        validates, and returns outcomes. Resilient: one media's failure yields
+        an "error" outcome for that item; the rest proceed.
+        """
+        post_dir = self.images_root / artist_slug / "patreon" / _post_dir_name(post)
+        outcomes: list[MediaOutcome] = []
+
+        for i, media in enumerate(media_items, start=1):
+            try:
+                outcomes.append(
+                    self._download_one(post, media, post_dir, artist_slug, i, is_seen)
+                )
+            except Exception as exc:  # resilient: isolate one item's failure
+                log.warning(
+                    "Patreon media failed (post %s, item %d): %s",
+                    post.get("id"), i, exc,
+                )
+                outcomes.append(
+                    MediaOutcome(media=media, status="error", path=None, error=str(exc))
+                )
+        return outcomes
+
+    # -- per-item ----------------------------------------------------------
+
+    def _download_one(
+        self,
+        post: dict,
+        media,
+        post_dir: Path,
+        artist_slug: str,
+        index: int,
+        is_seen: Callable[[object], bool],
+    ) -> MediaOutcome:
+        # tier-1: seen ledger (injected; no DB here).
+        if is_seen(media):
+            return MediaOutcome(media=media, status="skipped_seen", path=None, error=None)
+
+        nn = f"{index:02d}"
+        final_name = _sanitize(f"{nn}_{media.filename}")
+        media_path = post_dir / final_name
+
+        # tier-2: already on disk.
+        if media_path.exists():
+            return MediaOutcome(
+                media=media, status="skipped_disk", path=media_path, error=None
+            )
+        # Video may land at a different extension; honor a pre-existing remux.
+        if _is_video_url(media.url):
+            existing = self._existing_video_output(media_path)
+            if existing is not None:
+                return MediaOutcome(
+                    media=media, status="skipped_disk", path=existing, error=None
+                )
+
+        post_dir.mkdir(parents=True, exist_ok=True)
+
+        # Pace real downloads only (the skips above already returned). plan #703.
+        if self._rate_limit > 0:
+            time.sleep(self._rate_limit)
+
+        if _is_video_url(media.url):
+            out_path = self._run_ytdlp(media.url, media_path, _VIDEO_HEADERS)
+            if out_path is None or not Path(out_path).exists():
+                return MediaOutcome(
+                    media=media,
+                    status="error",
+                    path=None,
+                    error="yt-dlp produced no output",
+                )
+            out_path = Path(out_path)
+        else:
+            out_path = self._fetch_get(media.url, media_path)
+            invalid = self._validate_path(out_path, artist_slug)
+            if invalid is not None:
+                return MediaOutcome(
+                    media=media, status="error", path=None, error=invalid
+                )
+
+        self._write_sidecar(post, out_path)
+        return MediaOutcome(media=media, status="downloaded", path=out_path, error=None)
+
+    # -- download seams ----------------------------------------------------
+
+    def _fetch_get(self, url: str, dest: Path) -> Path:
+        """Stream `url` to a .part file then atomic-rename to `dest`.
+
+        Thin wrapper over `_fetch_to_file` so tests can stub either the whole
+        GET path (`_fetch_to_file`) or just `session.get`.
+        """
+        part = dest.with_name(dest.name + ".part")
+        try:
+            self._fetch_to_file(url, part)
+        except Exception:
+            with contextlib.suppress(OSError):
+                part.unlink()
+            raise
+        os.replace(part, dest)
+        return dest
+
+    def _fetch_to_file(self, url: str, dest: Path) -> None:
+        """Stream a non-video URL to `dest` via the (stubbable) session.
+
+        Retries a transient 429 with backoff (plan #703); any other non-2xx
+        falls through to raise_for_status → HTTPError, which download_post turns
+        into a resilient per-item error outcome.
+        """
+        attempt = 0
+        while True:
+            resp = self.session.get(url, stream=True, timeout=_TIMEOUT_SECONDS)
+            if resp.status_code == 429 and attempt < _MAX_MEDIA_429_RETRIES:
+                attempt += 1
+                delay = _retry_after_seconds(resp, attempt)
+                log.warning(
+                    "Patreon media 429 (%s) — backing off %.1fs (retry %d/%d)",
+                    url, delay, attempt, _MAX_MEDIA_429_RETRIES,
+                )
+                time.sleep(delay)
+                continue
+            break
+        resp.raise_for_status()
+        with open(dest, "wb") as fh:
+            for chunk in resp.iter_content(chunk_size=_CHUNK):
+                if chunk:
+                    fh.write(chunk)
+
+    def _run_ytdlp(self, url: str, dest: Path, headers: dict) -> Path | None:
+        """Invoke yt-dlp to fetch a Mux/HLS stream to (around) `dest`.
+
+        Returns the actual output path (yt-dlp may remux to a different
+        container, so we resolve the real file afterward). Overridden/
+        monkeypatched in tests to avoid spawning a real subprocess.
+
+        The output template uses `dest` without its extension; yt-dlp appends
+        the chosen container extension. We pass Referer/Origin (Mux JWT policy)
+        and the cookies file.
+        """
+        dest = Path(dest)
+        out_template = str(dest.with_suffix("")) + ".%(ext)s"
+        cmd = ["yt-dlp", "--no-progress", "-o", out_template]
+        for key, value in headers.items():
+            cmd += ["--add-header", f"{key}:{value}"]
+        if self.cookies_path and os.path.isfile(self.cookies_path):
+            cmd += ["--cookies", self.cookies_path]
+        cmd.append(url)
+        try:
+            subprocess.run(
+                cmd,
+                check=True,
+                capture_output=True,
+                text=True,
+                timeout=_TIMEOUT_SECONDS,
+            )
+        except (OSError, subprocess.SubprocessError) as exc:
+            log.warning("yt-dlp failed for %s: %s", url, exc)
+            return None
+        return self._existing_video_output(dest)
+
+    def _existing_video_output(self, dest: Path) -> Path | None:
+        """Find a yt-dlp output for `dest` regardless of chosen extension.
+
+        Returns `dest` itself if present, else any sibling sharing the same
+        stem (the remuxed container). None if nothing matched.
+        """
+        dest = Path(dest)
+        if dest.exists():
+            return dest
+        stem = dest.with_suffix("").name
+        parent = dest.parent
+        if not parent.is_dir():
+            return None
+        for cand in sorted(parent.iterdir()):
+            if cand.is_file() and cand.stem == stem and cand.name != dest.name:
+                return cand
+        return None
+
+    # -- validation --------------------------------------------------------
+
+    def _validate_path(self, path: Path, artist_slug: str) -> str | None:
+        """Validate a freshly-written file; quarantine + return reason if bad.
+
+        Mirrors gallery_dl._validate_and_quarantine: fail-open for unknown
+        formats, move the corrupt file to _quarantine/<slug>/patreon, and return
+        the failure reason string (None when ok / not validatable / disabled).
+        """
+        if not self._validate or not is_validatable(path):
+            return None
+        try:
+            result = validate_file(path)
+        except Exception as exc:
+            log.warning("Validator raised on %s: %s", path, exc)
+            return None
+        if result.ok:
+            return None
+        quarantine_root = self.images_root / "_quarantine" / artist_slug / "patreon"
+        try:
+            quarantine_root.mkdir(parents=True, exist_ok=True)
+            dest = quarantine_root / path.name
+            counter = 1
+            while dest.exists():
+                dest = quarantine_root / f"{path.stem}.{counter}{path.suffix}"
+                counter += 1
+            shutil.move(str(path), str(dest))
+        except OSError as exc:
+            log.error("Failed to quarantine %s: %s. File left in place.", path, exc)
+        return result.reason or "validation failed"
+
+    # -- sidecar -----------------------------------------------------------
+
+    def _write_sidecar(self, post: dict, media_path: Path) -> Path:
+        """Write the importer-consumed sidecar next to `media_path`.
+
+        Patreon uses base-default sidecar keys (parse_sidecar maps
+        category->platform, id->external_post_id, title->post_title,
+        content->description, published_at->post_date, url->post_url). Patreon
+        registers no derive_post_url, so `url` is trusted as the permalink — we
+        pass the post's attributes.url.
+        """
+        attrs = post.get("attributes") or {}
+        title = attrs.get("title")
+        content = attrs.get("content")
+        published = attrs.get("published_at")
+        url = attrs.get("url")
+        data = {
+            "category": "patreon",
+            "id": str(post.get("id") or ""),
+            "title": title if isinstance(title, str) else "",
+            "content": content if isinstance(content, str) else "",
+            "published_at": published if isinstance(published, str) else None,
+            "url": url if isinstance(url, str) else None,
+        }
+        sidecar_path = media_path.with_suffix(".json")
+        sidecar_path.write_text(json.dumps(data, indent=2))
+        return sidecar_path

backend/app/services/patreon_ingester.py

@@ -0,0 +1,414 @@
+"""Native Patreon ingester — phase-2 orchestrator (build step 3).
+
+Ties build steps 1 (`patreon_client`) and 2 (`patreon_downloader` +
+`patreon_seen_media`) together into a single sync walk that REPLACES the
+gallery-dl subprocess for Patreon. `download_service.download_source` calls
+`PatreonIngester.run(...)` from phase 2 (in a thread, via run_in_executor, since
+everything here is sync `requests`/`subprocess`) and gets back a
+`DownloadResult` — the exact shape gallery-dl returns — so phase 1 (DB setup)
+and phase 3 (import → pHash dedup → thumbnails → ML) are untouched and cannot
+tell the difference.
+
+Three modes (selected by `download_service` from `config_overrides` state):
+  - tick      — newest→oldest, skip seen (tier-1 ledger + tier-2 disk), early-out
+                after N contiguous already-have-it items (the cheap native
+                equivalent of gallery-dl's `exit:20`, now free of per-file HEADs).
+  - backfill  — full-history walk in a time-boxed chunk, resuming from the
+                pagination cursor checkpoint; reaches the bottom → "complete".
+  - recovery  — like backfill but BYPASSES the tier-1 seen-ledger, so
+                deliberately-dropped-and-deleted near-dups get re-fetched and
+                re-evaluated under the current pHash threshold (tier-2 disk skip
+                still spares files we kept). Triggered by the same #693 backfill
+                state machine plus the `_backfill_bypass_seen` flag, so the whole
+                cursor/chunk/complete/stall lifecycle is reused verbatim.
+
+Cursor contract: the ingester emits gallery-dl-style ``Cursor: <token>`` lines
+into the returned `stdout`, one per page it walks. That is exactly what
+`download_service`'s existing backfill lifecycle reads via
+`parse_last_cursor(stdout, stderr)` — so checkpointing, the TIMEOUT→PARTIAL
+reclassification, and completion detection all keep working unchanged.
+
+The seen-ledger lives in Postgres (`patreon_seen_media`). The ingester opens a
+SHORT-LIVED sync session per page batch (via an injected sessionmaker) — never
+held across a network fetch — so the multi-minute walk can't strand a checked-out
+connection for the server to reap ([[db-connection-held-across-subprocess]]).
+
+FC runs on a plain-HTTP homelab; nothing here uses a secure-context Web API.
+"""
+
+from __future__ import annotations
+
+import asyncio
+import logging
+import time
+from collections.abc import Callable
+from pathlib import Path
+
+from sqlalchemy import select
+from sqlalchemy.dialects.postgresql import insert as pg_insert
+
+from ..models import PatreonSeenMedia
+from .gallery_dl import DownloadResult, ErrorType
+from .patreon_client import (
+    MediaItem,
+    PatreonAPIError,
+    PatreonAuthError,
+    PatreonClient,
+    PatreonDriftError,
+)
+from .patreon_downloader import PatreonDownloader
+from .patreon_resolver import resolve_campaign_id_for_source
+
+log = logging.getLogger(__name__)
+
+# gallery-dl's `exit:20` default ported over: stop a tick after this many
+# CONTIGUOUS already-have-it media (seen-ledger or on-disk). Native walks have
+# zero per-file HEADs, so the only cost of a higher number is a few extra cheap
+# ledger lookups — 20 is operator-set headroom against paywalled/undownloadable
+# items interleaving with archived ones.
+_TICK_SEEN_THRESHOLD = 20
+
+# Ledger keys are stored in patreon_seen_media.filehash VARCHAR(128); bound any
+# synthesized key so a pathologically long file_name can't overflow the column.
+_LEDGER_KEY_MAX = 128
+
+
+def _ledger_key(media: MediaItem) -> str:
+    """Stable per-media identity for the cross-run seen-ledger.
+
+    A Patreon CDN URL carries a 32-char MD5 (`media.filehash`) — that is the
+    natural key. Some media have none: Mux/HLS video (`stream.mux.com`, no
+    content hash at discovery) and the odd inline-content `<img>` pointing at a
+    hashless URL. The plan calls the video case the ``video:<post_id>:<media_id>``
+    sentinel; `MediaItem` carries no media_id, so the post-scoped filename is the
+    stable proxy. Bounded to the column width.
+    """
+    if media.filehash:
+        return media.filehash
+    return f"{media.post_id}:{media.filename}"[:_LEDGER_KEY_MAX]
+
+
+class PatreonIngester:
+    """Walk a Patreon campaign's posts, download unseen media, return a
+    `DownloadResult`.
+
+    Construct with the per-source `cookies_path` and a sync sessionmaker for the
+    seen-ledger. `client` / `downloader` are injectable seams so unit tests run
+    without network, subprocess, or a real CDN.
+    """
+
+    def __init__(
+        self,
+        images_root: Path,
+        cookies_path: str | None,
+        session_factory: Callable[[], object],
+        *,
+        validate: bool = True,
+        rate_limit: float = 0.0,
+        request_sleep: float = 0.0,
+        client: PatreonClient | None = None,
+        downloader: PatreonDownloader | None = None,
+    ):
+        self.images_root = Path(images_root)
+        self.cookies_path = str(cookies_path) if cookies_path else None
+        self.session_factory = session_factory
+        # Pacing (plan #703): request_sleep paces the API page fetches,
+        # rate_limit paces the media downloads. Injected client/downloader (in
+        # tests) already carry their own pacing, so these only apply to the
+        # default-constructed ones.
+        self.client = (
+            client
+            if client is not None
+            else PatreonClient(cookies_path, request_sleep=request_sleep)
+        )
+        self.downloader = (
+            downloader
+            if downloader is not None
+            else PatreonDownloader(
+                self.images_root, cookies_path, validate=validate, rate_limit=rate_limit
+            )
+        )
+
+    # -- public ------------------------------------------------------------
+
+    def run(
+        self,
+        *,
+        source_id: int,
+        campaign_id: str,
+        artist_slug: str,
+        url: str,
+        mode: str,
+        resume_cursor: str | None = None,
+        time_budget_seconds: float = 870.0,
+        seen_threshold: int = _TICK_SEEN_THRESHOLD,
+    ) -> DownloadResult:
+        """Walk + download for one source, returning a gallery-dl-shaped result.
+
+        `mode` is "tick" | "backfill" | "recovery". Recovery bypasses the tier-1
+        seen-ledger (tier-2 disk still skips kept files). The walk stops on:
+          - budget exhaustion (time_budget_seconds)         → TIMEOUT / PARTIAL
+          - tick early-out (seen_threshold contiguous seen)  → success
+          - reaching the bottom of the feed                  → success (rc 0)
+        A client-level failure (drift / auth / network) fails the whole run loud.
+        """
+        bypass_seen = mode == "recovery"
+        start = time.monotonic()
+        log_lines: list[str] = []
+        written: list[str] = []
+        downloaded = 0
+        errors = 0
+        consecutive_seen = 0
+        emitted_cursor: str | None = None
+        reached_bottom = False
+        budget_hit = False
+        early_out = False
+
+        def _result(
+            *, success: bool, return_code: int,
+            error_type: ErrorType | None, error_message: str | None,
+        ) -> DownloadResult:
+            return DownloadResult(
+                success=success,
+                url=url,
+                artist_slug=artist_slug,
+                platform="patreon",
+                files_downloaded=downloaded,
+                files_quarantined=0,
+                quarantined_paths=[],
+                written_paths=written,
+                stdout="\n".join(log_lines),
+                stderr="",
+                return_code=return_code,
+                error_type=error_type,
+                error_message=error_message,
+                duration_seconds=time.monotonic() - start,
+            )
+
+        try:
+            for post, included, page_cursor in self.client.iter_posts(
+                campaign_id, cursor=resume_cursor
+            ):
+                # Checkpoint: emit the cursor that FETCHED this page once, the
+                # moment we START it — so a chunk cut mid-page resumes the page,
+                # not the one after it (matches the gallery-dl cursor semantics
+                # download_service's lifecycle already depends on).
+                if page_cursor and page_cursor != emitted_cursor:
+                    log_lines.append(f"Cursor: {page_cursor}")
+                    emitted_cursor = page_cursor
+
+                # Time-box check at the post boundary (coarse, like a gallery-dl
+                # chunk). Backfill/recovery resume from emitted_cursor next chunk.
+                if time.monotonic() - start >= time_budget_seconds:
+                    budget_hit = True
+                    break
+
+                media = self.client.extract_media(post, included)
+                if not media:
+                    continue
+
+                keys = [_ledger_key(m) for m in media]
+                seen = (
+                    set()
+                    if bypass_seen
+                    else self._seen_keys(source_id, keys)
+                )
+
+                def _is_seen(m: MediaItem, _seen=seen) -> bool:
+                    return _ledger_key(m) in _seen
+
+                outcomes = self.downloader.download_post(
+                    post, media, artist_slug, is_seen=_is_seen
+                )
+
+                to_mark: list[tuple[str, str]] = []
+                for media_item, outcome in zip(media, outcomes, strict=False):
+                    key = _ledger_key(media_item)
+                    if outcome.status == "downloaded":
+                        downloaded += 1
+                        if outcome.path is not None:
+                            written.append(str(outcome.path))
+                        to_mark.append((key, media_item.post_id))
+                        consecutive_seen = 0
+                    elif outcome.status == "skipped_disk":
+                        # Already on disk (a prior run). Reconcile the ledger so a
+                        # later tick skips it at tier-1 without a disk stat, but
+                        # do NOT re-feed it to phase 3 — attach_in_place would see
+                        # the duplicate sha256 and unlink the on-disk copy.
+                        to_mark.append((key, media_item.post_id))
+                        consecutive_seen += 1
+                    elif outcome.status == "skipped_seen":
+                        consecutive_seen += 1
+                    elif outcome.status == "error":
+                        errors += 1
+                        # An error neither advances nor resets the run-of-seen.
+
+                    if mode == "tick" and consecutive_seen >= seen_threshold:
+                        early_out = True
+                        break
+
+                # Mark seen AFTER the network fetch, on its own short session.
+                if to_mark:
+                    self._mark_seen(source_id, to_mark)
+
+                if early_out:
+                    break
+            else:
+                reached_bottom = True
+        except PatreonAPIError as exc:
+            # Base of PatreonAuthError + PatreonDriftError — catches every
+            # client-level failure; _failure_result maps it to a typed error.
+            return self._failure_result(exc, _result)
+
+        if errors:
+            log_lines.append(f"{errors} media item(s) failed")
+        log_lines.append(
+            f"Patreon ingest ({mode}): {downloaded} downloaded, "
+            f"{errors} error(s)"
+            + (", reached end" if reached_bottom else "")
+            + (", time-boxed" if budget_hit else "")
+        )
+
+        if budget_hit:
+            # A chunk that hit its time-box but made forward progress is a
+            # NORMAL chunk boundary, not a failure (PARTIAL → status "ok"); the
+            # next chunk resumes from the emitted cursor. No progress → TIMEOUT,
+            # which feeds download_service's backfill stall-guard. rc<0 mirrors
+            # subprocess TimeoutExpired so completion detection stays false.
+            made_progress = downloaded > 0 or emitted_cursor != resume_cursor
+            if made_progress:
+                return _result(
+                    success=False, return_code=-1,
+                    error_type=ErrorType.PARTIAL,
+                    error_message=(
+                        f"Patreon backfill chunk: {downloaded} file(s) — continuing"
+                    ),
+                )
+            return _result(
+                success=False, return_code=-1,
+                error_type=ErrorType.TIMEOUT,
+                error_message="Patreon chunk timed out with no progress",
+            )
+
+        # Normal success: reached the bottom, or a tick that early-outed. rc 0 +
+        # error_type None is REQUIRED for a backfill/recovery walk that reached
+        # the bottom to be marked COMPLETE by
+        # download_service._apply_backfill_lifecycle — so we return None even
+        # when downloaded == 0 (a re-confirming walk that found nothing new still
+        # completed). NO_NEW_CONTENT would read as "not finished" there and trip
+        # the stall guard. success=True maps to status "ok" regardless. A tick
+        # that early-outed also returns here; ticks never set backfill state so
+        # the lifecycle is a no-op for them.
+        return _result(
+            success=True, return_code=0,
+            error_type=None, error_message=None,
+        )
+
+    # -- failure mapping ---------------------------------------------------
+
+    def _failure_result(self, exc: Exception, _result) -> DownloadResult:
+        """Map a client-level exception to a loud, typed failed DownloadResult.
+
+        We NEVER return a silent zero-download "success" — the whole point of the
+        native ingester is to fail RED when Patreon's API shape or our auth
+        changes. The typed mapping lets FailingSourcesCard render the right chip
+        and tells the operator what to do:
+          - PatreonAuthError  → AUTH_ERROR  (rotate cookies)
+          - PatreonDriftError → API_DRIFT   (ingester field-set/parser needs update)
+          - HTTP 429 / 404    → RATE_LIMITED / NOT_FOUND
+          - other HTTP status → HTTP_ERROR;  transport failure → NETWORK_ERROR
+
+        PatreonAuthError and PatreonDriftError both subclass PatreonAPIError, so
+        they must be matched before the generic HTTP/transport fallthrough.
+        """
+        message = str(exc)
+        if isinstance(exc, PatreonAuthError):
+            error_type = ErrorType.AUTH_ERROR
+        elif isinstance(exc, PatreonDriftError):
+            error_type = ErrorType.API_DRIFT
+            message = f"Patreon API changed — ingester needs update: {message}"
+        else:  # generic PatreonAPIError: HTTP non-2xx (status_code set) or transport
+            status = getattr(exc, "status_code", None)
+            if status == 429:
+                error_type = ErrorType.RATE_LIMITED
+            elif status == 404:
+                error_type = ErrorType.NOT_FOUND
+            elif status is not None:
+                error_type = ErrorType.HTTP_ERROR
+            else:
+                error_type = ErrorType.NETWORK_ERROR
+        log.warning("Patreon ingest failed (%s): %s", error_type.value, message)
+        return _result(
+            success=False, return_code=1,
+            error_type=error_type, error_message=message,
+        )
+
+    # -- seen-ledger (short-lived sessions) --------------------------------
+
+    def _seen_keys(self, source_id: int, keys: list[str]) -> set[str]:
+        """Which of `keys` are already in the ledger for this source.
+
+        One short SELECT on its own session — opened and closed without any
+        network in between (the GETs happen after, in download_post).
+        """
+        if not keys:
+            return set()
+        with self.session_factory() as session:
+            rows = session.execute(
+                select(PatreonSeenMedia.filehash).where(
+                    PatreonSeenMedia.source_id == source_id,
+                    PatreonSeenMedia.filehash.in_(keys),
+                )
+            ).scalars().all()
+        return set(rows)
+
+    def _mark_seen(self, source_id: int, items: list[tuple[str, str]]) -> None:
+        """Idempotent upsert of (filehash, post_id) ledger rows for a page.
+
+        ON CONFLICT DO NOTHING against the (source_id, filehash) UNIQUE so a
+        re-sighting — or a concurrent walk — is a harmless no-op
+        ([[scalar_one_or_none-duplicates]]: never check-then-insert without the
+        DB constraint backing it). De-dup the batch locally first so a single
+        page can't present the same key twice to one INSERT.
+        """
+        seen_local: set[str] = set()
+        values = []
+        for key, post_id in items:
+            if key in seen_local:
+                continue
+            seen_local.add(key)
+            values.append(
+                {"source_id": source_id, "filehash": key, "post_id": post_id}
+            )
+        if not values:
+            return
+        with self.session_factory() as session:
+            stmt = pg_insert(PatreonSeenMedia).values(values)
+            stmt = stmt.on_conflict_do_nothing(
+                constraint="uq_patreon_seen_media_source_id"
+            )
+            session.execute(stmt)
+            session.commit()
+
+
+async def verify_patreon_credential(
+    url: str,
+    cookies_path: str | None,
+    overrides: dict | None,
+) -> tuple[bool | None, str]:
+    """Native Patreon credential probe — the verify counterpart to the ingester's
+    download path, sharing its campaign-id resolution. Resolves the campaign id
+    (override / id: URL / vanity) then does ONE authenticated `/api/posts` fetch
+    via PatreonClient.verify_auth. Returns the uniform `(ok, message)` contract
+    (True / False / None) so download_backends.verify_credential can treat it
+    interchangeably with the gallery-dl probe. No download, no DB.
+    """
+    campaign_id, _ = await resolve_campaign_id_for_source(url, cookies_path, overrides)
+    if not campaign_id:
+        return None, (
+            "Couldn't resolve the Patreon campaign id from the source URL — "
+            "can't verify (cookies expired, or the creator moved/renamed?)."
+        )
+    client = PatreonClient(cookies_path)
+    loop = asyncio.get_running_loop()
+    return await loop.run_in_executor(None, client.verify_auth, campaign_id)

backend/app/services/patreon_resolver.py

@@ -19,12 +19,22 @@ import asyncio
 import http.cookiejar
 import logging
 import os
+import re
 
 import requests
 
 log = logging.getLogger(__name__)
 
 _CAMPAIGNS_URL = "https://www.patreon.com/api/campaigns"
+
+# A source URL of the form `.../id:<digits>` already carries the campaign id
+# (no lookup needed). The vanity regex deliberately EXCLUDES the id: form so the
+# two paths don't overlap.
+_ID_URL_RE = re.compile(r"/id:(\d+)")
+_VANITY_RE = re.compile(
+    r"^https?://(?:www\.)?patreon\.com/(?:c/)?(?!id:)([^/?#]+)",
+    re.IGNORECASE,
+)
 _USER_AGENT = (
     "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 "
     "(KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36"
@@ -100,3 +110,38 @@ async def resolve_campaign_id(
     Never raises."""
     loop = asyncio.get_running_loop()
     return await loop.run_in_executor(None, _sync_lookup, vanity, cookies_path)
+
+
+def extract_vanity(url: str) -> str | None:
+    """The vanity slug from a Patreon creator URL, or None for an `id:` URL."""
+    m = _VANITY_RE.match(url or "")
+    return m.group(1) if m else None
+
+
+async def resolve_campaign_id_for_source(
+    url: str,
+    cookies_path: str | None,
+    overrides: dict | None,
+) -> tuple[str | None, str | None]:
+    """Resolve a Patreon source to its campaign id — the single resolution path
+    shared by the download ingester and the credential-verify probe.
+
+    Order: cached `patreon_campaign_id` override → an `id:<digits>` URL → a
+    vanity lookup against the campaigns API. Returns
+    `(campaign_id, newly_resolved_id)`: `newly_resolved_id` is non-None ONLY when
+    a vanity lookup actually ran, so the caller knows to cache it on the source
+    (the override/id: paths needed no lookup). `(None, None)` when unresolvable.
+    Never raises.
+    """
+    overrides = overrides or {}
+    cached = overrides.get("patreon_campaign_id")
+    if cached:
+        return cached, None
+    id_match = _ID_URL_RE.search(url or "")
+    if id_match:
+        return id_match.group(1), None
+    vanity = extract_vanity(url)
+    if vanity:
+        resolved = await resolve_campaign_id(vanity, cookies_path)
+        return resolved, resolved
+    return None, None

backend/app/services/source_service.py

@@ -64,6 +64,12 @@ class SourceRecord:
     consecutive_failures: int
     next_check_at: str | None
     backfill_runs_remaining: int
+    # plan #693: derived from config_overrides for the UI badge.
+    backfill_state: str | None  # "running" | "complete" | "stalled" | None (idle)
+    backfill_chunks: int
+    # plan #697: a running deep-walk that bypasses the Patreon seen-ledger
+    # (recovery) vs. a normal backfill. Lets the badge label it "Recovering".
+    backfill_bypass_seen: bool
 
     def to_dict(self) -> dict:
         return {
@@ -82,6 +88,9 @@ class SourceRecord:
             "consecutive_failures": self.consecutive_failures,
             "next_check_at": self.next_check_at,
             "backfill_runs_remaining": self.backfill_runs_remaining,
+            "backfill_state": self.backfill_state,
+            "backfill_chunks": self.backfill_chunks,
+            "backfill_bypass_seen": self.backfill_bypass_seen,
         }
 
 
@@ -89,10 +98,13 @@ class SourceRecord:
 
 _EDITABLE = {"enabled", "url", "config_overrides", "check_interval_override", "platform"}
 
-# Plan #544 follow-up: newly created enabled sources pre-arm backfill so
-# their first N polls walk gallery-dl's full post history with the longer
-# timeout (matches the manual "Deep scan" button's default).
-NEW_SOURCE_BACKFILL_RUNS = 3
+# Plan #693: backfill safety cap. "Start backfill" (and a newly created
+# enabled source) arms a run-until-done walk; this caps how many time-boxed
+# chunks it may spend before pausing as "stalled", so a pathological walk that
+# never reaches the bottom can't run forever. Generous on purpose — at
+# BACKFILL_CHUNK_SECONDS (600s) per chunk this is ~33h of cumulative walk, far
+# beyond any real catalog; the cursor stall-guard is the real terminator.
+BACKFILL_MAX_CHUNKS = 200
 
 
 class SourceService:
@@ -135,6 +147,7 @@ class SourceService:
         self, source: Source, artist: Artist, settings: ImportSettings,
     ) -> SourceRecord:
         nxt = compute_next_check_at(source, artist, settings)
+        co = source.config_overrides or {}
         return SourceRecord(
             id=source.id,
             artist_id=source.artist_id,
@@ -151,6 +164,9 @@ class SourceService:
             consecutive_failures=source.consecutive_failures or 0,
             next_check_at=nxt.isoformat() if nxt else None,
             backfill_runs_remaining=source.backfill_runs_remaining or 0,
+            backfill_state=co.get("_backfill_state"),
+            backfill_chunks=int(co.get("_backfill_chunks", 0)),
+            backfill_bypass_seen=bool(co.get("_backfill_bypass_seen")),
         )
 
     async def _row_to_record(self, source: Source) -> SourceRecord:
@@ -212,16 +228,17 @@ class SourceService:
             select(func.count(Source.id)).where(Source.artist_id == artist_id)
         )).scalar_one()
 
-        # Plan #544 follow-up: a freshly added subscription has no archive
-        # yet, so the first few polls would walk the full post history in
-        # tick mode and trip exit:20 after ~20 contiguous archive hits —
-        # except there are none yet, so tick mode would walk forever and
-        # blow the wall-clock cap. Pre-arm backfill so the initial syncs
-        # use the longer timeout + skip:True walk. Tick mode resumes once
-        # the budget is spent or the queue drains.
-        # Disabled sources (incl. sidecar synthetics, url='sidecar:...')
-        # are never polled, so leave their counter at 0.
-        backfill_runs = NEW_SOURCE_BACKFILL_RUNS if enabled else 0
+        # Plan #693: a freshly added subscription has no archive yet, so it
+        # should walk its full post history once. Arm run-until-done backfill
+        # (state="running" + the chunk cap); the time-boxed chunks march to the
+        # bottom across ticks, then flip to "complete" and tick mode takes over.
+        # Disabled sources (incl. sidecar synthetics, url='sidecar:...') are
+        # never polled, so leave them idle.
+        if enabled:
+            config_overrides = {**(config_overrides or {}), "_backfill_state": "running"}
+            backfill_runs = BACKFILL_MAX_CHUNKS
+        else:
+            backfill_runs = 0
         source = Source(
             artist_id=artist_id, platform=platform, url=url,
             enabled=enabled, config_overrides=config_overrides,
@@ -286,22 +303,69 @@ class SourceService:
         await self.session.commit()
         return await self._row_to_record(source)
 
-    async def set_backfill_runs(
-        self, source_id: int, runs: int,
-    ) -> SourceRecord:
-        """Plan #544: arm a source for backfill mode. The next `runs`
-        download runs will use gallery-dl's full-walk config (skip: True
-        + 30-min timeout) instead of the catch-up default. Runs must be
-        1..10 — bigger is rejected to keep the operator from accidentally
-        setting a runaway budget."""
-        if not isinstance(runs, int) or runs < 1 or runs > 10:
-            raise ValueError("runs must be an integer in [1, 10]")
+    async def start_backfill(self, source_id: int) -> SourceRecord:
+        """Plan #693: arm a run-until-done backfill. Sets state="running" and
+        the chunk cap; download runs then walk the full post history in
+        time-boxed chunks (skip:True + BACKFILL_CHUNK_SECONDS), resuming from
+        the cursor each chunk, until gallery-dl reaches the bottom (→ state
+        "complete") or the cap/stall-guard pauses it (→ "stalled"). Clears any
+        prior cursor/chunk/stall state so a re-start walks fresh from the top."""
         source = (await self.session.execute(
             select(Source).where(Source.id == source_id)
         )).scalar_one_or_none()
         if source is None:
             raise LookupError(f"source id={source_id} not found")
-        source.backfill_runs_remaining = runs
+        co = dict(source.config_overrides or {})
+        co["_backfill_state"] = "running"
+        for k in ("_backfill_cursor", "_backfill_cursor_stalls", "_backfill_chunks"):
+            co.pop(k, None)
+        source.config_overrides = co
+        source.backfill_runs_remaining = BACKFILL_MAX_CHUNKS
+        await self.session.commit()
+        return await self._row_to_record(source)
+
+    async def start_recovery(self, source_id: int) -> SourceRecord:
+        """Plan #697: arm a RECOVERY walk — a backfill that bypasses the Patreon
+        seen-ledger so deliberately-dropped-and-deleted near-dups get re-fetched
+        and re-evaluated under the CURRENT pHash threshold (tier-2 disk still
+        spares files we kept). Reuses the entire #693 backfill state machine
+        (time-boxed chunks, cursor checkpoint, complete/stall lifecycle) plus the
+        `_backfill_bypass_seen` flag that flips download mode to recovery. Clears
+        any prior cursor/chunk/stall state so it walks fresh from the top. The
+        flag is cleared on completion (download_service) and on stop.
+
+        Recovery is Patreon-only (the seen-ledger is Patreon's); for other
+        platforms the flag is inert (download_service ignores it) and the walk
+        runs as a plain backfill. The UI gates the action to Patreon sources."""
+        source = (await self.session.execute(
+            select(Source).where(Source.id == source_id)
+        )).scalar_one_or_none()
+        if source is None:
+            raise LookupError(f"source id={source_id} not found")
+        co = dict(source.config_overrides or {})
+        co["_backfill_state"] = "running"
+        co["_backfill_bypass_seen"] = True
+        for k in ("_backfill_cursor", "_backfill_cursor_stalls", "_backfill_chunks"):
+            co.pop(k, None)
+        source.config_overrides = co
+        source.backfill_runs_remaining = BACKFILL_MAX_CHUNKS
+        await self.session.commit()
+        return await self._row_to_record(source)
+
+    async def stop_backfill(self, source_id: int) -> SourceRecord:
+        """Plan #693: cancel an in-progress backfill — back to idle/tick mode.
+        Clears the running state + cursor/chunk/stall bookkeeping."""
+        source = (await self.session.execute(
+            select(Source).where(Source.id == source_id)
+        )).scalar_one_or_none()
+        if source is None:
+            raise LookupError(f"source id={source_id} not found")
+        co = dict(source.config_overrides or {})
+        for k in ("_backfill_state", "_backfill_cursor", "_backfill_cursor_stalls",
+                  "_backfill_chunks", "_backfill_bypass_seen"):
+            co.pop(k, None)
+        source.config_overrides = co
+        source.backfill_runs_remaining = 0
         await self.session.commit()
         return await self._row_to_record(source)
 

backend/app/tasks/download.py

@@ -31,7 +31,7 @@ _KEY_PATH = IMAGES_ROOT / "secrets" / "credential_key.b64"
 # SoftTimeLimitExceeded in-process, whereas the HARD limit SIGKILLs the
 # worker (no chance to finalize). Both gallery-dl subprocess budgets
 # (gallery_dl.py: _DEFAULT_GDL_TIMEOUT_SECONDS=870 tick,
-# BACKFILL_TIMEOUT_SECONDS=1170 backfill) MUST sit below the soft limit
+# BACKFILL_CHUNK_SECONDS=600 per backfill chunk, plan #693) MUST sit below the soft limit
 # so subprocess.run raises its own TimeoutExpired first — that path
 # captures partial stdout/stderr and finalizes the DownloadEvent. soft is
 # max-subprocess (1170) + ~180s phase-3 persist headroom; hard is soft +
@@ -143,6 +143,11 @@ def download_source(self, source_id: int) -> int:
                         gdl=gdl,
                         importer=importer,
                         cred_service=cred_service,
+                        # The native Patreon ingester opens its own short-lived
+                        # sync sessions for the seen-ledger (never held across
+                        # the walk). Same factory the importer's sync session
+                        # comes from — a different DB connection per checkout.
+                        sync_session_factory=SyncFactory,
                     )
                     return await svc.download_source(source_id)
         finally:

frontend/src/components/modal/ImageViewer.vue

@@ -203,14 +203,37 @@ function nextFrame() {
 }
 
 @media (max-width: 900px) {
-  .fc-viewer__body { flex-direction: column; }
-  /* Side panel drops below the image — the next arrow uses the full width. */
-  .fc-viewer__nav--next { right: 16px; }
+  /* Stacked layout (operator-flagged 2026-06-05): pin the image pane and
+     its controls at the top while the metadata panel scrolls beneath it.
+     Previously the image + a 40vh panel shared one fixed viewport and the
+     controls could be pushed out of view; now the body scrolls and the
+     media is sticky, so the image + prev/next/close (and the integrity
+     badge) stay visible no matter how far the panel is scrolled. */
+  .fc-viewer__body {
+    flex-direction: column;
+    overflow-y: auto;
+  }
+  .fc-viewer__media {
+    flex: none;
+    height: 55vh;
+    position: sticky;
+    top: 0;
+    z-index: 1;
+    /* Opaque obsidian so the scrolling panel never bleeds through the
+       haze behind the pinned image. */
+    background: rgb(20, 23, 26);
+  }
   .fc-viewer__side {
     width: 100%;
-    max-height: 40vh;
+    max-height: none;
     border-left: none;
     border-top: 1px solid rgb(var(--v-theme-surface-light));
   }
+  /* Re-center the prev/next arrows over the 55vh image band (their base
+     top:50% would land on the scrolling panel); next uses the full width
+     now that the panel is below, not beside. Close + integrity badge keep
+     their top:16px/72px — already within the pinned band. */
+  .fc-viewer__nav { top: 27.5vh; }
+  .fc-viewer__nav--next { right: 16px; }
 }
 </style>

frontend/src/components/modal/TagAutocomplete.vue

@@ -65,8 +65,17 @@ const store = useTagStore()
 // Vuetify's v-text-field exposes .focus() on the component instance;
 // nextTick waits for the modal's mount to finish so the inner <input>
 // element exists.
+//
+// EXCEPTION — not on mobile (operator-flagged 2026-06-05): focusing the
+// field pops the soft keyboard, which shrinks the visual viewport and
+// shoves the pinned image + its nav/close controls out of view. 900px is
+// the modal's stacked-layout breakpoint (ImageViewer.vue). matchMedia is
+// safe on plain HTTP (not a secure-context API).
 const inputRef = ref(null)
-onMounted(() => { nextTick(() => inputRef.value?.focus?.()) })
+onMounted(() => {
+  if (window.matchMedia?.('(max-width: 900px)')?.matches) return
+  nextTick(() => inputRef.value?.focus?.())
+})
 
 // Single text input; no kind dropdown. Client-side mirror of the
 // backend's parse_kind_prefix lives below — kept in sync with

frontend/src/components/subscriptions/FailingSourcesCard.vue

@@ -93,6 +93,7 @@ const ERROR_TYPE_COLOR = {
   unsupported_url: 'error',
   http_error: 'error',
   unknown_error: 'error',
+  api_drift: 'error',
   partial: 'info',
   tier_limited: 'info',
   no_new_content: 'info',
@@ -108,6 +109,7 @@ const ERROR_TYPE_HINT = {
   http_error: 'Generic HTTP error — see Logs.',
   unsupported_url: 'gallery-dl does not support this URL pattern.',
   unknown_error: 'Could not classify — see Logs.',
+  api_drift: 'Patreon changed its API shape — the native ingester needs a code update.',
 }
 function errorTypeColor(t) { return ERROR_TYPE_COLOR[t] || 'error' }
 function errorTypeHint(t) { return ERROR_TYPE_HINT[t] || '' }

frontend/src/components/subscriptions/SourceCard.vue

@@ -25,9 +25,18 @@
         size="x-small" color="error" variant="tonal" label
       >{{ source.consecutive_failures }} err</v-chip>
       <v-chip
-        v-else-if="(source.backfill_runs_remaining || 0) > 0"
+        v-else-if="source.backfill_state === 'running'"
         size="x-small" color="info" variant="tonal" label
-      >backfill ({{ source.backfill_runs_remaining }}×)</v-chip>
+      >{{ source.backfill_bypass_seen ? 'Recovering' : 'Backfilling'
+        }}{{ source.backfill_chunks ? ` (${source.backfill_chunks})` : '' }}</v-chip>
+      <v-chip
+        v-else-if="source.backfill_state === 'complete'"
+        size="x-small" color="success" variant="tonal" label
+      >Backfilled</v-chip>
+      <v-chip
+        v-else-if="source.backfill_state === 'stalled'"
+        size="x-small" color="warning" variant="tonal" label
+      >Stalled</v-chip>
     </div>
 
     <div class="fc-source-card__actions">
@@ -40,11 +49,25 @@
       </v-btn>
       <v-btn
         size="x-small" variant="text"
-        :disabled="(source.backfill_runs_remaining || 0) > 0"
+        :color="source.backfill_state === 'running' ? 'warning' : undefined"
         @click.stop="$emit('backfill', source)"
       >
-        <v-icon>mdi-magnify-scan</v-icon>
-        <v-tooltip activator="parent" location="top">Deep scan</v-tooltip>
+        <v-icon>{{ source.backfill_state === 'running' ? 'mdi-stop' : 'mdi-magnify-scan' }}</v-icon>
+        <v-tooltip activator="parent" location="top">
+          {{ source.backfill_state === 'running'
+            ? (source.backfill_bypass_seen ? 'Stop recovery' : 'Stop backfill')
+            : 'Backfill full history' }}
+        </v-tooltip>
+      </v-btn>
+      <v-btn
+        v-if="source.platform === 'patreon' && source.backfill_state !== 'running'"
+        size="x-small" variant="text"
+        @click.stop="$emit('recover', source)"
+      >
+        <v-icon>mdi-backup-restore</v-icon>
+        <v-tooltip activator="parent" location="top">
+          Recover — re-fetch dropped near-dups &amp; re-evaluate under the current threshold
+        </v-tooltip>
       </v-btn>
       <v-btn size="x-small" variant="text" @click.stop="$emit('edit', source)">
         <v-icon>mdi-pencil</v-icon>
@@ -73,7 +96,7 @@ const props = defineProps({
   checking: { type: Boolean, default: false },
   warningThreshold: { type: Number, default: 5 },
 })
-const emit = defineEmits(['edit', 'remove', 'toggle', 'check', 'backfill'])
+const emit = defineEmits(['edit', 'remove', 'toggle', 'check', 'backfill', 'recover'])
 
 function onToggleEnabled(value) {
   emit('toggle', { source: props.source, enabled: value })

frontend/src/components/subscriptions/SourceRow.vue

@@ -32,11 +32,18 @@
         size="x-small" color="error" variant="tonal" label
       >{{ source.consecutive_failures }}</v-chip>
       <v-chip
-        v-else-if="(source.backfill_runs_remaining || 0) > 0"
+        v-else-if="source.backfill_state === 'running'"
         size="x-small" color="info" variant="tonal" label
-      >
-        backfill ({{ source.backfill_runs_remaining }}×)
-      </v-chip>
+      >{{ source.backfill_bypass_seen ? 'Recovering' : 'Backfilling'
+        }}{{ source.backfill_chunks ? ` (${source.backfill_chunks})` : '' }}</v-chip>
+      <v-chip
+        v-else-if="source.backfill_state === 'complete'"
+        size="x-small" color="success" variant="tonal" label
+      >Backfilled</v-chip>
+      <v-chip
+        v-else-if="source.backfill_state === 'stalled'"
+        size="x-small" color="warning" variant="tonal" label
+      >Stalled</v-chip>
       <span v-else class="fc-source-row__zero">0</span>
     </td>
     <td class="fc-source-row__actions">
@@ -49,13 +56,25 @@
         <v-tooltip activator="parent" location="top">Check now</v-tooltip>
       </v-btn>
       <v-btn
-        icon="mdi-magnify-scan" size="x-small" variant="text"
-        :disabled="(source.backfill_runs_remaining || 0) > 0"
+        size="x-small" variant="text"
+        :color="source.backfill_state === 'running' ? 'warning' : undefined"
         @click.stop="$emit('backfill', source)"
       >
-        <v-icon>mdi-magnify-scan</v-icon>
+        <v-icon>{{ source.backfill_state === 'running' ? 'mdi-stop' : 'mdi-magnify-scan' }}</v-icon>
         <v-tooltip activator="parent" location="top">
-          Deep scan — walk full history for next few runs
+          {{ source.backfill_state === 'running'
+            ? (source.backfill_bypass_seen ? 'Stop recovery' : 'Stop backfill')
+            : 'Backfill — walk the full post history until complete' }}
+        </v-tooltip>
+      </v-btn>
+      <v-btn
+        v-if="source.platform === 'patreon' && source.backfill_state !== 'running'"
+        size="x-small" variant="text"
+        @click.stop="$emit('recover', source)"
+      >
+        <v-icon>mdi-backup-restore</v-icon>
+        <v-tooltip activator="parent" location="top">
+          Recover — re-fetch dropped near-dups &amp; re-evaluate under the current threshold
         </v-tooltip>
       </v-btn>
       <v-btn
@@ -85,7 +104,7 @@ const props = defineProps({
   checking: { type: Boolean, default: false },
   warningThreshold: { type: Number, default: 5 },
 })
-const emit = defineEmits(['edit', 'remove', 'toggle', 'check', 'backfill'])
+const emit = defineEmits(['edit', 'remove', 'toggle', 'check', 'backfill', 'recover'])
 
 function onToggleEnabled(value) {
   emit('toggle', { source: props.source, enabled: value })

frontend/src/components/subscriptions/SubscriptionsTab.vue

@@ -175,6 +175,7 @@
                     @toggle="toggleSourceEnabled"
                     @check="onCheck"
                     @backfill="onBackfill"
+                    @recover="onRecover"
                   />
                   <tr v-if="item.sources.length === 0">
                     <td colspan="8" class="fc-subs__sources-empty">
@@ -251,6 +252,7 @@
             @toggle="toggleSourceEnabled"
             @check="onCheck"
             @backfill="onBackfill"
+            @recover="onRecover"
           />
           <div v-if="item.sources.length === 0" class="fc-subs__sources-empty">
             No sources yet. Tap + to add one.
@@ -532,31 +534,39 @@ async function onCheck(source) {
   }
 }
 
-// Plan #544: arm a source for backfill mode (gallery-dl walks the full
-// post history) for the next N download runs. Default 3 — enough budget
-// to finish a deep creator without re-prompting the operator across
-// timeout boundaries. The chip on the row reflects the remaining count.
+// Plan #693: toggle a run-until-done backfill. Starting walks the full post
+// history in time-boxed chunks across ticks until it reaches the bottom (the
+// row badge tracks progress / completion); stopping cancels back to tick mode.
 async function onBackfill(source) {
-  const raw = globalThis.window?.prompt(
-    `Deep scan "${source.artist_name} (${source.platform})" — walk full history for the next how many download runs? (1–10, default 3)`,
-    '3',
-  )
-  if (raw == null) return
-  const runs = parseInt(raw, 10)
-  if (!Number.isFinite(runs) || runs < 1 || runs > 10) {
-    toast({ text: 'Deep scan: runs must be 1–10', type: 'error' })
-    return
-  }
+  const running = source.backfill_state === 'running'
   try {
-    await store.setBackfill(source.id, runs, source.artist_id)
-    toast({
-      text: `Deep scan armed for ${runs} run${runs === 1 ? '' : 's'}`,
-      type: 'success',
-    })
+    if (running) {
+      await store.stopBackfill(source.id, source.artist_id)
+      toast({ text: `Backfill stopped for ${source.artist_name}`, type: 'success' })
+    } else {
+      await store.startBackfill(source.id, source.artist_id)
+      toast({ text: `Backfill started for ${source.artist_name}`, type: 'success' })
+    }
     await store.loadAll()
   } catch (e) {
     toast({
-      text: `Deep scan failed: ${e?.detail || e?.message || e}`,
+      text: `Backfill ${running ? 'stop' : 'start'} failed: ${e?.detail || e?.message || e}`,
+      type: 'error',
+    })
+  }
+}
+
+// Plan #697: arm a recovery walk (Patreon-only) — re-fetches dropped-and-deleted
+// near-dups and re-evaluates them under the current pHash threshold. Reuses the
+// backfill lifecycle/badge; stop via the same Stop control (onBackfill).
+async function onRecover(source) {
+  try {
+    await store.recoverSource(source.id, source.artist_id)
+    toast({ text: `Recovery started for ${source.artist_name}`, type: 'success' })
+    await store.loadAll()
+  } catch (e) {
+    toast({
+      text: `Recovery start failed: ${e?.detail || e?.message || e}`,
       type: 'error',
     })
   }

frontend/src/stores/sources.js

@@ -85,11 +85,24 @@ export const useSourcesStore = defineStore('sources', () => {
     }
   }
 
-  // Plan #544: arm a source for backfill mode. The next `runs` download
-  // runs (default 3) walk gallery-dl's full post history instead of
-  // exiting early at the first contiguous archived block.
-  async function setBackfill(id, runs = 3, artistIdHint = null) {
-    const body = await api.post(`/api/sources/${id}/backfill`, { body: { runs } })
+  // Plan #693: start/stop a run-until-done backfill. 'start' walks the full
+  // post history in time-boxed chunks until it reaches the bottom (then the
+  // source shows backfill_state 'complete'); 'stop' cancels back to tick mode.
+  async function startBackfill(id, artistIdHint = null) {
+    const body = await api.post(`/api/sources/${id}/backfill`, { body: { action: 'start' } })
+    _invalidate(artistIdHint ?? body.artist_id)
+    return body
+  }
+  async function stopBackfill(id, artistIdHint = null) {
+    const body = await api.post(`/api/sources/${id}/backfill`, { body: { action: 'stop' } })
+    _invalidate(artistIdHint ?? body.artist_id)
+    return body
+  }
+  // Plan #697: arm a recovery walk — a backfill that bypasses the Patreon
+  // seen-ledger to re-fetch dropped-and-deleted near-dups and re-evaluate them
+  // under the current pHash threshold. Stop with stopBackfill (shared lifecycle).
+  async function recoverSource(id, artistIdHint = null) {
+    const body = await api.post(`/api/sources/${id}/backfill`, { body: { action: 'recover' } })
     _invalidate(artistIdHint ?? body.artist_id)
     return body
   }
@@ -120,7 +133,9 @@ export const useSourcesStore = defineStore('sources', () => {
     loadAll, loadForArtist,
     create, update, remove,
     checkNow,
-    setBackfill,
+    startBackfill,
+    stopBackfill,
+    recoverSource,
     findOrCreateArtist, autocompleteArtist,
     loadScheduleStatus,
     sourcesByArtistGrouped,

tests/fixtures/patreon_posts_page1.json

@@ -0,0 +1,121 @@
+{
+  "data": [
+    {
+      "id": "1001",
+      "type": "post",
+      "attributes": {
+        "title": "Image gallery post",
+        "published_at": "2026-05-01T12:00:00.000+00:00",
+        "post_type": "image_file",
+        "content": "<p>just a gallery</p>",
+        "url": "https://www.patreon.com/posts/1001",
+        "image": {
+          "large_url": "https://c10.patreonusercontent.com/4/large/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/gallery-one.jpg",
+          "url": "https://c10.patreonusercontent.com/4/orig/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/gallery-one.jpg"
+        }
+      },
+      "relationships": {
+        "images": {
+          "data": [
+            {"id": "9001", "type": "media"},
+            {"id": "9002", "type": "media"}
+          ]
+        }
+      }
+    },
+    {
+      "id": "1002",
+      "type": "post",
+      "attributes": {
+        "title": "Attachment post",
+        "published_at": "2026-04-15T09:30:00.000+00:00",
+        "post_type": "text_only",
+        "content": "<p>here is a zip</p>",
+        "url": "https://www.patreon.com/posts/1002",
+        "post_file": {
+          "name": "bonus-pack.zip",
+          "url": "https://www.patreon.com/file?h=cccccccccccccccccccccccccccccccc&i=1002"
+        }
+      },
+      "relationships": {
+        "attachments_media": {
+          "data": [
+            {"id": "9003", "type": "media"}
+          ]
+        }
+      }
+    },
+    {
+      "id": "1003",
+      "type": "post",
+      "attributes": {
+        "title": "Inline content post",
+        "published_at": "2026-04-01T08:00:00.000+00:00",
+        "post_type": "text_only",
+        "content": "<p>look</p><figure><img src=\"https://c10.patreonusercontent.com/4/orig/dddddddddddddddddddddddddddddddd/inline.png?token=x&amp;v=2\" alt=\"inline\"></figure>",
+        "url": "https://www.patreon.com/posts/1003"
+      },
+      "relationships": {}
+    },
+    {
+      "id": "1004",
+      "type": "post",
+      "attributes": {
+        "title": "Video post",
+        "published_at": "2026-03-20T18:45:00.000+00:00",
+        "post_type": "video_external_file",
+        "content": "<p>watch</p>",
+        "url": "https://www.patreon.com/posts/1004",
+        "post_file": {
+          "name": "clip.m3u8",
+          "url": "https://stream.mux.com/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee.m3u8?token=jwt"
+        }
+      },
+      "relationships": {}
+    }
+  ],
+  "included": [
+    {
+      "id": "9001",
+      "type": "media",
+      "attributes": {
+        "file_name": "gallery-one.jpg",
+        "download_url": "https://c10.patreonusercontent.com/4/orig/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/gallery-one.jpg",
+        "image_urls": {
+          "original": "https://c10.patreonusercontent.com/4/orig/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/gallery-one.jpg",
+          "default": "https://c10.patreonusercontent.com/4/default/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/gallery-one.jpg"
+        }
+      }
+    },
+    {
+      "id": "9002",
+      "type": "media",
+      "attributes": {
+        "file_name": "gallery-two.jpg",
+        "download_url": "https://c10.patreonusercontent.com/4/orig/bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb/gallery-two.jpg",
+        "image_urls": {
+          "original": "https://c10.patreonusercontent.com/4/orig/bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb/gallery-two.jpg"
+        }
+      }
+    },
+    {
+      "id": "9003",
+      "type": "media",
+      "attributes": {
+        "file_name": "bonus-pack.zip",
+        "download_url": "https://www.patreon.com/file/download?h=cccccccccccccccccccccccccccccccc"
+      }
+    },
+    {
+      "id": "5555",
+      "type": "campaign",
+      "attributes": {
+        "name": "Example Creator",
+        "url": "https://www.patreon.com/example"
+      }
+    }
+  ],
+  "links": {
+    "next": "https://www.patreon.com/api/posts?filter%5Bcampaign_id%5D=5555&page%5Bcursor%5D=NEXTCURSOR123&sort=-published_at"
+  }
+}

tests/test_api_credentials.py

@@ -155,6 +155,8 @@ async def test_verify_no_enabled_source_is_untestable(client):
 
 @pytest.mark.asyncio
 async def test_verify_runs_gallery_dl_and_stamps_on_success(client, db, monkeypatch):
+    """A gallery-dl platform routes through GalleryDLService.verify; success
+    stamps last_verified (platform-agnostic endpoint behavior)."""
     from backend.app.models import Artist, Source
     from backend.app.services import gallery_dl as gdl_mod
 
@@ -163,6 +165,45 @@ async def test_verify_runs_gallery_dl_and_stamps_on_success(client, db, monkeypa
         return (True, "Credentials valid — the feed authenticated.")
     monkeypatch.setattr(gdl_mod.GalleryDLService, "verify", _fake_verify)
 
+    await client.post("/api/credentials", json={
+        "platform": "subscribestar", "credential_type": "cookies", "data": _NETSCAPE,
+    })
+    artist = Artist(name="Maewix", slug="maewix")
+    db.add(artist)
+    await db.flush()
+    db.add(Source(
+        artist_id=artist.id, platform="subscribestar",
+        url="https://www.subscribestar.com/maewix", enabled=True, config_overrides={},
+    ))
+    await db.commit()
+
+    resp = await client.post("/api/credentials/subscribestar/verify")
+    body = await resp.get_json()
+    assert body["valid"] is True
+    assert body["last_verified"] is not None
+
+    # The stamp is persisted on the credential record.
+    rec = await (await client.get("/api/credentials/subscribestar")).get_json()
+    assert rec["last_verified"] is not None
+
+
+@pytest.mark.asyncio
+async def test_verify_patreon_uses_native_ingester_not_gallery_dl(client, db, monkeypatch):
+    """plan #697 cutover: Patreon credential verify routes through the native
+    ingester (verify_patreon_credential), NOT gallery-dl --simulate."""
+    from backend.app.models import Artist, Source
+    from backend.app.services import gallery_dl as gdl_mod
+    from backend.app.services import patreon_ingester as pi_mod
+
+    async def _native_verify(url, cookies_path, overrides):
+        return (True, "Credentials valid — the Patreon feed authenticated.")
+    monkeypatch.setattr(pi_mod, "verify_patreon_credential", _native_verify)
+
+    # gallery-dl must NOT be consulted for Patreon.
+    async def _boom(self, *args, **kwargs):
+        raise AssertionError("gallery-dl verify must not run for patreon")
+    monkeypatch.setattr(gdl_mod.GalleryDLService, "verify", _boom)
+
     await client.post("/api/credentials", json={
         "platform": "patreon", "credential_type": "cookies", "data": _NETSCAPE,
     })
@@ -180,10 +221,6 @@ async def test_verify_runs_gallery_dl_and_stamps_on_success(client, db, monkeypa
     assert body["valid"] is True
     assert body["last_verified"] is not None
 
-    # The stamp is persisted on the credential record.
-    rec = await (await client.get("/api/credentials/patreon")).get_json()
-    assert rec["last_verified"] is not None
-
 
 @pytest.mark.asyncio
 async def test_verify_reports_auth_failure(client, db, monkeypatch):

tests/test_api_sources.py

@@ -199,7 +199,7 @@ async def test_list_derives_next_check_at_when_last_checked_set(
 
 
 @pytest.mark.asyncio
-async def test_backfill_endpoint_arms_source(client, artist, db):
+async def test_backfill_endpoint_start_and_stop(client, artist, db):
     src = Source(
         artist_id=artist.id, platform="patreon",
         url="https://patreon.com/alice-backfill", enabled=True,
@@ -208,18 +208,21 @@ async def test_backfill_endpoint_arms_source(client, artist, db):
     await db.commit()
     sid = src.id
 
-    resp = await client.post(f"/api/sources/{sid}/backfill", json={"runs": 5})
+    resp = await client.post(f"/api/sources/{sid}/backfill", json={"action": "start"})
     assert resp.status_code == 200
     body = await resp.get_json()
-    assert body["backfill_runs_remaining"] == 5
+    assert body["backfill_state"] == "running"
 
-    # GET reflects the new state.
+    # GET reflects the running state.
     one = await client.get(f"/api/sources/{sid}")
-    assert (await one.get_json())["backfill_runs_remaining"] == 5
+    assert (await one.get_json())["backfill_state"] == "running"
+
+    stopped = await client.post(f"/api/sources/{sid}/backfill", json={"action": "stop"})
+    assert (await stopped.get_json())["backfill_state"] is None
 
 
 @pytest.mark.asyncio
-async def test_backfill_endpoint_defaults_to_three(client, artist, db):
+async def test_backfill_endpoint_defaults_to_start(client, artist, db):
     src = Source(
         artist_id=artist.id, platform="patreon",
         url="https://patreon.com/alice-backfill-default", enabled=True,
@@ -228,26 +231,47 @@ async def test_backfill_endpoint_defaults_to_three(client, artist, db):
     await db.commit()
     resp = await client.post(f"/api/sources/{src.id}/backfill", json={})
     body = await resp.get_json()
-    assert body["backfill_runs_remaining"] == 3
+    assert body["backfill_state"] == "running"
 
 
 @pytest.mark.asyncio
-async def test_backfill_endpoint_rejects_out_of_range(client, artist, db):
+async def test_backfill_endpoint_rejects_bad_action(client, artist, db):
     src = Source(
         artist_id=artist.id, platform="patreon",
         url="https://patreon.com/alice-backfill-bad", enabled=True,
     )
     db.add(src)
     await db.commit()
-    bad = await client.post(f"/api/sources/{src.id}/backfill", json={"runs": 0})
+    bad = await client.post(f"/api/sources/{src.id}/backfill", json={"action": "nope"})
     assert bad.status_code == 400
-    too_big = await client.post(
-        f"/api/sources/{src.id}/backfill", json={"runs": 99}
-    )
-    assert too_big.status_code == 400
 
 
 @pytest.mark.asyncio
 async def test_backfill_endpoint_404_when_source_missing(client):
-    resp = await client.post("/api/sources/999999/backfill", json={"runs": 3})
+    resp = await client.post("/api/sources/999999/backfill", json={"action": "start"})
     assert resp.status_code == 404
+
+
+@pytest.mark.asyncio
+async def test_backfill_endpoint_recover_arms_bypass(client, artist, db):
+    """Plan #697: action='recover' arms a backfill that bypasses the Patreon
+    seen-ledger; the response exposes backfill_bypass_seen=True so the UI badge
+    can label it 'Recovering'. Stop clears it."""
+    src = Source(
+        artist_id=artist.id, platform="patreon",
+        url="https://patreon.com/alice-recover", enabled=True,
+    )
+    db.add(src)
+    await db.commit()
+    sid = src.id
+
+    resp = await client.post(f"/api/sources/{sid}/backfill", json={"action": "recover"})
+    assert resp.status_code == 200
+    body = await resp.get_json()
+    assert body["backfill_state"] == "running"
+    assert body["backfill_bypass_seen"] is True
+
+    stopped = await client.post(f"/api/sources/{sid}/backfill", json={"action": "stop"})
+    stopped_body = await stopped.get_json()
+    assert stopped_body["backfill_state"] is None
+    assert stopped_body["backfill_bypass_seen"] is False

tests/test_download_backends.py

@@ -0,0 +1,23 @@
+"""download_backends — the single predicate that routes a platform to the
+native ingester vs. gallery-dl. Pure, no DB."""
+
+from backend.app.services.download_backends import (
+    NATIVE_INGESTER_PLATFORMS,
+    uses_native_ingester,
+)
+
+
+def test_patreon_is_native():
+    assert uses_native_ingester("patreon") is True
+    assert "patreon" in NATIVE_INGESTER_PLATFORMS
+
+
+def test_gallery_dl_platforms_are_not_native():
+    # The five platforms still served by gallery-dl must NOT route to the
+    # native ingester — guards an accidental over-broad migration.
+    for platform in ("subscribestar", "hentaifoundry", "discord", "pixiv", "deviantart"):
+        assert uses_native_ingester(platform) is False
+
+
+def test_unknown_platform_is_not_native():
+    assert uses_native_ingester("nonsense") is False

tests/test_download_service.py

@@ -94,6 +94,23 @@ def _fake_gdl_with_result(result):
     return fake
 
 
+def _stub_patreon_ingester(svc, result, resolved_campaign_id=None):
+    """Route the Patreon phase-2 branch (plan #697 native ingester) to a canned
+    DownloadResult so these tests exercise download_service's
+    phase-2-result→phase-3 handling (status mapping, backfill lifecycle, health)
+    without the real ingester's network/DB. The ingester itself is covered by
+    test_patreon_ingester.py. Returns a list capturing (ctx, source_config, mode)
+    per call so a test can assert mode / resume_cursor threading."""
+    calls = []
+
+    async def fake(ctx, source_config, mode):
+        calls.append({"ctx": ctx, "source_config": source_config, "mode": mode})
+        return result, resolved_campaign_id
+
+    svc._run_patreon_ingester = fake
+    return calls
+
+
 @pytest.mark.asyncio
 async def test_download_source_attaches_written_files(
     db, db_sync, tmp_path, seed_artist_and_source,
@@ -112,12 +129,13 @@ async def test_download_source_attaches_written_files(
     _make_jpg(f1, split="h")
     _make_jpg(f2, split="v")
 
-    fake_gdl = _fake_gdl_with_result(_make_fake_dl_result(
+    result = _make_fake_dl_result(
         success=True,
         written_paths=[str(f1), str(f2)],
         files_downloaded=2,
         stdout=f"{f1}\n{f2}\n",
-    ))
+    )
+    fake_gdl = _fake_gdl_with_result(result)
 
     sync_settings = db_sync.execute(
         select(ImportSettings).where(ImportSettings.id == 1)
@@ -137,6 +155,7 @@ async def test_download_source_attaches_written_files(
         async_session=db, sync_session=db_sync,
         gdl=fake_gdl, importer=importer, cred_service=cred_service,
     )
+    _stub_patreon_ingester(svc, result)
     event_id = await svc.download_source(source.id)
 
     ev = (await db.execute(
@@ -214,40 +233,19 @@ async def test_in_flight_idempotency_returns_existing_event(
 
 
 @pytest.mark.asyncio
-async def test_patreon_retry_caches_campaign_id(
-    db, db_sync, tmp_path, seed_artist_and_source, monkeypatch,
+async def test_patreon_resolved_campaign_id_is_cached(
+    db, db_sync, tmp_path, seed_artist_and_source,
 ):
+    """plan #697: the native ingester resolves a Patreon vanity → campaign id
+    on the fly (replacing gallery-dl's reactive campaign-id retry). When phase 2
+    reports a freshly-resolved id, phase 3 caches it on the source so later runs
+    skip the lookup. Stub the ingester to report a resolved id; assert it lands
+    in config_overrides."""
     from backend.app.services.download_service import DownloadService
     from backend.app.services.importer import Importer
 
     _artist, source = seed_artist_and_source
 
-    failed = _make_fake_dl_result(
-        success=False, written_paths=[], stdout="",
-        stderr="[patreon][error] Failed to extract campaign ID for alice\n",
-    )
-    succeeded = _make_fake_dl_result(success=True, written_paths=[])
-
-    download_calls = []
-
-    async def fake_download(url, **k):
-        download_calls.append(url)
-        return failed if len(download_calls) == 1 else succeeded
-
-    fake_gdl = MagicMock()
-    fake_gdl.download = fake_download
-    fake_gdl._compute_run_stats = lambda *a, **k: {
-        "exit_code": 0, "downloaded_count": 0, "skipped_count": 0,
-        "per_item_failures": 0, "warning_count": 0, "tier_gated_count": 0,
-    }
-    fake_gdl._extract_errors_warnings = lambda *a, **k: ""
-    fake_gdl._truncate_log = lambda x, **k: x
-
-    monkeypatch.setattr(
-        "backend.app.services.download_service.resolve_campaign_id",
-        AsyncMock(return_value="99"),
-    )
-
     sync_settings = db_sync.execute(
         select(ImportSettings).where(ImportSettings.id == 1)
     ).scalar_one()
@@ -261,19 +259,104 @@ async def test_patreon_retry_caches_campaign_id(
 
     svc = DownloadService(
         async_session=db, sync_session=db_sync,
-        gdl=fake_gdl, importer=importer, cred_service=cred_service,
+        gdl=_fake_gdl_with_result(_make_fake_dl_result(success=True)),
+        importer=importer, cred_service=cred_service,
+    )
+    _stub_patreon_ingester(
+        svc, _make_fake_dl_result(success=True, written_paths=[]),
+        resolved_campaign_id="99",
     )
     await svc.download_source(source.id)
 
-    assert len(download_calls) == 2
-    assert "id:99" in download_calls[1]
-
     overrides = db_sync.execute(
         select(Source.config_overrides).where(Source.id == source.id)
     ).scalar_one()
     assert overrides.get("patreon_campaign_id") == "99"
 
 
+@pytest.mark.asyncio
+async def test_run_patreon_ingester_resolves_vanity_and_runs(
+    db, db_sync, tmp_path, seed_artist_and_source, monkeypatch,
+):
+    """_run_patreon_ingester: with no cached campaign id, resolve the vanity and
+    pass the resolved id straight to the ingester; report it back so phase 3 can
+    cache it."""
+    from backend.app.services import download_service as dl_mod
+    from backend.app.services.download_service import DownloadService
+    from backend.app.services.gallery_dl import SourceConfig
+
+    _artist, source = seed_artist_and_source
+
+    monkeypatch.setattr(
+        dl_mod, "resolve_campaign_id_for_source",
+        AsyncMock(return_value=("4242", "4242")),
+    )
+    run_kwargs = {}
+
+    class _FakeIngester:
+        def __init__(self, **kw):
+            pass
+
+        def run(self, **kw):
+            run_kwargs.update(kw)
+            return _make_fake_dl_result(success=True, written_paths=[])
+
+    monkeypatch.setattr(dl_mod, "PatreonIngester", _FakeIngester)
+
+    svc = DownloadService(
+        async_session=db, sync_session=db_sync,
+        gdl=_fake_gdl_with_result(_make_fake_dl_result(success=True)),
+        importer=MagicMock(), cred_service=MagicMock(),
+        sync_session_factory=MagicMock(),
+    )
+    ctx = {
+        "source_id": source.id, "url": "https://patreon.com/alice",
+        "artist_slug": "alice", "cookies_path": None,
+        "config_overrides": {},
+    }
+    result, resolved = await svc._run_patreon_ingester(
+        ctx, SourceConfig.from_dict({}), "tick",
+    )
+    assert result.success is True
+    assert resolved == "4242"
+    assert run_kwargs["campaign_id"] == "4242"
+    assert run_kwargs["mode"] == "tick"
+
+
+@pytest.mark.asyncio
+async def test_run_patreon_ingester_unresolvable_fails_loud(
+    db, db_sync, tmp_path, seed_artist_and_source, monkeypatch,
+):
+    """A campaign id we can't resolve is a loud NOT_FOUND failure, never a
+    silent empty success."""
+    from backend.app.services import download_service as dl_mod
+    from backend.app.services.download_service import DownloadService
+    from backend.app.services.gallery_dl import ErrorType, SourceConfig
+
+    _artist, source = seed_artist_and_source
+
+    monkeypatch.setattr(
+        dl_mod, "resolve_campaign_id_for_source",
+        AsyncMock(return_value=(None, None)),
+    )
+    svc = DownloadService(
+        async_session=db, sync_session=db_sync,
+        gdl=MagicMock(), importer=MagicMock(), cred_service=MagicMock(),
+        sync_session_factory=MagicMock(),
+    )
+    ctx = {
+        "source_id": source.id, "url": "https://patreon.com/alice",
+        "artist_slug": "alice", "cookies_path": None,
+        "config_overrides": {},
+    }
+    result, resolved = await svc._run_patreon_ingester(
+        ctx, SourceConfig.from_dict({}), "tick",
+    )
+    assert result.success is False
+    assert result.error_type == ErrorType.NOT_FOUND
+    assert resolved is None
+
+
 # --- FC-3d: finalize hook updates Source health columns -------------------
 
 
@@ -372,32 +455,20 @@ async def test_finalize_skipped_preserves_failures_clears_error(db):
     assert row.last_checked_at is not None
 
 
-# --- Plan #544: backfill lifecycle + PARTIAL → status=ok -------------------
+# --- Plan #693: backfill state machine (time-boxed chunks, run-until-done) ---
 
 
-@pytest.mark.asyncio
-async def test_backfill_decrements_after_run(
-    db, db_sync, tmp_path, seed_artist_and_source,
-):
-    """When backfill_runs_remaining > 0 going in, a non-clean / non-empty
-    run decrements by 1 — operator gets N runs to complete the deep scan
-    before tick mode resumes."""
+def _backfill_svc(db, db_sync, tmp_path, result):
+    """DownloadService wired with a real importer (so empty written_paths just
+    attaches nothing) whose Patreon phase-2 branch is stubbed to return `result`.
+
+    The seeded source is Patreon, so phase 2 routes to the native ingester
+    (plan #697); the stub returns the canned result + captures the per-call
+    (ctx, source_config, mode). Returns (svc, ingester_calls)."""
     from backend.app.services.download_service import DownloadService
     from backend.app.services.importer import Importer
 
-    _artist, source = seed_artist_and_source
-    source.backfill_runs_remaining = 3
-    await db.commit()
-
     images_root = tmp_path / "images"
-    f1 = images_root / "alice" / "patreon" / "post" / "a.jpg"
-    _make_jpg(f1, split="h")
-
-    fake_gdl = _fake_gdl_with_result(_make_fake_dl_result(
-        success=True, written_paths=[str(f1)], files_downloaded=1,
-        stdout=f"{f1}\n",
-    ))
-
     sync_settings = db_sync.execute(
         select(ImportSettings).where(ImportSettings.id == 1)
     ).scalar_one()
@@ -406,97 +477,245 @@ async def test_backfill_decrements_after_run(
         thumbnailer=Thumbnailer(images_root=images_root), settings=sync_settings,
     )
     cred_service = CredentialService(db, CredentialCrypto(tmp_path / "key.b64", bootstrap_ok=True))
+    fake_gdl = _fake_gdl_with_result(result)
     svc = DownloadService(
         async_session=db, sync_session=db_sync,
         gdl=fake_gdl, importer=importer, cred_service=cred_service,
     )
-    await svc.download_source(source.id)
-
-    remaining = (await db.execute(
-        select(Source.backfill_runs_remaining).where(Source.id == source.id)
-    )).scalar_one()
-    assert remaining == 2
+    calls = _stub_patreon_ingester(svc, result)
+    return svc, calls
 
 
 @pytest.mark.asyncio
-async def test_backfill_auto_resets_on_clean_zero_files(
+async def test_backfill_chunk_progress_advances_cursor(
     db, db_sync, tmp_path, seed_artist_and_source,
 ):
-    """A clean run (rc=0) that downloaded zero files means the backfill
-    queue drained — reset to 0 immediately instead of wasting the rest of
-    the N-run budget on no-op walks."""
-    from backend.app.services.download_service import DownloadService
-    from backend.app.services.importer import Importer
-
+    """A running backfill chunk that didn't finish but advanced (new cursor)
+    stays 'running', checkpoints the cursor, bumps the chunk counter, and
+    spends one safety-cap chunk."""
     _artist, source = seed_artist_and_source
-    source.backfill_runs_remaining = 3
+    source.config_overrides = {"_backfill_state": "running"}
+    source.backfill_runs_remaining = 5
     await db.commit()
 
-    fake_result = _make_fake_dl_result(
-        success=True, written_paths=[], files_downloaded=0,
-    )
-    fake_gdl = _fake_gdl_with_result(fake_result)
-
-    sync_settings = db_sync.execute(
-        select(ImportSettings).where(ImportSettings.id == 1)
-    ).scalar_one()
-    importer = Importer(
-        session=db_sync, images_root=tmp_path / "images",
-        import_root=tmp_path / "images",
-        thumbnailer=Thumbnailer(images_root=tmp_path / "images"),
-        settings=sync_settings,
-    )
-    cred_service = CredentialService(db, CredentialCrypto(tmp_path / "key.b64", bootstrap_ok=True))
-    svc = DownloadService(
-        async_session=db, sync_session=db_sync,
-        gdl=fake_gdl, importer=importer, cred_service=cred_service,
-    )
+    svc, _ = _backfill_svc(db, db_sync, tmp_path, _make_fake_dl_result(
+        success=False, written_paths=[], files_downloaded=0,
+        stderr="[patreon][debug] Cursor: 03:PAGE2:xyz\n",
+    ))
     await svc.download_source(source.id)
 
-    remaining = (await db.execute(
-        select(Source.backfill_runs_remaining).where(Source.id == source.id)
+    remaining, co = (await db.execute(
+        select(Source.backfill_runs_remaining, Source.config_overrides)
+        .where(Source.id == source.id)
+    )).one()
+    assert co.get("_backfill_state") == "running"
+    assert co.get("_backfill_cursor") == "03:PAGE2:xyz"
+    assert co.get("_backfill_chunks") == 1
+    assert remaining == 4
+
+
+@pytest.mark.asyncio
+async def test_backfill_state_running_selects_backfill_mode_and_resumes(
+    db, db_sync, tmp_path, seed_artist_and_source,
+):
+    """state=='running' drives backfill mode (chunk budget) and threads the
+    stored cursor to the native ingester as the resume point."""
+    from backend.app.services.gallery_dl import BACKFILL_CHUNK_SECONDS
+
+    _artist, source = seed_artist_and_source
+    source.config_overrides = {"_backfill_state": "running", "_backfill_cursor": "03:RESUME:here"}
+    source.backfill_runs_remaining = 5
+    await db.commit()
+
+    svc, calls = _backfill_svc(db, db_sync, tmp_path, _make_fake_dl_result(
+        success=False, written_paths=[],
+        stderr="[patreon][debug] Cursor: 03:RESUME2:next\n",
+    ))
+    await svc.download_source(source.id)
+
+    assert len(calls) == 1
+    assert calls[0]["mode"] == "backfill"
+    assert calls[0]["source_config"].resume_cursor == "03:RESUME:here"
+    assert calls[0]["source_config"].timeout == BACKFILL_CHUNK_SECONDS
+
+    co = (await db.execute(
+        select(Source.config_overrides).where(Source.id == source.id)
     )).scalar_one()
+    assert co.get("_backfill_cursor") == "03:RESUME2:next"
+
+
+@pytest.mark.asyncio
+async def test_backfill_clean_exit_marks_complete(
+    db, db_sync, tmp_path, seed_artist_and_source,
+):
+    """A clean rc=0 chunk = gallery-dl reached the bottom → state 'complete',
+    cursor cleared, returns to tick mode."""
+    _artist, source = seed_artist_and_source
+    source.config_overrides = {"_backfill_state": "running", "_backfill_cursor": "03:NEAR:bottom"}
+    source.backfill_runs_remaining = 5
+    await db.commit()
+
+    svc, _ = _backfill_svc(db, db_sync, tmp_path, _make_fake_dl_result(
+        success=True, written_paths=[], files_downloaded=0,
+    ))
+    await svc.download_source(source.id)
+
+    remaining, co = (await db.execute(
+        select(Source.backfill_runs_remaining, Source.config_overrides)
+        .where(Source.id == source.id)
+    )).one()
+    assert co.get("_backfill_state") == "complete"
+    assert "_backfill_cursor" not in co
     assert remaining == 0
 
 
 @pytest.mark.asyncio
-async def test_tick_mode_does_not_touch_backfill_counter(
+async def test_backfill_cap_exhaustion_stalls(
     db, db_sync, tmp_path, seed_artist_and_source,
 ):
-    """When backfill_runs_remaining is already 0, downloads don't go
-    negative or otherwise mutate the counter."""
-    from backend.app.services.download_service import DownloadService
-    from backend.app.services.importer import Importer
-
+    """A progressing chunk that spends the last safety-cap chunk without
+    reaching the bottom pauses as 'stalled' (doesn't loop forever)."""
     _artist, source = seed_artist_and_source
-    assert source.backfill_runs_remaining == 0
+    source.config_overrides = {"_backfill_state": "running"}
+    source.backfill_runs_remaining = 1
+    await db.commit()
 
-    fake_gdl = _fake_gdl_with_result(_make_fake_dl_result(
-        success=True, written_paths=[], files_downloaded=0,
+    svc, _ = _backfill_svc(db, db_sync, tmp_path, _make_fake_dl_result(
+        success=False, written_paths=[],
+        stderr="[patreon][debug] Cursor: 03:MORE:left\n",
     ))
-
-    sync_settings = db_sync.execute(
-        select(ImportSettings).where(ImportSettings.id == 1)
-    ).scalar_one()
-    importer = Importer(
-        session=db_sync, images_root=tmp_path / "images",
-        import_root=tmp_path / "images",
-        thumbnailer=Thumbnailer(images_root=tmp_path / "images"),
-        settings=sync_settings,
-    )
-    cred_service = CredentialService(db, CredentialCrypto(tmp_path / "key.b64", bootstrap_ok=True))
-    svc = DownloadService(
-        async_session=db, sync_session=db_sync,
-        gdl=fake_gdl, importer=importer, cred_service=cred_service,
-    )
     await svc.download_source(source.id)
 
-    remaining = (await db.execute(
-        select(Source.backfill_runs_remaining).where(Source.id == source.id)
-    )).scalar_one()
+    remaining, co = (await db.execute(
+        select(Source.backfill_runs_remaining, Source.config_overrides)
+        .where(Source.id == source.id)
+    )).one()
+    assert co.get("_backfill_state") == "stalled"
     assert remaining == 0
 
 
+@pytest.mark.asyncio
+async def test_backfill_stuck_guard_stalls_after_two_no_advance(
+    db, db_sync, tmp_path, seed_artist_and_source,
+):
+    """Two consecutive chunks that fail to advance the cursor → 'stalled',
+    cursor cleared, so a wedged walk can't re-strand forever."""
+    from unittest.mock import MagicMock
+
+    from backend.app.services.download_service import DownloadService
+
+    _artist, source = seed_artist_and_source
+    source.config_overrides = {"_backfill_state": "running", "_backfill_cursor": "stuck"}
+    source.backfill_runs_remaining = 5
+    await db.commit()
+
+    svc = DownloadService(
+        async_session=db, sync_session=db_sync,
+        gdl=MagicMock(), importer=MagicMock(), cred_service=MagicMock(),
+    )
+    ctx = {
+        "source_id": source.id, "platform": "patreon",
+        "config_overrides": {"_backfill_state": "running", "_backfill_cursor": "stuck"},
+        "backfill_runs_remaining": 5,
+    }
+    stuck = _make_fake_dl_result(success=False, stderr="Cursor: stuck\n")
+
+    await svc._apply_backfill_lifecycle(ctx, stuck)
+    await db.commit()
+    co = (await db.execute(
+        select(Source.config_overrides).where(Source.id == source.id)
+    )).scalar_one()
+    assert co.get("_backfill_state") == "running"
+    assert co.get("_backfill_cursor_stalls") == 1
+
+    ctx["config_overrides"] = dict(co)
+    await svc._apply_backfill_lifecycle(ctx, stuck)
+    await db.commit()
+    co2 = (await db.execute(
+        select(Source.config_overrides).where(Source.id == source.id)
+    )).scalar_one()
+    assert co2.get("_backfill_state") == "stalled"
+    assert "_backfill_cursor" not in co2
+
+
+@pytest.mark.asyncio
+async def test_backfill_timeout_chunk_reclassified_to_ok(
+    db, db_sync, tmp_path, seed_artist_and_source,
+):
+    """A backfill chunk that hit its time-box (TIMEOUT) but advanced is
+    reclassified to PARTIAL → event status 'ok' (progress, not error), and
+    consecutive_failures is not bumped."""
+    from backend.app.services.gallery_dl import ErrorType
+
+    _artist, source = seed_artist_and_source
+    source.config_overrides = {"_backfill_state": "running"}
+    source.backfill_runs_remaining = 5
+    await db.commit()
+
+    svc, _ = _backfill_svc(db, db_sync, tmp_path, _make_fake_dl_result(
+        success=False, files_downloaded=3,
+        error_type=ErrorType.TIMEOUT,
+        error_message="Download timed out",
+        stderr="[patreon][debug] Cursor: 03:NEXT:page\n",
+    ))
+    event_id = await svc.download_source(source.id)
+
+    ev = (await db.execute(
+        select(DownloadEvent).where(DownloadEvent.id == event_id)
+    )).scalar_one()
+    assert ev.status == "ok"
+    failures = (await db.execute(
+        select(Source.consecutive_failures).where(Source.id == source.id)
+    )).scalar_one()
+    assert failures == 0
+
+
+@pytest.mark.asyncio
+async def test_tick_mode_when_not_running_leaves_state_untouched(
+    db, db_sync, tmp_path, seed_artist_and_source,
+):
+    """No _backfill_state → not backfilling; the lifecycle is a no-op and the
+    counter/state aren't mutated."""
+    _artist, source = seed_artist_and_source
+    assert (source.config_overrides or {}).get("_backfill_state") is None
+
+    svc, _ = _backfill_svc(db, db_sync, tmp_path, _make_fake_dl_result(
+        success=True, written_paths=[], files_downloaded=0,
+    ))
+    await svc.download_source(source.id)
+
+    co = (await db.execute(
+        select(Source.config_overrides).where(Source.id == source.id)
+    )).scalar_one()
+    assert (co or {}).get("_backfill_state") is None
+
+
+@pytest.mark.asyncio
+async def test_recovery_mode_selected_and_flag_cleared_on_complete(
+    db, db_sync, tmp_path, seed_artist_and_source,
+):
+    """plan #697: `_backfill_bypass_seen` alongside a running backfill selects
+    recovery mode (ingester bypasses the seen-ledger). A clean rc=0 walk
+    completes the shared lifecycle AND clears the bypass flag so the next tick
+    honors the ledger again."""
+    _artist, source = seed_artist_and_source
+    source.config_overrides = {"_backfill_state": "running", "_backfill_bypass_seen": True}
+    source.backfill_runs_remaining = 5
+    await db.commit()
+
+    svc, calls = _backfill_svc(db, db_sync, tmp_path, _make_fake_dl_result(
+        success=True, written_paths=[], files_downloaded=0,
+    ))
+    await svc.download_source(source.id)
+
+    assert calls[0]["mode"] == "recovery"
+    co = (await db.execute(
+        select(Source.config_overrides).where(Source.id == source.id)
+    )).scalar_one()
+    assert co.get("_backfill_state") == "complete"
+    assert "_backfill_bypass_seen" not in co
+
+
 @pytest.mark.asyncio
 async def test_partial_error_type_maps_to_ok_status(
     db, db_sync, tmp_path, seed_artist_and_source,
@@ -534,6 +753,7 @@ async def test_partial_error_type_maps_to_ok_status(
         async_session=db, sync_session=db_sync,
         gdl=fake_gdl, importer=importer, cred_service=cred_service,
     )
+    _stub_patreon_ingester(svc, fake_result)
     event_id = await svc.download_source(source.id)
 
     ev = (await db.execute(
@@ -569,10 +789,11 @@ async def test_download_enqueues_thumbnail_and_ml_per_attached_image(
     _make_jpg(f1, split="h")
     _make_jpg(f2, split="v")
 
-    fake_gdl = _fake_gdl_with_result(_make_fake_dl_result(
+    result = _make_fake_dl_result(
         success=True, written_paths=[str(f1), str(f2)],
         files_downloaded=2, stdout=f"{f1}\n{f2}\n",
-    ))
+    )
+    fake_gdl = _fake_gdl_with_result(result)
 
     sync_settings = db_sync.execute(
         select(ImportSettings).where(ImportSettings.id == 1)
@@ -605,6 +826,7 @@ async def test_download_enqueues_thumbnail_and_ml_per_attached_image(
         async_session=db, sync_session=db_sync,
         gdl=fake_gdl, importer=importer, cred_service=cred_service,
     )
+    _stub_patreon_ingester(svc, result)
     await svc.download_source(source.id)
 
     # Two files attached → two thumbnail enqueues + two ML enqueues, IDs
@@ -619,11 +841,11 @@ async def test_download_enqueues_thumbnail_and_ml_per_attached_image(
 async def test_releases_db_connections_before_subprocess(
     db, db_sync, tmp_path, seed_artist_and_source, monkeypatch,
 ):
-    """Phase 1's DB connections must be released BEFORE the (up to ~19.5-min
-    in backfill) gallery-dl subprocess, so they don't idle-die and strand
-    phase 3 with ConnectionDoesNotExistError (Anduo #40014). Spy on the
-    async session close and assert it happened before gdl.download runs;
-    phase 3 must still finalize the event."""
+    """Phase 1's DB connections must be released BEFORE the (multi-minute)
+    phase-2 fetch, so they don't idle-die and strand phase 3 with
+    ConnectionDoesNotExistError (Anduo #40014). Spy on the async session close
+    and assert it happened before the phase-2 work (here the native Patreon
+    ingester) runs; phase 3 must still finalize the event."""
     from backend.app.services.download_service import DownloadService
     from backend.app.services.importer import Importer
 
@@ -639,19 +861,9 @@ async def test_releases_db_connections_before_subprocess(
     monkeypatch.setattr(db, "close", spy_close)
 
     seen = {}
-
-    async def fake_download(url, **k):
-        seen["closed_before_download"] = closed["async"]
-        return _make_fake_dl_result(success=True, written_paths=[], stdout="")
-
-    fake_gdl = MagicMock()
-    fake_gdl.download = fake_download
-    fake_gdl._compute_run_stats = lambda *a, **k: {
-        "exit_code": 0, "downloaded_count": 0, "skipped_count": 0,
-        "per_item_failures": 0, "warning_count": 0, "tier_gated_count": 0,
-    }
-    fake_gdl._extract_errors_warnings = lambda *a, **k: ""
-    fake_gdl._truncate_log = lambda x, **k: x
+    fake_gdl = _fake_gdl_with_result(
+        _make_fake_dl_result(success=True, written_paths=[], stdout="")
+    )
 
     sync_settings = db_sync.execute(
         select(ImportSettings).where(ImportSettings.id == 1)
@@ -668,9 +880,15 @@ async def test_releases_db_connections_before_subprocess(
         async_session=db, sync_session=db_sync,
         gdl=fake_gdl, importer=importer, cred_service=cred_service,
     )
+
+    async def fake_ingest(ctx, source_config, mode):
+        seen["closed_before_phase2"] = closed["async"]
+        return _make_fake_dl_result(success=True, written_paths=[], stdout=""), None
+
+    svc._run_patreon_ingester = fake_ingest
     event_id = await svc.download_source(source.id)
 
-    assert seen["closed_before_download"] is True
+    assert seen["closed_before_phase2"] is True
     ev = (await db.execute(
         select(DownloadEvent).where(DownloadEvent.id == event_id)
     )).scalar_one()

tests/test_download_source_task.py

@@ -34,7 +34,7 @@ def test_timeout_ladder_keeps_subprocess_budgets_under_soft_limit():
     preempts it. soft must in turn sit below the hard SIGKILL cap."""
     from backend.app.services.gallery_dl import (
         _DEFAULT_GDL_TIMEOUT_SECONDS,
-        BACKFILL_TIMEOUT_SECONDS,
+        BACKFILL_CHUNK_SECONDS,
     )
     from backend.app.tasks.download import (
         DOWNLOAD_HARD_TIME_LIMIT,
@@ -42,7 +42,7 @@ def test_timeout_ladder_keeps_subprocess_budgets_under_soft_limit():
     )
 
     assert _DEFAULT_GDL_TIMEOUT_SECONDS < DOWNLOAD_SOFT_TIME_LIMIT
-    assert BACKFILL_TIMEOUT_SECONDS < DOWNLOAD_SOFT_TIME_LIMIT
+    assert BACKFILL_CHUNK_SECONDS < DOWNLOAD_SOFT_TIME_LIMIT
     assert DOWNLOAD_SOFT_TIME_LIMIT < DOWNLOAD_HARD_TIME_LIMIT
 
 

tests/test_gallery_dl_service.py

@@ -8,6 +8,7 @@ from backend.app.services.gallery_dl import (
     ErrorType,
     GalleryDLService,
     SourceConfig,
+    parse_last_cursor,
 )
 
 
@@ -259,7 +260,7 @@ def test_build_config_emits_tick_skip_value(gdl):
     scans once 20 contiguous archived items are seen."""
     from backend.app.services.gallery_dl import TICK_SKIP_VALUE
     cfg = gdl._build_config_for_source(
-        platform="patreon",
+        platform="subscribestar",
         source_config=SourceConfig(),
         artist_slug="alice",
         skip_value=TICK_SKIP_VALUE,
@@ -272,7 +273,7 @@ def test_build_config_emits_backfill_skip_value(gdl):
     full post history."""
     from backend.app.services.gallery_dl import BACKFILL_SKIP_VALUE
     cfg = gdl._build_config_for_source(
-        platform="patreon",
+        platform="subscribestar",
         source_config=SourceConfig(),
         artist_slug="alice",
         skip_value=BACKFILL_SKIP_VALUE,
@@ -317,12 +318,26 @@ def test_categorize_tier_limited_wins_over_partial(gdl):
     assert etype == ErrorType.TIER_LIMITED
 
 
-def test_default_config_forwards_patreon_referer_to_ytdl(gdl):
-    """Operator-flagged 2026-06-01: Mux video playback restrictions reject
-    yt-dlp's manifest fetch when Referer/Origin don't match Patreon. The
-    fix is a static `downloader.ytdl.raw-options.http_headers` block, so
-    it's enough to assert the keys land in the default config."""
-    cfg = gdl._get_default_config()
-    headers = cfg["downloader"]["ytdl"]["raw-options"]["http_headers"]
-    assert headers["Referer"] == "https://www.patreon.com/"
-    assert headers["Origin"] == "https://www.patreon.com"
+# --- Cursor parsing (plan #689 / native ingester #697) ---------------------
+# parse_last_cursor is retained post-cutover: the native Patreon ingester emits
+# `Cursor: <token>` per page into DownloadResult.stdout and download_service
+# checkpoints the last one. (The gallery-dl Patreon `files`/`cursor` config and
+# the Mux yt-dlp Referer block were removed at the #697 cutover, along with the
+# tests that pinned them.)
+
+
+def test_parse_last_cursor_returns_last_match_across_streams():
+    # One `Cursor: <token>` line per page; the last is the furthest-progressed
+    # resume point.
+    stderr = (
+        "[patreon][debug] Cursor: 03:AAAA:bbb\n"
+        "[urllib3] GET ...\n"
+        "[patreon][debug] Cursor: 03:CCCC:ddd\n"
+    )
+    assert parse_last_cursor("", stderr) == "03:CCCC:ddd"
+
+
+def test_parse_last_cursor_scans_stdout_too_and_none_when_absent():
+    assert parse_last_cursor("Cursor: 99:ZZZ", "") == "99:ZZZ"
+    assert parse_last_cursor("no marker here", "still nothing") is None
+    assert parse_last_cursor("", "") is None

tests/test_patreon_client.py

@@ -0,0 +1,339 @@
+"""PatreonClient tests — parsing only, no network.
+
+The fixture is loaded from disk and fed directly to the pure parsing methods
+(_transform / extract_media / _validate_response / parse_cursor_from_url); no
+live requests call is exercised here.
+"""
+
+import json
+from pathlib import Path
+
+import pytest
+
+from backend.app.services import patreon_client as pc_mod
+from backend.app.services.patreon_client import (
+    MediaItem,
+    PatreonAPIError,
+    PatreonAuthError,
+    PatreonClient,
+    PatreonDriftError,
+    _retry_after_seconds,
+    parse_cursor_from_url,
+)
+
+_FIXTURE = Path(__file__).parent / "fixtures" / "patreon_posts_page1.json"
+
+
+@pytest.fixture
+def response():
+    return json.loads(_FIXTURE.read_text())
+
+
+@pytest.fixture
+def client():
+    # No cookies file → empty session, but we never make a request in tests.
+    return PatreonClient(cookies_path=None)
+
+
+def _post_by_id(response, post_id):
+    for post in response["data"]:
+        if post["id"] == post_id:
+            return post
+    raise AssertionError(f"no post {post_id} in fixture")
+
+
+def test_transform_indexes_included(client, response):
+    index = client._transform(response)
+    assert index[("media", "9001")]["file_name"] == "gallery-one.jpg"
+    assert index[("media", "9003")]["file_name"] == "bonus-pack.zip"
+    assert index[("campaign", "5555")]["name"] == "Example Creator"
+    # Unknown keys are absent, not errors.
+    assert ("media", "0000") not in index
+
+
+def test_extract_gallery_dedups_image_large(client, response):
+    index = client._transform(response)
+    post = _post_by_id(response, "1001")
+    items = client.extract_media(post, index)
+
+    # Two gallery images; the image_large cover shares filehash aaaa... with
+    # gallery image 9001 → collapses to one, leaving exactly 2 items.
+    assert len(items) == 2
+    assert all(isinstance(m, MediaItem) for m in items)
+
+    kinds = [m.kind for m in items]
+    assert kinds == ["images", "images"]  # image_large deduped away
+
+    filenames = {m.filename for m in items}
+    assert filenames == {"gallery-one.jpg", "gallery-two.jpg"}
+
+    hashes = {m.filehash for m in items}
+    assert hashes == {"a" * 32, "b" * 32}
+    assert all(m.post_id == "1001" for m in items)
+
+
+def test_extract_attachment_postfile_same_file_collapses(client, response):
+    index = client._transform(response)
+    post = _post_by_id(response, "1002")
+    items = client.extract_media(post, index)
+
+    # The attachment (attachments_media 9003) and the post_file are the SAME
+    # zip — both carry filehash c…. attachments resolve before postfile, so the
+    # postfile collapses into the attachment by filehash → exactly one survives.
+    # (postfile-as-a-kind is exercised separately by the video post test.)
+    assert len(items) == 1
+    item = items[0]
+    assert item.kind == "attachments"
+    assert item.filename == "bonus-pack.zip"
+    assert item.filehash == "c" * 32
+
+
+def test_extract_inline_content_img(client, response):
+    index = client._transform(response)
+    post = _post_by_id(response, "1003")
+    items = client.extract_media(post, index)
+
+    assert len(items) == 1
+    item = items[0]
+    assert item.kind == "content"
+    assert item.filehash == "d" * 32
+    # & in the src must be unescaped to & .
+    assert "&" not in item.url
+    assert "token=x&v=2" in item.url
+
+
+def test_extract_video_postfile(client, response):
+    index = client._transform(response)
+    post = _post_by_id(response, "1004")
+    items = client.extract_media(post, index)
+
+    assert len(items) == 1
+    item = items[0]
+    assert item.kind == "postfile"
+    assert item.url.startswith("https://stream.mux.com/")
+    assert item.filehash == "e" * 32
+
+
+def test_parse_cursor_from_url_extracts_cursor(response):
+    next_url = response["links"]["next"]
+    assert parse_cursor_from_url(next_url) == "NEXTCURSOR123"
+
+
+def test_parse_cursor_from_url_none_when_absent():
+    assert parse_cursor_from_url("https://www.patreon.com/api/posts?sort=-x") is None
+    assert parse_cursor_from_url(None) is None
+
+
+def test_iter_posts_yields_triples_and_paginates(client, response, monkeypatch):
+    # Page 1 = the fixture (4 posts, links.next → NEXTCURSOR123); page 2 = one
+    # post, no links.next → stop. Monkeypatch _fetch so no network is touched.
+    page2 = {
+        "data": [{"id": "1005", "type": "post", "attributes": {"title": "older"}}],
+        "included": [],
+        "links": {},
+    }
+
+    def fake_fetch(campaign_id, cursor):
+        return page2 if cursor == "NEXTCURSOR123" else response
+
+    monkeypatch.setattr(client, "_fetch", fake_fetch)
+
+    seen = list(client.iter_posts("5555"))
+    # 4 posts on page 1 + 1 on page 2.
+    assert [p["id"] for p, _idx, _cur in seen] == ["1001", "1002", "1003", "1004", "1005"]
+    # page_cursor is the cursor that FETCHED the post's page.
+    cursors = {p["id"]: cur for p, _idx, cur in seen}
+    assert cursors["1001"] is None and cursors["1005"] == "NEXTCURSOR123"
+    # included_index is the page's flattened resources, ready for extract_media.
+    page1_index = next(idx for p, idx, _cur in seen if p["id"] == "1001")
+    assert page1_index[("media", "9001")]["file_name"] == "gallery-one.jpg"
+
+
+def test_missing_data_raises_drift(client):
+    with pytest.raises(PatreonDriftError):
+        client._validate_response({"included": []})
+
+
+def test_non_list_data_raises_drift(client):
+    with pytest.raises(PatreonDriftError):
+        client._validate_response({"data": {"id": "1"}})
+
+
+def test_media_missing_file_name_raises_drift(client):
+    # A media resource referenced by a gallery relationship but lacking
+    # file_name is drift from the contract.
+    post = {
+        "id": "2000",
+        "type": "post",
+        "attributes": {"title": "broken"},
+        "relationships": {"images": {"data": [{"id": "7777", "type": "media"}]}},
+    }
+    index = {
+        ("media", "7777"): {
+            "download_url": "https://c10.patreonusercontent.com/4/orig/"
+            + "f" * 32
+            + "/x.jpg"
+        }
+    }
+    with pytest.raises(PatreonDriftError):
+        client.extract_media(post, index)
+
+
+def test_media_referenced_but_absent_raises_drift(client):
+    post = {
+        "id": "2001",
+        "type": "post",
+        "attributes": {"title": "dangling"},
+        "relationships": {"images": {"data": [{"id": "8888", "type": "media"}]}},
+    }
+    with pytest.raises(PatreonDriftError):
+        client.extract_media(post, {})
+
+
+# -- HTTP status classification (plan #697 step 4) -------------------------
+
+
+class _FakeResp:
+    def __init__(self, status_code, *, json_data=None, raise_json=False, headers=None):
+        self.status_code = status_code
+        self._json_data = json_data
+        self._raise_json = raise_json
+        self.headers = headers or {}
+
+    def json(self):
+        if self._raise_json:
+            raise ValueError("Expecting value: line 1 column 1")
+        return self._json_data
+
+
+def _client_returning(monkeypatch, resp):
+    client = PatreonClient(cookies_path=None)
+    monkeypatch.setattr(client._session, "get", lambda *a, **k: resp)
+    return client
+
+
+@pytest.mark.parametrize("status", [401, 403])
+def test_fetch_auth_status_raises_auth_error(monkeypatch, status):
+    client = _client_returning(monkeypatch, _FakeResp(status))
+    with pytest.raises(PatreonAuthError) as ei:
+        client._fetch("5555", None)
+    assert ei.value.status_code == status
+
+
+def test_fetch_non_json_body_is_auth_not_drift(monkeypatch):
+    # An HTML login/challenge page (non-JSON) means the session expired — auth,
+    # actionable as "rotate cookies", NOT API drift.
+    client = _client_returning(monkeypatch, _FakeResp(200, raise_json=True))
+    with pytest.raises(PatreonAuthError):
+        client._fetch("5555", None)
+
+
+@pytest.mark.parametrize("status", [404, 429, 500])
+def test_fetch_other_status_raises_api_error_with_code(monkeypatch, status):
+    client = _client_returning(monkeypatch, _FakeResp(status))
+    with pytest.raises(PatreonAPIError) as ei:
+        client._fetch("5555", None)
+    assert ei.value.status_code == status
+    # Not auth — the ingester maps these by status, not to auth_error.
+    assert not isinstance(ei.value, PatreonAuthError)
+
+
+def test_fetch_ok_returns_payload(monkeypatch):
+    client = _client_returning(monkeypatch, _FakeResp(200, json_data={"data": []}))
+    assert client._fetch("5555", None) == {"data": []}
+
+
+# -- verify_auth (credential probe; (True/False/None, message) contract) ---
+
+
+def test_verify_auth_ok_when_page_authenticates(monkeypatch):
+    client = _client_returning(monkeypatch, _FakeResp(200, json_data={"data": []}))
+    ok, msg = client.verify_auth("5555")
+    assert ok is True
+    assert "valid" in msg.lower()
+
+
+@pytest.mark.parametrize("status", [401, 403])
+def test_verify_auth_false_when_rejected(monkeypatch, status):
+    client = _client_returning(monkeypatch, _FakeResp(status))
+    ok, _msg = client.verify_auth("5555")
+    assert ok is False
+
+
+def test_verify_auth_inconclusive_on_drift(monkeypatch):
+    # 200 + JSON but missing top-level 'data' → drift → inconclusive, NOT a
+    # credential verdict (our parser is stale, the cookie may be fine).
+    client = _client_returning(monkeypatch, _FakeResp(200, json_data={"included": []}))
+    ok, msg = client.verify_auth("5555")
+    assert ok is None
+    assert "api shape changed" in msg.lower()
+
+
+def test_verify_auth_inconclusive_on_network(monkeypatch):
+    import requests
+    client = PatreonClient(cookies_path=None)
+
+    def _raise(*a, **k):
+        raise requests.ConnectionError("boom")
+    monkeypatch.setattr(client._session, "get", _raise)
+    ok, _msg = client.verify_auth("5555")
+    assert ok is None
+
+
+# -- 429 backoff + pacing (plan #703) --------------------------------------
+
+
+def test_retry_after_seconds_honors_numeric_header():
+    assert _retry_after_seconds(_FakeResp(429, headers={"Retry-After": "7"}), 1) == 7.0
+
+
+def test_retry_after_seconds_exponential_without_header():
+    resp = _FakeResp(429)
+    assert _retry_after_seconds(resp, 1) == 2.0
+    assert _retry_after_seconds(resp, 2) == 4.0
+    assert _retry_after_seconds(resp, 3) == 8.0
+
+
+def test_retry_after_seconds_caps():
+    assert _retry_after_seconds(_FakeResp(429), 10) == 30.0
+    assert _retry_after_seconds(_FakeResp(429, headers={"Retry-After": "999"}), 1) == 30.0
+
+
+def _client_with_sequence(monkeypatch, responses):
+    """A client whose session yields `responses` in order; time.sleep stubbed so
+    backoff never really sleeps. Returns (client, slept_list)."""
+    client = PatreonClient(cookies_path=None)
+    it = iter(responses)
+    monkeypatch.setattr(client._session, "get", lambda *a, **k: next(it))
+    slept: list[float] = []
+    monkeypatch.setattr(pc_mod.time, "sleep", lambda s: slept.append(s))
+    return client, slept
+
+
+def test_fetch_retries_then_succeeds_on_429(monkeypatch):
+    client, slept = _client_with_sequence(monkeypatch, [
+        _FakeResp(429, headers={"Retry-After": "5"}),
+        _FakeResp(200, json_data={"data": []}),
+    ])
+    assert client._fetch("5555", None) == {"data": []}
+    assert 5.0 in slept  # backed off once before the retry
+
+
+def test_fetch_persistent_429_raises_after_retries(monkeypatch):
+    client, _slept = _client_with_sequence(monkeypatch, [_FakeResp(429)] * 10)
+    with pytest.raises(PatreonAPIError) as ei:
+        client._fetch("5555", None)
+    assert ei.value.status_code == 429
+    assert not isinstance(ei.value, PatreonAuthError)
+
+
+def test_request_sleep_paces_before_fetch(monkeypatch):
+    client = PatreonClient(cookies_path=None, request_sleep=1.5)
+    monkeypatch.setattr(
+        client._session, "get",
+        lambda *a, **k: _FakeResp(200, json_data={"data": []}),
+    )
+    slept: list[float] = []
+    monkeypatch.setattr(pc_mod.time, "sleep", lambda s: slept.append(s))
+    client._fetch("5555", None)
+    assert slept == [1.5]

tests/test_patreon_contract.py

@@ -0,0 +1,72 @@
+"""Patreon API contract test (native ingester build step 4).
+
+The drift tripwire the plan calls for: if the field-set we SEND or the parser we
+resolve responses against drifts from what real Patreon returns, this build goes
+RED — instead of the ingester silently importing nothing in production (the exact
+failure mode the native ingester exists to escape).
+
+Two halves:
+  - the recorded `/api/posts` fixture must still parse end-to-end (no drift), and
+  - the request params must still carry every field the parser depends on (the
+    fixture already has the data, so trimming the request would NOT trip the
+    parse half — this half guards the request shape directly).
+
+Pure: no network, no DB.
+"""
+
+import json
+from pathlib import Path
+
+from backend.app.services.patreon_client import MediaItem, PatreonClient
+
+_FIXTURE = Path(__file__).parent / "fixtures" / "patreon_posts_page1.json"
+
+# Pinned media total across the 4 fixture posts: 1001→2 (gallery, image_large
+# cover deduped), 1002→1 (attachment+postfile collapse), 1003→1 (inline content
+# img), 1004→1 (video postfile). A parser change that drops or doubles media
+# trips this.
+_EXPECTED_MEDIA_TOTAL = 5
+_KNOWN_KINDS = {"images", "image_large", "attachments", "postfile", "content"}
+
+
+def test_recorded_fixture_parses_end_to_end():
+    response = json.loads(_FIXTURE.read_text())
+    client = PatreonClient(cookies_path=None)
+
+    client._validate_response(response)  # top-level shape must hold
+    index = client._transform(response)
+
+    total = 0
+    for post in response["data"]:
+        items = client.extract_media(post, index)  # must not raise drift
+        for m in items:
+            assert isinstance(m, MediaItem)
+            assert m.url, f"empty url in post {post['id']}"
+            assert m.filename, f"empty filename in post {post['id']}"
+            assert m.kind in _KNOWN_KINDS, f"unknown kind {m.kind!r}"
+            assert m.post_id == post["id"]
+        total += len(items)
+
+    assert total == _EXPECTED_MEDIA_TOTAL
+
+
+def test_request_field_set_carries_parser_dependencies():
+    """The params we SEND must keep requesting the fields the parser resolves
+    against. Trimming `fields[media]=file_name`, an `include` relationship, or a
+    `fields[post]` key would make real responses parse to nothing — caught here,
+    not by the fixture parse above."""
+    params = PatreonClient(cookies_path=None)._params("5555", None)
+
+    media_fields = params["fields[media]"]
+    assert "file_name" in media_fields
+    assert "image_urls" in media_fields or "download_url" in media_fields
+
+    includes = params["include"]
+    for rel in ("images", "attachments_media", "media"):
+        assert rel in includes, f"missing include relationship {rel}"
+
+    post_fields = params["fields[post]"]
+    for field in ("content", "post_file", "image"):
+        assert field in post_fields, f"missing post field {field}"
+
+    assert params["filter[campaign_id]"] == "5555"

tests/test_patreon_downloader.py

@@ -0,0 +1,313 @@
+"""Unit tests for PatreonDownloader (build step 2b).
+
+No network, no real subprocess. The HTTP layer is stubbed via the `session`
+seam (a fake session whose `.get` returns a fake streaming response) and yt-dlp
+via monkeypatching `_run_ytdlp`. PURE module → no DB, so unmarked (fast lane).
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+import requests
+
+from backend.app.services import patreon_downloader as pd_mod
+from backend.app.services.patreon_client import MediaItem
+from backend.app.services.patreon_downloader import (
+    MediaOutcome,
+    PatreonDownloader,
+    _sanitize,
+)
+from backend.app.utils.sidecar import find_sidecar
+
+# Minimal valid PNG so the file_validator passes on the happy path.
+_PNG_HEAD = b"\x89PNG\r\n\x1a\n"
+_PNG_TAIL = b"\x00\x00\x00\x00IEND\xaeB`\x82"
+_PNG_BYTES = _PNG_HEAD + (b"\x00" * 16) + _PNG_TAIL
+
+
+class _FakeResponse:
+    def __init__(self, payload: bytes, status_code: int = 200, headers=None):
+        self._payload = payload
+        self.status_code = status_code
+        self.headers = headers or {}
+
+    def raise_for_status(self):
+        if self.status_code >= 400:
+            raise requests.HTTPError(f"HTTP {self.status_code}")
+        return None
+
+    def iter_content(self, chunk_size=65536):
+        for i in range(0, len(self._payload), chunk_size):
+            yield self._payload[i : i + chunk_size]
+
+
+class _FakeSession:
+    """Records GETs and returns canned bytes (per-URL, default _PNG_BYTES)."""
+
+    def __init__(self, payloads: dict[str, bytes] | None = None):
+        self.payloads = payloads or {}
+        self.calls: list[str] = []
+
+    def get(self, url, stream=False, timeout=None):
+        self.calls.append(url)
+        return _FakeResponse(self.payloads.get(url, _PNG_BYTES))
+
+
+class _SeqSession:
+    """Returns the queued responses in order (for retry tests)."""
+
+    def __init__(self, responses: list[_FakeResponse]):
+        self._responses = list(responses)
+        self.calls: list[str] = []
+
+    def get(self, url, stream=False, timeout=None):
+        self.calls.append(url)
+        return self._responses.pop(0)
+
+
+def _post(post_id="1001", title="My Post Title", published="2026-05-01T12:00:00Z"):
+    return {
+        "id": post_id,
+        "attributes": {
+            "title": title,
+            "content": "<p>body</p>",
+            "published_at": published,
+            "url": f"https://www.patreon.com/posts/{post_id}",
+        },
+    }
+
+
+def _img(name, post_id="1001", url=None):
+    return MediaItem(
+        url=url or f"https://cdn.patreon.com/{name}",
+        filename=name,
+        kind="images",
+        filehash=None,
+        post_id=post_id,
+    )
+
+
+def _downloader(tmp_path: Path, session=None, validate=True):
+    return PatreonDownloader(
+        images_root=tmp_path,
+        cookies_path=None,
+        validate=validate,
+        session=session or _FakeSession(),
+    )
+
+
+def test_path_layout_two_images(tmp_path):
+    dl = _downloader(tmp_path)
+    items = [_img("media1.png"), _img("media2.png")]
+    outcomes = dl.download_post(_post(), items, "artist-x")
+
+    post_dir = tmp_path / "artist-x" / "patreon" / "2026-05-01_1001_My Post Title"
+    p1 = post_dir / "01_media1.png"
+    p2 = post_dir / "02_media2.png"
+    assert p1.is_file()
+    assert p2.is_file()
+    assert [o.status for o in outcomes] == ["downloaded", "downloaded"]
+    assert outcomes[0].path == p1
+    assert p1.read_bytes() == _PNG_BYTES
+
+
+def test_dir_sanitized(tmp_path):
+    dl = _downloader(tmp_path)
+    post = _post(title='bad/name:with*chars?')
+    dl.download_post(post, [_img("a.png")], "artist-x")
+    patreon_dir = tmp_path / "artist-x" / "patreon"
+    children = list(patreon_dir.iterdir())
+    assert len(children) == 1
+    name = children[0].name
+    assert "/" not in name
+    assert not any(c in name for c in '<>:"\\|?*')
+
+
+def test_no_date_prefix_when_unparseable(tmp_path):
+    dl = _downloader(tmp_path)
+    post = _post(published="not-a-date")
+    dl.download_post(post, [_img("a.png")], "artist-x")
+    patreon_dir = tmp_path / "artist-x" / "patreon"
+    children = [c.name for c in patreon_dir.iterdir()]
+    assert children == ["1001_My Post Title"]
+
+
+def test_sidecar_written_and_findable(tmp_path):
+    dl = _downloader(tmp_path)
+    outcomes = dl.download_post(_post(), [_img("media1.png")], "artist-x")
+    media_path = outcomes[0].path
+
+    sidecar = find_sidecar(media_path)
+    assert sidecar is not None
+    assert sidecar.name == "01_media1.json"
+
+    import json
+
+    data = json.loads(sidecar.read_text())
+    assert data["category"] == "patreon"
+    assert data["id"] == "1001"
+    assert data["title"] == "My Post Title"
+    assert data["url"] == "https://www.patreon.com/posts/1001"
+
+
+def test_skip_seen(tmp_path):
+    session = _FakeSession()
+    dl = _downloader(tmp_path, session=session)
+    outcomes = dl.download_post(
+        _post(), [_img("media1.png")], "artist-x", is_seen=lambda m: True
+    )
+    assert outcomes[0].status == "skipped_seen"
+    assert outcomes[0].path is None
+    assert session.calls == []
+    # No file written anywhere.
+    assert not (tmp_path / "artist-x").exists()
+
+
+def test_skip_disk(tmp_path):
+    dl = _downloader(tmp_path)
+    post_dir = tmp_path / "artist-x" / "patreon" / "2026-05-01_1001_My Post Title"
+    post_dir.mkdir(parents=True)
+    existing = post_dir / "01_media1.png"
+    existing.write_bytes(b"already here")
+
+    outcomes = dl.download_post(_post(), [_img("media1.png")], "artist-x")
+    assert outcomes[0].status == "skipped_disk"
+    assert outcomes[0].path == existing
+    assert existing.read_bytes() == b"already here"  # untouched
+
+
+def test_video_routes_to_ytdlp(tmp_path, monkeypatch):
+    session = _FakeSession()
+    dl = _downloader(tmp_path, session=session)
+    captured = {}
+
+    def fake_ytdlp(url, dest, headers):
+        captured["url"] = url
+        captured["headers"] = headers
+        out = Path(dest).with_suffix(".mp4")
+        out.parent.mkdir(parents=True, exist_ok=True)
+        out.write_bytes(b"video-bytes")
+        return out
+
+    monkeypatch.setattr(dl, "_run_ytdlp", fake_ytdlp)
+
+    video = MediaItem(
+        url="https://stream.mux.com/abc123.m3u8",
+        filename="clip.mp4",
+        kind="postfile",
+        filehash=None,
+        post_id="1001",
+    )
+    outcomes = dl.download_post(_post(), [video], "artist-x")
+
+    assert captured["url"] == "https://stream.mux.com/abc123.m3u8"
+    assert captured["headers"]["Referer"] == "https://www.patreon.com/"
+    assert captured["headers"]["Origin"] == "https://www.patreon.com"
+    assert session.calls == []  # NOT the plain-GET path
+    assert outcomes[0].status == "downloaded"
+    assert outcomes[0].path.read_bytes() == b"video-bytes"
+    # Sidecar written next to the actual (remuxed) output.
+    assert find_sidecar(outcomes[0].path) is not None
+
+
+def test_one_failure_isolated(tmp_path):
+    class _BoomSession(_FakeSession):
+        def get(self, url, stream=False, timeout=None):
+            self.calls.append(url)
+            if "bad" in url:
+                raise RuntimeError("network boom")
+            return _FakeResponse(_PNG_BYTES)
+
+    dl = _downloader(tmp_path, session=_BoomSession())
+    items = [
+        _img("good.png", url="https://cdn.patreon.com/good.png"),
+        _img("bad.png", url="https://cdn.patreon.com/bad.png"),
+    ]
+    outcomes = dl.download_post(_post(), items, "artist-x")
+    assert outcomes[0].status == "downloaded"
+    assert outcomes[1].status == "error"
+    assert "boom" in outcomes[1].error
+
+
+def test_validation_quarantines_corrupt(tmp_path):
+    # A .png whose bytes are not a valid PNG → validator fails → error +
+    # quarantine move; with validate=False it would pass.
+    bad = b"not a real png"
+    session = _FakeSession({"https://cdn.patreon.com/corrupt.png": bad})
+    dl = _downloader(tmp_path, session=session, validate=True)
+    item = _img("corrupt.png", url="https://cdn.patreon.com/corrupt.png")
+    outcomes = dl.download_post(_post(), [item], "artist-x")
+    assert outcomes[0].status == "error"
+    post_dir = tmp_path / "artist-x" / "patreon" / "2026-05-01_1001_My Post Title"
+    assert not (post_dir / "01_corrupt.png").exists()
+    quarantine = tmp_path / "_quarantine" / "artist-x" / "patreon"
+    assert quarantine.is_dir()
+    assert any(quarantine.iterdir())
+
+
+def test_validation_off_keeps_bytes(tmp_path):
+    bad = b"not a real png"
+    session = _FakeSession({"https://cdn.patreon.com/x.png": bad})
+    dl = _downloader(tmp_path, session=session, validate=False)
+    item = _img("x.png", url="https://cdn.patreon.com/x.png")
+    outcomes = dl.download_post(_post(), [item], "artist-x")
+    assert outcomes[0].status == "downloaded"
+    assert outcomes[0].path.read_bytes() == bad
+
+
+def test_sanitize_helper():
+    assert _sanitize('a/b') == "a_b"
+    assert _sanitize('x<>:"|?*y') == "x_______y"
+    assert _sanitize("trail.  ") == "trail"
+    assert _sanitize("") == "_"
+
+
+def test_media_outcome_shape():
+    o = MediaOutcome(media=None, status="downloaded", path=Path("/tmp/x"), error=None)
+    assert o.status == "downloaded"
+    assert o.path == Path("/tmp/x")
+
+
+# -- pacing + 429 backoff (plan #703) --------------------------------------
+
+
+def test_rate_limit_paces_each_real_download(tmp_path, monkeypatch):
+    slept: list[float] = []
+    monkeypatch.setattr(pd_mod.time, "sleep", lambda s: slept.append(s))
+    dl = PatreonDownloader(
+        images_root=tmp_path, cookies_path=None, validate=False,
+        rate_limit=2.0, session=_FakeSession(),
+    )
+    dl.download_post(_post(), [_img("a.png"), _img("b.png")], "artist-x")
+    # One pacing sleep per actual download (two media downloaded).
+    assert slept == [2.0, 2.0]
+
+
+def test_skips_do_not_pace(tmp_path, monkeypatch):
+    slept: list[float] = []
+    monkeypatch.setattr(pd_mod.time, "sleep", lambda s: slept.append(s))
+    dl = PatreonDownloader(
+        images_root=tmp_path, cookies_path=None, validate=False,
+        rate_limit=2.0, session=_FakeSession(),
+    )
+    # is_seen → skipped_seen, never reaches the download/pacing path.
+    dl.download_post(_post(), [_img("a.png")], "artist-x", is_seen=lambda m: True)
+    assert slept == []
+
+
+def test_media_429_retried_then_succeeds(tmp_path, monkeypatch):
+    slept: list[float] = []
+    monkeypatch.setattr(pd_mod.time, "sleep", lambda s: slept.append(s))
+    session = _SeqSession([
+        _FakeResponse(b"", status_code=429, headers={"Retry-After": "4"}),
+        _FakeResponse(_PNG_BYTES, status_code=200),
+    ])
+    dl = PatreonDownloader(
+        images_root=tmp_path, cookies_path=None, validate=False, session=session,
+    )
+    outcomes = dl.download_post(_post(), [_img("a.png")], "artist-x")
+    assert outcomes[0].status == "downloaded"
+    assert 4.0 in slept  # backed off before the retry
+    assert len(session.calls) == 2

tests/test_patreon_ingester.py

@@ -0,0 +1,401 @@
+"""PatreonIngester tests (native ingester build step 3).
+
+The HTTP client and the media downloader are stubbed (injected seams), so these
+exercise the ingester's own logic — mode behavior, the two-tier skip, cursor
+emission, the budget cutoff, and the Postgres seen-ledger — without network or a
+real CDN. The ledger is real (a sync sessionmaker bound to the test engine), so
+the tier-1 skip and the idempotent mark-seen run against actual rows.
+"""
+
+import pytest
+from sqlalchemy import func, select
+from sqlalchemy.orm import sessionmaker
+
+from backend.app.models import Artist, PatreonSeenMedia, Source
+from backend.app.services.gallery_dl import ErrorType
+from backend.app.services.patreon_client import (
+    MediaItem,
+    PatreonAPIError,
+    PatreonAuthError,
+    PatreonDriftError,
+)
+from backend.app.services.patreon_downloader import MediaOutcome
+from backend.app.services.patreon_ingester import PatreonIngester, _ledger_key
+
+pytestmark = pytest.mark.integration
+
+
+# --- fakes ----------------------------------------------------------------
+
+
+def _media(post_id, n, *, filehash=None, kind="images"):
+    # Deterministic 32-hex-ish key, unique per (post_id, n).
+    fh = filehash if filehash is not None else f"{post_id}{n}".encode().hex().ljust(32, "0")[:32]
+    return MediaItem(
+        url=f"https://cdn.patreon.com/{fh}/{n}.jpg",
+        filename=f"{n}.jpg",
+        kind=kind,
+        filehash=fh,
+        post_id=post_id,
+    )
+
+
+class _FakeClient:
+    """Stub PatreonClient. `pages` is a list of (page_cursor, [posts]); each post
+    is (post_id, [MediaItem]). `raise_on_first` lets a test trip drift."""
+
+    def __init__(self, pages, raise_exc=None):
+        self._pages = pages
+        self._raise_exc = raise_exc
+        self.consumed_posts = 0
+
+    def iter_posts(self, campaign_id, cursor=None):
+        if self._raise_exc is not None:
+            raise self._raise_exc
+        for page_cursor, posts in self._pages:
+            for post_id, media in posts:
+                self.consumed_posts += 1
+                yield {"id": post_id, "_media": media}, {}, page_cursor
+
+    def extract_media(self, post, included_index):
+        return post["_media"]
+
+
+class _FakeDownloader:
+    """Stub PatreonDownloader. Honors the injected is_seen (tier-1); media in
+    `on_disk` report skipped_disk (tier-2); everything else downloads."""
+
+    def __init__(self, tmp_path, on_disk=None):
+        self.tmp_path = tmp_path
+        self.on_disk = set(on_disk or ())
+        self.download_calls = 0
+
+    def download_post(self, post, media_items, artist_slug, *, is_seen):
+        outcomes = []
+        for m in media_items:
+            if is_seen(m):
+                outcomes.append(MediaOutcome(media=m, status="skipped_seen", path=None, error=None))
+            elif _ledger_key(m) in self.on_disk:
+                p = self.tmp_path / f"{m.post_id}_{m.filename}"
+                outcomes.append(MediaOutcome(media=m, status="skipped_disk", path=p, error=None))
+            else:
+                self.download_calls += 1
+                p = self.tmp_path / f"{m.post_id}_{m.filename}"
+                p.write_bytes(b"x")
+                outcomes.append(MediaOutcome(media=m, status="downloaded", path=p, error=None))
+        return outcomes
+
+
+@pytest.fixture
+async def source_id(db):
+    artist = Artist(name="Ingest", slug="ingest")
+    db.add(artist)
+    await db.flush()
+    source = Source(
+        artist_id=artist.id, platform="patreon",
+        url="https://patreon.com/ingest", enabled=True, config_overrides={},
+    )
+    db.add(source)
+    await db.commit()
+    return source.id
+
+
+def _ingester(sync_engine, tmp_path, client, downloader):
+    factory = sessionmaker(sync_engine, expire_on_commit=False)
+    return PatreonIngester(
+        images_root=tmp_path, cookies_path=None, session_factory=factory,
+        client=client, downloader=downloader,
+    )
+
+
+def _count_ledger(sync_engine, source_id):
+    factory = sessionmaker(sync_engine, expire_on_commit=False)
+    with factory() as s:
+        return s.execute(
+            select(func.count(PatreonSeenMedia.id)).where(
+                PatreonSeenMedia.source_id == source_id
+            )
+        ).scalar_one()
+
+
+# --- tick -----------------------------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_tick_downloads_unseen_and_marks_seen(source_id, sync_engine, tmp_path):
+    m1, m2 = _media("p1", 1), _media("p1", 2)
+    client = _FakeClient([(None, [("p1", [m1, m2])])])
+    downloader = _FakeDownloader(tmp_path)
+    ing = _ingester(sync_engine, tmp_path, client, downloader)
+
+    result = ing.run(
+        source_id=source_id, campaign_id="c1", artist_slug="ingest",
+        url="https://patreon.com/ingest", mode="tick",
+    )
+
+    assert result.success is True
+    assert result.return_code == 0
+    assert result.files_downloaded == 2
+    assert len(result.written_paths) == 2
+    assert _count_ledger(sync_engine, source_id) == 2
+
+
+@pytest.mark.asyncio
+async def test_tick_skips_seen_via_ledger(source_id, sync_engine, tmp_path):
+    m1 = _media("p1", 1)
+    # Pre-seed the ledger with m1's key.
+    factory = sessionmaker(sync_engine, expire_on_commit=False)
+    with factory() as s:
+        s.add(PatreonSeenMedia(source_id=source_id, filehash=_ledger_key(m1), post_id="p1"))
+        s.commit()
+
+    client = _FakeClient([(None, [("p1", [m1])])])
+    downloader = _FakeDownloader(tmp_path)
+    ing = _ingester(sync_engine, tmp_path, client, downloader)
+
+    result = ing.run(
+        source_id=source_id, campaign_id="c1", artist_slug="ingest",
+        url="https://patreon.com/ingest", mode="tick",
+    )
+    assert result.files_downloaded == 0
+    assert downloader.download_calls == 0
+
+
+@pytest.mark.asyncio
+async def test_tick_early_out_after_threshold(source_id, sync_engine, tmp_path):
+    # Three posts, one already-seen media each; threshold 2 → stop before the 3rd.
+    seen_media = [_media(f"p{i}", 1) for i in range(1, 4)]
+    factory = sessionmaker(sync_engine, expire_on_commit=False)
+    with factory() as s:
+        for m in seen_media:
+            s.add(PatreonSeenMedia(source_id=source_id, filehash=_ledger_key(m), post_id=m.post_id))
+        s.commit()
+
+    pages = [(None, [(m.post_id, [m]) for m in seen_media])]
+    client = _FakeClient(pages)
+    downloader = _FakeDownloader(tmp_path)
+    ing = _ingester(sync_engine, tmp_path, client, downloader)
+
+    result = ing.run(
+        source_id=source_id, campaign_id="c1", artist_slug="ingest",
+        url="https://patreon.com/ingest", mode="tick", seen_threshold=2,
+    )
+    assert result.success is True
+    # Stopped after the 2nd contiguous seen item — never consumed the 3rd post.
+    assert client.consumed_posts == 2
+
+
+# --- backfill -------------------------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_backfill_reaches_bottom_signals_complete(source_id, sync_engine, tmp_path):
+    pages = [
+        (None, [("p1", [_media("p1", 1)])]),
+        ("CUR2", [("p2", [_media("p2", 1)])]),
+    ]
+    client = _FakeClient(pages)
+    downloader = _FakeDownloader(tmp_path)
+    ing = _ingester(sync_engine, tmp_path, client, downloader)
+
+    result = ing.run(
+        source_id=source_id, campaign_id="c1", artist_slug="ingest",
+        url="https://patreon.com/ingest", mode="backfill",
+    )
+    # rc 0 + error_type None is what _apply_backfill_lifecycle reads as "complete".
+    assert result.return_code == 0
+    assert result.error_type is None
+    assert result.files_downloaded == 2
+    # The page-2 cursor was emitted for checkpointing.
+    assert "Cursor: CUR2" in result.stdout
+
+
+@pytest.mark.asyncio
+async def test_backfill_budget_cut_returns_partial_with_progress(
+    source_id, sync_engine, tmp_path, monkeypatch,
+):
+    # Deterministic clock: start=0, post1 check=10 (ok), post2 check=200 (>budget).
+    import backend.app.services.patreon_ingester as mod
+    ticks = iter([0.0, 10.0, 200.0, 250.0])
+    last = [0.0]
+
+    def fake_monotonic():
+        try:
+            last[0] = next(ticks)
+        except StopIteration:
+            pass
+        return last[0]
+
+    monkeypatch.setattr(mod.time, "monotonic", fake_monotonic)
+
+    pages = [
+        ("CUR1", [("p1", [_media("p1", 1)])]),
+        ("CUR2", [("p2", [_media("p2", 1)])]),
+    ]
+    client = _FakeClient(pages)
+    downloader = _FakeDownloader(tmp_path)
+    ing = _ingester(sync_engine, tmp_path, client, downloader)
+
+    result = ing.run(
+        source_id=source_id, campaign_id="c1", artist_slug="ingest",
+        url="https://patreon.com/ingest", mode="backfill",
+        resume_cursor=None, time_budget_seconds=100.0,
+    )
+    assert result.error_type == ErrorType.PARTIAL
+    assert result.return_code == -1
+    assert result.files_downloaded == 1  # post1 downloaded before the cut
+    assert downloader.download_calls == 1  # post2's body never ran
+    assert "Cursor: CUR1" in result.stdout
+
+
+# --- recovery -------------------------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_recovery_bypasses_seen_ledger(source_id, sync_engine, tmp_path):
+    m1 = _media("p1", 1)
+    factory = sessionmaker(sync_engine, expire_on_commit=False)
+    with factory() as s:
+        s.add(PatreonSeenMedia(source_id=source_id, filehash=_ledger_key(m1), post_id="p1"))
+        s.commit()
+
+    client = _FakeClient([(None, [("p1", [m1])])])
+    downloader = _FakeDownloader(tmp_path)
+    ing = _ingester(sync_engine, tmp_path, client, downloader)
+
+    result = ing.run(
+        source_id=source_id, campaign_id="c1", artist_slug="ingest",
+        url="https://patreon.com/ingest", mode="recovery",
+    )
+    # Ledger says seen, but recovery bypasses tier-1 → re-downloaded for a fresh
+    # pHash evaluation under the current threshold.
+    assert result.files_downloaded == 1
+    assert downloader.download_calls == 1
+
+
+@pytest.mark.asyncio
+async def test_recovery_tier2_disk_still_skips(source_id, sync_engine, tmp_path):
+    m1 = _media("p1", 1)
+    client = _FakeClient([(None, [("p1", [m1])])])
+    # File still on disk (a kept image) → tier-2 spares it even under recovery.
+    downloader = _FakeDownloader(tmp_path, on_disk={_ledger_key(m1)})
+    ing = _ingester(sync_engine, tmp_path, client, downloader)
+
+    result = ing.run(
+        source_id=source_id, campaign_id="c1", artist_slug="ingest",
+        url="https://patreon.com/ingest", mode="recovery",
+    )
+    assert result.files_downloaded == 0
+    assert downloader.download_calls == 0
+    # Disk-skip still reconciles the ledger so a later tick skips at tier-1.
+    assert _count_ledger(sync_engine, source_id) == 1
+
+
+# --- ledger + drift -------------------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_mark_seen_is_idempotent(source_id, sync_engine, tmp_path):
+    m1 = _media("p1", 1)
+    client = _FakeClient([(None, [("p1", [m1])])])
+    downloader = _FakeDownloader(tmp_path)
+    ing = _ingester(sync_engine, tmp_path, client, downloader)
+
+    # Same media downloaded twice across two runs — the second marks seen again.
+    ing._mark_seen(source_id, [(_ledger_key(m1), "p1")])
+    ing._mark_seen(source_id, [(_ledger_key(m1), "p1")])
+    assert _count_ledger(sync_engine, source_id) == 1
+
+
+def _run_with_client_error(source_id, sync_engine, tmp_path, exc):
+    client = _FakeClient([], raise_exc=exc)
+    ing = _ingester(sync_engine, tmp_path, client, _FakeDownloader(tmp_path))
+    return ing.run(
+        source_id=source_id, campaign_id="c1", artist_slug="ingest",
+        url="https://patreon.com/ingest", mode="tick",
+    )
+
+
+@pytest.mark.asyncio
+async def test_drift_maps_to_api_drift_and_fails_loud(source_id, sync_engine, tmp_path):
+    result = _run_with_client_error(
+        source_id, sync_engine, tmp_path,
+        PatreonDriftError("missing top-level 'data' key"),
+    )
+    assert result.success is False
+    assert result.error_type == ErrorType.API_DRIFT
+    assert "Patreon API changed" in (result.error_message or "")
+
+
+@pytest.mark.asyncio
+async def test_auth_error_maps_to_auth_error(source_id, sync_engine, tmp_path):
+    result = _run_with_client_error(
+        source_id, sync_engine, tmp_path,
+        PatreonAuthError("HTTP 403 — auth rejected", status_code=403),
+    )
+    assert result.success is False
+    assert result.error_type == ErrorType.AUTH_ERROR
+
+
+@pytest.mark.asyncio
+async def test_rate_limit_status_maps_to_rate_limited(source_id, sync_engine, tmp_path):
+    result = _run_with_client_error(
+        source_id, sync_engine, tmp_path,
+        PatreonAPIError("HTTP 429", status_code=429),
+    )
+    assert result.error_type == ErrorType.RATE_LIMITED
+
+
+@pytest.mark.asyncio
+async def test_not_found_status_maps_to_not_found(source_id, sync_engine, tmp_path):
+    result = _run_with_client_error(
+        source_id, sync_engine, tmp_path,
+        PatreonAPIError("HTTP 404", status_code=404),
+    )
+    assert result.error_type == ErrorType.NOT_FOUND
+
+
+@pytest.mark.asyncio
+async def test_transport_error_maps_to_network_error(source_id, sync_engine, tmp_path):
+    result = _run_with_client_error(
+        source_id, sync_engine, tmp_path,
+        PatreonAPIError("connection reset"),  # no status_code → transport
+    )
+    assert result.error_type == ErrorType.NETWORK_ERROR
+
+
+def test_ledger_key_video_has_no_filehash():
+    video = MediaItem(
+        url="https://stream.mux.com/abc.m3u8", filename="clip.mp4",
+        kind="postfile", filehash=None, post_id="p9",
+    )
+    assert _ledger_key(video) == "p9:clip.mp4"
+
+
+# --- verify_patreon_credential (the verify counterpart, plan #697) ---------
+
+
+@pytest.mark.asyncio
+async def test_verify_patreon_credential_unresolvable_is_inconclusive():
+    from backend.app.services.patreon_ingester import verify_patreon_credential
+
+    # No campaign id resolvable from a non-Patreon URL → can't test → None.
+    ok, msg = await verify_patreon_credential("not-a-patreon-url", None, {})
+    assert ok is None
+    assert "campaign id" in msg.lower()
+
+
+@pytest.mark.asyncio
+async def test_verify_patreon_credential_delegates_to_client(monkeypatch):
+    import backend.app.services.patreon_ingester as mod
+
+    async def _fake_resolve(url, cookies_path, overrides):
+        return "123", None
+    monkeypatch.setattr(mod, "resolve_campaign_id_for_source", _fake_resolve)
+    monkeypatch.setattr(
+        mod.PatreonClient, "verify_auth",
+        lambda self, campaign_id: (True, f"ok:{campaign_id}"),
+    )
+    ok, msg = await mod.verify_patreon_credential("https://patreon.com/x", None, {})
+    assert ok is True
+    assert msg == "ok:123"

tests/test_patreon_resolver.py

@@ -2,7 +2,10 @@ from unittest.mock import MagicMock, patch
 
 import pytest
 
-from backend.app.services.patreon_resolver import resolve_campaign_id
+from backend.app.services.patreon_resolver import (
+    resolve_campaign_id,
+    resolve_campaign_id_for_source,
+)
 
 
 @pytest.mark.asyncio
@@ -86,3 +89,48 @@ async def test_loads_cookies_file_when_present(tmp_path):
     assert result == "9"
     _, kwargs = mock_get.call_args
     assert kwargs.get("cookies") is not None
+
+
+# -- resolve_campaign_id_for_source (shared by download + verify) ----------
+
+
+@pytest.mark.asyncio
+async def test_for_source_uses_cached_override_without_lookup():
+    with patch("backend.app.services.patreon_resolver.requests.get") as mock_get:
+        cid, resolved = await resolve_campaign_id_for_source(
+            "https://patreon.com/alice", None, {"patreon_campaign_id": "999"},
+        )
+    assert cid == "999"
+    assert resolved is None  # cached → no newly-resolved id to cache
+    mock_get.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_for_source_extracts_id_url_without_lookup():
+    with patch("backend.app.services.patreon_resolver.requests.get") as mock_get:
+        cid, resolved = await resolve_campaign_id_for_source(
+            "https://www.patreon.com/id:4242", None, {},
+        )
+    assert cid == "4242"
+    assert resolved is None
+    mock_get.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_for_source_resolves_vanity_and_reports_it():
+    fake = MagicMock()
+    fake.status_code = 200
+    fake.json.return_value = {"data": [{"id": "777", "type": "campaign"}]}
+    with patch("backend.app.services.patreon_resolver.requests.get", return_value=fake):
+        cid, resolved = await resolve_campaign_id_for_source(
+            "https://patreon.com/alice", None, {},
+        )
+    assert cid == "777"
+    assert resolved == "777"  # newly resolved → caller caches it
+
+
+@pytest.mark.asyncio
+async def test_for_source_unresolvable_returns_none():
+    cid, resolved = await resolve_campaign_id_for_source("not-a-patreon-url", None, {})
+    assert cid is None
+    assert resolved is None

tests/test_patreon_seen_media.py

@@ -0,0 +1,73 @@
+import pytest
+from sqlalchemy import func, select
+from sqlalchemy.exc import IntegrityError
+
+from backend.app.models import Artist, PatreonSeenMedia, Source
+
+pytestmark = pytest.mark.integration
+
+
+async def _source(db):
+    artist = Artist(name="Seen Ledger Artist", slug="seen-ledger-artist")
+    db.add(artist)
+    await db.flush()
+    source = Source(
+        artist_id=artist.id,
+        platform="patreon",
+        url="https://www.patreon.com/seenledger",
+    )
+    db.add(source)
+    await db.flush()
+    return source.id
+
+
+@pytest.mark.asyncio
+async def test_patreon_seen_media_dedup(db):
+    source_id = await _source(db)
+    db.add(
+        PatreonSeenMedia(
+            source_id=source_id,
+            filehash="0123456789abcdef0123456789abcdef",
+            post_id="123456",
+        )
+    )
+    await db.flush()
+
+    seen_at = await db.scalar(
+        select(PatreonSeenMedia.seen_at).where(
+            PatreonSeenMedia.source_id == source_id
+        )
+    )
+    assert seen_at is not None
+
+    # A second sighting of the same (source_id, filehash) is rejected by the
+    # unique constraint. Wrap in a savepoint so the IntegrityError doesn't
+    # poison the outer transaction.
+    with pytest.raises(IntegrityError):
+        async with db.begin_nested():
+            db.add(
+                PatreonSeenMedia(
+                    source_id=source_id,
+                    filehash="0123456789abcdef0123456789abcdef",
+                    post_id="654321",
+                )
+            )
+            await db.flush()
+
+    # Same filehash but a different post_id sentinel still inserts: the
+    # dedup axis is (source_id, filehash), not post_id.
+    db.add(
+        PatreonSeenMedia(
+            source_id=source_id,
+            filehash="video:123456:7890",
+            post_id="123456",
+        )
+    )
+    await db.flush()
+
+    count = await db.scalar(
+        select(func.count(PatreonSeenMedia.id)).where(
+            PatreonSeenMedia.source_id == source_id
+        )
+    )
+    assert count == 2

tests/test_source_service.py

@@ -175,58 +175,107 @@ async def test_list_hides_sidecar_synthetic_anchors(db):
 
 
 @pytest.mark.asyncio
-async def test_set_backfill_runs_arms_source(db):
-    """The service method overrides backfill_runs_remaining (regardless of
-    the auto-arm-on-create starting value) and returns the updated record
-    so the API can echo it back."""
+async def test_start_backfill_arms_run_until_done(db):
+    """start_backfill sets state=running + the chunk cap and clears any prior
+    cursor/chunk state, returning the updated record for the API to echo."""
+    from backend.app.services.source_service import BACKFILL_MAX_CHUNKS
+
     artist = await _artist(db, "Alice")
     svc = SourceService(db)
     rec = await svc.create(
         artist_id=artist.id, platform="patreon",
         url="https://patreon.com/alice",
     )
-    updated = await svc.set_backfill_runs(rec.id, 5)
-    assert updated.backfill_runs_remaining == 5
+    # Simulate a prior, finished walk leaving stale checkpoint state.
+    await db.execute(
+        Source.__table__.update().where(Source.id == rec.id).values(
+            config_overrides={"_backfill_state": "complete", "_backfill_cursor": "old",
+                              "_backfill_chunks": 7},
+        )
+    )
+    await db.commit()
 
-    db_value = (await db.execute(
-        select(Source.backfill_runs_remaining).where(Source.id == rec.id)
+    updated = await svc.start_backfill(rec.id)
+    assert updated.backfill_state == "running"
+    assert updated.backfill_chunks == 0
+    assert updated.backfill_runs_remaining == BACKFILL_MAX_CHUNKS
+
+    co = (await db.execute(
+        select(Source.config_overrides).where(Source.id == rec.id)
     )).scalar_one()
-    assert db_value == 5
+    assert co.get("_backfill_state") == "running"
+    assert "_backfill_cursor" not in co
 
 
 @pytest.mark.asyncio
-async def test_set_backfill_runs_rejects_out_of_range(db):
+async def test_stop_backfill_returns_to_idle(db):
     artist = await _artist(db, "Alice")
     svc = SourceService(db)
     rec = await svc.create(
         artist_id=artist.id, platform="patreon",
         url="https://patreon.com/alice",
     )
-    with pytest.raises(ValueError):
-        await svc.set_backfill_runs(rec.id, 0)
-    with pytest.raises(ValueError):
-        await svc.set_backfill_runs(rec.id, 11)
+    await svc.start_backfill(rec.id)
+    updated = await svc.stop_backfill(rec.id)
+    assert updated.backfill_state is None
+    assert updated.backfill_runs_remaining == 0
+    co = (await db.execute(
+        select(Source.config_overrides).where(Source.id == rec.id)
+    )).scalar_one()
+    assert "_backfill_state" not in (co or {})
 
 
 @pytest.mark.asyncio
-async def test_set_backfill_runs_raises_when_source_missing(db):
+async def test_start_recovery_arms_bypass_flag(db):
+    """Plan #697: start_recovery arms the backfill state machine PLUS the
+    _backfill_bypass_seen flag (recovery), surfaced on the record so the UI badge
+    can label it 'Recovering'. Clears any prior checkpoint state."""
+    from backend.app.services.source_service import BACKFILL_MAX_CHUNKS
+
+    artist = await _artist(db, "Alice")
+    svc = SourceService(db)
+    rec = await svc.create(
+        artist_id=artist.id, platform="patreon",
+        url="https://patreon.com/alice",
+    )
+    updated = await svc.start_recovery(rec.id)
+    assert updated.backfill_state == "running"
+    assert updated.backfill_bypass_seen is True
+    assert updated.backfill_runs_remaining == BACKFILL_MAX_CHUNKS
+
+    co = (await db.execute(
+        select(Source.config_overrides).where(Source.id == rec.id)
+    )).scalar_one()
+    assert co.get("_backfill_bypass_seen") is True
+
+    # Stop clears the bypass flag too (shared lifecycle).
+    stopped = await svc.stop_backfill(rec.id)
+    assert stopped.backfill_bypass_seen is False
+    co2 = (await db.execute(
+        select(Source.config_overrides).where(Source.id == rec.id)
+    )).scalar_one()
+    assert "_backfill_bypass_seen" not in (co2 or {})
+
+
+@pytest.mark.asyncio
+async def test_start_backfill_raises_when_source_missing(db):
     svc = SourceService(db)
     with pytest.raises(LookupError):
-        await svc.set_backfill_runs(99999, 3)
+        await svc.start_backfill(99999)
 
 
 @pytest.mark.asyncio
 async def test_new_enabled_source_starts_in_backfill_mode(db):
-    """Plan #544 follow-up: freshly added enabled sources have no archive
-    yet, so the first few polls would blow the wall-clock cap in tick
-    mode. Pre-arm backfill so the initial walks use the longer timeout."""
+    """Plan #693: freshly added enabled sources have no archive yet, so they
+    arm run-until-done backfill — state 'running' — to walk the full history
+    on the first ticks instead of blowing the wall-clock cap in tick mode."""
     artist = await _artist(db, "Alice")
     svc = SourceService(db)
     rec = await svc.create(
         artist_id=artist.id, platform="patreon",
         url="https://patreon.com/alice-new",
     )
-    assert rec.backfill_runs_remaining == 3
+    assert rec.backfill_state == "running"
 
 
 @pytest.mark.asyncio