diff --git a/src/scribe/mcp/server.py b/src/scribe/mcp/server.py
index 149d12c..fee91c4 100644
--- a/src/scribe/mcp/server.py
+++ b/src/scribe/mcp/server.py
@@ -37,7 +37,12 @@ in local files (CLAUDE.md, auto-memory); Scribe holds the single copy.
 
 Hierarchy: Project -> Milestone -> Task/Note. The map, by purpose:
 - ORIENT: enter_project(id) at session start — rules, open tasks, recent
-  notes, Systems and design system in one call.
+  notes, Systems and design system in one call. If it returns `inception`,
+  the project's inheritance was never decided: raise that ask once, then
+  decide_project_inception.
+- START a project: create_project takes what it inherits — always-on
+  rulebooks to exclude, rulebooks to subscribe, design system, seed
+  Systems. Ask the operator first; never create a project bare by default.
 - DO: create_task. Fixed a problem? kind="issue" (symptom -> root cause ->
   fix), never a work-log line on an unrelated task. Log with add_task_log;
   keep status honest — in_progress on start, done on finish.
diff --git a/src/scribe/mcp/tools/projects.py b/src/scribe/mcp/tools/projects.py
index f74b3ed..b2620d6 100644
--- a/src/scribe/mcp/tools/projects.py
+++ b/src/scribe/mcp/tools/projects.py
@@ -20,6 +20,7 @@ from scribe.mcp._context import current_user_id
 from scribe.mcp.tools import systems as systems_tools
 from scribe.services import coverage as coverage_svc
 from scribe.services import design_systems as design_systems_svc
+from scribe.services import inception as inception_svc
 from scribe.services import milestones as milestones_svc
 from scribe.services import notes as notes_svc
 from scribe.services import projects as projects_svc
@@ -80,6 +81,12 @@ async def enter_project(project_id: int) -> dict:
     create it with create_system rather than leaving the area unmodelled. Read
     a subsystem's accumulated records with list_system_records.
 
+    `inception` (milestone 297) appears ONLY when the project is yours and
+    nobody has decided what it inherits: it carries the current defaults
+    (which always-on rulebooks bind, design system, Systems), what to ask the
+    operator — once — and the decide_project_inception call that answers it;
+    it repeats on every enter until a decision is recorded.
+
     `systems_bootstrap` appears ONLY when the project has many records and no
     Systems at all — act on it before starting other work: create_system a
     starter vocabulary from the areas the project's records name, directly
@@ -141,6 +148,14 @@ async def enter_project(project_id: int) -> dict:
             uid, project_id
         )
 
+    # The inception ask (milestone 297): a project nobody has decided on
+    # inherits its defaults silently — always-on rulebooks, no design system,
+    # no Systems. Owner-only (deciding is the owner's), and only until a
+    # decision is recorded; the key is ABSENT otherwise (#2483).
+    inception_ask = None
+    if project.user_id == uid and not inception_svc.is_decided(project):
+        inception_ask = await inception_svc.inception_ask(uid, project_id)
+
     # Probably the largest surfacing by volume, and it emitted nothing — so
     # the pulls it caused floated unattributed and the surfaced:pulled ratio
     # ran against a denominator missing its biggest contributor (#2477). An
@@ -213,6 +228,8 @@ async def enter_project(project_id: int) -> dict:
     # readers to skip it (#2483), and this one exists to be acted on.
     if systems_bootstrap:
         out["systems_bootstrap"] = systems_bootstrap
+    if inception_ask:
+        out["inception"] = inception_ask
     return out
 
 
@@ -238,14 +255,43 @@ async def get_project(project_id: int) -> dict:
     return data
 
 
+def _inception_choices(
+    exclude_always_on_rulebooks, subscribe_rulebooks, design_system_id, seed_systems,
+) -> dict | None:
+    """The tool args → an inception choices object, or None when no inception
+    arg was given at all (a bare create stays undecided and enter_project
+    asks). design_system_id: 0 = not stated, -1 = explicitly none, n = that
+    system."""
+    if (exclude_always_on_rulebooks is None and subscribe_rulebooks is None
+            and not design_system_id and seed_systems is None):
+        return None
+    return {
+        "exclude_always_on_rulebooks": list(exclude_always_on_rulebooks or []),
+        "subscribe_rulebooks": list(subscribe_rulebooks or []),
+        "design_system_id": None if design_system_id in (0, -1) else design_system_id,
+        "seed_systems": bool(seed_systems),
+    }
+
+
 async def create_project(
     title: str,
     description: str = "",
     goal: str = "",
     status: str = "active",
     color: str = "",
+    exclude_always_on_rulebooks: list[int] | None = None,
+    subscribe_rulebooks: list[int] | None = None,
+    design_system_id: int = 0,
+    seed_systems: bool | None = None,
 ) -> dict:
-    """Create a new project in Scribe.
+    """Create a new project in Scribe — and decide what it inherits.
+
+    A project's inheritance is a decision, not a default (milestone 297):
+    before calling, ask the operator the four inception questions and pass
+    the answers; a project created without any of them is UNDECIDED and
+    enter_project will ask until decide_project_inception records it.
+    Defaults if nobody decides: every always-on rulebook binds, nothing is
+    subscribed, no design system, no Systems.
 
     Args:
         title: Project name (required).
@@ -253,6 +299,14 @@ async def create_project(
         goal: The desired outcome or definition of done for the project.
         status: one of active (default), paused, completed, archived.
         color: Optional hex colour for the project card (e.g. "#6366f1").
+        exclude_always_on_rulebooks: always-on rulebook ids this project does
+            NOT inherit ([] = inherit them all). list_rulebooks shows which are
+            always_on.
+        subscribe_rulebooks: rulebook ids to subscribe (the non-always-on ones).
+        design_system_id: the design system this project's UI is built from
+            (list_design_systems); -1 = explicitly none; 0 = not stated.
+        seed_systems: true mints the standard starter Systems (CI & Release,
+            Auth & Access, …) so records can be tagged from day one.
     """
     uid = current_user_id()
     project = await projects_svc.create_project(
@@ -263,7 +317,52 @@ async def create_project(
         status=status,
         color=color or None,
     )
-    return project.to_dict()
+    data = project.to_dict()
+    choices = _inception_choices(
+        exclude_always_on_rulebooks, subscribe_rulebooks, design_system_id, seed_systems,
+    )
+    if choices is not None:
+        decided = await inception_svc.decide(uid, project.id, choices=choices, via="mcp")
+        data["inception"] = decided["inception"]
+        data["inception_effects"] = decided["effects"]
+    else:
+        data["inception_hint"] = (
+            "Undecided: this project inherits its defaults until "
+            "decide_project_inception records what it should inherit "
+            "(enter_project will ask)."
+        )
+    return data
+
+
+async def decide_project_inception(
+    project_id: int,
+    exclude_always_on_rulebooks: list[int] | None = None,
+    subscribe_rulebooks: list[int] | None = None,
+    design_system_id: int = 0,
+    seed_systems: bool | None = None,
+) -> dict:
+    """Record what a project inherits — answer enter_project's `inception` ask,
+    or re-decide later (milestone 297).
+
+    Owner-only. Applies the effects through the ordinary tools' paths —
+    exclude_always_on_rulebook, subscribe_project_to_rulebook,
+    set_project_design_system, the standard Systems seed — and writes the
+    decision on the project last, so get_project/enter_project can say why
+    the project has the rules, design and Systems it has. Re-deciding is
+    additive for exclusions/subscriptions (use include_always_on_rulebook /
+    unsubscribe_project_from_rulebook to undo one), replaces the design
+    system, and never re-seeds Systems a project already has.
+
+    Args: as create_project's inception args. Passing nothing records an
+    inherit-all decision (every always-on rulebook binds, no subscriptions,
+    no design system, no seed) — a valid answer, stated.
+    """
+    uid = current_user_id()
+    choices = _inception_choices(
+        exclude_always_on_rulebooks, subscribe_rulebooks, design_system_id, seed_systems,
+    ) or {}
+    decided = await inception_svc.decide(uid, project_id, choices=choices, via="mcp")
+    return {"project_id": project_id, **decided}
 
 
 async def update_project(
@@ -320,6 +419,6 @@ def register(mcp) -> None:
         get_project,
         create_project,
         update_project,
-        delete_project,
+        delete_project, decide_project_inception,
     ):
         mcp.tool(name=fn.__name__)(fn)
diff --git a/src/scribe/routes/projects.py b/src/scribe/routes/projects.py
index 2a45fe4..fd9b954 100644
--- a/src/scribe/routes/projects.py
+++ b/src/scribe/routes/projects.py
@@ -5,6 +5,7 @@ from quart import Blueprint, g, jsonify, request
 
 from scribe.auth import login_required, get_current_user_id
 from scribe.routes.utils import not_found, parse_pagination
+from scribe.services import inception as inception_svc
 from scribe.services.milestones import list_milestones
 from scribe.services.notes import list_notes
 from scribe.services.projects import (
@@ -66,6 +67,15 @@ async def create_project_route():
     status = data.get("status", "active")
     if status not in ("active", "paused", "completed", "archived"):
         return jsonify({"error": "status must be 'active', 'paused', 'completed', or 'archived'"}), 400
+    # The inception decision rides the create (milestone 297): the UI's
+    # second step sends `inception: {choices}`; absent = undecided, and the
+    # project page shows the card until it is. Validated before the create
+    # so a bad decision never leaves a half-made project behind.
+    inception = data.get("inception")
+    if inception is not None:
+        error = inception_svc.validate_inception(inception)
+        if error:
+            return jsonify({"error": error}), 400
     project = await create_project(
         uid,
         title=data["title"],
@@ -74,7 +84,44 @@ async def create_project_route():
         color=data.get("color"),
         status=status,
     )
-    return jsonify(project.to_dict()), 201
+    out = project.to_dict()
+    if inception is not None:
+        try:
+            decided = await inception_svc.decide(uid, project.id, choices=inception, via="ui")
+        except ValueError as exc:
+            return jsonify({"error": str(exc), "project": out}), 400
+        out["inception"] = decided["inception"]
+        out["inception_effects"] = decided["effects"]
+    return jsonify(out), 201
+
+
+@projects_bp.route("/<int:project_id>/inception", methods=["POST"])
+@login_required
+async def decide_inception_route(project_id: int):
+    """Record (or re-record) what a project inherits — milestone 297.
+    Body: the choices object {exclude_always_on_rulebooks, subscribe_rulebooks,
+    design_system_id, seed_systems}; owner-only."""
+    uid = get_current_user_id()
+    data = await request.get_json() or {}
+    choices = data.get("choices", data)
+    try:
+        decided = await inception_svc.decide(uid, project_id, choices=choices, via="ui")
+    except ValueError as exc:
+        msg = str(exc)
+        status = 404 if "not found" in msg else 400
+        return jsonify({"error": msg}), status
+    return jsonify({"project_id": project_id, **decided})
+
+
+@projects_bp.route("/<int:project_id>/inception/defaults", methods=["GET"])
+@login_required
+async def inception_defaults_route(project_id: int):
+    """What the project inherits if nobody decides — the card's payload."""
+    uid = get_current_user_id()
+    try:
+        return jsonify(await inception_svc.current_defaults(uid, project_id))
+    except ValueError:
+        return not_found("Project")
 
 
 @projects_bp.route("/<int:project_id>", methods=["GET"])
diff --git a/src/scribe/services/inception.py b/src/scribe/services/inception.py
index 3a5e0af..65d18ee 100644
--- a/src/scribe/services/inception.py
+++ b/src/scribe/services/inception.py
@@ -237,3 +237,36 @@ async def decide(
         },
     }
 
+
+async def inception_ask(user_id: int, project_id: int) -> dict:
+    """The enter_project ask for an undecided project (milestone 297) — the
+    sibling of the systems-bootstrap ask (#2683): the project's OWN current
+    defaults, what to ask the operator, and the exact call that answers it.
+    Fail-open: a hint must never break the call it rides on."""
+    try:
+        defaults = await current_defaults(user_id, project_id)
+    except Exception:
+        return {}
+    always = ", ".join(f"{r['title']} (#{r['id']})" for r in defaults["always_on_rulebooks"]) or "none"
+    others = ", ".join(f"{r['title']} (#{r['id']})" for r in defaults["other_rulebooks"]) or "none"
+    designs = ", ".join(f"{d['title']} (#{d['id']})" for d in defaults["design_systems"]) or "none"
+    return {
+        "defaults": defaults,
+        "ask": (
+            "This project has no inception decision: nobody has said what it "
+            f"inherits. Today, by default: always-on rulebooks binding it — {always}; "
+            f"rulebooks it could subscribe to — {others}; design system — "
+            f"{'#' + str(defaults['design_system_id']) if defaults['design_system_id'] else 'none'} "
+            f"(available: {designs}); Systems — {defaults['systems']}. Ask the operator, "
+            "once: which always-on rulebooks to EXCLUDE here (default: none), which "
+            "rulebooks to subscribe, which design system (or none), and whether to seed "
+            "the standard starter Systems — then record the answers. This ask repeats on "
+            "every enter_project until a decision is recorded."
+        ),
+        "call": (
+            f"decide_project_inception(project_id={project_id}, "
+            "exclude_always_on_rulebooks=[...], subscribe_rulebooks=[...], "
+            "design_system_id=<id | -1 for none>, seed_systems=<true|false>)"
+        ),
+    }
+
diff --git a/tests/test_mcp_tool_projects.py b/tests/test_mcp_tool_projects.py
index a434ee4..5f7ef98 100644
--- a/tests/test_mcp_tool_projects.py
+++ b/tests/test_mcp_tool_projects.py
@@ -391,3 +391,81 @@ def test_enter_project_registered_in_register():
 
     register(mcp)
     assert "enter_project" in mcp.names
+
+
+# --- milestone 297: the inception doors ---------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_create_project_without_inception_args_stays_undecided():
+    p = fake_project(id=5, title="P", inception=None)
+    with patch("scribe.mcp.tools.projects.projects_svc.create_project", AsyncMock(return_value=p)), \
+         patch("scribe.mcp.tools.projects.inception_svc.decide", AsyncMock()) as decide:
+        out = await create_project(title="P")
+    decide.assert_not_awaited()
+    assert "inception_hint" in out and "inception_effects" not in out
+
+
+@pytest.mark.asyncio
+async def test_create_project_with_inception_args_decides_via_mcp():
+    p = fake_project(id=5, title="P", inception=None)
+    decided = {"inception": {"via": "mcp", "choices": {}}, "effects": {"systems_seeded": []}}
+    with patch("scribe.mcp.tools.projects.projects_svc.create_project", AsyncMock(return_value=p)), \
+         patch("scribe.mcp.tools.projects.inception_svc.decide", AsyncMock(return_value=decided)) as decide:
+        out = await create_project(title="P", exclude_always_on_rulebooks=[1], design_system_id=-1, seed_systems=True)
+    kw = decide.await_args.kwargs
+    assert decide.await_args.args[1] == 5 and kw["via"] == "mcp"
+    assert kw["choices"] == {"exclude_always_on_rulebooks": [1], "subscribe_rulebooks": [],
+                             "design_system_id": None, "seed_systems": True}
+    assert out["inception"]["via"] == "mcp" and "inception_effects" in out
+
+
+@pytest.mark.asyncio
+async def test_decide_project_inception_tool_records_an_inherit_all_decision_when_given_nothing():
+    from scribe.mcp.tools.projects import decide_project_inception
+    decided = {"inception": {"via": "mcp"}, "effects": {}}
+    with patch("scribe.mcp.tools.projects.inception_svc.decide", AsyncMock(return_value=decided)) as decide:
+        out = await decide_project_inception(project_id=5)
+    assert decide.await_args.kwargs["choices"] == {}
+    assert out["project_id"] == 5 and out["inception"]["via"] == "mcp"
+
+
+@pytest.mark.asyncio
+async def test_enter_project_carries_the_inception_ask_only_for_an_undecided_own_project():
+    applicable = {"rules": [], "project_rules": [], "truncated": False,
+                  "subscribed_rulebooks": [], "excluded_always_on": []}
+    ask = {"defaults": {}, "ask": "decide", "call": "decide_project_inception(...)"}
+
+    async def run(project):
+        with patch("scribe.mcp.tools.projects.projects_svc.get_project", AsyncMock(return_value=project)), \
+             patch("scribe.mcp.tools.projects.rulebooks_svc.get_applicable_rules", AsyncMock(return_value=applicable)), \
+             patch("scribe.mcp.tools.projects.milestones_svc.get_project_milestone_summary", AsyncMock(return_value=[])), \
+             patch("scribe.mcp.tools.projects.notes_svc.list_notes", AsyncMock(side_effect=[([], 0), ([], 0)])), \
+             patch("scribe.mcp.tools.projects.systems_svc.list_systems", AsyncMock(return_value=[])), \
+             patch("scribe.mcp.tools.projects.systems_tools.bootstrap_systems_ask", AsyncMock(return_value=None)), \
+             patch("scribe.mcp.tools.projects.inception_svc.inception_ask", AsyncMock(return_value=ask)) as asked:
+            return await enter_project(project_id=5), asked
+
+    # Own + undecided → the ask rides along.
+    out, asked = await run(fake_project(id=5, title="P", user_id=7, inception=None))
+    assert out["inception"] == ask and asked.await_count == 1
+    # Decided → absent, and the ask is not even built.
+    out, asked = await run(fake_project(id=5, title="P", user_id=7, inception={"via": "legacy"}))
+    assert "inception" not in out and asked.await_count == 0
+    # Someone else's (shared) project, undecided → not this caller's to decide.
+    out, asked = await run(fake_project(id=5, title="P", user_id=8, inception=None))
+    assert "inception" not in out and asked.await_count == 0
+
+
+def test_inception_routes_and_tool_are_registered():
+    from scribe.app import create_app
+    from scribe.mcp.server import build_mcp_server
+    rules = {r.rule for r in create_app().url_map.iter_rules()}
+    assert "/api/projects/<int:project_id>/inception" in rules
+    assert "/api/projects/<int:project_id>/inception/defaults" in rules
+    mcp = build_mcp_server()
+    assert mcp._tool_manager.get_tool("decide_project_inception") is not None
+    tool = mcp._tool_manager.get_tool("create_project")
+    for name in ("exclude_always_on_rulebooks", "subscribe_rulebooks", "design_system_id", "seed_systems"):
+        assert name in tool.parameters.get("properties", {}), name
+