diff --git a/plugin/.claude-plugin/plugin.json b/plugin/.claude-plugin/plugin.json
index e67ef7b..2b8533f 100644
--- a/plugin/.claude-plugin/plugin.json
+++ b/plugin/.claude-plugin/plugin.json
@@ -1,7 +1,7 @@
 {
   "name": "scribe",
   "description": "Scribe for Claude Code: connects the scribe MCP server, adds the hooks that deliver live project state and relevant records at the right moment, ships the shared client-neutral Scribe skills (using-scribe, writing-plans, reporting-back, systematic-debugging, verification, brainstorming, reusing-code, shape-accounting), and syncs your saved Scribe Processes as skills (/scribe:sync).",
-  "version": "2026.09.15.1921",
+  "version": "2026.09.16.1232",
   "author": {
     "name": "Bryan Van Deusen"
   },
diff --git a/plugin/hooks/hooks.json b/plugin/hooks/hooks.json
index c55be67..ff1d27b 100644
--- a/plugin/hooks/hooks.json
+++ b/plugin/hooks/hooks.json
@@ -55,6 +55,16 @@
         ]
       }
     ],
+    "PreCompact": [
+      {
+        "hooks": [
+          {
+            "type": "command",
+            "command": "bash \"${CLAUDE_PLUGIN_ROOT}/hooks/scribe_precompact_preserve.sh\""
+          }
+        ]
+      }
+    ],
     "Stop": [
       {
         "hooks": [
diff --git a/plugin/hooks/scribe_after_write.sh b/plugin/hooks/scribe_after_write.sh
index 977c7fb..1510983 100644
--- a/plugin/hooks/scribe_after_write.sh
+++ b/plugin/hooks/scribe_after_write.sh
@@ -105,12 +105,9 @@ done <<< "$current"
 [ -n "$changed" ] || exit 0
 
 scribe_config || :   # sets url/token; the call below is guarded on them
-repo=$(git -C "$repo_root" remote get-url origin 2>/dev/null || true)
+scope=$(scribe_scope_query "$repo_root")
 repo_q=""
-if [ -n "$repo" ]; then
-  enc=$(printf '%s' "$repo" | jq -sRr '@uri' 2>/dev/null) || enc=""
-  [ -n "$enc" ] && repo_q="&repo=${enc}"
-fi
+[ -n "$scope" ] && repo_q="&${scope}"
 
 # The dedup channels are the PRE-write hook's files, on purpose (see header).
 state_dir="${TMPDIR:-/tmp}/scribe-priorart"
diff --git a/plugin/hooks/scribe_autoinject.sh b/plugin/hooks/scribe_autoinject.sh
index c32d324..956d8a2 100755
--- a/plugin/hooks/scribe_autoinject.sh
+++ b/plugin/hooks/scribe_autoinject.sh
@@ -65,14 +65,11 @@ q=$(printf '%s' "$prompt" | head -c 2000)
 # worth retrieving against were exactly the ones silently dropped. -s slurps.
 q_enc=$(printf '%s' "$q" | jq -sRr '@uri' 2>/dev/null) || exit 0
 
-# Resolve the working repo's remote so the server can scope to the bound project.
+# Scope to this directory's project — a `.scribe` marker, else the git remote.
 repo_dir=${event_cwd:-${CLAUDE_PROJECT_DIR:-$PWD}}
-repo=$(git -C "$repo_dir" remote get-url origin 2>/dev/null || true)
+scope=$(scribe_scope_query "$repo_dir")
 repo_q=""
-if [ -n "$repo" ]; then
-  enc=$(printf '%s' "$repo" | jq -sRr '@uri' 2>/dev/null) || enc=""
-  [ -n "$enc" ] && repo_q="&repo=${enc}"
-fi
+[ -n "$scope" ] && repo_q="&${scope}"
 
 # Per-session dedup: ids already injected this session are skipped.
 state_dir="${TMPDIR:-/tmp}/scribe-autoinject"
diff --git a/plugin/hooks/scribe_defs.sh b/plugin/hooks/scribe_defs.sh
index 86ea6bb..4d75438 100644
--- a/plugin/hooks/scribe_defs.sh
+++ b/plugin/hooks/scribe_defs.sh
@@ -19,6 +19,11 @@
 #   scribe_rules_live FILE     live rule ids from the exclusion ledger,
 #                              comma-joined; entries age out (#3751)
 #   scribe_rules_append FILE   stdin ids -> the ledger, timestamped
+#   scribe_scope_query DIR     `project_id=N` or `repo=<enc>` for DIR — the
+#                              project-scope key EVERY hook sends (#4085).
+#                              Helpers: scribe_marker_file, scribe_url_host,
+#                              scribe_marker_read (id<TAB>why-not),
+#                              scribe_marker_project (the id alone)
 #
 # Sourced, not executed: `. "$(dirname "${BASH_SOURCE[0]}")/scribe_defs.sh"`.
 
@@ -283,3 +288,124 @@ scribe_rules_append() {
   now=$(date +%s 2>/dev/null) || now=0
   awk -v ts="$now" 'NF { print $1 "\t" ts }' >> "$f" 2>/dev/null || true
 }
+
+# ---------------------------------------------------------------------------
+# WHICH PROJECT IS THIS DIRECTORY'S? (#4085)
+#
+# Every hook here scopes its request to a project, and until this existed all
+# six did it the same single way: `git remote get-url origin`, resolved
+# server-side through the repo bindings. That works well inside a bound repo
+# and not at all outside one — a session in a plain directory got no project
+# scope from ANY hook, silently, because the one key the whole chain turns on
+# only exists in a git repo.
+#
+# The second key is a `.scribe` file in the directory (or above it, the way
+# git finds its root), naming the project the work belongs to. It is a
+# POINTER, not a copy: an id and enough to check the id means what it says.
+# Nothing Scribe should be holding goes in it.
+#
+#   {"instance": "https://scribe.example.com", "project_id": 2,
+#    "project": "FabledScribe"}
+#
+#   instance    WHICH Scribe the id belongs to, and the reason this file is
+#               not just a number. A project id means nothing on its own: id 2
+#               is a different project on every instance, so a marker that
+#               travels — a copied directory, a shared machine, a repo someone
+#               else clones — would silently scope a session to the wrong
+#               project. Compared HOST-ONLY against the configured endpoint, so
+#               http/https and a trailing slash don't cause a false mismatch.
+#               A mismatch drops the id: no project beats the wrong project.
+#   project_id  the pointer itself. Required.
+#   project     a human label. NOTHING READS IT. It is there so the file
+#               answers "what is this?" when opened, and so a stale one is
+#               visible rather than inert.
+#
+# A bare integer is also accepted (`echo 2 > .scribe`), because it is what a
+# person writes by hand and it parses as JSON already. It skips the instance
+# check by having nothing to check — deliberate, and the reason the written
+# form carries `instance`.
+#
+# THE MARKER WINS over a git remote. Someone put the file there on purpose;
+# a remote is just where the code happens to be pushed. That also makes the
+# marker the way to override a binding for one directory.
+
+# Nearest `.scribe` at or above DIR. Walks up to the filesystem root, capped so
+# a pathological path cannot spin.
+scribe_marker_file() {
+  local dir="$1" depth=0
+  [ -n "$dir" ] || return 0
+  while [ "$depth" -lt 40 ]; do
+    [ -f "$dir/.scribe" ] && { printf '%s' "$dir/.scribe"; return 0; }
+    case "$dir" in ""|"/") return 0 ;; esac
+    dir=$(dirname -- "$dir" 2>/dev/null) || return 0
+    depth=$((depth + 1))
+  done
+  return 0
+}
+
+# Host of a URL, lowercased, port kept. "" for empty input.
+scribe_url_host() {
+  printf '%s' "${1:-}" \
+    | sed -e 's#^[A-Za-z][A-Za-z0-9+.-]*://##' -e 's#^[^/@]*@##' -e 's#[/?].*$##' \
+    | tr 'A-Z' 'a-z'
+}
+
+# Read a marker file: prints "ID<TAB>REASON", at most one of them non-empty.
+#
+#   "7\t"            use project 7
+#   "\tnames no …"   a file is there and deliberately NOT used; say why
+#   "\t"             no marker file at all — the ordinary case, say nothing
+#
+# One line rather than an id plus a global, because every caller reads this
+# through `$( )` and a global set inside a command substitution dies with the
+# subshell. The caller would then read an unset variable, which under the
+# `set -u` these hooks all run with aborts the hook and costs the whole
+# session's context — a failure far larger than the message it was fetching.
+scribe_marker_read() {
+  local f="$1" id inst want
+  [ -n "$f" ] && [ -f "$f" ] || { printf '\t'; return 0; }
+  command -v jq >/dev/null 2>&1 || { printf '\t'; return 0; }
+  # A bare integer is valid JSON, so one filter reads both forms.
+  id=$(jq -r 'if type=="number" then (.|floor|tostring)
+              elif type=="object" then (.project_id // empty | tostring)
+              else empty end' "$f" 2>/dev/null) || id=""
+  case "$id" in ''|*[!0-9]*) id="" ;; esac
+  if [ -z "$id" ] || [ "$id" = "0" ]; then
+    printf '\tnames no project_id'
+    return 0
+  fi
+  inst=$(jq -r 'if type=="object" then (.instance // empty) else empty end' "$f" 2>/dev/null) || inst=""
+  if [ -n "$inst" ]; then
+    want=$(scribe_url_host "${url:-}")
+    inst=$(scribe_url_host "$inst")
+    if [ -n "$want" ] && [ "$inst" != "$want" ]; then
+      printf '\tpoints at %s, but this session is configured for %s' "$inst" "$want"
+      return 0
+    fi
+  fi
+  printf '%s\t' "$id"
+}
+
+# Just the id a marker names, or "" — the half scribe_scope_query needs.
+scribe_marker_project() {
+  scribe_marker_read "$1" | cut -f1
+}
+
+# The query args identifying DIR's project — `project_id=N` or `repo=<enc>` —
+# with NO leading `?` or `&`, so each caller keeps its own separator. Empty
+# when neither key is available. Requires `url` to be set (scribe_config) for
+# the marker's instance check; without it a marker is still honoured, since an
+# unconfigured hook is not going to send the request anyway.
+scribe_scope_query() {
+  local dir="$1" id repo enc
+  id=$(scribe_marker_project "$(scribe_marker_file "$dir")")
+  if [ -n "$id" ]; then
+    printf 'project_id=%s' "$id"
+    return 0
+  fi
+  repo=$(git -C "$dir" remote get-url origin 2>/dev/null || true)
+  [ -n "$repo" ] || return 0
+  command -v jq >/dev/null 2>&1 || return 0
+  enc=$(printf '%s' "$repo" | jq -sRr '@uri' 2>/dev/null) || enc=""
+  [ -n "$enc" ] && printf 'repo=%s' "$enc"
+}
diff --git a/plugin/hooks/scribe_precompact_preserve.sh b/plugin/hooks/scribe_precompact_preserve.sh
new file mode 100644
index 0000000..bb5536d
--- /dev/null
+++ b/plugin/hooks/scribe_precompact_preserve.sh
@@ -0,0 +1,74 @@
+#!/usr/bin/env bash
+# Scribe plugin — PreCompact: tell the summarizer what must survive (#3680).
+#
+# WHAT THIS HOOK ACTUALLY DOES, and why it is not what the design first assumed.
+#
+# Spike #3680 asked whether a PreCompact hook can reach the model, and note
+# #3679 assumed the channel would be `hookSpecificOutput.additionalContext`
+# plus a block. Both halves of that are wrong, read out of the installed build
+# (Claude Code 2.1.273):
+#
+#   * `additionalContext` is NEVER read on PreCompact. The hook-output schema
+#     has no PreCompact variant at all; the field is honoured for SessionStart,
+#     SubagentStart, Stop and friends, and silently dropped here.
+#
+#   * A PreCompact hook's STDOUT becomes the compaction's custom instructions.
+#     The handler collects every hook that exited 0 with non-empty stdout and
+#     returns it as `newCustomInstructions`, which is merged with whatever the
+#     operator typed after `/compact` and passed into the prompt that writes
+#     the summary. Every path does this — manual, auto and partial compaction.
+#
+# So there IS a model-reaching channel, and it is better than the one designed:
+# we do not interrupt the compaction, we steer the summary it produces. The
+# summary is what the next turn reads, so text that survives into it survives
+# the compaction.
+#
+# WHAT NOT TO DO HERE: never block. A PreCompact block (exit 2, or
+# `{"decision":"block"}`) does not pause for the model and cannot tell it
+# anything — the compaction is SKIPPED, a warning goes to the operator's
+# screen, and the session continues uncompacted toward its context limit with
+# no summary at all. That failure is silent from the model's side, which is
+# exactly the outcome #3680 existed to avoid shipping. This hook exits 0 on
+# every path.
+#
+# SCOPE: in a subagent the handler discards hook stdout and keeps only a block,
+# so this steers the main session's compaction and nothing else. That is the
+# one we care about — a subagent's summary does not outlive it.
+#
+# NO NETWORK, NO CONFIG. What must be preserved is already in the conversation
+# being summarized; this hook's job is to say which parts of it are load-bearing
+# so the summarizer keeps them literally instead of compressing them away.
+# Naming the in-flight task ids from the instance would need a server round-trip
+# inside the compaction path, which is a separate, measurable question.
+#
+# PROOF THAT IT FIRED: on a manual `/compact` the handler shows the operator
+# `PreCompact [<command>] completed successfully: <stdout>`, so the hook's own
+# text is the receipt. (Auto-compaction suppresses that notification.)
+set -uo pipefail
+
+# Drain the event so the caller never sees a broken pipe. Nothing in it changes
+# what we emit: the instruction is the same whether the operator typed
+# `/compact` or the session hit its limit, and it composes with any custom
+# instructions they gave, which are merged ahead of ours.
+cat >/dev/null 2>&1 || true
+
+cat <<'EOF'
+Preserve the following literally in the summary — copied through, not
+paraphrased or counted:
+
+- Every Scribe record the conversation refers to, by id AND title: tasks,
+  issues, milestones, notes, rules, systems. A bare "#4061" is not enough; a
+  record whose name is lost has to be looked up again before it can be used.
+- Which task is in progress and what its status was last set to, plus the
+  milestone it sits under.
+- Work that was done but NOT yet recorded in Scribe — an edit with no work-log,
+  a fix not filed as an issue, a decision not written down. Carry these over as
+  outstanding; they exist nowhere else once this conversation is summarized.
+- Any rule or preference that was retrieved and still governs the work, by id
+  and title.
+- Anything the operator asked for that has not been done yet, in their words.
+
+Everything else here can be recovered from the repository or from Scribe. These
+cannot: they are this session's only copy.
+EOF
+exit 0
diff --git a/plugin/hooks/scribe_prior_art.sh b/plugin/hooks/scribe_prior_art.sh
index d0dce6f..db2081f 100755
--- a/plugin/hooks/scribe_prior_art.sh
+++ b/plugin/hooks/scribe_prior_art.sh
@@ -150,13 +150,10 @@ q=$(printf '%s' "$code" | head -c 1200)
 path_enc=$(printf '%s' "$rel_path" | jq -sRr '@uri' 2>/dev/null) || exit 0
 code_enc=$(printf '%s' "$q" | jq -sRr '@uri' 2>/dev/null) || code_enc=""
 
-# Resolve the working repo's remote so the server can scope to the bound project.
-repo=$(git -C "$lookup_dir" remote get-url origin 2>/dev/null || true)
+# Scope to this directory's project — a `.scribe` marker, else the git remote.
+scope=$(scribe_scope_query "$lookup_dir")
 repo_q=""
-if [ -n "$repo" ]; then
-  enc=$(printf '%s' "$repo" | jq -sRr '@uri' 2>/dev/null) || enc=""
-  [ -n "$enc" ] && repo_q="&repo=${enc}"
-fi
+[ -n "$scope" ] && repo_q="&${scope}"
 
 # Per-session dedup, in its own file rather than sharing auto-inject's. Each
 # surface shows a given snippet at most once per session, but they don't silence
diff --git a/plugin/hooks/scribe_report_check.sh b/plugin/hooks/scribe_report_check.sh
index 54cf313..1b79045 100644
--- a/plugin/hooks/scribe_report_check.sh
+++ b/plugin/hooks/scribe_report_check.sh
@@ -149,11 +149,8 @@ report() {
     enc=$(printf '%s' "$m" | jq -sRr '@uri' 2>/dev/null) || enc=""
     q="${q}&missing=${enc}"
   fi
-  repo=$(git -C "${event_cwd:-${CLAUDE_PROJECT_DIR:-$PWD}}" remote get-url origin 2>/dev/null || true)
-  if [ -n "$repo" ]; then
-    enc=$(printf '%s' "$repo" | jq -sRr '@uri' 2>/dev/null) || enc=""
-    [ -n "$enc" ] && q="${q}&repo=${enc}"
-  fi
+  scope=$(scribe_scope_query "${event_cwd:-${CLAUDE_PROJECT_DIR:-$PWD}}")
+  [ -n "$scope" ] && q="${q}&${scope}"
   curl -fsS --max-time 4 \
     -H "Authorization: Bearer ${token}" \
     "${url%/}/api/plugin/report-check?${q}" 2>/dev/null
diff --git a/plugin/hooks/scribe_session_context.sh b/plugin/hooks/scribe_session_context.sh
index b486800..85aa216 100755
--- a/plugin/hooks/scribe_session_context.sh
+++ b/plugin/hooks/scribe_session_context.sh
@@ -24,9 +24,15 @@
 # fires after a compaction (SessionStart input `source` == "compact"), when
 # earlier turns have just been summarized and in-flight state is most at risk.
 # On that source we lead with a banner telling the model to reload project +
-# in-flight tasks from Scribe. (PreCompact is the wrong tool here — a host hook
-# can't make the model flush, and can't know the in-flight task ids; the durable
-# path is record-as-you-go + this post-compaction reload.)
+# in-flight tasks from Scribe. This stays the durable path: record-as-you-go
+# plus a post-compaction reload from the instance.
+#
+# The other half arrived with #3680. A host hook still cannot make the model
+# flush before a compaction — but scribe_precompact_preserve.sh steers the
+# SUMMARY, because a PreCompact hook's stdout becomes the compaction's custom
+# instructions. The two are complementary, and neither replaces the other: that
+# hook decides what survives into the summary, this one reloads from the record
+# once the summary lands.
 #
 # IMPORTANT: do NOT pass config via `${user_config.*}` substitution in a
 # shell-form hooks.json command — Claude Code rejects that outright (splicing a
@@ -145,14 +151,19 @@ scribe_config || :
 dyn=""
 status=""
 if [ -n "$url" ] && [ -n "$token" ] && command -v curl >/dev/null 2>&1; then
-  # Resolve the working repo's remote so the server can map it to a project.
+  # Which project is this directory's? A `.scribe` marker first, then the git
+  # remote (#4085). scribe_scope_query answers that, and is shared with the
+  # other five hooks so a directory scopes the same way everywhere; the pieces
+  # are re-read here only to explain what happened when nothing resolved.
   repo_dir=${CLAUDE_PROJECT_DIR:-$PWD}
+  marker=$(scribe_marker_file "$repo_dir")
+  marker_read=$(scribe_marker_read "$marker")
+  marker_id=${marker_read%%$'\t'*}
+  marker_why=${marker_read#*$'\t'}
   repo=$(git -C "$repo_dir" remote get-url origin 2>/dev/null || true)
+  scope=$(scribe_scope_query "$repo_dir")
   q=""
-  if [ -n "$repo" ]; then
-    enc=$(printf '%s' "$repo" | jq -sRr '@uri' 2>/dev/null) || enc=""
-    [ -n "$enc" ] && q="?repo=${enc}"
-  fi
+  [ -n "$scope" ] && q="?${scope}"
   body=$(curl -fsS --max-time 8 \
     -H "Authorization: Bearer ${token}" \
     "${url%/}/api/plugin/context${q}" 2>/dev/null) || body=""
@@ -178,6 +189,29 @@ fi
 [ -n "$dyn" ]    && append "$dyn"
 [ -n "$status" ] && append "$status"
 
+# --- Nothing resolved: say WHICH nothing, and what would fix it (#4085) ---
+#
+# The server can say "no project is bound to this working directory", and
+# until now that was the whole answer. It is the same sentence for a directory
+# that is not a repo, a repo whose remote nobody bound, and a marker file
+# naming a project this account cannot read — three different problems with
+# three different fixes, and no way to tell them apart from inside the session.
+#
+# The marker is the adapter's convention, so the adapter explains it: the
+# server reports whether a project resolved, and this hook — which knows what
+# it sent and why — turns that into the sentence the operator can act on. The
+# repo case is left to the server's existing "bind this repo" hint.
+if [ -n "$dyn" ] && [ -z "$(printf '%s' "$body" | jq -r '.project.id // empty' 2>/dev/null)" ]; then
+  host=$(scribe_url_host "$url")
+  if [ -n "$marker_why" ]; then
+    append "> ⚠️ Scribe: the marker file \`${marker}\` ${marker_why}, so no project context was loaded. Fix the file, or ignore it and bind this directory another way."
+  elif [ -n "$marker_id" ]; then
+    append "> ⚠️ Scribe: \`${marker}\` names project ${marker_id}, which this account cannot read on ${host} — it may belong to a different Scribe instance, or the project may have been deleted. Check with \`list_projects()\` and correct the file."
+  elif [ -z "$repo" ]; then
+    append "> ℹ️ Scribe: this directory is not a git repository and has no \`.scribe\` marker, so no project context was loaded — every hook this session is unscoped. If this work belongs to a Scribe project, call \`list_projects()\` and write the marker: \`{\"instance\": \"${url%/}\", \"project_id\": <id>, \"project\": \"<title>\"}\` in \`${repo_dir}/.scribe\`. Future sessions here load that project on their own."
+  fi
+fi
+
 # Compaction re-grounding: lead with a reload banner when this fire is a compact.
 if [ "$source" = "compact" ]; then
   prepend "> ⟳ This session was just COMPACTED — earlier turns are now a summary, so in-flight detail may be lost. Any rules that had been retrieved went into that summary with everything else, so treat yourself as holding none: before the next consequential act, ask again with \`search(content_type=\"rule\")\` rather than trusting a half-remembered one. Re-run \`enter_project()\` for the active project, check its recent milestones and open tasks, and reconcile what you are mid-way through against what Scribe records. Scribe is the record."
diff --git a/plugin/hooks/scribe_tool_rules.sh b/plugin/hooks/scribe_tool_rules.sh
index 16a1bd4..3262460 100644
--- a/plugin/hooks/scribe_tool_rules.sh
+++ b/plugin/hooks/scribe_tool_rules.sh
@@ -63,11 +63,8 @@ tool_enc=$(printf '%s' "$tool_name" | jq -sRr '@uri' 2>/dev/null) || exit 0
 
 repo_q=""
 lookup_dir=${event_cwd:-${CLAUDE_PROJECT_DIR:-$PWD}}
-repo_remote=$(git -C "$lookup_dir" remote get-url origin 2>/dev/null || true)
-if [ -n "$repo_remote" ]; then
-  repo_enc=$(printf '%s' "$repo_remote" | jq -sRr '@uri' 2>/dev/null) || repo_enc=""
-  [ -n "$repo_enc" ] && repo_q="&repo=${repo_enc}"
-fi
+scope=$(scribe_scope_query "$lookup_dir")
+[ -n "$scope" ] && repo_q="&${scope}"
 
 # THE SHARED SESSION LEDGER, and the thing most worth getting right here.
 #
diff --git a/plugin/skills/using-scribe/SKILL.md b/plugin/skills/using-scribe/SKILL.md
index 3ada364..972ee1a 100644
--- a/plugin/skills/using-scribe/SKILL.md
+++ b/plugin/skills/using-scribe/SKILL.md
@@ -13,10 +13,23 @@ asked for.
 
 ## Do this first (every session)
 
-If the working repo maps to a Scribe project (you're in a known repo, or
-`list_repo_bindings` shows a binding), call `enter_project(id)` — it returns the
-project's goal, the milestones and open tasks worked on most recently, its
-Systems and the titles of its own rules in one shot.
+If the working directory maps to a Scribe project, call `enter_project(id)` —
+it returns the project's goal, the milestones and open tasks worked on most
+recently, its Systems and the titles of its own rules in one shot.
+
+**A directory does not have to be a git repo to have a project.** A repo is
+bound by its remote (`list_repo_bindings` shows the bindings). Anything else —
+a notes folder, a server's config directory, a scratch directory — is bound by
+a `.scribe` file naming the project:
+
+    {"instance": "https://scribe.example.com", "project_id": 2, "project": "Homelab"}
+
+`instance` is what makes the id trustworthy. An id means nothing on its own —
+it is a different project on every Scribe — so a marker that has travelled to
+another instance is ignored rather than followed to the wrong project. A bare
+`2` also works when writing the file by hand. When work plainly belongs to a
+project and the directory names none, offer to write the marker;
+`list_projects` has the id.
 
 Then **ask before you act**: before anything hard to reverse or outward-facing,
 search the rules for what you are about to do. Reflex 2 below is why asking,
diff --git a/src/scribe/mcp/tools/milestones.py b/src/scribe/mcp/tools/milestones.py
index 4fd6943..5476d33 100644
--- a/src/scribe/mcp/tools/milestones.py
+++ b/src/scribe/mcp/tools/milestones.py
@@ -44,7 +44,10 @@ async def get_milestone(milestone_id: int) -> dict:
     rules surface again on recall.
 
     Returns: milestone (incl. body), progress, steps (its tasks ordered by
-    status then update), and applicable_rules / project_rules.
+    status then update), and applicable_rules / project_rules. Each step says
+    what it is and where it stands, not its whole body — read a step in full
+    with get_task(id). A plan with forty long steps is otherwise too big to
+    arrive inline, and the design is in the milestone body.
     """
     uid = current_user_id()
     milestone = await milestones_svc.get_milestone(uid, milestone_id)
@@ -61,7 +64,7 @@ async def get_milestone(milestone_id: int) -> dict:
     out.update(progress)
     return {
         "milestone": out,
-        "steps": [t.to_dict() for t in steps],
+        "steps": [notes_svc.brief_row(t, {milestone.id: milestone.title}) for t in steps],
         **rulebooks_svc.rules_payload(applicable, user_id=uid, source="get_milestone"),
     }
 
diff --git a/src/scribe/mcp/tools/notes.py b/src/scribe/mcp/tools/notes.py
index 51b3cd4..d13b490 100644
--- a/src/scribe/mcp/tools/notes.py
+++ b/src/scribe/mcp/tools/notes.py
@@ -44,6 +44,9 @@ async def list_notes(
     Prefer `search` for a pure lookup — it returns scores and reaches
     everything readable; this adds the lifecycle filters on top.
 
+    Each row says what the note is — id, title, description, type, project,
+    tags, updated_at — and not what it says: read one in full with get_note(id).
+
     Args:
         project_id: Scope to one project. PASS THE ACTIVE PROJECT'S ID whenever a
             project is in scope so you list that project's notes, not every
@@ -60,7 +63,7 @@ async def list_notes(
         limit=max(1, min(limit, 100)),
         offset=max(0, offset),
     )
-    return {"notes": [n.to_dict() for n in rows], "total": total}
+    return {"notes": [notes_svc.brief_row(n) for n in rows], "total": total}
 
 
 
diff --git a/src/scribe/mcp/tools/systems.py b/src/scribe/mcp/tools/systems.py
index df0050e..bd8784b 100644
--- a/src/scribe/mcp/tools/systems.py
+++ b/src/scribe/mcp/tools/systems.py
@@ -14,6 +14,7 @@ from __future__ import annotations
 
 from scribe.mcp._context import current_user_id
 from scribe.services import canonical_systems as canonical_systems_svc
+from scribe.services import milestones as milestones_svc
 from scribe.services import notes as notes_svc
 from scribe.services import systems as systems_svc
 
@@ -267,16 +268,18 @@ async def get_system(system_id: int) -> dict:
     """Fetch a System plus the records associated with it.
 
     Returns the system, plus its associated records split into `issues`,
-    `tasks` (work/plan), and `notes`.
+    `tasks` (work/plan), and `notes` — each saying what the record is and where
+    it sits, not what it says (open one with get_note / get_task).
     """
     uid = current_user_id()
     system = await systems_svc.get_system(uid, system_id)
     if system is None:
         raise ValueError(f"system {system_id} not found")
     records = await systems_svc.list_records_for_system(uid, system_id)
+    titles = await milestones_svc.titles_for({r.milestone_id for r in records})
     issues, tasks, notes = [], [], []
     for r in records:
-        d = r.to_dict()
+        d = notes_svc.brief_row(r, titles)
         if r.status is None:
             notes.append(d)
         elif r.task_kind == "issue":
@@ -339,12 +342,16 @@ async def list_system_records(
         kind: filter by task_kind — 'issue', 'work', 'spike' (or the retired
             'plan'). Omit for all.
         open_only: limit to tasks not done/cancelled (e.g. open issues only).
+
+    Each record says what it is and where it sits, not what it says — open one
+    with get_note / get_task / get_snippet.
     """
     uid = current_user_id()
     rows = await systems_svc.list_records_for_system(
         uid, system_id, kind=kind or None, open_only=open_only,
     )
-    return {"records": [r.to_dict() for r in rows]}
+    titles = await milestones_svc.titles_for({r.milestone_id for r in rows})
+    return {"records": [notes_svc.brief_row(r, titles) for r in rows]}
 
 
 async def delete_system(system_id: int) -> dict:
diff --git a/src/scribe/mcp/tools/tasks.py b/src/scribe/mcp/tools/tasks.py
index d3fcbb7..093dfce 100644
--- a/src/scribe/mcp/tools/tasks.py
+++ b/src/scribe/mcp/tools/tasks.py
@@ -22,6 +22,7 @@ from scribe.mcp._context import current_user_id
 from scribe.mcp.tools import systems as systems_tools
 from scribe.services import access as access_svc
 from scribe.services import dedup as dedup_svc
+from scribe.services import milestones as milestones_svc
 from scribe.services import notes as notes_svc
 # Imported by NAME, not reached through notes_svc: minted_kind is pure
 # validation, not a service call, and a test that stubs the service module to
@@ -58,7 +59,10 @@ async def list_tasks(
         kind: Filter by task kind — 'work', 'issue', 'spike' (or the retired
             'plan'). Omit (empty) for all kinds.
 
-    Results are ordered by last-updated descending.
+    Results are ordered by last-updated descending. Each row says what the task
+    is and where it sits — id, title, status, kind, priority, milestone (id and
+    title), tags, updated_at, plus description, parent and due date when set —
+    and not what it says: read one in full with get_task(id).
     """
     uid = current_user_id()
     rows, total = await notes_svc.list_notes(
@@ -70,7 +74,8 @@ async def list_tasks(
         limit=max(1, min(limit, 100)),
         offset=max(0, offset),
     )
-    return {"tasks": [n.to_dict() for n in rows], "total": total}
+    titles = await milestones_svc.titles_for({n.milestone_id for n in rows})
+    return {"tasks": [notes_svc.brief_row(n, titles) for n in rows], "total": total}
 
 
 async def get_task(task_id: int) -> dict:
diff --git a/src/scribe/routes/plugin.py b/src/scribe/routes/plugin.py
index b812980..ee9e6e6 100644
--- a/src/scribe/routes/plugin.py
+++ b/src/scribe/routes/plugin.py
@@ -64,8 +64,11 @@ async def session_context():
             resolves it to the bound project (see services/repo_bindings); an
             unbound repo yields a "bind this repo" hint instead. This is how the
             active project is determined — the plugin never pins a project id.
-        project_id (optional int) — explicit override, mainly for manual/ad-hoc
-            curl testing; takes precedence over `repo` when set.
+        project_id (optional int) — the project named directly, and the only
+            key a caller outside a git repo has (#4085): the plugin's hooks
+            send it when a `.scribe` marker file names a project. Takes
+            precedence over `repo`. Access-checked like any other read — an id
+            this account cannot read loads no project rather than failing.
     """
     project_id, _repo, unbound_repo = await _project_scope()
     result = await plugin_ctx_svc.build_session_context(
diff --git a/src/scribe/services/milestones.py b/src/scribe/services/milestones.py
index 0e99a8e..cada46c 100644
--- a/src/scribe/services/milestones.py
+++ b/src/scribe/services/milestones.py
@@ -72,6 +72,26 @@ async def get_milestone(user_id: int, milestone_id: int) -> Milestone | None:
         return result.scalars().first()
 
 
+async def titles_for(milestone_ids: set[int]) -> dict[int, str]:
+    """{id: title} for the given milestones, for rows that name where a record sits.
+
+    No ownership filter, deliberately: the callers are listings whose rows the
+    caller could already read, and a milestone title is part of "where does
+    this record sit". Filtering here would blank the placement of a shared
+    task in someone else's plan while still showing the task.
+    """
+    ids = {i for i in milestone_ids if i}
+    if not ids:
+        return {}
+    async with async_session() as session:
+        rows = (await session.execute(
+            select(Milestone.id, Milestone.title).where(
+                Milestone.id.in_(ids), Milestone.deleted_at.is_(None),
+            )
+        )).all()
+    return {mid: title for mid, title in rows}
+
+
 async def get_milestone_in_project(project_id: int, milestone_id: int) -> Milestone | None:
     """Fetch a milestone by id within a project, without a user_id ownership check.
     Callers must verify project access separately before using this."""
diff --git a/src/scribe/services/notes.py b/src/scribe/services/notes.py
index 31d1c8e..758e963 100644
--- a/src/scribe/services/notes.py
+++ b/src/scribe/services/notes.py
@@ -7,6 +7,7 @@ from sqlalchemy import func, or_, select, text
 
 from scribe.models import async_session
 from scribe.models.note import Note, TaskKind, TaskPriority, TaskStatus
+from scribe.models.base import iso
 
 logger = logging.getLogger(__name__)
 
@@ -1057,3 +1058,40 @@ async def get_note_for_user(
     async with async_session() as session:
         note = await session.get(Note, note_id)
     return (note, perm) if note else None
+
+
+# What a LISTING row carries (#4061): what the record is and where it sits,
+# never what it says. list_tasks once returned every row's to_dict(), body
+# included, and a project's todo list came to 93-165k characters, past what an
+# MCP client accepts inline, so the list arrived as a file to page through. The
+# same failure #4045 fixed for enter_project, one call over. get_task / get_note
+# read a record in full; a list is for choosing which one to open.
+#
+# A field most rows leave empty (a one-line description, a parent, a due date)
+# is attached only when set: a hundred rows of `null` are a hundred chances to
+# learn to skip the key (#2483), and the bytes are the thing being cut.
+def brief_row(note: Note, milestone_titles: dict[int, str] | None = None) -> dict:
+    row = {
+        "id": note.id,
+        "title": note.title,
+        "note_type": note.note_type or "note",
+        "project_id": note.project_id,
+        "tags": note.tags or [],
+        "updated_at": iso(note.updated_at),
+    }
+    if note.description:
+        row["description"] = note.description
+    if note.is_task:
+        row.update({
+            "status": note.status,
+            "task_kind": note.task_kind,
+            "priority": note.priority,
+            "milestone_id": note.milestone_id,
+        })
+        if milestone_titles is not None and note.milestone_id:
+            row["milestone_title"] = milestone_titles.get(note.milestone_id)
+        if note.parent_id:
+            row["parent_id"] = note.parent_id
+        if note.due_date:
+            row["due_date"] = iso(note.due_date)
+    return row
diff --git a/src/scribe/services/plugin_context.py b/src/scribe/services/plugin_context.py
index 63e82a6..acea2bb 100644
--- a/src/scribe/services/plugin_context.py
+++ b/src/scribe/services/plugin_context.py
@@ -2171,7 +2171,10 @@ async def build_session_context(
     Args:
         user_id: the operator.
         project_id: the resolved active project (0 = none). The endpoint
-            resolves this from the working repo's remote, not from config.
+            resolves this from the working repo's remote, or from a `.scribe`
+            marker file naming the project directly — the only key a session
+            outside a git repo has (#4085). A non-zero id that does not
+            resolve is reported rather than silently dropped.
         unbound_repo: when the hook sent a repo remote that maps to no project,
             its normalized key — triggers a one-line "bind this repo" hint so
             the binding is self-healing.
@@ -2241,18 +2244,34 @@ async def build_session_context(
                         f"`get_design_system({design['id']})` → "
                         f"`resolved_guidance`.",
                     ]
-    elif unbound_repo:
-        lines += [
-            "",
-            "## Repository not yet bound",
-            f"This repo (`{unbound_repo}`) isn't mapped to a Scribe project, so "
-            "no project context was loaded. Bind it once with "
-            f'`bind_repo(repo_url="{unbound_repo}", project_id=<id>)` '
-            "(call `list_projects` to find the id) and future sessions here will "
-            "auto-load that project's context.",
-        ]
-    else:
-        lines += ["", "No Scribe project is bound to this working directory."]
+    # Nothing loaded — say which nothing (#4085). This used to hang off the
+    # `if project_id:` above as an `elif`, which meant an id that was SENT and
+    # did not resolve produced no message at all: the outer branch was taken,
+    # the inner one was not, and the caller got a context that simply omitted
+    # the project it had asked for. That is the one case worth being loudest
+    # about, because the caller is holding a pointer it believes in.
+    if project_dict is None:
+        if project_id:
+            lines += [
+                "",
+                f"## Project {project_id} could not be loaded",
+                f"This session asked for project {project_id}, but this account "
+                "cannot read it — the id may belong to a different Scribe "
+                "instance, or the project may have been deleted. "
+                "`list_projects` shows what is readable here.",
+            ]
+        elif unbound_repo:
+            lines += [
+                "",
+                "## Repository not yet bound",
+                f"This repo (`{unbound_repo}`) isn't mapped to a Scribe project, so "
+                "no project context was loaded. Bind it once with "
+                f'`bind_repo(repo_url="{unbound_repo}", project_id=<id>)` '
+                "(call `list_projects` to find the id) and future sessions here will "
+                "auto-load that project's context.",
+            ]
+        else:
+            lines += ["", "No Scribe project is bound to this working directory."]
 
     context = "\n".join(line for line in lines if line is not None)
     if len(context) > _MAX_CHARS:
diff --git a/tests/test_list_rows_brief.py b/tests/test_list_rows_brief.py
new file mode 100644
index 0000000..faab13e
--- /dev/null
+++ b/tests/test_list_rows_brief.py
@@ -0,0 +1,93 @@
+"""List tools return rows that say what a record is, never what it says (#4061).
+
+list_tasks once returned every row's to_dict(), body included. A project's todo
+list came to 93-165k characters, past what an MCP client accepts as a tool
+result, so the list arrived as a file to page through — the failure #4045 fixed
+for enter_project, one call over. A list is for choosing which record to open;
+get_task / get_note read one in full.
+"""
+import json
+from datetime import datetime, timezone
+from types import SimpleNamespace
+from unittest.mock import AsyncMock, patch
+
+import pytest
+
+from scribe.mcp.tools.notes import list_notes
+from scribe.mcp.tools.systems import list_system_records
+from scribe.mcp.tools.tasks import list_tasks
+from scribe.services.notes import brief_row
+
+pytestmark = pytest.mark.usefixtures("_bind_user")
+
+STEP_PLAN = "A step plan paragraph long enough to matter. " * 110  # ~5k chars
+WHEN = datetime(2026, 9, 15, tzinfo=timezone.utc)
+
+
+def _row(nid: int, *, is_task: bool = True, milestone_id: int | None = 415) -> SimpleNamespace:
+    """A real-shaped Note: every attribute brief_row or to_dict could read."""
+    return SimpleNamespace(
+        id=nid, title=f"Step {nid} — something worth doing", body=STEP_PLAN,
+        description=None, note_type="note", project_id=2, tags=["retrieval"],
+        updated_at=WHEN, created_at=WHEN, is_task=is_task,
+        status="todo" if is_task else None, task_kind="work", priority="high",
+        milestone_id=milestone_id if is_task else None, parent_id=None, due_date=None,
+    )
+
+
+def test_a_task_row_names_what_it_is_and_where_it_sits_but_not_its_body():
+    row = brief_row(_row(7), {415: "An existing plan is found"})
+    assert "body" not in row
+    assert row["milestone_title"] == "An existing plan is found"
+    assert {"id", "title", "status", "task_kind", "priority", "milestone_id",
+            "tags", "updated_at", "project_id"} <= set(row)
+    # Empty optional fields are left off rather than sent as null (#2483).
+    assert not {"description", "parent_id", "due_date"} & set(row)
+    assert row["updated_at"] == WHEN.isoformat()
+
+
+def test_a_note_row_carries_no_task_fields():
+    row = brief_row(_row(8, is_task=False))
+    assert "body" not in row and "status" not in row and "milestone_title" not in row
+
+
+def test_a_task_outside_any_milestone_says_so_rather_than_inventing_a_title():
+    row = brief_row(_row(9, milestone_id=None), {})
+    assert row["milestone_id"] is None and "milestone_title" not in row
+
+
+@pytest.mark.asyncio
+async def test_a_full_page_of_long_tasks_fits_inline():
+    """The ceiling. 100 rows (list_tasks' own limit cap) of ~5k-character step
+    plans: as to_dict() rows this was over half a million characters."""
+    rows = [_row(i) for i in range(100)]
+    with patch("scribe.mcp.tools.tasks.notes_svc.list_notes",
+               AsyncMock(return_value=(rows, 100))), \
+         patch("scribe.mcp.tools.tasks.milestones_svc.titles_for",
+               AsyncMock(return_value={415: "An existing plan is found"})) as titles:
+        out = await list_tasks(project_id=2, limit=100)
+    size = len(json.dumps(out))
+    assert size < 40_000, f"list_tasks page is {size} characters"
+    assert titles.await_args.args[0] == {415}
+    assert out["tasks"][0]["milestone_title"] == "An existing plan is found"
+
+
+@pytest.mark.asyncio
+async def test_list_notes_rows_leave_the_body_to_get_note():
+    rows = [_row(i, is_task=False) for i in range(3)]
+    with patch("scribe.mcp.tools.notes.notes_svc.list_notes",
+               AsyncMock(return_value=(rows, 3))):
+        out = await list_notes(project_id=2)
+    assert all("body" not in r for r in out["notes"])
+
+
+@pytest.mark.asyncio
+async def test_list_system_records_rows_leave_the_body_to_the_getters():
+    rows = [_row(1), _row(2, is_task=False)]
+    with patch("scribe.mcp.tools.systems.systems_svc.list_records_for_system",
+               AsyncMock(return_value=rows)), \
+         patch("scribe.mcp.tools.systems.milestones_svc.titles_for",
+               AsyncMock(return_value={415: "Plan"})):
+        out = await list_system_records(system_id=3)
+    assert [r["id"] for r in out["records"]] == [1, 2]
+    assert all("body" not in r for r in out["records"])
diff --git a/tests/test_mcp_tool_milestones.py b/tests/test_mcp_tool_milestones.py
index 9390761..19a4b07 100644
--- a/tests/test_mcp_tool_milestones.py
+++ b/tests/test_mcp_tool_milestones.py
@@ -6,7 +6,7 @@ import pytest
 from scribe.mcp.tools.milestones import (
     list_milestones, get_milestone, create_milestone, update_milestone,
 )
-from tests.helpers import fake_milestone
+from tests.helpers import fake_milestone, fake_task
 
 
 pytestmark = pytest.mark.usefixtures("_bind_user")
@@ -111,8 +111,7 @@ async def test_update_milestone_sends_body():
 @pytest.mark.asyncio
 async def test_get_milestone_returns_body_steps_and_rules():
     m = fake_milestone(id=5, project_id=3, body="## Goal")
-    step = MagicMock()
-    step.to_dict.return_value = {"id": 9, "title": "step 1", "status": "todo"}
+    step = fake_task(id=9, title="step 1", milestone_id=5, body="a long step body")
     applicable = {"rules": [{"id": 1, "title": "r"}], "truncated": False,
                   "project_rules": [{"id": 3, "title": "own"}]}
     with patch("scribe.mcp.tools.milestones.milestones_svc.get_milestone",
@@ -126,7 +125,10 @@ async def test_get_milestone_returns_body_steps_and_rules():
         out = await get_milestone(milestone_id=5)
     assert out["milestone"]["body"] == "## Goal"
     assert out["milestone"]["total"] == 1
-    assert out["steps"] == [{"id": 9, "title": "step 1", "status": "todo"}]
+    assert [(s["id"], s["title"], s["status"]) for s in out["steps"]] == [(9, "step 1", "todo")]
+    # A step's body is get_task's job (#4061); its placement is not.
+    assert "body" not in out["steps"][0]
+    assert out["steps"][0]["milestone_title"] == m.title
     assert out["applicable_rules"] == [{"id": 1, "title": "r"}]
 
 
diff --git a/tests/test_mcp_tool_systems.py b/tests/test_mcp_tool_systems.py
index 9432553..6f8c79e 100644
--- a/tests/test_mcp_tool_systems.py
+++ b/tests/test_mcp_tool_systems.py
@@ -2,7 +2,7 @@
 from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
-from tests.helpers import fake_note, fake_system
+from tests.helpers import fake_note, fake_system, fake_task
 
 
 # The name assessment both doors run before minting (milestone 307). A test
@@ -87,9 +87,9 @@ async def test_create_system_duplicate_names_the_existing_one_and_creates_nothin
 
 @pytest.mark.asyncio
 async def test_get_system_splits_records_by_kind():
-    issue = MagicMock(); issue.to_dict.return_value = {"id": 10}; issue.task_kind = "issue"; issue.status = "todo"
-    work = MagicMock(); work.to_dict.return_value = {"id": 11}; work.task_kind = "work"; work.status = "todo"
-    note = MagicMock(); note.to_dict.return_value = {"id": 12}; note.task_kind = "work"; note.status = None
+    issue = fake_task(id=10, task_kind="issue", milestone_id=None)
+    work = fake_task(id=11, milestone_id=None)
+    note = fake_note(id=12, status=None, milestone_id=None)
     with patch("scribe.mcp.tools.systems.current_user_id", return_value=1), \
          patch("scribe.mcp.tools.systems.systems_svc") as svc:
         svc.get_system = AsyncMock(return_value=fake_system(id=3))
diff --git a/tests/test_mcp_tool_tasks.py b/tests/test_mcp_tool_tasks.py
index 47db67a..bcbc8d0 100644
--- a/tests/test_mcp_tool_tasks.py
+++ b/tests/test_mcp_tool_tasks.py
@@ -16,7 +16,7 @@ pytestmark = pytest.mark.usefixtures("_bind_user")
 
 @pytest.mark.asyncio
 async def test_list_tasks_passes_is_task_true_and_repackages():
-    rows = [fake_task(id=1), fake_task(id=2)]
+    rows = [fake_task(id=1, milestone_id=None), fake_task(id=2, milestone_id=None)]
     mock = AsyncMock(return_value=(rows, 2))
     with patch("scribe.mcp.tools.tasks.notes_svc.list_notes", mock):
         out = await list_tasks()
diff --git a/tests/test_precompact_hook.py b/tests/test_precompact_hook.py
new file mode 100644
index 0000000..f07f77d
--- /dev/null
+++ b/tests/test_precompact_hook.py
@@ -0,0 +1,138 @@
+"""The PreCompact hook steers the summary and never blocks the compaction (#3680).
+
+The mechanism this pins was read out of the installed Claude Code build, not
+out of the documentation, which describes a different one. Three facts decide
+whether the hook works at all, and all three are properties of what the shell
+writes rather than of anything Scribe runs:
+
+  * **Exit 0.** The handler keeps a hook's stdout only when it `succeeded`,
+    which is `status === 0`. A non-zero exit sends the same bytes down the
+    failure branch instead, where they become a line on the operator's screen
+    and reach the model not at all.
+
+  * **Plain text on stdout.** That text is returned as `newCustomInstructions`
+    and merged into the prompt that writes the summary. JSON is not unwrapped
+    for this event — the hook-output schema has no PreCompact variant — so a
+    JSON envelope would be spliced into the summarizer's instructions verbatim,
+    braces and all.
+
+  * **Never blocked.** `exit 2` or `{"decision": "block"}` makes the handler
+    SKIP the compaction. The model is never told; the session simply runs on
+    uncompacted toward its context limit with no summary. That is strictly
+    worse than having no hook, and it is the outcome the spike existed to keep
+    out of the plugin — so it is pinned here rather than left to review.
+
+The fourth test is the one that catches a rewrite drifting back toward the
+original design: a future edit that reaches for `additionalContext` would look
+correct beside every other hook in this directory and would inject nothing.
+"""
+from __future__ import annotations
+
+import json
+import shutil
+import subprocess
+from pathlib import Path
+
+import pytest
+
+ROOT = Path(__file__).resolve().parents[1]
+HOOK = ROOT / "plugin" / "hooks" / "scribe_precompact_preserve.sh"
+HOOKS_JSON = ROOT / "plugin" / "hooks" / "hooks.json"
+
+EVENT = {"session_id": "s1", "transcript_path": "/tmp/t.jsonl", "cwd": "/repo",
+         "hook_event_name": "PreCompact", "trigger": "manual",
+         "custom_instructions": None}
+
+
+def _run(event: dict) -> subprocess.CompletedProcess:
+    if shutil.which("bash") is None:
+        pytest.skip("bash not installed")
+    return subprocess.run(["bash", str(HOOK)], input=json.dumps(event),
+                          capture_output=True, text=True, timeout=30)
+
+
+def _code() -> str:
+    """The script with its comments and its heredoc removed.
+
+    The static checks below are about what the shell DOES. Run over the whole
+    file they also read the header — which quotes `{"decision":"block"}` in the
+    course of explaining why this hook must never emit one — and the emitted
+    instructions, which use the word "decision" in a sentence. Both are the
+    file doing its job, and neither is code.
+    """
+    lines, in_heredoc = [], False
+    for line in HOOK.read_text().splitlines():
+        if in_heredoc:
+            in_heredoc = line.strip() != "EOF"
+            continue
+        if line.lstrip().startswith("cat <<'EOF'"):
+            in_heredoc = True
+            continue
+        if not line.lstrip().startswith("#"):
+            lines.append(line)
+    return "\n".join(lines)
+
+
+def test_the_comment_stripper_still_leaves_the_shell_behind():
+    """Guard on the three checks below it. `_code()` returning nothing would
+    make every one of them pass while checking an empty string — the same
+    circularity the plugin version check has to defend against."""
+    code = _code()
+    assert "set -uo pipefail" in code and "exit 0" in code
+    # It really did strip: both of the words the checks look for are present
+    # in the file, and neither is in the code.
+    assert "decision" in HOOK.read_text()
+
+
+@pytest.mark.parametrize("trigger", ["manual", "auto"])
+def test_it_exits_zero_with_instructions_on_stdout(trigger):
+    """Exit 0 plus non-empty stdout is the entire contract for reaching the
+    summarizer; either half missing and the hook is decoration."""
+    out = _run({**EVENT, "trigger": trigger})
+    assert out.returncode == 0, out.stderr
+    assert out.stdout.strip(), "empty stdout is dropped by the handler"
+
+
+def test_the_instructions_name_what_has_to_survive():
+    """The summary is the next turn's only copy of these, so the hook says so
+    in the words a summarizer can act on."""
+    said = _run(EVENT).stdout.lower()
+    assert "id" in said and "title" in said
+    for anchor in ("in progress", "scribe", "not yet recorded"):
+        assert anchor in said, f"the instruction no longer mentions {anchor!r}"
+
+
+def test_it_emits_text_and_not_a_json_envelope():
+    """Every other hook here answers in JSON. This one must not: for PreCompact
+    the envelope is not unwrapped, it is pasted into the summarizer's prompt."""
+    assert not _run(EVENT).stdout.lstrip().startswith("{")
+
+
+def test_it_never_blocks_the_compaction():
+    """A block skips compaction silently from the model's side. Nothing in the
+    script may produce one — not an exit code, not a decision."""
+    code = _code()
+    assert "decision" not in code, "a block decision would skip the compaction"
+    assert "exit 2" not in code
+    # A truncated or absent event must not turn into a non-zero exit either.
+    for event in ("", "not json", "{}"):
+        out = subprocess.run(["bash", str(HOOK)], input=event,
+                             capture_output=True, text=True, timeout=30)
+        assert out.returncode == 0, f"{event!r} → {out.returncode}: {out.stderr}"
+
+
+def test_additional_context_is_not_how_this_event_works():
+    """SessionStart's channel, which does not exist on PreCompact. A rewrite
+    that reaches for it would read as consistent with the other hooks and
+    inject nothing at all."""
+    assert "additionalContext" not in _code()
+
+
+def test_the_plugin_registers_it_on_precompact():
+    entries = json.loads(HOOKS_JSON.read_text())["hooks"]["PreCompact"]
+    commands = [h["command"] for e in entries for h in e["hooks"]]
+    assert any(HOOK.name in c for c in commands)
+    assert all(h["type"] == "command" for e in entries for h in e["hooks"]), (
+        "PreCompact accepts command hooks only — a prompt or agent hook is "
+        "rejected at registration"
+    )
diff --git a/tests/test_rule_usage_wiring.py b/tests/test_rule_usage_wiring.py
index 952b29b..d589587 100644
--- a/tests/test_rule_usage_wiring.py
+++ b/tests/test_rule_usage_wiring.py
@@ -735,14 +735,27 @@ def test_the_hook_and_the_route_agree_on_every_parameter_name():
     import re
 
     hook = Path("plugin/hooks/scribe_tool_rules.sh").read_text()
+    defs = Path("plugin/hooks/scribe_defs.sh").read_text()
     route = Path("src/scribe/routes/plugin.py").read_text()
     handler = route.split("async def pre_tool_rules")[1].split("\n@plugin_bp")[0]
 
     sent = set(re.findall(r"[?&]([a-z_]+)=", hook))
-    assert sent == {"tool", "command", "repo", "exclude_rule_ids"}, sent
+    assert sent == {"tool", "command", "exclude_rule_ids"}, sent
 
-    # `repo` is read by the shared _project_scope() helper, not inline.
+    # The project-scope key is the shared helper's to choose (#4085): the hook
+    # splices in `scribe_scope_query`'s output, which is `repo=` inside a git
+    # repo and `project_id=` where a `.scribe` marker names the project. Both
+    # halves are one contract with the route, so both are pinned.
+    assert "scribe_scope_query" in hook, "hook no longer asks for a project scope"
+    assert set(re.findall(r"printf '([a-z_]+)=", defs)) == {"repo", "project_id"}
+
+    # Both scope keys are read by the shared _project_scope() helper, not inline.
     assert "_project_scope()" in handler
+    scope = route.split("async def _project_scope")[1].split("\n@plugin_bp")[0]
+    for arg in ("project_id", "repo"):
+        assert f'request.args.get("{arg}"' in scope, (
+            f"the hooks can send {arg!r} and the route never reads it"
+        )
     for arg in ("tool", "command", "exclude_rule_ids"):
         assert f'request.args.get("{arg}")' in handler, (
             f"the hook sends {arg!r} and the route never reads it"
diff --git a/tests/test_scribe_marker.py b/tests/test_scribe_marker.py
new file mode 100644
index 0000000..7af04f3
--- /dev/null
+++ b/tests/test_scribe_marker.py
@@ -0,0 +1,150 @@
+"""`.scribe` — the second key a directory can be scoped by (#4085).
+
+Every hook in `plugin/hooks/` scopes its request to a project, and until this
+existed all six turned on one key: `git remote get-url origin`. That key does
+not exist outside a git repo, so a session in a plain directory was unscoped
+everywhere at once — silently, because a missing remote is indistinguishable
+from a remote nobody bound.
+
+`scribe_scope_query` is the shared answer, so these run the real shell rather
+than a reimplementation of it. What they pin:
+
+  * the marker is found from a subdirectory, the way git finds its root;
+  * a bare integer works, because that is what a person writes by hand;
+  * the marker BEATS a git remote, since someone put the file there on purpose;
+  * an `instance` naming a different Scribe is refused — the case the field
+    exists for. A project id means nothing on its own: id 2 is a different
+    project on every instance, so a marker that travels would otherwise scope
+    the session to the wrong project, confidently and without a word.
+
+That last one is the reason the file is JSON and not a number, so it is tested
+from both directions: the matching host is honoured, the mismatched one is not.
+"""
+from __future__ import annotations
+
+import json
+import os
+import shutil
+import subprocess
+from pathlib import Path
+
+import pytest
+
+ROOT = Path(__file__).resolve().parents[1]
+DEFS = ROOT / "plugin" / "hooks" / "scribe_defs.sh"
+INSTANCE = "https://scribe.example.com"
+
+
+def _sh(script: str, cwd: Path, env_extra: dict | None = None) -> str:
+    for tool in ("bash", "jq"):
+        if shutil.which(tool) is None:
+            pytest.skip(f"hook runtime tool {tool!r} not installed")
+    env = {"PATH": os.environ["PATH"], "HOME": str(cwd)}
+    env.update(env_extra or {})
+    body = f'set -uo pipefail\n. "{DEFS}"\nurl="{INSTANCE}"\n{script}\n'
+    out = subprocess.run(["bash", "-c", body], cwd=cwd, capture_output=True,
+                         text=True, env=env, timeout=30)
+    assert out.returncode == 0, out.stderr
+    return out.stdout.strip()
+
+
+def _marker(d: Path, **fields) -> None:
+    (d / ".scribe").write_text(json.dumps(fields))
+
+
+def _git_repo(d: Path, remote: str) -> None:
+    env = {"PATH": os.environ["PATH"], "HOME": str(d)}
+    subprocess.run(["git", "init", "-q"], cwd=d, check=True, env=env)
+    subprocess.run(["git", "remote", "add", "origin", remote], cwd=d, check=True, env=env)
+
+
+def test_a_bare_integer_is_a_valid_marker(tmp_path):
+    """What someone writes by hand. It parses as JSON already, so one filter
+    reads it and the written form alike."""
+    (tmp_path / ".scribe").write_text("7\n")
+    assert _sh(f'scribe_scope_query "{tmp_path}"', tmp_path) == "project_id=7"
+
+
+def test_the_marker_is_found_from_a_subdirectory(tmp_path):
+    _marker(tmp_path, instance=INSTANCE, project_id=2, project="FabledScribe")
+    deep = tmp_path / "src" / "scribe" / "services"
+    deep.mkdir(parents=True)
+    assert _sh(f'scribe_scope_query "{deep}"', tmp_path) == "project_id=2"
+
+
+def test_a_matching_instance_is_honoured(tmp_path):
+    """Host-only comparison, so http/https and a trailing slash are not a
+    mismatch — only a genuinely different Scribe is."""
+    _marker(tmp_path, instance="http://scribe.example.com/", project_id=2)
+    assert _sh(f'scribe_scope_query "{tmp_path}"', tmp_path) == "project_id=2"
+
+
+def test_a_marker_for_another_instance_is_refused_with_a_reason(tmp_path):
+    """The case the `instance` field exists for. No project beats the wrong
+    project, and the reason is carried so the session can say which it was."""
+    _marker(tmp_path, instance="https://someone-elses.example.org", project_id=2)
+    assert _sh(f'scribe_scope_query "{tmp_path}"', tmp_path) == ""
+    said = _sh(f'scribe_marker_read "{tmp_path}/.scribe"', tmp_path)
+    assert "someone-elses.example.org" in said and "scribe.example.com" in said
+
+
+def test_the_marker_beats_a_git_remote(tmp_path):
+    """Someone put the file there deliberately; a remote is only where the
+    code happens to be pushed. This is also how a directory overrides its
+    binding."""
+    _git_repo(tmp_path, "git@git.example.com:someone/thing.git")
+    assert _sh(f'scribe_scope_query "{tmp_path}"', tmp_path).startswith("repo=")
+    _marker(tmp_path, instance=INSTANCE, project_id=2)
+    assert _sh(f'scribe_scope_query "{tmp_path}"', tmp_path) == "project_id=2"
+
+
+def test_without_a_marker_the_git_remote_still_answers(tmp_path):
+    """The path every existing install is on — it must not have moved."""
+    _git_repo(tmp_path, "git@git.example.com:someone/thing.git")
+    got = _sh(f'scribe_scope_query "{tmp_path}"', tmp_path)
+    assert got.startswith("repo=") and "git.example.com" in got.replace("%2F", "/")
+
+
+def test_a_plain_directory_with_no_marker_scopes_to_nothing(tmp_path):
+    """Not an error — the caller sends no scope and the server says so."""
+    assert _sh(f'scribe_scope_query "{tmp_path}"', tmp_path) == ""
+
+
+@pytest.mark.parametrize("body", ["", "not json at all", "{}", '{"project_id": 0}',
+                                  '{"project_id": "../../etc"}', "[1,2,3]"])
+def test_an_unusable_marker_is_refused_rather_than_sent(tmp_path, body):
+    """A marker is operator-written and can say anything. Nothing that is not
+    a positive integer may reach the query string."""
+    (tmp_path / ".scribe").write_text(body)
+    assert _sh(f'scribe_scope_query "{tmp_path}"', tmp_path) == ""
+
+
+def test_the_reason_survives_the_command_substitution_that_fetches_it(tmp_path):
+    """Regression on a bug this nearly shipped with.
+
+    The reason used to be a global the function set, which every caller reads
+    through `$( )` — a subshell, so the assignment died with it and the caller
+    saw an UNSET variable. The hooks all run `set -u`, where reading one aborts
+    the script: a directory with a misaddressed marker would have cost the
+    session its entire SessionStart context, to fetch a warning about a file.
+
+    So the reason comes back through stdout with the id, and this asserts on
+    the shape the caller actually uses: read in a subshell, split, and used
+    under `set -u` without the shell dying.
+    """
+    _marker(tmp_path, instance="https://elsewhere.example.org", project_id=2)
+    got = _sh(
+        f'read_out=$(scribe_marker_read "$(scribe_marker_file "{tmp_path}")")\n'
+        'printf "id=[%s] why=[%s]" "${read_out%%$\'\\t\'*}" "${read_out#*$\'\\t\'}"',
+        tmp_path,
+    )
+    assert got.startswith("id=[]")
+    assert "elsewhere.example.org" in got
+
+
+def test_the_walk_up_terminates_at_the_root(tmp_path):
+    """No marker anywhere above: the loop must end rather than spin. tmp_path
+    is several levels down from /, so this really does walk."""
+    deep = tmp_path / "a" / "b" / "c"
+    deep.mkdir(parents=True)
+    assert _sh(f'scribe_scope_query "{deep}"', tmp_path) == ""
diff --git a/tests/test_services_plugin_context.py b/tests/test_services_plugin_context.py
index 33bc3d4..fff5f62 100644
--- a/tests/test_services_plugin_context.py
+++ b/tests/test_services_plugin_context.py
@@ -215,6 +215,31 @@ async def test_build_session_context_unbound_repo_emits_bind_hint():
     assert "## Active project" not in ctx
 
 
+@pytest.mark.asyncio
+async def test_a_project_id_that_does_not_resolve_is_reported_not_dropped():
+    """A `.scribe` marker names a project directly (#4085), so for the first
+    time a caller arrives holding a pointer it BELIEVES in. If the id is for
+    another instance, or names a deleted project, the session has to be told —
+    it cannot infer it from an absence.
+
+    This used to render nothing whatsoever: the branch hung off `if project_id`
+    as an `elif`, so an id that was sent and failed took the outer arm, found
+    no project, and fell out of the block having said nothing at all.
+    """
+    from scribe.services.plugin_context import build_session_context
+    with patch("scribe.services.plugin_context.projects_svc.get_project",
+               AsyncMock(return_value=None)):
+        out = await build_session_context(user_id=7, project_id=41)
+
+    ctx = out["context"]
+    assert out["project"] is None
+    assert "## Project 41 could not be loaded" in ctx
+    assert "list_projects" in ctx
+    # Not mistaken for the repo case, which has a different remedy.
+    assert "## Repository not yet bound" not in ctx
+    assert "No Scribe project is bound" not in ctx
+
+
 @pytest.mark.asyncio
 async def test_build_process_manifest_renders_stub_specs():
     items = [
diff --git a/tests/test_write_path_trigger.py b/tests/test_write_path_trigger.py
index d6dd323..84af7cd 100644
--- a/tests/test_write_path_trigger.py
+++ b/tests/test_write_path_trigger.py
@@ -931,10 +931,16 @@ def test_route_reads_every_arg_the_hook_sends():
         assert f'request.args.get("{arg}"' in src, f"route ignores {arg}"
 
     hook = HOOK.read_text()
-    for arg in ("path=", "code=", "repo=", "exclude_ids=", "exclude_sync_ids=",
-                "shapes="):
+    for arg in ("path=", "code=", "exclude_ids=", "exclude_sync_ids=", "shapes="):
         assert arg in hook, f"hook never sends {arg}"
 
+    # The project-scope key is no longer spelled in the hook: since #4085 it is
+    # whichever of `repo=` / `project_id=` scribe_scope_query picks, so the hook
+    # splices in its output and the helper is the other half of the contract.
+    assert "scribe_scope_query" in hook, "hook no longer asks for a project scope"
+    defs = (HOOK.parent / "scribe_defs.sh").read_text()
+    assert set(re.findall(r"printf '([a-z_]+)=", defs)) == {"repo", "project_id"}
+
 
 def test_route_resolves_repo_to_a_project_not_to_a_location_filter():
     """A snippet's `repo` is a label the operator typed; the hook sends a git