diff --git a/CLAUDE.md b/CLAUDE.md
index e11e2d6..d0c5de3 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -31,16 +31,17 @@ deltas below** (don't flatten them).
 
 - **Helper scripts** — every adapter co-locates each script with its invoker: hook
   scripts in `hooks/` (next to `hooks.json`), skill scripts in the skill's own
-  `scripts/`. `claude-code` is the reference (it has all six). Copies:
+  `scripts/`. `claude-code` is the reference (it has all seven). Copies:
   - `register.py` (add skill) → `claude-code/skills/add/scripts/`, `codex/skills/add/scripts/`, `copilot/skills/debt-ops-add/scripts/`, `skills/debt-ops-add/scripts/`
   - `review.py` (review skill) → `claude-code/skills/review/scripts/`, `codex/skills/review/scripts/`, `copilot/skills/debt-ops-review/scripts/`, `skills/debt-ops-review/scripts/`
+  - `toggle.py` (disable skill) → `claude-code/skills/disable/scripts/`, `codex/skills/disable/scripts/`, `copilot/skills/debt-ops-disable/scripts/`, `skills/debt-ops-disable/scripts/` (claude resolves the cache like `register.py`; the rest use `cache_base`)
   - `feedback.py`, `session-start.py` (hooks) → `claude-code/hooks/`, `codex/hooks/`, `copilot/hooks/`
   - `stop.py` (hook) → `claude-code/hooks/`, `codex/hooks/`, `copilot/hooks/` (copilot on `agentStop`)
   - `drop.py` (hook) → `claude-code/hooks/`, `codex/hooks/` (no copilot — `userPromptSubmitted` output isn't processed)
 - **Within-script helpers** repeated across most of the above — change one, change
-  all: `git_toplevel`, `repo_hash`, `cache_base`, `read_registry_dir`, `log_metric`,
-  `letter_for`, `parse_frontmatter`, `days_since`.
-- **Skills (`SKILL.md`)** — `add`, `review`, `metrics`, `init` each live in
+  all: `git_toplevel`, `repo_hash`, `repo_disabled`, `cache_base`, `read_registry_dir`,
+  `log_metric`, `letter_for`, `parse_frontmatter`, `days_since`.
+- **Skills (`SKILL.md`)** — `add`, `review`, `metrics`, `init`, `disable` each live in
   `claude-code/skills/`, `codex/skills/`, `copilot/skills/`, and top-level `skills/`.
   Dir names differ by namespace (see deltas): bare (`add`) under the namespaced
   plugins, `debt-ops-`-prefixed under copilot + portable.
diff --git a/README.md b/README.md
index dd1f0a1..9476f8b 100644
--- a/README.md
+++ b/README.md
@@ -72,6 +72,7 @@ Claude Code `/debt-ops:<name>` · Codex `$<name>`:
 - **review**: audit and rank the registry, then walk paydown.
 - **init** *(opt-in)*: write the disciplines into `CLAUDE.md`/`AGENTS.md` so the team shares them.
 - **metrics**: read-only health summary of the registry.
+- **disable**: turn debt-ops off for the current repo (run again to re-enable). Flips a per-repo marker in the plugin cache — nothing is written to your working tree. Per-machine, not committed.
 
 </details>
 
diff --git a/claude-code/hooks/drop.py b/claude-code/hooks/drop.py
index 6f3829b..950d2e9 100755
--- a/claude-code/hooks/drop.py
+++ b/claude-code/hooks/drop.py
@@ -59,6 +59,11 @@ def repo_hash(toplevel):
     return hashlib.sha1(str(toplevel).encode()).hexdigest()[:12]
 
 
+# True if this repo has a debt-ops disable sentinel in its cache dir (ADR 0020).
+def repo_disabled(cache_dir):
+    return (cache_dir / "disabled").is_file()
+
+
 def emit_block(reason):
     payload = {
         "decision": "block",
@@ -140,6 +145,10 @@ def main():
     cache_base = Path(os.environ.get("CLAUDE_PLUGIN_DATA") or (Path.home() / ".cache" / "debt-ops"))
     cache_dir = cache_base / "cache" / repo_hash(toplevel)
 
+    # Idle out if debt-ops is disabled for this repo (ADR 0020).
+    if repo_disabled(cache_dir):
+        return 0
+
     # Look in both files: current-turn.txt (just-finished turn, not yet rotated)
     # and last-batch.txt (turn before that). Merge with current-turn winning.
     current = read_batch(cache_dir / "current-turn.txt")
diff --git a/claude-code/hooks/feedback.py b/claude-code/hooks/feedback.py
index c280836..5c8d138 100755
--- a/claude-code/hooks/feedback.py
+++ b/claude-code/hooks/feedback.py
@@ -56,6 +56,11 @@ def repo_hash(toplevel):
     return hashlib.sha1(str(toplevel).encode()).hexdigest()[:12]
 
 
+# True if this repo has a debt-ops disable sentinel in its cache dir (ADR 0020).
+def repo_disabled(cache_dir):
+    return (cache_dir / "disabled").is_file()
+
+
 # Pulls the just-edited file path out of the hook's stdin JSON payload.
 def changed_file_from_stdin():
     try:
@@ -228,6 +233,10 @@ def main():
     cache_base = Path(os.environ.get("CLAUDE_PLUGIN_DATA") or (Path.home() / ".cache" / "debt-ops"))
     cache_dir = cache_base / "cache" / repo_hash(toplevel)
 
+    # Idle out if debt-ops is disabled for this repo (ADR 0020).
+    if repo_disabled(cache_dir):
+        return 0
+
     changed = changed_file_from_stdin()
     changed_files = [changed] if changed else []
     env = os.environ.copy()
diff --git a/claude-code/hooks/session-start.py b/claude-code/hooks/session-start.py
index 4b96d50..3c69afe 100755
--- a/claude-code/hooks/session-start.py
+++ b/claude-code/hooks/session-start.py
@@ -62,6 +62,11 @@ def repo_hash(toplevel):
     return hashlib.sha1(str(toplevel).encode()).hexdigest()[:12]
 
 
+# True if this repo has a debt-ops disable sentinel in its cache dir (ADR 0020).
+def repo_disabled(cache_dir):
+    return (cache_dir / "disabled").is_file()
+
+
 def manifest_hash(toplevel):
     paths = [toplevel / n for n in MANIFEST_FILES if (toplevel / n).is_file()]
     if not paths:
@@ -301,6 +306,11 @@ def main():
 
     cache_base = Path(os.environ.get("CLAUDE_PLUGIN_DATA") or (Path.home() / ".cache" / "debt-ops"))
     cache_dir = cache_base / "cache" / repo_hash(toplevel)
+
+    # Idle out silently if debt-ops is disabled for this repo (ADR 0020).
+    if repo_disabled(cache_dir):
+        return 0
+
     stateless = False
     try:
         cache_dir.mkdir(parents=True, exist_ok=True)
diff --git a/claude-code/hooks/stop.py b/claude-code/hooks/stop.py
index 36bc9b7..7f8b2d8 100644
--- a/claude-code/hooks/stop.py
+++ b/claude-code/hooks/stop.py
@@ -65,6 +65,11 @@ def repo_hash(toplevel):
     return hashlib.sha1(str(toplevel).encode()).hexdigest()[:12]
 
 
+# True if this repo has a debt-ops disable sentinel in its cache dir (ADR 0020).
+def repo_disabled(cache_dir):
+    return (cache_dir / "disabled").is_file()
+
+
 # Debug log path — only when DEBT_OPS_DEBUG=1 is set in the environment.
 def debug_path(cache_dir):
     if not os.environ.get(DEBUG_ENV):
@@ -331,6 +336,11 @@ def main():
 
     cache_base = Path(os.environ.get("CLAUDE_PLUGIN_DATA") or (Path.home() / ".cache" / "debt-ops"))
     cache_dir = cache_base / "cache" / repo_hash(toplevel)
+
+    # Idle out if debt-ops is disabled for this repo (ADR 0020).
+    if repo_disabled(cache_dir):
+        return 0
+
     dpath = debug_path(cache_dir)
     state_path = cache_dir / "stop-state"
     session_blocks_path = cache_dir / "session-blocks"
diff --git a/claude-code/skills/disable/SKILL.md b/claude-code/skills/disable/SKILL.md
new file mode 100644
index 0000000..2465ef8
--- /dev/null
+++ b/claude-code/skills/disable/SKILL.md
@@ -0,0 +1,35 @@
+---
+name: disable
+description: Turn debt-ops off (or back on) for the current repo. Run ONLY when the user explicitly asks to disable, turn off, silence, or re-enable debt-ops here — never auto-invoke. Flips a per-repo marker in the plugin cache; nothing is written to the working tree.
+disable-model-invocation: true
+allowed-tools: Bash(python3 *)
+# Hidden from `npx skills` discovery — this copy ships in the Claude Code plugin (uses ${CLAUDE_PLUGIN_ROOT}); the portable skills/ copy is the one for the skills CLI.
+metadata:
+  internal: true
+---
+
+# /debt-ops:disable — turn debt-ops off for this repo
+
+Call `toggle.py` via Bash. It flips a `disabled` marker in this repo's plugin
+cache dir (ADR 0020). While the marker is present, every hook idles silently —
+no session inject, no write-time feedback, no stop nudge. Nothing lands in the
+working tree, so it never shows up in `git status`.
+
+The marker is per-machine, not committed — it disables debt-ops for *you* in
+*this* repo. The script's stdout IS the confirmation; add no commentary.
+
+## The call
+
+```bash
+# Toggle (or pass `disable` / `enable` to force a direction):
+python3 ${CLAUDE_PLUGIN_ROOT}/skills/disable/scripts/toggle.py disable
+python3 ${CLAUDE_PLUGIN_ROOT}/skills/disable/scripts/toggle.py enable
+```
+
+Match the user's intent: pass `disable` when they ask to turn it off, `enable`
+when they ask to turn it back on. Omit the argument only when they say "toggle."
+
+## Don't
+
+- Don't run this as part of normal work — only on an explicit request.
+- Don't echo or paraphrase the script's output; the Bash result is already visible.
diff --git a/claude-code/skills/disable/scripts/toggle.py b/claude-code/skills/disable/scripts/toggle.py
new file mode 100644
index 0000000..901f49f
--- /dev/null
+++ b/claude-code/skills/disable/scripts/toggle.py
@@ -0,0 +1,104 @@
+#!/usr/bin/env python3
+"""debt-ops disable toggle: flip the per-repo disable sentinel (ADR 0020).
+
+Writes (or removes) a `disabled` marker in this repo's plugin cache dir. While
+the marker is present every hook idles silently — no session inject, no
+write-time feedback, no stop nudge. Nothing is written to the working tree.
+
+With no argument it toggles; pass `disable` or `enable` to force a direction.
+"""
+
+import argparse
+import hashlib
+import os
+import subprocess
+import sys
+from pathlib import Path
+
+
+def git_toplevel():
+    try:
+        out = subprocess.run(
+            ["git", "rev-parse", "--show-toplevel"],
+            capture_output=True, text=True, check=True, timeout=2,
+        )
+        s = out.stdout.strip()
+        return Path(s) if s else None
+    except (subprocess.SubprocessError, FileNotFoundError):
+        return None
+
+
+def repo_hash(toplevel):
+    return hashlib.sha1(str(toplevel).encode()).hexdigest()[:12]
+
+
+# Locate this repo's plugin cache — same resolution order as register.py.
+# CLAUDE_PLUGIN_DATA is set for hook subprocesses but NOT for skill Bash (where
+# this runs), so fall back to the standard plugin-data dir, then the legacy
+# cache path. The sentinel must land where the hooks read it.
+def resolve_cache_dir(toplevel):
+    h = repo_hash(toplevel)
+    candidates = []
+    pd = os.environ.get("CLAUDE_PLUGIN_DATA")
+    if pd:
+        candidates.append(Path(pd) / "cache" / h)
+    candidates += sorted(
+        (Path.home() / ".claude" / "plugins" / "data").glob(f"debt-ops*/cache/{h}")
+    )
+    candidates.append(Path.home() / ".cache" / "debt-ops" / "cache" / h)
+    for c in candidates:
+        if c.is_dir():
+            return c
+    return candidates[0]
+
+
+def parse_args():
+    p = argparse.ArgumentParser(description="Toggle debt-ops for this repo.")
+    p.add_argument("action", nargs="?", choices=["disable", "enable"],
+                   help="force a direction; omit to toggle")
+    return p.parse_args()
+
+
+def main():
+    args = parse_args()
+
+    toplevel = git_toplevel()
+    if toplevel is None:
+        sys.stderr.write("debt-ops: not in a git repo\n")
+        return 2
+
+    cache_dir = resolve_cache_dir(toplevel)
+    sentinel = cache_dir / "disabled"
+    currently_disabled = sentinel.is_file()
+
+    if args.action == "disable":
+        want_disabled = True
+    elif args.action == "enable":
+        want_disabled = False
+    else:
+        want_disabled = not currently_disabled
+
+    if want_disabled:
+        try:
+            cache_dir.mkdir(parents=True, exist_ok=True)
+            sentinel.write_text("", encoding="utf-8")
+        except OSError as e:
+            sys.stderr.write(f"debt-ops: could not disable: {e}\n")
+            return 1
+        sys.stdout.write("debt-ops disabled for this repo (run again to re-enable).\n")
+    else:
+        try:
+            sentinel.unlink(missing_ok=True)
+        except OSError as e:
+            sys.stderr.write(f"debt-ops: could not re-enable: {e}\n")
+            return 1
+        sys.stdout.write("debt-ops re-enabled for this repo.\n")
+    return 0
+
+
+if __name__ == "__main__":
+    try:
+        sys.exit(main())
+    except Exception as e:
+        sys.stderr.write(f"debt-ops disable: {e}\n")
+        sys.exit(1)
diff --git a/codex/hooks/drop.py b/codex/hooks/drop.py
index 7fb5744..382c0f9 100644
--- a/codex/hooks/drop.py
+++ b/codex/hooks/drop.py
@@ -67,6 +67,11 @@ def repo_hash(toplevel):
     return hashlib.sha1(str(toplevel).encode()).hexdigest()[:12]
 
 
+# True if this repo has a debt-ops disable sentinel in its cache dir (ADR 0020).
+def repo_disabled(cache_dir):
+    return (cache_dir / "disabled").is_file()
+
+
 def emit_block(reason):
     payload = {
         "decision": "block",
@@ -147,6 +152,10 @@ def main():
 
     cache_dir = cache_base() / "cache" / repo_hash(toplevel)
 
+    # Idle out if debt-ops is disabled for this repo (ADR 0020).
+    if repo_disabled(cache_dir):
+        return 0
+
     # Look in both files: current-turn.txt (just-finished turn, not yet rotated)
     # and last-batch.txt (turn before that). Merge with current-turn winning.
     current = read_batch(cache_dir / "current-turn.txt")
diff --git a/codex/hooks/feedback.py b/codex/hooks/feedback.py
index 48b4d1d..8ea8085 100644
--- a/codex/hooks/feedback.py
+++ b/codex/hooks/feedback.py
@@ -72,6 +72,11 @@ def repo_hash(toplevel):
     return hashlib.sha1(str(toplevel).encode()).hexdigest()[:12]
 
 
+# True if this repo has a debt-ops disable sentinel in its cache dir (ADR 0020).
+def repo_disabled(cache_dir):
+    return (cache_dir / "disabled").is_file()
+
+
 # Pull the V4A patch text out of an apply_patch tool_input. Codex may place it
 # in any string field (or hand tool_input as a raw string), so we sniff for the
 # envelope markers rather than guessing the field name.
@@ -287,6 +292,10 @@ def main():
 
     cache_dir = cache_base() / "cache" / repo_hash(toplevel)
 
+    # Idle out if debt-ops is disabled for this repo (ADR 0020).
+    if repo_disabled(cache_dir):
+        return 0
+
     changed_files = changed_files_from_stdin()
     changed = " ".join(changed_files)
     env = os.environ.copy()
diff --git a/codex/hooks/session-start.py b/codex/hooks/session-start.py
index 03670da..e487866 100644
--- a/codex/hooks/session-start.py
+++ b/codex/hooks/session-start.py
@@ -73,6 +73,11 @@ def repo_hash(toplevel):
     return hashlib.sha1(str(toplevel).encode()).hexdigest()[:12]
 
 
+# True if this repo has a debt-ops disable sentinel in its cache dir (ADR 0020).
+def repo_disabled(cache_dir):
+    return (cache_dir / "disabled").is_file()
+
+
 def manifest_hash(toplevel):
     paths = [toplevel / n for n in MANIFEST_FILES if (toplevel / n).is_file()]
     if not paths:
@@ -311,6 +316,11 @@ def main():
         return 0
 
     cache_dir = cache_base() / "cache" / repo_hash(toplevel)
+
+    # Idle out silently if debt-ops is disabled for this repo (ADR 0020).
+    if repo_disabled(cache_dir):
+        return 0
+
     stateless = False
     try:
         cache_dir.mkdir(parents=True, exist_ok=True)
diff --git a/codex/hooks/stop.py b/codex/hooks/stop.py
index 15378d0..e8e093f 100644
--- a/codex/hooks/stop.py
+++ b/codex/hooks/stop.py
@@ -70,6 +70,11 @@ def repo_hash(toplevel):
     return hashlib.sha1(str(toplevel).encode()).hexdigest()[:12]
 
 
+# True if this repo has a debt-ops disable sentinel in its cache dir (ADR 0020).
+def repo_disabled(cache_dir):
+    return (cache_dir / "disabled").is_file()
+
+
 # Debug log path — only when DEBT_OPS_DEBUG=1 is set in the environment.
 def debug_path(cache_dir):
     if not os.environ.get(DEBUG_ENV):
@@ -335,6 +340,11 @@ def main():
         return 0
 
     cache_dir = cache_base() / "cache" / repo_hash(toplevel)
+
+    # Idle out if debt-ops is disabled for this repo (ADR 0020).
+    if repo_disabled(cache_dir):
+        return 0
+
     dpath = debug_path(cache_dir)
     state_path = cache_dir / "stop-state"
     session_blocks_path = cache_dir / "session-blocks"
diff --git a/codex/skills/disable/SKILL.md b/codex/skills/disable/SKILL.md
new file mode 100644
index 0000000..6f1df1d
--- /dev/null
+++ b/codex/skills/disable/SKILL.md
@@ -0,0 +1,30 @@
+---
+name: disable
+description: Turn debt-ops off (or back on) for the current repo. Run ONLY when the user explicitly asks to disable, turn off, silence, or re-enable debt-ops here — never auto-invoke. Flips a per-repo marker in the plugin cache; nothing is written to the working tree.
+---
+
+# disable — turn debt-ops off for this repo
+
+Call `toggle.py` via Bash. It flips a `disabled` marker in this repo's plugin
+cache dir (ADR 0020). While the marker is present, every hook idles silently —
+no session inject, no write-time feedback, no stop nudge. Nothing lands in the
+working tree, so it never shows up in `git status`.
+
+The marker is per-machine, not committed — it disables debt-ops for *you* in
+*this* repo. The script's stdout IS the confirmation; add no commentary.
+
+## The call
+
+```bash
+# Toggle (or pass `disable` / `enable` to force a direction):
+python3 scripts/toggle.py disable
+python3 scripts/toggle.py enable
+```
+
+Match the user's intent: pass `disable` when they ask to turn it off, `enable`
+when they ask to turn it back on. Omit the argument only when they say "toggle."
+
+## Don't
+
+- Don't run this as part of normal work — only on an explicit request.
+- Don't echo or paraphrase the script's output; the Bash result is already visible.
diff --git a/codex/skills/disable/scripts/toggle.py b/codex/skills/disable/scripts/toggle.py
new file mode 100644
index 0000000..3e7bf56
--- /dev/null
+++ b/codex/skills/disable/scripts/toggle.py
@@ -0,0 +1,90 @@
+#!/usr/bin/env python3
+"""debt-ops disable toggle: flip the per-repo disable sentinel (ADR 0020).
+
+Writes (or removes) a `disabled` marker in this repo's plugin cache dir. While
+the marker is present every hook idles silently — no session inject, no
+write-time feedback, no stop nudge. Nothing is written to the working tree.
+
+With no argument it toggles; pass `disable` or `enable` to force a direction.
+"""
+
+import argparse
+import hashlib
+import os
+import subprocess
+import sys
+from pathlib import Path
+
+
+def git_toplevel():
+    try:
+        out = subprocess.run(
+            ["git", "rev-parse", "--show-toplevel"],
+            capture_output=True, text=True, check=True, timeout=2,
+        )
+        s = out.stdout.strip()
+        return Path(s) if s else None
+    except (subprocess.SubprocessError, FileNotFoundError):
+        return None
+
+
+def repo_hash(toplevel):
+    return hashlib.sha1(str(toplevel).encode()).hexdigest()[:12]
+
+
+# Single deterministic cache base, shared with the hooks (override DEBT_OPS_CACHE).
+def cache_base():
+    override = os.environ.get("DEBT_OPS_CACHE")
+    return Path(override) if override else (Path.home() / ".cache" / "debt-ops")
+
+
+def parse_args():
+    p = argparse.ArgumentParser(description="Toggle debt-ops for this repo.")
+    p.add_argument("action", nargs="?", choices=["disable", "enable"],
+                   help="force a direction; omit to toggle")
+    return p.parse_args()
+
+
+def main():
+    args = parse_args()
+
+    toplevel = git_toplevel()
+    if toplevel is None:
+        sys.stderr.write("debt-ops: not in a git repo\n")
+        return 2
+
+    cache_dir = cache_base() / "cache" / repo_hash(toplevel)
+    sentinel = cache_dir / "disabled"
+    currently_disabled = sentinel.is_file()
+
+    if args.action == "disable":
+        want_disabled = True
+    elif args.action == "enable":
+        want_disabled = False
+    else:
+        want_disabled = not currently_disabled
+
+    if want_disabled:
+        try:
+            cache_dir.mkdir(parents=True, exist_ok=True)
+            sentinel.write_text("", encoding="utf-8")
+        except OSError as e:
+            sys.stderr.write(f"debt-ops: could not disable: {e}\n")
+            return 1
+        sys.stdout.write("debt-ops disabled for this repo (run again to re-enable).\n")
+    else:
+        try:
+            sentinel.unlink(missing_ok=True)
+        except OSError as e:
+            sys.stderr.write(f"debt-ops: could not re-enable: {e}\n")
+            return 1
+        sys.stdout.write("debt-ops re-enabled for this repo.\n")
+    return 0
+
+
+if __name__ == "__main__":
+    try:
+        sys.exit(main())
+    except Exception as e:
+        sys.stderr.write(f"debt-ops disable: {e}\n")
+        sys.exit(1)
diff --git a/copilot/hooks/feedback.py b/copilot/hooks/feedback.py
index f3773c2..731aafb 100644
--- a/copilot/hooks/feedback.py
+++ b/copilot/hooks/feedback.py
@@ -93,6 +93,11 @@ def repo_hash(toplevel):
     return hashlib.sha1(str(toplevel).encode()).hexdigest()[:12]
 
 
+# True if this repo has a debt-ops disable sentinel in its cache dir (ADR 0020).
+def repo_disabled(cache_dir):
+    return (cache_dir / "disabled").is_file()
+
+
 # Single deterministic cache base, shared with the skills (override DEBT_OPS_CACHE).
 def cache_base():
     override = os.environ.get("DEBT_OPS_CACHE")
@@ -313,6 +318,10 @@ def main():
 
     cache_dir = cache_base() / "cache" / repo_hash(toplevel)
 
+    # Idle out if debt-ops is disabled for this repo (ADR 0020).
+    if repo_disabled(cache_dir):
+        return 0
+
     tool_name, changed = changed_file(data)
     # Copilot fires postToolUse on every tool; only edits concern us.
     if not changed:
diff --git a/copilot/hooks/session-start.py b/copilot/hooks/session-start.py
index ae9c914..68589ff 100644
--- a/copilot/hooks/session-start.py
+++ b/copilot/hooks/session-start.py
@@ -51,6 +51,11 @@ def repo_hash(toplevel):
     return hashlib.sha1(str(toplevel).encode()).hexdigest()[:12]
 
 
+# True if this repo has a debt-ops disable sentinel in its cache dir (ADR 0020).
+def repo_disabled(cache_dir):
+    return (cache_dir / "disabled").is_file()
+
+
 def cache_base():
     override = os.environ.get("DEBT_OPS_CACHE")
     return Path(override) if override else (Path.home() / ".cache" / "debt-ops")
@@ -172,6 +177,11 @@ def main():
         return 0
 
     cache_dir = cache_base() / "cache" / repo_hash(toplevel)
+
+    # Idle out silently if debt-ops is disabled for this repo (ADR 0020).
+    if repo_disabled(cache_dir):
+        return 0
+
     try:
         cache_dir.mkdir(parents=True, exist_ok=True)
     except OSError:
diff --git a/copilot/hooks/stop.py b/copilot/hooks/stop.py
index 873e6d2..73549f2 100644
--- a/copilot/hooks/stop.py
+++ b/copilot/hooks/stop.py
@@ -72,6 +72,11 @@ def repo_hash(toplevel):
     return hashlib.sha1(str(toplevel).encode()).hexdigest()[:12]
 
 
+# True if this repo has a debt-ops disable sentinel in its cache dir (ADR 0020).
+def repo_disabled(cache_dir):
+    return (cache_dir / "disabled").is_file()
+
+
 # Debug log path — only when DEBT_OPS_DEBUG=1 is set in the environment.
 def debug_path(cache_dir):
     if not os.environ.get(DEBUG_ENV):
@@ -355,6 +360,11 @@ def main():
         return 0
 
     cache_dir = cache_base() / "cache" / repo_hash(toplevel)
+
+    # Idle out if debt-ops is disabled for this repo (ADR 0020).
+    if repo_disabled(cache_dir):
+        return 0
+
     dpath = debug_path(cache_dir)
     state_path = cache_dir / "stop-state"
     session_blocks_path = cache_dir / "session-blocks"
diff --git a/copilot/skills/debt-ops-disable/SKILL.md b/copilot/skills/debt-ops-disable/SKILL.md
new file mode 100644
index 0000000..c58c039
--- /dev/null
+++ b/copilot/skills/debt-ops-disable/SKILL.md
@@ -0,0 +1,28 @@
+---
+name: debt-ops-disable
+description: Turn debt-ops off (or back on) for the current repo. Run ONLY when the user explicitly asks to disable, turn off, silence, or re-enable debt-ops here — never auto-invoke. Flips a per-repo marker in the plugin cache; nothing is written to the working tree.
+---
+
+# debt-ops-disable — turn debt-ops off for this repo
+
+**Run only on explicit user request** ("disable debt-ops here", "turn debt-ops
+off", "re-enable debt-ops"). Do not invoke this as part of normal work.
+
+Call `toggle.py` via Bash. It flips a `disabled` marker in this repo's plugin
+cache dir (ADR 0020). While the marker is present, every hook idles silently —
+no write-time feedback, no agentStop nudge. Nothing lands in the working tree,
+so it never shows up in `git status`.
+
+The marker is per-machine, not committed — it disables debt-ops for *you* in
+*this* repo. The script's stdout IS the confirmation; add no commentary.
+
+## The call
+
+```bash
+# Toggle (or pass `disable` / `enable` to force a direction):
+python3 scripts/toggle.py disable
+python3 scripts/toggle.py enable
+```
+
+Match the user's intent: pass `disable` when they ask to turn it off, `enable`
+when they ask to turn it back on. Omit the argument only when they say "toggle."
diff --git a/copilot/skills/debt-ops-disable/scripts/toggle.py b/copilot/skills/debt-ops-disable/scripts/toggle.py
new file mode 100644
index 0000000..3e7bf56
--- /dev/null
+++ b/copilot/skills/debt-ops-disable/scripts/toggle.py
@@ -0,0 +1,90 @@
+#!/usr/bin/env python3
+"""debt-ops disable toggle: flip the per-repo disable sentinel (ADR 0020).
+
+Writes (or removes) a `disabled` marker in this repo's plugin cache dir. While
+the marker is present every hook idles silently — no session inject, no
+write-time feedback, no stop nudge. Nothing is written to the working tree.
+
+With no argument it toggles; pass `disable` or `enable` to force a direction.
+"""
+
+import argparse
+import hashlib
+import os
+import subprocess
+import sys
+from pathlib import Path
+
+
+def git_toplevel():
+    try:
+        out = subprocess.run(
+            ["git", "rev-parse", "--show-toplevel"],
+            capture_output=True, text=True, check=True, timeout=2,
+        )
+        s = out.stdout.strip()
+        return Path(s) if s else None
+    except (subprocess.SubprocessError, FileNotFoundError):
+        return None
+
+
+def repo_hash(toplevel):
+    return hashlib.sha1(str(toplevel).encode()).hexdigest()[:12]
+
+
+# Single deterministic cache base, shared with the hooks (override DEBT_OPS_CACHE).
+def cache_base():
+    override = os.environ.get("DEBT_OPS_CACHE")
+    return Path(override) if override else (Path.home() / ".cache" / "debt-ops")
+
+
+def parse_args():
+    p = argparse.ArgumentParser(description="Toggle debt-ops for this repo.")
+    p.add_argument("action", nargs="?", choices=["disable", "enable"],
+                   help="force a direction; omit to toggle")
+    return p.parse_args()
+
+
+def main():
+    args = parse_args()
+
+    toplevel = git_toplevel()
+    if toplevel is None:
+        sys.stderr.write("debt-ops: not in a git repo\n")
+        return 2
+
+    cache_dir = cache_base() / "cache" / repo_hash(toplevel)
+    sentinel = cache_dir / "disabled"
+    currently_disabled = sentinel.is_file()
+
+    if args.action == "disable":
+        want_disabled = True
+    elif args.action == "enable":
+        want_disabled = False
+    else:
+        want_disabled = not currently_disabled
+
+    if want_disabled:
+        try:
+            cache_dir.mkdir(parents=True, exist_ok=True)
+            sentinel.write_text("", encoding="utf-8")
+        except OSError as e:
+            sys.stderr.write(f"debt-ops: could not disable: {e}\n")
+            return 1
+        sys.stdout.write("debt-ops disabled for this repo (run again to re-enable).\n")
+    else:
+        try:
+            sentinel.unlink(missing_ok=True)
+        except OSError as e:
+            sys.stderr.write(f"debt-ops: could not re-enable: {e}\n")
+            return 1
+        sys.stdout.write("debt-ops re-enabled for this repo.\n")
+    return 0
+
+
+if __name__ == "__main__":
+    try:
+        sys.exit(main())
+    except Exception as e:
+        sys.stderr.write(f"debt-ops disable: {e}\n")
+        sys.exit(1)
diff --git a/docs/adr/0020-per-repo-disable-via-cache-sentinel.md b/docs/adr/0020-per-repo-disable-via-cache-sentinel.md
new file mode 100644
index 0000000..eff89a0
--- /dev/null
+++ b/docs/adr/0020-per-repo-disable-via-cache-sentinel.md
@@ -0,0 +1,60 @@
+# 0020 — Disable debt-ops per-repo via a cache sentinel, not a repo file
+
+**Date:** 2026-06-10
+**Status:** Accepted
+
+## Context
+
+There was no way to turn debt-ops off for a single repo. The hooks fire on
+every session, edit, and stop, and the only escape was uninstalling the plugin
+globally — too blunt when you want it on everywhere except one repo (a vendored
+tree, a throwaway spike, a repo whose owner just doesn't want it).
+
+We needed an on/off switch that is per-repo, easy to flip, and survives across
+sessions. The open question was *where the off-state lives*.
+
+## Decision
+
+Store the disable flag as a sentinel file `disabled` inside the plugin's
+existing per-repo cache dir (`<cache>/cache/<repo_hash>/disabled`) — the same
+place `registry-dir`, `feedback.list`, and the turn batch already live. Every
+hook already resolves `git_toplevel()` → `cache_dir`; we add one
+`repo_disabled(cache_dir)` check right there and idle silently if the sentinel
+exists (the same clean exit as "not a git repo").
+
+Flipping it is the `/debt-ops:disable` skill (`$debt-ops-disable` on
+non-Claude), backed by a small `toggle.py` that resolves the cache the same way
+`register.py` does and creates or removes the sentinel, printing the resulting
+state. Run it again to re-enable. The skill never auto-invokes — it only runs
+on explicit request.
+
+## What this means for you
+
+- Disable a repo: run `/debt-ops:disable` (Claude) / `$debt-ops-disable`
+  (Codex/Copilot/portable). Run it again to re-enable. The hooks go quiet
+  immediately — no session inject, no write-time feedback, no stop nudge.
+- Nothing is written to your working tree. The flag lives in the plugin's
+  cache, so it never shows up in `git status` or a diff.
+- Because the cache is per-machine, the off-state is **per developer machine**,
+  not shared with the team. Each person who wants it off in a repo flips it
+  themselves. (See the trade-off below.)
+- The explicitly-invoked skills still work while disabled — disabling targets
+  the automatic hook behaviors, which is what's intrusive.
+
+## Alternatives we ruled out
+
+- **A committed repo file** (`.debt-ops-disabled`, a config key). Would make the
+  decision team-wide and version-controlled, but it puts a file in the user's
+  tree — the one thing we were asked to avoid. The cache sentinel keeps the
+  working tree clean at the cost of being per-machine.
+- **An env var** (`DEBT_OPS_DISABLE=1`). Easy, but it's per-shell, not
+  per-repo, and not persistent — you'd forget it's set. It doesn't answer "off
+  for *this repo*."
+- **Claude Code's native per-project plugin disable** (`.claude/settings.json`).
+  Claude-only (not Codex/Copilot/portable) and still a committed repo file.
+
+## When to revisit
+
+If users ask for a *shared*, team-wide per-repo disable, add a committed-file
+mechanism alongside this one (the hook check can honor either) — at that point
+the working-tree-cleanliness trade-off is worth reopening.
diff --git a/skills/debt-ops-disable/SKILL.md b/skills/debt-ops-disable/SKILL.md
new file mode 100644
index 0000000..6a6dadc
--- /dev/null
+++ b/skills/debt-ops-disable/SKILL.md
@@ -0,0 +1,28 @@
+---
+name: debt-ops-disable
+description: Turn debt-ops off (or back on) for the current repo. Run ONLY when the user explicitly asks to disable, turn off, silence, or re-enable debt-ops here — never auto-invoke. Flips a per-repo marker in the plugin cache; nothing is written to the working tree.
+---
+
+# debt-ops-disable — turn debt-ops off for this repo
+
+**Run only on explicit user request** ("disable debt-ops here", "turn debt-ops
+off", "re-enable debt-ops"). Do not invoke this as part of normal work.
+
+Call `toggle.py` via Bash. It flips a `disabled` marker in this repo's plugin
+cache dir (ADR 0020). While the marker is present, every hook idles silently —
+no session inject, no write-time feedback, no stop nudge. Nothing lands in the
+working tree, so it never shows up in `git status`.
+
+The marker is per-machine, not committed — it disables debt-ops for *you* in
+*this* repo. The script's stdout IS the confirmation; add no commentary.
+
+## The call
+
+```bash
+# Toggle (or pass `disable` / `enable` to force a direction):
+python3 scripts/toggle.py disable
+python3 scripts/toggle.py enable
+```
+
+Match the user's intent: pass `disable` when they ask to turn it off, `enable`
+when they ask to turn it back on. Omit the argument only when they say "toggle."
diff --git a/skills/debt-ops-disable/scripts/toggle.py b/skills/debt-ops-disable/scripts/toggle.py
new file mode 100644
index 0000000..3e7bf56
--- /dev/null
+++ b/skills/debt-ops-disable/scripts/toggle.py
@@ -0,0 +1,90 @@
+#!/usr/bin/env python3
+"""debt-ops disable toggle: flip the per-repo disable sentinel (ADR 0020).
+
+Writes (or removes) a `disabled` marker in this repo's plugin cache dir. While
+the marker is present every hook idles silently — no session inject, no
+write-time feedback, no stop nudge. Nothing is written to the working tree.
+
+With no argument it toggles; pass `disable` or `enable` to force a direction.
+"""
+
+import argparse
+import hashlib
+import os
+import subprocess
+import sys
+from pathlib import Path
+
+
+def git_toplevel():
+    try:
+        out = subprocess.run(
+            ["git", "rev-parse", "--show-toplevel"],
+            capture_output=True, text=True, check=True, timeout=2,
+        )
+        s = out.stdout.strip()
+        return Path(s) if s else None
+    except (subprocess.SubprocessError, FileNotFoundError):
+        return None
+
+
+def repo_hash(toplevel):
+    return hashlib.sha1(str(toplevel).encode()).hexdigest()[:12]
+
+
+# Single deterministic cache base, shared with the hooks (override DEBT_OPS_CACHE).
+def cache_base():
+    override = os.environ.get("DEBT_OPS_CACHE")
+    return Path(override) if override else (Path.home() / ".cache" / "debt-ops")
+
+
+def parse_args():
+    p = argparse.ArgumentParser(description="Toggle debt-ops for this repo.")
+    p.add_argument("action", nargs="?", choices=["disable", "enable"],
+                   help="force a direction; omit to toggle")
+    return p.parse_args()
+
+
+def main():
+    args = parse_args()
+
+    toplevel = git_toplevel()
+    if toplevel is None:
+        sys.stderr.write("debt-ops: not in a git repo\n")
+        return 2
+
+    cache_dir = cache_base() / "cache" / repo_hash(toplevel)
+    sentinel = cache_dir / "disabled"
+    currently_disabled = sentinel.is_file()
+
+    if args.action == "disable":
+        want_disabled = True
+    elif args.action == "enable":
+        want_disabled = False
+    else:
+        want_disabled = not currently_disabled
+
+    if want_disabled:
+        try:
+            cache_dir.mkdir(parents=True, exist_ok=True)
+            sentinel.write_text("", encoding="utf-8")
+        except OSError as e:
+            sys.stderr.write(f"debt-ops: could not disable: {e}\n")
+            return 1
+        sys.stdout.write("debt-ops disabled for this repo (run again to re-enable).\n")
+    else:
+        try:
+            sentinel.unlink(missing_ok=True)
+        except OSError as e:
+            sys.stderr.write(f"debt-ops: could not re-enable: {e}\n")
+            return 1
+        sys.stdout.write("debt-ops re-enabled for this repo.\n")
+    return 0
+
+
+if __name__ == "__main__":
+    try:
+        sys.exit(main())
+    except Exception as e:
+        sys.stderr.write(f"debt-ops disable: {e}\n")
+        sys.exit(1)