Context Check Agent Skill

context-check

An optional, on-demand drift audit for bypass cases: a merge or an external

edit drifted a tracked source file you are not about to commit, so commit-gate's

Phase 5.5 auto-heal did not fire. This skill reports stale docs and lets you

act on each one individually.

This skill is NOT in the daily loop. Commit-gate auto-heal (Phase 5.5,

heal_worklist) owns the routine maintenance path. Invoke this only when drift

was introduced outside a commit (e.g. a direct push, a merge you did not

author, a manual file edit).

Pre-flight

Read these before computing drift:

• .codearbiter/.provenance/ — the per-doc provenance records. Load all

records via load_provenance_dir from

${CLAUDE_PLUGIN_ROOT}/hooks/_provenancelib.py.

• .codearbiter/code-map.md — coarse concern map; read to orient on which

modules the stale docs govern.

Flow

Step 1 — Compute drift

Use _provenancelib helpers in this order:

• load_provenance_dir(root + "/.codearbiter/.provenance/") — returns the

provenance map {doc: record}.

• Collect all drift_trigger: true paths across all records.
• batch_hash(paths, runner) — hash every existing path in one git call.
• compute_drift(provenance_map, current_hashes) — returns a drift report

{doc: [{path, kind}]} for docs that have stale sources.

Alternatively reuse the same logic as startup_drift_line by calling it for

a human-readable summary, then inspecting compute_drift directly for detail.

If the drift report is empty: report "no stale docs — provenance is fresh"

and exit. No further action required.

Step 2 — Report stale docs

For each doc in the drift report, call changed_scope(doc_provenance, drift)

to list its drifted paths. Present a concise report before offering actions:

Stale docs (N):
  <doc>: <path1>, <path2>  (changed | missing)
  ...

Step 3 — Per-doc action loop

For each stale doc, present three choices and wait for the user to select one:

re-scout — dispatch an incremental re-scout of the drifted paths for this

doc, scoped to those paths only (like commit-gate Phase 5.5 heal but manually

invoked). The scout re-reads the changed paths and reports whether claims still

hold. If claims still hold: silently re-baseline the hashes via rebaseline.

If claims changed: surface the proposed doc edits for the user to accept before

re-baselining.

re-baseline — acknowledge the drift without re-scouting: call

rebaseline(provenance, current_hashes) to update the stored hashes silently.

Use this when the source change is cosmetic (formatting, comments, whitespace)

and the derived doc claims are still accurate.

defer — do nothing for this doc now. The drift line will reappear at the

next SessionStart. Use when the change is in-progress and the doc update should

wait for a later commit.

After processing all stale docs, summarize which docs were re-scouted,

re-baselined, or deferred.

Hard rule

This skill MUST NOT commit. If re-scout or re-baseline produces updated

.codearbiter/.provenance/ records, those file changes ride the next

user-initiated commit through commit-gate normally. No staging, no commits here.