Assemble task context: matching decisions with rationale, approval, owner, sources, last review, and freshness, plus related tests, file impact, and any available map entries. Map verification is rechecked against sampled source contents; stale or unknown verification requires a fresh review, and recordedVerdict preserves the historical verdict. Proposals are suggestions; legacy records are unreviewed; accepted decisions are constraints subject to freshness. No initialization or map required. Pass task and optional files. map.status and diagnostics preserve missing or invalid knowledge. Impact covers up to three unique files, expanding directory anchors.

Trace historical co-change partners, related tests, and references with evidence: resolved imports, explicit paths, or uncertain name candidates. Candidates are not proven dependencies. Deterministic and read-only; no initialization or concept map required.

Return the optional feature-to-file architecture map with drift and trust evidence. Map verification is rechecked against sampled source contents; stale or unknown verification requires a fresh review, and recordedVerdict preserves the historical verdict. If no map exists, returns exists:false and points to decision context. Decision capture, get_context, and get_impact still work. No initialization required.

Inspect installed automation, observed host events, pending decision records and the notification baseline, or check all retained documentation findings across sessions. status is read-only; check saves local baselines and verification reports without editing source, approving advisories or consuming pending completion notices. Returns concise results with a full report path. Works without a map.

Check how far the concept map has drifted from HEAD. Deterministic (git + filesystem, no LLM). Returns which features/flows are stale and the changed files behind them, new source files not yet mapped, ghost files (mapped but deleted), renames, and a recommendation: up-to-date (nothing to do), incremental (update just the stale entries via save_snapshot), or full-rebuild (broad source review required). Call this before trusting the map in a long session, or when maintaining an existing map.

Record assistant instruction setup locally in ignored .mason/local/project.json, with feature settings in shared .mason/config.json. Other tools work without this marker. Repeated calls preserve the original setup time and existing settings.

Inspect this project now: returns documentation audit findings, committed-diff review findings, decision/map status, and a quickstart playbook. Quickstart is read-only and deterministic. Explicit mode: setup validates shared configuration and activates locally without editing shared files; mode: init explicitly prepares MCP, instructions and lifecycle hooks for review and commit. Neither runs audits or prepares repairs; use only when requested. Optional host selects codex or claude. Optional base selects the review comparison; evidence imports CI manifests with check outcomes, commit freshness, and links to changed files and accepted decisions. Repeat calls refresh findings even after setup.

Prepare a decision review: returns the claim and any operative accepted revision, provenance, the latest inspection and history event (notes shortened), changed files with hunk and line counts and anchor commits since the latest valid inspection for both sets of anchors, and a reviewToken. Request the diff (optionally for specific diffFiles), source previews or full history with include; the token is unchanged. For accepted-guidance inspection use inspectionScope operative on both prepare and inspect; pending proposals remain unassessed. Default all scope covers both revisions. After source inspection, record inspect with inspector, note and token to report no contradiction found without human acceptance. For human review, prepare with all scope, then record accept, reaffirm, or retire with its token, the authorized reviewer, and a reason. Acceptance replaces the operative revision; retirement withdraws the entire record including its proposal. Acceptance requires owner, source, readable Git HEAD, and committed anchor changes. Changed records or code invalidate the token. Identities and approvals are recorded assertions for normal PR review, not authenticated proof.

Capture or revise a decision proposal as soon as the lesson is supported by evidence, without waiting for implementation or merge. Keep unimplemented remedies tentative. Include rationale, anchors, optional owner, sources, and a known actor. Compare matching get_context records and pending proposals before saving. When new evidence changes the same lesson's assumptions, scope, or recommended action, pass its existing id, including for accepted records. Preserve supported rationale and sources and replace obsolete instructions. Create a new record for a genuinely distinct lesson; skip unchanged restatements. No setup or map required. Writes a local record and preserves content history. Changes create a pending proposal while the last accepted revision remains operative; unchanged content does not re-verify or refresh it. Use review_decision for authorized acceptance or reaffirmation. A proposal cannot supersede a record with an operative accepted revision; review its replacement and retire the original separately.

Save a concept-to-files map as a persistent project snapshot. Maps feature names and data flows to the files that implement them. Retained for direct maintenance of legacy maps; the managed map-build workflow has been removed. Persists across conversations — future sessions can call get_snapshot to instantly find relevant files. No API key needed — you are the LLM generating the map.

Record verify_snapshot verdicts using each entry’s kind and reviewToken. Missing tokens request a fresh review; changed or deleted entries return conflicts without being stamped. Entries judged ok are stamped verifiedAt; failures are flagged verificationFailed with your note and surface in get_context, get_snapshot, and mason_check_drift until corrected. Verdict notes are required for failures.

Spot-check the concept map's CORRECTNESS (drift checks freshness; this checks entries were right to begin with). Returns a sample of entries — always the never-verified and least-recently-verified first — with skeletons of their claimed files, for you to judge whether the files actually implement what the entry claims. Report verdicts back via save_verification with each entry’s kind and reviewToken. Tokens bind the entry and bounded source evidence; changed evidence requires a fresh review. Run periodically, or after an automated refresh wrote entries no human reviewed.