TheColliery Drift Canary (Contract & Schema Drift Audit)
Language: Generate EVERYTHING at runtime in the user's language — questions, answer options, menu labels, recommendations, report narrative. Detect from their messages; never default to English just because this file is English. English is allowed only for technical terms: commands, paths, code identifiers, severity labels (CRITICAL/HIGH/MEDIUM/LOW), and tier names (Light/Standard/Heavy).
Config reads — every config key, always the CASCADE, never the bare project file: ~/.claude/.coalmine.json first, then the project config (own agent dir → other known agent dirs → legacy <gitroot>/.claude/.coalmine.json, then <gitroot>/.coalmine.json), project wins per key. A bare project read is ABSENT on a machine configured only globally, so it silently yields defaults.
Audit code to ensure changes do not break backward compatibility or cause database/API mismatches.
Auditing Categories
- Breaking Schema Migrations — dropping columns, changing types, or adding non-null columns without defaults (crashes on deploy).
- API Contract breaking changes — modifying existing REST/GraphQL properties, removing endpoints, or adding required query fields that break old clients.
- Serialization mismatches — editing properties in serialized payloads (JSON, Protobuf, XML) without deserialization fallbacks.
- Library Contract Drift — changing a public method signature in a shared library without a deprecated wrapper.
- Environment Configuration drift — introducing new required config keys (
.env/ OS vars) without defaults or fallback.
Expand/contract migration rules, per-format serialization fallbacks, and the breaking-vs-additive API checklist: read references/checks.md before scanning.
Scope: honor .coalmine.json schemaPaths / migrationDirs if set — scan those globs/dirs; else infer by inspecting the repo.
Discipline
- Style Drift Resolution (Fix mode): when an approved fix touches mixed-style code, conform the minority patterns to the dominant style (highest average usage) to minimize churn — never start a standalone style refactor.
Fix mode (choice-gated)
In Agent Context, after the report, present via ask_question:
- Apply safe deprecations: mark endpoints/methods deprecated + add backward-compatibility mapping wrappers. Each fix: checkpoint (git stash/commit in a git repo; else copy the file aside — never assume git) → apply → build + tests → auto-revert if newly red.
- Let me pick: user selects specific compatibility fixes.
- Report only: exit unchanged.
Grants & denials (CLASSIFY-BLOCK)
| class | step it powers | grant | on denial |
|---|---|---|---|
| read | scan schema/API/serialization surfaces for the categories above | Read·Grep·Glob |
refuse that file, name it — never a clean bill |
| write | Fix mode's deprecation/compat-wrapper apply, incl. checkpoint → build+tests → auto-revert if newly red | Edit·Bash (checkpoint/build/revert need exec) |
report the fix as NOT applied AND the checkpoint/revert as NOT available, never claim done |
A denial reaches the WORKER as a visible message and propagates no further — never to a caller, never as a catchable condition. Every row above states a grant or an explicit death; a step that dies says so in the output, never as a false "done"/"skipped"/"clean".
- read denied → refuse before scanning; never a false clean bill.
- write denied → report the change as NOT applied — never claim done.
- network denied/unfetchable →
⚠️ unverified: check [source]. - spawn denied → degrade per Escalation's own capability-lever fallback (never fake parallelism) and say the fan-out did not happen — already discharged there; a row above is only for a spawn this skill does OUTSIDE tier escalation.
Output
| file:line | contract interface | severity | finding | migration path |
Severity: CRITICAL (breaking DB schema mutation / breaking API change) · HIGH (serialization type change) · MEDIUM (unmapped new required env key) · LOW (missing deprecation doc)
Reporting: call ReportFindings when callable — file/line MUST be the defect site, never the enclosing function; an unresolvable line reports your best guess, named imprecise in the wrap-up — never dropped, never faked. Severity prefixed in summary (e.g. [HIGH] …), ranked most-severe first, SUSPECTED as verdict: PLAUSIBLE; chat then carries only the wrap-up line (counts · coverage gaps · overflow past 32 · any imprecise-line findings) + the fix menu, never a restatement of findings. Not callable → the table above, unchanged. An Apply-fixes click = consent to the safe-fix class only — gated the same as this skill's own fix-mode (Hook Context needs an interactive session, per the Hook Context rule below) — composing with (never bypassing) the fix-mode discipline. After any fix round, re-report the same findings with outcome: fixed/skipped/no_change_needed — skipping this leaves the round UNFINISHED.
Escalation — Scope & Model Quality
Tiers are capability targets, not platform commands — resolve each to your host's nearest lever. No lever for one? Degrade gracefully — never fake parallelism you can't do; escalate via model tier + reasoning depth instead.
| Level | Intent | Capability target | Cost |
|---|---|---|---|
| Light | Spot contract check, key interfaces only | Cheapest model · single agent, no sub-agents. | Low |
| Standard | Balanced drift audit, multi-category | Balanced model · raised reasoning · sub-agents per category only if your platform runs concurrent workers (else single-agent). | Balanced |
| Heavy | Full 5-category audit + adversarial compatibility verify | Most capable model + largest context · deepest reasoning · max sub-agent fan-out if supported · adversarial cross-check where available. | High |
Per-platform Heavy levers + Heavy-run durability: read references/escalation.md before a Heavy run. No concurrent fan-out on your host → escalate by model + reasoning only.
Agent Context (interactive): score the tier rubric, then call ask_question once with the 3 tiers — the pick marked ✓, score shown, labels localized — and wait for the choice before starting. ask_question = your platform's question tool: Claude Code AskUserQuestion · Cline ask_question · Copilot askQuestions · Gemini CLI ask_user (business-tier product; individual tiers ended 2026-06-18 → Antigravity CLI) · Codex request_user_input · Cursor/Devin Desktop (ex-Windsurf)/Antigravity built-in prompts; none → numbered text menu.
Tier rubric (deterministic): +1 each — ① >20 files or whole-repo/cross-module reach ② >2 of this skill's categories relevant ③ release/security/pre-ship context ④ findings will drive code changes. 0–1 Light · 2–3 Standard · 4 Heavy. Freshness cap: scope already audited ≥Standard this session → cap at Light (re-auditing fresh ground wastes tokens; scope to what changed). Default tier: honor .coalmine.json defaultTier unless the user requests a tier for that run — an explicit request overrides everything.
Hook Context (auto-triggered): auto-Light, no tier question, no sub-agents — report first. Interactive session (a user is present) → follow this skill's own Fix mode section, if it defines one, for what to offer after the report; non-interactive → report-only. Where a Fix mode section exists, never fix without a chosen option.
Entanglement: after the report, if confirmed findings fall in another canary's domain, offer it once via ask_question (one line, max one offer): perf/N+1 → scale-canary · contract/serialization/config → drift-canary · failure-path/retry → resilience-audit · logging/metrics → telemetry-canary · coupling/DI → testability-canary · dependency/CVE → supply-chain-audit · unverified version-sensitive claim → source-grounding · missing/stale rule → gold-standard.
Self error-report: if this skill misbehaves (contradictory instruction, broken procedure, wrong finding class), OFFER to file it at https://github.com/HetCreep/CoalMine/issues/new/choose with a user-reviewed summary — never auto-submit, never include unapproved code or paths.