ai-agents-change-control

name	ai-agents-change-control
description	Change control for this repo. Classify a change (docs-only, investigation-only, code, plugin content, hook, workflow, ADR governance), map each class to the gates it triggers, and hold the non-negotiables with the incident behind each rule. Use when you say `classify this change`, `what gates does this change trigger`, `which rules are non-negotiable`. Do NOT use for producing test evidence (use `ai-agents-validation-and-qa`) or incident history (use `ai-agents-failure-archaeology`).
version	1.0.0
license	MIT

AI Agents Change Control

How a change moves through this repository, and the rules that never bend. This repo runs verification-based enforcement, not trust-based. The protocol states it directly: "Labels like 'MANDATORY' or 'NON-NEGOTIABLE' are insufficient. Each requirement MUST have a verification mechanism" (.agents/SESSION-PROTOCOL.md:36). Every rule below therefore names two things: the gate that enforces it, and the incident that created it. If you are tempted to argue with a rule, read its incident first.

Jargon used once: a "gate" is an automated check that blocks progress (commit, push, or merge) until satisfied. A "drift gate" compares generated output trees against their canonical sources. A "canonical source" is the single tree you are allowed to edit; everything generated from it is read-only output.

Triggers

• classify this change
• what gates does this change trigger
• which rules are non-negotiable
• why does this gate exist

Process

Phase 1: Classify the change

Every change belongs to at least one class. A mixed change inherits the union of all its classes' obligations. Classify against the working tree, not against your intent: one staged file in a stricter class pulls the whole change up.

Class	You touched	Marker or obligation
Docs-only	Markdown prose only; no code, no generated trees	QA evidence row SKIPPED: docs-only (case-insensitive; ADR-034 cites it as the pre-existing pattern)
Investigation-only	Nothing outside the ADR-034 allowlist (below)	QA evidence row SKIPPED: investigation-only
Code	Python, scripts, tests, libs	Full QA evidence per .agents/governance/TESTING-RIGOR.md; see ai-agents-validation-and-qa
Plugin content	Anything under .claude/, src/claude/, or src/copilot-cli/	No manifest edit. The .claude-plugin/plugin.json files carry no version; Claude Code resolves freshness from the commit SHA (ADR-092)
Git hook configuration	lefthook.yml	Named-job validation and relevant validator tests
Claude lifecycle hook	.claude/hooks/**, hook generators	Dual-registration sync; runtime-contract tests; scripts/validation/validate_hook_anchoring.py
Workflow	.github/workflows/*.yml	No logic in YAML (ADR-006); SHA-pinned actions; run changed workflows before push (AGENTS.md Always list)
ADR / governance	Any ADR-*.md or SESSION-PROTOCOL.md create or edit	Fires the adr-review multi-agent debate gate (AGENTS.md "ADR Review"); governance changes need human approval plus an ADR

The OPERATIVE investigation-only allowlist is the enforcement module scripts/modules/investigation_allowlist.py (docstring: "Single source of truth for investigation artifact path patterns"; consumed by validate_session_json.py, the session skill, and validate_investigation_claims.py). It allows 8 patterns as of 2026-07-30 (display form from get_investigation_allowlist_display()):

• .agents/sessions/ (session logs)
• .agents/analysis/ (investigation outputs)
• .agents/retrospective/ (learnings)
• .serena/memories/ (cross-session context)
• .agents/security/ (security assessments)
• .agents/memory/ (memory artifacts)
• .agents/architecture/REVIEW-* (review artifacts)
• .agents/critique/ (critique outputs)

Former divergence, now closed: the ADR-034 text (.agents/architecture/ADR-034-investigation-session-qa-exemption.md:78-87) once listed only the first 5 paths, and #2958 reconciled it to the same 8 the module enforces. The code list is still what the gate enforces, so re-check the module rather than the ADR when they disagree.

One staged file outside the enforced list voids the exemption. The session then needs real QA evidence, or you split the work into two sessions.

Special case, generated trees. src/vs-code-agents/ and src/copilot-cli/agents/ are generated from templates/agents/*.shared.md. The .github/instructions/ tree and most of src/copilot-cli/ are generated from .claude/ sources. Never hand-edit a generated tree; edit the canonical source and regenerate (the operating procedure lives in ai-agents-generation-and-release, the seam rationale in ai-agents-architecture-contract). The generator enforces one direction itself: build/scripts/build_all.py:962-967 fails the build if any generator writes into .claude/ (REQ-003-010). History note: on 2025-12-15 an agent "fixed" a drift failure by editing the canonical source to match the generated output; the commit was reverted. Drift output shows difference, not direction. Always ask which side is canonical before touching either.

Phase 2: Map the class to its triggered gates

Class	Extra gates it triggers
Docs-only	Scoped markdownlint on changed files; dash prohibition; session log still required
Investigation-only	Staged-file allowlist check in the pre-commit QA validator (ADR-034)
Code	Full test rigor: positive, negative, edge, branch coverage, mocked I/O; coverage floors 100 security / 80 business / 60 docs (AGENTS.md Standards)
Plugin content	Version-field gate at two layers: pre_pr.py wrapping build/scripts/validate_plugin_version_bump.py at pre-push, CI .github/workflows/validate-plugin-version-bump.yml
Hook	Anchoring validator; runtime-contract tests (tests/build_scripts/test_generate_hooks_runtime_contract.py); keep .claude/settings.json and .claude/hooks/hooks.json in sync by hand
Workflow	SHA-pin validation; yamllint style; local workflow run gate in pre-push (SKIP_WORKFLOW_LOCAL_TEST escape exists for unrunnable workflows; semantics in ai-agents-config-catalog)
ADR / governance	adr-review debate to consensus; blocking git_hook_policy.py adr-review Lefthook job
Any canonical-source edit	Drift gates: uv run python build/generate_agents.py --validate and uv run python build/scripts/build_all.py --check; CI mirrors in agent-drift-detection.yml and drift-detection.yml

Drift-gate bypass exists but is not free. [skip-drift-check] anywhere in a commit message on the PR skips agent drift detection (.github/workflows/agent-drift-detection.yml:17). Using it demands a stated reason and human approval; an unexplained bypass marker reads as the session 1187 escape-hatch abuse pattern (told in references/incident-history.md) and will be challenged in review.

Phase 3: Run the gates, local to CI

The gate ladder runs in feedback-cost order: pre-commit beats CI beats code review beats documentation, so catch violations at rung 1 (uv run python scripts/validation/pre_pr.py, --quick skips slow checks), not rung 4 (CI round-trip plus reviewer attention). Local hooks fire only after Lefthook is installed: uv run --frozen lefthook install --reset-hooks-path, then verify with uv run --frozen lefthook check-install. Commit-discipline caps: 5 files or fewer per commit, 20 commits per PR, or 40 when the branch merges main, blocking only above that cap (warn at 10, alert at 15, via git rev-list --count HEAD ^origin/main), and scope markdownlint to changed files only.

The full four-rung ladder (shift-left runner, pre-commit, pre-push, CI required checks with their exact commands and exit codes), the commit-discipline enforcement points, and the PR #908 story that set the caps are in references/gate-ladder.md. Consult it before your first push in a session.

Phase 4: Hold the non-negotiables

Check this table before any push. The incident column is the answer to "why"; do not re-litigate settled incidents in PR threads (deep history lives in ai-agents-failure-archaeology). If you believe you have new evidence against a rule, propose an ADR, which itself fires adr-review.

Rule	Enforcement mechanism	Incident / rationale
No new bash scripts; Python for all new scripts	Review + .claude/rules/universal.md SHOULD 3 ("MUST NOT create new bash scripts")	ADR-042 (Accepted)
No logic in YAML workflows	ADR-006 + .claude/rules/universal.md MUST NOT 4	Workflow YAML cannot be tested locally. Amendment 2026-04-28 allows pure config-data YAML under 7 conditions in templates/platforms/ and build/ only; run: block logic stays banned
No em or en dashes in authored text	validate_dash_prohibition (scripts/validation/checks_dash.py via pre_pr.py) + dash-guard hook; tests/hooks/fixtures/ exempt	.claude/rules/universal.md MUST NOT 5: bot reviewers open one or more threads per dash, every PR (Issue #1923)
SHA-pin all GitHub Actions	Pre-commit hook + workflow validation (.agents/governance/PROJECT-CONSTRAINTS.md:162)	Tags are mutable, so pinning blocks supply-chain tag-moving. Operative rule: pin everything unless a human explicitly approves the GP-006 first-party actions/* tag allowance, and disclose the tension in your PR description when you hit it. Fuller writeup in references/incident-history.md
Generated and released hook artifacts fail closed and loud (ADR-066 D1, ADR-071). Scoped, not blanket: push guards fail open on infrastructure errors by design (.claude/hooks/PreToolUse/push_guard_base.py docstring); repo-wide audit tracked in #2271. Per-family table: ai-agents-architecture-contract Phase 3	validate_hook_anchoring.py, runtime-contract tests, named Lefthook jobs, and CI enforcement	#2205 customer wedge; policy reversal in the incident history
No version field in any plugin manifest or marketplace entry	pre_pr.py + validate-plugin-version-bump.yml	ADR-092: the field pins freshness to a hand-bumped string and conflicts across every concurrent PR (issue #4080 measured 14 of 22)
Block-style YAML arrays only in frontmatter	.agents/governance/PROJECT-CONSTRAINTS.md:224 ("Exceptions: None")

Escape hatches (env vars, commit markers, skip semantics) exist for several gates. They are deliberately narrow after session 1187, and each is cataloged with its abuse story in ai-agents-config-catalog. Do not invent a new one inline; a new flag is itself a governance change.

Six of the table's incidents compress a multi-round failure and are told in full in references/incident-history.md: the #2205 fail-closed reversal, the PR #1942 stale-cache plugin bump, the session 1187 escape-hatch abuse, FM-9 and PR #1887 verbatim quoting, FM-10 and PR #1965 silent defaults, and the SHA-pinning tension. The other rationale cells are briefer. Read the incident before you argue with its rule.

Anti-Patterns

Anti-pattern	Why it fails here
Editing a generated tree to silence a drift gate	Inverts the source of truth (2025-12-15 incident, reverted). Ask which side is canonical first
Using [skip-drift-check] or commit-limit-bypass without a stated reason and human approval	Bypass markers are audited; unexplained use reads as the session 1187 pattern
Adding a version back to a plugin.json or marketplace entry	The gate fails on the field's presence (ADR-092). Freshness already tracks the commit SHA, so the field only re-creates the merge conflict it was deleted for
Adding a fail-open wrapper so a broken hook "does not block anyone"	Rejected pattern (#2230, recorded in ADR-071): silent exit 0 disables the hook while looking like success, exactly the #2205 failure
Classifying a mixed session as investigation-only	One staged file outside the ADR-034 allowlist voids the exemption; split the work
Fixing a bot-flagged dash or style claim without byte-level verification	Bots false-positive; count the actual bytes before editing (PR #1873 observation: an em-dash flag on a line with zero em-dashes)
Citing ADR-008/033/035/062 fail-open language for a new hook	Stale; the operative policy is fail-closed and loud (the #2205 reversal, told in references/incident-history.md)
Re-arguing a settled non-negotiable in a PR thread	The incident column is the answer; new evidence goes in an ADR, which fires adr-review

Verification

Before you push, confirm:

• Change classified (Phase 1) and every class obligation from Phase 2 satisfied
• uv run python scripts/validation/pre_pr.py exits 0
• uv run --frozen lefthook check-install exits 0
• Touched .claude/, src/claude/, or src/copilot-cli/? The matching plugin.json still carries no version field (python3 build/scripts/validate_plugin_version_bump.py exits 0)
• Touched a canonical generation source? uv run python build/scripts/build_all.py --check and uv run python build/generate_agents.py --validate both pass
• Commit count under 20 (git rev-list --count HEAD ^origin/main), each commit 5 files or fewer
• Created or edited an ADR or SESSION-PROTOCOL.md? adr-review gate acknowledged
• No em or en dashes in changed files: python3 -c "import sys; b=open(sys.argv[1],'rb').read(); print(b.count(chr(0x2014).encode())+b.count(chr(0x2013).encode()))" FILE prints 0

Provenance and Maintenance

Authored 2026-07-03, facts re-verified against the working tree on 2026-07-30. A selected index of the drift-prone cited source lines, each paired with its re-verify command, is in references/provenance.md. Consult and update it when you edit this skill or any reference it points to.

Maintenance rule: any edit to a cited source line number or ADR status invalidates the matching row. Re-run the re-verify command and update the row in the same commit. This file is plugin content, so regenerate the Copilot mirror (uv run python build/scripts/build_all.py) in the same commit. No manifest bump: the manifests carry no version (ADR-092).