interlocks 0.1.4

Zero-config Python quality interlocks: lint, format, typecheck, test, coverage, acceptance, audit, deps, architecture, complexity, CRAP, mutation — all behind `interlocks <task>` (or `il <task>`).

interlocks

For DevEx and platform teams standardizing Python quality across repositories:

cd your-python-project
uvx --from interlocks interlocks doctor  # try without installing
pipx install interlocks                  # or: uv tool install interlocks
interlocks setup                         # local hooks, agent docs, Claude skill
interlocks check                         # local edit loop
interlocks ci                            # CI parity

interlocks gives one local/hook/CI command surface for ruff, basedpyright, coverage.py, mutmut, deptry, import-linter, pip-audit, and lizard, while driving the project's pytest/unittest tests and pytest-bdd or behave acceptance suite when available. New repositories can start with auto-detected paths and bundled tool defaults; mature repositories can opt into named presets or explicit [tool.interlocks] thresholds when they need stronger gates.

Who This Is For

Use interlocks when you want one deterministic Python quality loop across a repo or an organization, especially when local checks, CI, and agent-authored PRs are drifting apart.

It is not a hosted dashboard, a polyglot quality platform, or a replacement for project-owned tests. It standardizes the repeatable Python gates so humans and agents review against the same evidence.

First-Run Adoption Loop

1. Install

pipx install interlocks
# or
uv tool install interlocks

The core quality tools ship with the CLI. Project-owned test runners and acceptance runners are invoked when the target repo already uses them.

2. Install Local Integrations

cd your-python-project
interlocks setup
interlocks setup --check

setup idempotently installs local feedback loops: git pre-commit hook, Claude Code Stop hook, AGENTS.md / CLAUDE.md interlocks block, and bundled Claude skill at .claude/skills/interlocks/SKILL.md. setup --check is read-only and exits non-zero when any local integration is missing or stale.

3. Diagnose Readiness

interlocks doctor

doctor performs static local inspection only: nearest pyproject.toml, detected source/test/features paths, runner, invoker, active preset, resolved gate values, PATH visibility, blockers, warnings, local integration state, and shortest next steps. It does not run tests, typecheck, coverage, mutation, dependency audit, or network checks.

If the repository is ready, doctor points you at interlocks check and CI wiring. If it is blocked, it prioritizes the minimum setup fixes first, such as interlocks init, missing paths, unreadable config, unsupported presets, or missing runnable tool resolution.

4. Run Local Checks

interlocks check

check runs the local edit loop: fix, format, typecheck, tests, optional acceptance tests, advisory dependency hygiene, cached CRAP feedback when fresh coverage exists, and the suppressions report. It is the command to run after edits before pushing.

5. Wire CI

The direct CI command is:

interlocks ci

For GitHub Actions, copy this workflow:

name: interlocks

on:
  pull_request:
  push:
    branches: [main]

jobs:
  interlocks:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: 0xjgv/interlocks@v1

The reusable action installs interlocks, runs interlocks ci, and writes a concise GITHUB_STEP_SUMMARY when GitHub provides the summary file. The action does not duplicate lint, typecheck, coverage, CRAP, dependency, architecture, acceptance, or mutation logic; the CLI remains the source of truth.

Why This Matters for AI-Authored Code

When agents write most of the PRs, human review stops being the quality floor. Deterministic gates become the part that scales:

• crap catches complex code the agent shipped without matching tests.
• mutation catches tests the agent wrote that do not actually test the code.
• coverage and complexity trends feed drift telemetry — signal that agent output is regressing before users notice.
• trust combines those into one actionable report, so reviewers (human or LLM-based) have a stable ground truth.

interlocks is complementary to LLM-based reviewers such as CodeRabbit, Greptile, or Diamond. They catch style, design, and intent. interlocks catches what is machine-verifiable: complexity, coverage, mutation survival, dependency hygiene, architectural drift. Runs in seconds, same command locally and in CI.

Before Interlocks

Python quality often accretes as scattered Ruff, pyright, pytest, coverage, deptry, pip-audit, import-linter, and mutmut config. Local checks drift from protected-branch checks, and agent-written tests can look green while missing behavior. interlocks turns that sprawl into one repeatable gate with explicit thresholds and closure commands.

Adoption Presets

Presets are optional defaults under [tool.interlocks]. Explicit values in the same layer override preset defaults, so you can manually tune thresholds in pyproject.toml after choosing a preset.

[tool.interlocks]
preset = "baseline"  # "baseline" | "strict" | "legacy"

• baseline lowers first-adoption friction: advisory CRAP, relaxed thresholds, mutation off in CI, acceptance off in check.
• strict is for mature repositories: stronger thresholds, blocking CRAP and mutation, mutation in CI, acceptance in check, and required Gherkin coverage.
• legacy is for ratcheting existing repositories: very permissive thresholds, advisory gates, mutation off in CI.

agent-safe is intentionally unsupported. If configured, interlocks doctor reports it as an unsupported preset instead of resolving agent-specific defaults.

Configuration

Nothing is required. interlocks walks up from CWD to the nearest pyproject.toml and auto-detects:

• project root: first directory with pyproject.toml
• test runner: pytest if pytest config or declared deps are present, otherwise unittest
• test dir: first existing of tests/, test/, src/tests/
• source dir: build-backend declarations, package layouts, src/<pkg>, top-level packages, or the project root
• test invoker: uv run when uv.lock exists, else python -m
• features dir: first existing of tests/features/, features/, <test_dir>/features/

Override anything via [tool.interlocks] in pyproject.toml:

[tool.interlocks]
preset = "baseline"

# Paths / runners
src_dir = "mypkg"
test_dir = "tests"
test_runner = "pytest"            # "pytest" | "unittest"
test_invoker = "python"           # "python" | "uv"
pytest_args = ["-q", "-x"]

# Thresholds
coverage_min = 80
crap_max = 30.0
complexity_max_ccn = 15
complexity_max_args = 7
complexity_max_loc = 100
mutation_min_coverage = 70.0
mutation_max_runtime = 600
mutation_min_score = 80.0

# Gate behavior
enforce_crap = true
run_mutation_in_ci = false
enforce_mutation = false
mutation_ci_mode = "off"          # "off" | "incremental" | "full"
mutation_since_ref = "origin/main"

# Acceptance
acceptance_runner = "pytest-bdd"  # "pytest-bdd" | "behave" | "off"
features_dir = "tests/features"
run_acceptance_in_check = false
require_acceptance = false        # true → fail stages when no Gherkin scenarios are present

# Evaluation policy / cached evidence
evaluate_dependency_freshness = false
# Explicit freshness check; not part of default PR CI.
dependency_freshness_command = "interlocks deps-freshness"
dependency_freshness_stage = "interlocks nightly"
audit_severity_threshold = "high"  # "low" | "medium" | "high" | "critical"
pr_ci_runtime_budget_seconds = 0
pr_ci_evidence_max_age_hours = 24
ci_evidence_path = ".interlocks/ci.json"

Precedence, lowest to highest:

1. Bundled dataclass defaults.
2. Project preset defaults from [tool.interlocks].
3. Project explicit values.
4. CLI flags inside tasks, such as --min=, --max=, --max-runtime=, --min-score=, and --min-coverage=.

Run interlocks help to see the active preset and resolved values. Run interlocks presets to see preset options, their main thresholds, and copyable config. Run interlocks presets set baseline to set a project preset from the CLI.

Stages

Stage	When	What runs
interlocks check	Local edit loop	fix -> format -> parallel(typecheck, test, acceptance when opted in) -> deps advisory -> cached CRAP advisory or refresh hint -> suppressions
interlocks pre-commit	Git pre-commit hook	fix/format staged Python files, re-stage, typecheck, tests when source changed
interlocks ci	Pull requests and protected branches	format-check, lint, complexity, audit, deps, typecheck, coverage, arch, acceptance -> CRAP -> optional mutation (per mutation_ci_mode); writes .interlocks/ci.json timing evidence
interlocks nightly	Scheduled jobs	coverage -> audit (warn-skips on transient pip-audit failures) -> mutation, always blocking on mutation_min_score
interlocks post-edit	Editor/agent hook interface	advisory ruff fix + format on changed Python files
interlocks setup	Local onboarding	installs/checks hooks, agent docs, and Claude skill
interlocks setup-hooks	Narrow hook installer	writes hooks that call interlocks pre-commit and interlocks post-edit
interlocks clean	Local cleanup	removes caches, build artifacts, coverage output, mutation state, and __pycache__/

interlocks pre-commit and interlocks post-edit are the stable hook interfaces. interlocks setup is the default local onboarding command. interlocks setup --check verifies hooks, agent docs, and the Claude skill without writing. Narrow commands (setup-hooks, agents, setup-skill) remain available as escape hatches.

mutation_ci_mode picks how interlocks ci invokes mutmut:

• "off" — skip mutation in CI (default; run_mutation_in_ci = true legacy flag still forces a full run)
• "incremental" — mutates only files changed vs mutation_since_ref (default origin/main); fast PR signal — runtime scales with PR diff. Empty diff is a clean skip.
• "full" — full mutmut suite

Nightly always runs the full suite + score gate, so PRs trade some signal for speed; the scheduled job catches anything the incremental pass misses.

Tasks Reference

Correctness:

• fix / format: ruff lint-fix and format, mutating files.
• lint / format-check: read-only equivalents for CI.
• typecheck: basedpyright.
• test: pytest or unittest, auto-detected.
• acceptance: Gherkin via pytest-bdd or behave. When require_acceptance = true, registered public behavior IDs must be covered by runnable scenarios.

Hygiene:

• audit: pip-audit CVE scan; audit_severity_threshold makes high-severity policy explicit in evaluate.
• deps: deptry unused, missing, and transitive import checks.
• deps-freshness: explicit package-index check for outdated dependencies; not part of default PR CI.
• arch: import-linter contracts; default contract forbids source importing tests.

Advanced gates:

• coverage --min=N: coverage.py with fail-under. --min=N overrides coverage_min. uv-managed projects get Coverage.py injected via uv run --with; no project dep required.
• crap --max=N [--changed-only]: CRAP complexity x coverage gate. Blocking depends on enforce_crap.
• mutation --max-runtime=N [--min-coverage=N] [--min-score=N] [--changed-only]: mutmut. Advisory unless enforce_mutation = true or --min-score= is passed.
• trust [--refresh] [--no-trend]: actionable trust report combining coverage, CRAP, mutation, suspicious-test AST inspection, recent git diff, and next actions. --refresh runs coverage first with --min=0.
• evaluate: static quality checklist scoring 11 automatable checks (acceptance, unit-tests, coverage, mutation, complexity, deps, deps-freshness, security, audit-severity, pr-speed, ci) for a 0–33 verdict. Reports gap-closure command, task/stage kind, and rationale without running tests, audits, mutation, or package-index lookups. Three checks read explicit policy: evaluate_dependency_freshness (deps-freshness), audit_severity_threshold (audit-severity), pr_ci_runtime_budget_seconds + .interlocks/ci.json (pr-speed).

Scaffolding:

• init: writes a greenfield pyproject.toml, tests/__init__.py, and tests/test_smoke.py; refuses to overwrite.
• init-acceptance: writes a working pytest-bdd example under tests/features/ and tests/step_defs/; refuses to overwrite.

Utility:

• config: list every [tool.interlocks] key with type, default, description, and current resolved value (read-only). Single source of truth for agents driving setup.
• doctor: adoption diagnostic. Exempt from the pyproject.toml preflight gate.
• setup: install hooks, agent docs, and Claude skill. setup --check verifies them read-only.
• help: command list plus detected paths, active preset, and thresholds.
• presets: show preset options, current values, copyable config, and set a project preset with interlocks presets set <preset>.
• version: print the installed interlocks version.

Acceptance Tests

Drop .feature files under tests/features/ and step definitions under tests/step_defs/; interlocks acceptance runs them via pytest-bdd and shares coverage with test. Or run interlocks init-acceptance for a working example.

Behavior coverage uses explicit IDs for observable public behavior. For interlocks itself, IDs live in interlocks/behavior_coverage.py near public-boundary inventory entries. Downstream projects with no registry keep zero-config behavior.

Mark scenarios with either syntax immediately above Scenario or Scenario Outline:

# req: task-coverage
@req-stage-ci
Scenario: quality gates run
  Given a project

Multiple IDs may attach to one scenario. Comments or tags inside scenario steps do not count. Under require_acceptance = true, runnable projects fail when a live behavior ID is uncovered, a scenario marker is stale, or duplicate live IDs exist. Remediation names the behavior ID and suggests adding # req: <id> or @req-<id>.

Advisory trace evidence is separate from behavior markers. Set INTERLOCKS_ACCEPTANCE_TRACE=1 to request runtime public-symbol evidence; trace failures, missing evidence, or newly untraced symbols are diagnostic-only in this release and do not change acceptance, ci, or check exit codes.

Runner detection order:

1. acceptance_runner in config ("pytest-bdd", "behave", or "off").
2. Behave layout: features_dir/steps/ plus features_dir/environment.py.
3. behave declared as a dependency but not pytest-bdd.
4. Default to pytest-bdd.

Acceptance always runs in interlocks ci when a features directory exists. It is opt-in for interlocks check via run_acceptance_in_check = true. Set require_acceptance = true under [tool.interlocks] to make missing Gherkin scenarios and missing behavior markers stage failures; the strict preset enables this by default. check enforces only when run_acceptance_in_check = true.

Bundled Tool Defaults

When the target project has no config for a given tool, interlocks injects its bundled default.

File	Consumed by	Detected via	Injected flag
ruff.toml	fix, format, lint, format-check	[tool.ruff], ruff.toml, .ruff.toml	--config
pyrightconfig.json	typecheck	[tool.basedpyright], pyrightconfig.{json,toml}	--project
coveragerc	coverage	[tool.coverage.*], .coveragerc	--rcfile=
importlinter_template.ini	arch	[tool.importlinter], .importlinter, setup.cfg	formatted tempfile plus --config
bdd_example.feature	init-acceptance	none	direct copy
bdd_test_example.py	init-acceptance	none	direct copy
bdd_conftest.py	init-acceptance	none	direct copy
agents_block.md	setup, agents	existing interlocks doc reference	appended/created
skill/SKILL.md	setup, setup-skill	byte match at .claude/skills/interlocks/SKILL.md	direct copy
scaffold_pyproject.toml	init	none	read plus {project_name} substitution
scaffold_test_example.py	init	none	direct copy

interlocks deps and interlocks mutation ship no bundled fallback: deptry applies its built-ins, and mutmut reads the project's pyproject.toml.

Hooks

Use the stable hook interfaces directly when integrating with your own hook manager:

interlocks pre-commit
interlocks post-edit

Use the default local onboarding command when you want interlocks to write common integrations:

interlocks setup
interlocks setup --check

It installs:

• .git/hooks/pre-commit: runs interlocks pre-commit. Skip with git commit --no-verify when necessary.
• .claude/settings.json Stop hook: runs interlocks post-edit after Claude Code sessions and preserves existing Stop hooks.
• AGENTS.md / CLAUDE.md: appends the interlocks guidance block when no interlocks reference exists.
• .claude/skills/interlocks/SKILL.md: installs the bundled Claude skill.

interlocks setup --check verifies those same artifacts without writing. Use interlocks doctor for full project readiness. Narrow commands (setup-hooks, agents, setup-skill) remain available when you want one integration only.

Hooks reference the Python that installed interlocks, so rerun interlocks setup after switching install locations or interpreters.

Crash Reporting

When interlocks itself crashes, the CLI prints a pre-filled GitHub Issues URL to stderr alongside the canonical Python traceback. The URL opens in your default browser if one is available; the URL on stderr is the contract, browser-open is convenience. interlocks never opens a network connection of its own — only your browser does, only if you choose to follow the link.

What gets captured:

• interlocks version, Python version, platform (uname -s/uname -m)
• subcommand that crashed (e.g. check, lint)
• exception type name
• traceback frames inside interlocks/ (third-party frames collapse to <external frames: N>)
• UTC timestamp, CI boolean (from CI env), 16-hex fingerprint

What does NOT leave the machine — by construction:

• No source code, file contents, or local variables
• No environment variables or sys.argv values
• No hostnames, usernames, or absolute paths (paths are scrubbed to ~/... or project-relative)
• No automatic HTTP requests — socket, urllib.request, http.client, requests, httpx are forbidden in interlocks/crash/transport.py and enforced by an introspection test

How to opt out:

[tool.interlocks]
crash_reports = "off"

Or per-invocation: INTERLOCKS_CRASH_REPORTS=off interlocks <command>. The env var beats config; config beats the default. The default ("auto") suppresses the URL on CI and surfaces it locally.

Where local files live:

• ~/.cache/interlocks/crashes/<fingerprint>.json — full payload, mode 0600 in mode 0700 dir
• ~/.cache/interlocks/crashes/dedup.json — 30-day fingerprint window so repeat crashes do not re-prompt

Inspect cache state any time with interlocks doctor (look for the [crash reports] row) or directly with ls ~/.cache/interlocks/crashes/.

To share a crash manually, attach the payload JSON to your issue or paste relevant fields. The same fields are pre-filled in the URL body the browser opens.

Inspiration

Inspired by Uncle Bob Martin. Since Clean Code, we tend to forget the fundamentals — clean code, deterministic gates, fast feedback. These fundamentals are back stronger than ever, especially as agents write more of the code.

Maintainer Release Process

Maintainer-only release details live in PYPI_RELEASE_CHECKLIST.md.

Package identity:

• PyPI distribution: interlocks
• import package: interlocks
• CLI command: interlocks

Trusted Publishing setup:

• PyPI: owner 0xjgv, repo interlocks, workflow release.yml, environment pypi
• TestPyPI: owner 0xjgv, repo interlocks, workflow release.yml, environment testpypi
• No PyPI API token required.

Release checklist:

1. Set pyproject.toml version to the next release.
2. Set interlocks/__init__.py __version__ to the same release.
3. Update CHANGELOG.md for the release.
4. Run uv run interlocks ci.
5. Run uv build.
6. Trigger release manually to publish to TestPyPI.
7. Create matching vX.Y.Z tag.
8. Push tag.
9. Confirm PyPI release, GitHub release assets, and attestations.

See CHANGELOG.md for release history.