# BAT-007 Planning

## Scope

- Implement REQ-007: MCP response contract versioning governance.
- Implement REQ-008: representative contract regression and lint required checks.
- Preserve existing success response shapes; runtime `contract_version` remains unexposed.
- Use synthetic/temp data only for tests and evidence.

## Dependencies

- dcy-007 confirmed Discovery and approved REQ-007/REQ-008.
- Existing BAT-006 CI workflow and synthetic fixture policy.
- Existing service-layer functions that accept `db_path` for temp fixture tests.

## Work plan

1. Add BAT-007 standard batch docs and index entry.
2. Add contract version `1.0` governance and CI required-check contract to baseline docs.
3. Add representative contract snapshot metadata and pytest regression for health/status, list, report, and mutation success envelope scopes.
4. Add `ruff` dev dependency/config and CI `lint`/`contract-regression` jobs while preserving existing job names.
5. Run narrow local verification: contract pytest, ruff, targeted regression that includes the new test, then full pytest if narrow gates pass.
6. If evidence satisfies ACs, move REQ-007 and REQ-008 to Implemented.

## Risks and mitigations

- Over-strict snapshot failures: mitigate by required-subset/type checks so optional additive fields pass.
- Existing code lint churn: mitigate by conservative initial `ruff` rule set (`E9`, `F`).
- Branch protection cannot be toggled from code: document as external operator setting and keep stable job names.