I2348 — A gate's result is reused only for the exact inputs it judged, and a skipped gate carries the proof that nothing it reads changed

✕BLOCKED wave 1 · p2 · implementation profile · parallel safe

Part of ci-critical-path — The critical path from a change to its verdict, and from a merge to its verified deploy, runs under a minute warm.

Objective

Join the path-class gates and their implications with the affected closure, a cache key, a proof for each skipped gate, integrity of a remote against a local cache, concurrency and precise invalidation, so that a stale verification is never reused.

Why

The plan already skips gates a change cannot affect, by pattern. It keeps no record that would let a later reader, or a merge commit, check that the skip was right, and every refresh of a branch runs the whole selected suite again for inputs it judged an hour before. Source: autopilot prompts/05-performance.md Issue 3 'Reusable CI selection'. Revived on 2026-10-18 from the delivery-packs rescue sweep into ci-critical-path, because its milestone derive-does-only-what-a-change-requires never landed; its dependency on I2324 was dropped, because no record of I2324 exists on master.

Current state

scripts/ci-plan selects gates from path classes in .ai/repo/ci/gates.yaml, escalates an unmatched path to the full plan, and the verdict accepts a skipped gate the plan left out (scripts/ci/verdict). Caches for the toolchain and the built executable are keyed in the workflow (docs/CI.md). No gate result is keyed by its inputs.

Desired state

A gate declares what it reads, as the derive's nodes do. A result is recorded with the digest of those inputs and the gate's own version, as evidence. The plan may substitute a recorded pass only when the digest matches exactly, and it records the substitution with the run it reuses. A skipped gate's row in the verdict names the unchanged digest. The required status and the branch rules are obeyed as before.

Scope

• scripts/ci-plan
• scripts/ci/run-plan
• scripts/ci/verdict
• .ai/repo/ci/gates.yaml
• .github/workflows/validate.yml
• scripts/ci/evidence-collect
• docs/CI.md

Out of scope

• Skipping a gate the branch rules require to report.
• Reusing a result across a changed gate script.

Dependencies

• I2350○READY One gate model names what a local check, a pull request, an integration and a release must run, and no second inventory exists

What waits on this

• I3238✕BLOCKED A pull request runs the cases its change can affect, chosen from what each case declares it reads, and a change of unknown impact runs them all

Acceptance criteria

• A gate whose declared inputs are unchanged is satisfied by its recorded pass, and the verdict shows which run it reused
• Changing one declared input, or the gate's own script, makes the gate run
• A recorded failure is never reused as a pass, and a result older than its inputs is refused
• A gate with no declaration of what it reads is never reused

Validation

• bin/majordomus plan validate
• scripts/ci-plan --check
• MJ_TEST_JOBS=4 bash test/run.sh 26_ci_wiring 94_ci_plan <the cases this issue adds>

Evidence required

• gate_result_reuse_case
• stale_result_refused_case

Evidence

None recorded. Every token above needs a command or an artifact behind it before this issue can be completed; narrative is refused.

Timeline

started

—

verified

—

completed

—

Those three fields, the evidence above and the state of the dependencies are all the status is made of. There is no status field to disagree with them.

Canonical record: .ai/repo/project/issues/I2348.yaml. Read it back with majordomus plan show I2348.