Proof Loop
A sprint is not done until every acceptance criterion has a PASS verdict from a fresh verifier session.
Read references/workflow.md for the full loop spec.
Read references/brief-template.md for the agent brief format.
Read references/artifacts.md for the artifact schema.
Read references/loopsmith-bridge.md when deciding whether a repeated Proof Loop failure should become a Loopsmith eval case.
Activation and Safety Boundaries
Use this skill only when the user explicitly asks for Proof Loop, proof artifacts, acceptance-criterion verification, fresh verifier separation, or an evidence-gated coding sprint. Do not activate it for ordinary code edits where the user did not request this protocol.
Proof Loop may create or update files under .agent/tasks/<TASK_ID>/ in the current repository. Confirm the task id and repository root before creating artifacts. Do not publish artifacts, run remote validation, change repository permissions, moderate users, request full-access sandboxing, or touch credentials unless the user explicitly asks for that separate action in the current conversation.
Run helper scripts with the least privilege available. If a command could modify source files outside .agent/tasks/<TASK_ID>/, ask first and record the command in the evidence artifact.
The Loop
spec freeze -> build -> evidence -> FRESH verify -> fix -> FRESH verify
^ |
|______________________|
(repeat until all ACs = PASS)
Four Roles — Always Separate
| Role | Does | Never |
|---|---|---|
| Spec-Freezer | Writes spec.md with explicit ACs | Edits production code |
| Builder | Implements against frozen spec | Verifies own work |
| Verifier | Fresh session — verdicts each AC | Edits production code |
| Fixer | Minimal fix for what verifier flagged | Signs off on completion |
The verifier is always a fresh session. The agent that built cannot judge its own work.
Acceptance Criteria Format
Every sprint brief must include explicit ACs before build starts:
AC1: [specific, testable condition — not a task description]
AC2: [specific, testable condition]
AC3: [specific, testable condition]
Good: "AC1: A German-locale user sees all prompt form field labels in German" Bad: "AC1: Translate the form fields"
Helper Scripts
Use these when the repository has the proof-loop folder available:
python3 scripts/init_task.py TASK_ID --title "Task title"
python3 scripts/check_task.py .agent/tasks/TASK_ID
check_task.py is the mechanical done gate. It returns success only when the verifier artifacts show every AC as PASS and no open problems remain.
Sprint is DONE Only When
- Every AC has a PASS verdict in the verifier's
verdict.json - No problems remain in
problems.md - Full regression suite passes (if applicable)
Artifacts (stored in repo)
.agent/tasks/<TASK_ID>/
spec.md -- frozen ACs + constraints + non-goals
verdict.json -- AC verdicts per phase (PASS/FAIL/UNKNOWN)
problems.md -- specific failures with file/line refs (if any)
See references/artifacts.md for schemas.