Proof Loop

Multi-agent sprint protocol that prevents AI coding agents from declaring done without proof. Enforces spec freeze before build, role-separated subagents (builder never verifies own work), explicit acceptance criteria (AC1, AC2...), and durable verdict artifacts in the repo. Use when briefing agents on any non-trivial coding task, sprint, or feature where you need verifiable proof of completion. Works with Codex, Claude Code, OpenClaw subagents, or any multi-agent setup.

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.

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"

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.