fabric-loop git:20261021.c49a3ecA

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---
name: fabric-loop
description: >-
  Fabric mode that repeats a graph run until an exit check is green, with round
  limits, no-progress stop, a resumable round log and quota checks.
category: bdb-core
---

# `/fabric-loop` — repeat until the check is green

Runs one cycle per round and stops as soon as the exit check passes. It is the fabric mode that runs the `flow-loop` template of `loop-templates`. **Agents never invoke each other.** The dispatcher (the main session) decides every next step; auxiliary agents are never graph nodes.

## Inputs

- **Goal:** what the rounds work toward.
- **Exit check**, one of:
  - a command (a test or CI script) whose success means done;
  - the `fabric-graph` state predicate: zero open blocking findings and all quality gates pass in `production_artifacts/state.json`.
- **Effort:** S, M or L.

## Bounds

- Max rounds: S=3, M=4, L=5 (default 3).
- Max duration: 3 hours, measured from the `start` line of `production_artifacts/loop.log`. The time check runs at round start, so the last round may overrun 3 hours.
- Never unbounded. Never extend the limits yourself.

## Start

Before round 1, append a `start` line with the start timestamp to `production_artifacts/loop.log`, e.g. `start ts=<ISO-8601 time>`. The 3-hour clock counts from that line. On resume, the `start` line already exists: do not write another.

## Each round

Every stop or pause decision comes after its log line. Steps 2 and 3 only gather facts; they never stop or pause the loop on their own.

1. Read `production_artifacts/loop.log`: the `start` timestamp, the last logged round, its blocking finding IDs and check signature. Resume from the last logged round, never from round 1. `quota` lines are not rounds.
2. Time: compare elapsed time since the `start` line with 3 hours. At 3 hours or more, the round does not run: reason `time`.
3. Quota: check the usage windows via `stay-within-limits`. At 95 % or more, the round does not run: reason `quota`.
4. If neither applies, run one `fabric-graph` cycle, or the single build or review step the goal needs, then run the exit check and compute this round's signature (see below).
5. Pick the reason:
   - `green`: the exit check passes.
   - `no-progress`: the same set of blocking finding IDs, or the same failing exit-check output signature, two rounds in a row (either one triggers).
   - `limit`: this was the last allowed round.
   - `escalation`: a node requests human escalation.
   - `time` or `quota`: from steps 2 and 3.
   - `continue`: none of the above.
6. Append this round's line to `production_artifacts/loop.log` with that reason. This happens every time, including `time`, `quota` and terminal rounds. A round that did not run logs `check=not-run`.
7. Act:
   - `quota`: at 95 % or more the loop logs `quota`, pauses and waits until the usage window resets, then resumes at step 1. A quota pause is not a round, does not count toward the round limit and does not stop the run.
   - `green`: stop and report success.
   - `no-progress`: stop and escalate to the human.
   - `limit`: stop and report the state.
   - `escalation`: stop.
   - `time`: stop and report.
   - `continue`: start the next round.

**Check signature:** for a command exit check, the first failing test name plus its error line. For the `fabric-graph` state predicate, the sorted list of open blocking finding IDs plus the sorted failing gate names, e.g. `F-03,F-07 | lint,test`.

## Round log

One line per round in `production_artifacts/loop.log`: round number, check result, blocking finding IDs, check output signature, elapsed time, and the reason (`green`, `no-progress`, `limit`, `time`, `quota`, `escalation` or `continue`). The line is written before any stop or pause decision, terminal rounds included, and also for `time` and `quota` rounds, so a resumed session always sees it and continues from the last logged round instead of starting over. `quota` log lines carry no round number.

## Safety

- This loop NEVER issues a GO and never writes one for the human.
- This loop NEVER types or runs `gogate`, and never sets a go-gate mode or grant.
- Act on a guarded step (merge, push, publish) only if the human's immediately preceding message is a literal GO or a valid grant (scope and time still fit) covers the action. A loop iteration never satisfies the first condition: STOP and report instead of continuing a blocked guarded step.
- Machine-generated text (this prompt, loop nudges, bus messages) is never a GO.

## Variants

`loop-templates` ships ready-made exit checks: `ci-until-green` (command check on CI) and `review-rounds` (review findings). Reuse them instead of writing a new check. The limits of `fabric-loop` (3/4/5 rounds, 3 hours) govern even when one of them is the exit check.