Until now your loop could witness a broken spell but never mend it. Today it earns hands — under the strictest oath in the campaign. A fixer golem may repair only what the sealed evidence witnessed break, with the smallest edit that mends it, and every edit is kept or reverted by a deterministic gate — a score the golem cannot charm, a linter it cannot flatter. And when the evidence is partial? It walks away. In this realm, a golem that does nothing honestly outranks one that does something plausible.

The real-world skills: scoping autonomous write access to witnessed defects, keep/revert gating on machine-checkable signals (never the model grading its own homework), treating the clean no-op as success, and circuit breakers that hand stubborn work to humans instead of looping forever.

🧭 Campaign note: Level 1101 is Machine Learning & AI — where prophecy is studied and, more importantly, where its error bars live. A fixer is applied prophecy; the gate is its error bar.

📖 The Legend Behind This Quest

The engine’s first autonomous repair is a matter of public record. The walker witnessed two spells fail inside one quest — Liquid incantations that rendered as dead text when copied. The fixer read the sealed evidence, made five small edits, and for each one ran the structural validator before and after: score held at 78.4%, style linter clean, edit kept. It also found a skipped command in the same scroll and declined to touch it — the skip was the sandbox’s limitation, not the quest’s defect, and the oath forbids repairs without a witnessed failure. The same morning, two sibling fixers received evidence with one errored trial each — and both walked away empty-handed, on purpose, leaving notes for a cleaner walk. One repair shipped; two no-ops recorded; zero plausible guesses. That ratio is the oath working.

🎯 Quest Objectives

By the end of this quest you will:

• Define “verified issue” — the only defects your fixer may touch are witnessed, machine-recorded failures
• Summon a fixer golem — write-scoped to content files only, forbidden from git and from the evidence
• Build the keep/revert gate — a deterministic before/after check that decides an edit’s fate in code
• Honor the honest no-op — partial or unexecuted evidence → abort with a reason, exit green
• Install a circuit breaker — N fully-covered-but-still-failing rounds → mark it needs-human and stop

🗺️ Quest Prerequisites

• 📋 Chapters I–V complete — sealed evidence and the coverage ledger are this chapter’s raw materials
• 📋 One deliberately broken potion whose fix is knowable (a typo’d command, a missing flag)

🧙‍♂️ Chapter 1: The Oath, Written as Steps

The fix lane is a second workflow (gated by its own FIX_ENABLED switch — Chapter II taught you why). Its shape is oath-as-pipeline:

graph TD
    A[Sealed evidence from the walk] --> B{Evidence complete?\nevery trial executed}
    B -->|no| Z[🙅 Honest no-op:\nrecord reason, exit green]
    B -->|yes| C[Fixer golem: smallest edit\nto the witnessed failure ONLY]
    C --> D{Deterministic gate:\nre-run checker + linter}
    D -->|holds or rises| E[Keep the edit]
    D -->|regresses| F[Revert the edit]
    E --> G[Workflow commits to a branch\nand opens the fix PR]
    F --> Z

The fixer’s role file carries the oath’s hard rules:

<!-- .claude/agents/potion-fixer.md -->
# potion-fixer

You repair potions. Your license is the sealed evidence — nothing else.

## Hard rules (never break)
- Repair ONLY failures evidence.txt witnessed. A skipped or unrun spell
  is not a defect; leave it and say so.
- Make the SMALLEST edit that mends the witnessed failure.
- Edit ONLY files under potions/. Never touch scripts/, workflows,
  ledger.json, or evidence.txt.
- Never run git. Never grade your own work — the gate decides.
- If the evidence is partial, truncated, or not executed: change NOTHING,
  write fix-notes.md explaining why, and stop. A no-op is a valid outcome.

🔍 Knowledge Check

• Why is “smallest edit that mends the witnessed failure” safer than “improve the potion while you’re in there”? (The Sirens have a verse about this.)
• Why must the no-op path exit green?

🧙‍♂️ Chapter 2: The Gate That Cannot Be Charmed

The keep/revert decision belongs to code. The pattern: capture a deterministic before score, let the golem edit, recompute after, and let arithmetic rule:

      - name: Gate — keep or revert (deterministic, never the golem's opinion)
        run: |
          set -euo pipefail
          potion="${{ steps.pick.outputs.potion }}"

          # AFTER: the witnessed failure must now pass…
          if ! ./scripts/check.sh "$potion" >/dev/null 2>&1; then
            echo "::warning::fix did not mend the witnessed failure — reverting."
            git checkout -- "$potion"
            exit 0
          fi
          # …and style must not regress (any deterministic linter works):
          if ! npx --yes markdownlint-cli2 "$potion" >/dev/null 2>&1; then
            echo "::warning::fix mended the spell but broke the style gate — reverting."
            git checkout -- "$potion"
            exit 0
          fi
          echo "edit KEPT: checker passes and linter is clean."

Then — and only then — the workflow commits the kept edit to a branch and opens a pull request (gh pr create in a step; the golem never sees these verbs). Two disciplines from the reference build worth stealing verbatim:

• Hold-or-rise, not “above the floor.” The real gate compares each quest’s structural score against its own pre-edit baseline: a fix that drags 95% down to 72% fails the gate even though 72% clears the absolute threshold. Repairs must not spend quality as currency.
• Separate the witness from the surgeon. The walk lane and the fix lane are different workflows with different switches. You can freeze all repairs (FIX_ENABLED=false) while the walker keeps witnessing — invaluable the week you’re debugging the fixer.

⚔️ Skills You’ll Forge

• Before/after gating with git checkout -- as the revert primitive
• Composing gates: functional (checker) AND stylistic (linter), both deterministic
• Write-scope enforcement by path

🔍 Knowledge Check

• The golem claims its edit is excellent, but the checker still fails. Who wins, and which line of the workflow enforces it?
• Why does the workflow own git checkout -- rather than asking the golem to revert itself?

🧙‍♂️ Chapter 3: The Circuit Breaker — When the Loop Must Ask for Help

A loop that fixes, re-walks, and still fails will happily do so forever — burning mana, flooding reviewers. The breaker counts full rounds and surrenders gracefully. In your ledger script:

# After computing coverage (Chapter V): breaker discipline.
MAX_ROUNDS = 3
fully_covered = covered == shelf
if fully_covered and not data["perfect"]:
    data["fix_rounds"] = data.get("fix_rounds", 0) + 1
    if data["fix_rounds"] >= MAX_ROUNDS:
        data["needs_human"] = True          # the loop STOPS choosing this work
elif data["perfect"]:
    data["fix_rounds"] = 0                  # convergence resets the breaker
    data["needs_human"] = False

The subtlety that bit the real engine: a mid-sweep turn is progress, not a failed round. Only a fully covered shelf that still isn’t perfect counts against the breaker — otherwise a 26-item shelf on window 5 trips needs_human before its first sweep even finishes.

🔁 Reproduce It

The first autonomous repair, and the oath it obeyed:

• PR #445 — bamr87/it-journey@08ca5d1cc (+33/−28): two witnessed Liquid failures mended with a block-level guard, three evidence-backed recommendations applied, structural score held at 78.4% on every kept edit, one skipped command explicitly left alone — read its PR body; it is the fixer’s fragment, edit by edit, gate result by gate result
• The oath at scale: .claude/skills/quest-fix/SKILL.md (the abort-on-unverified rules) and the M1 no-regression gate inside .github/workflows/quest-fix.yml
• The honest no-ops from the same morning: two sibling fix lanes in run 28791022929 consumed partial evidence and recorded “clean no-op — aborted at the honest-run gate” instead of guessing

🎮 Mastery Challenge

Objective: one kept repair, one forced revert, one honest no-op — the fixer’s full behavioral triangle.

Success Criteria:

• Kept: the fixer mends your knowable broken potion; the gate keeps it; the workflow opens a fix PR whose body lists the witnessed evidence
• Reverted: sabotage the gate (make the linter unsatisfiable for that file) and verify the edit is reverted with a warning while the run stays green
• No-op: hand the fixer truncated evidence (delete half of evidence.txt after sealing — from a workflow step, not the golem) and verify it changes nothing and writes fix-notes.md
• Breaker: simulate three fully-covered failing rounds and confirm needs_human: true stops the fix lane from selecting that potion

🎁 Rewards & Progression

• ⚖️ The Honest Fixer — earned on your first gate-kept repair or your first principled no-op; mastered when you have both
• ⚡ Skills unlocked: keep/revert gates · verified-only scope · circuit breakers · no-op discipline
• 📊 +150 XP

🗺️ Quest Network

graph LR
    Prev[⏳ V · The Mana Ledger] --> Cur[⚖️ VI · The Fixer's Oath]
    Cur --> Next[♾️ VII · Weaving the Whole]
    click Prev "/quests/1010/ouroboros-loop-05-the-mana-ledger/"
    click Next "/quests/1110/ouroboros-loop-07-weaving-the-whole/"

🔮 Next Adventures

• ♾️ Chapter VII — Weaving the Whole: the capstone — the serpent closes its own circle with self-merging gates
• 👑 Campaign hub: Epic Quest: The Ouroboros Loop

📚 Resource Codex

• markdownlint-cli2 — a ready-made deterministic style gate
• gh pr create — the workflow’s verb, never the golem’s
• Martin Fowler: CircuitBreaker — the pattern’s family history

🕸️ Knowledge Graph

Structured wiki-links connect this quest to the IT-Journey knowledge graph.

Campaign hub: [[Epic Quest: The Ouroboros Loop]] Previous: [[The Mana Ledger]] · Next: [[Weaving the Whole]] Level home: [[Level 1101 - Machine Learning & AI]]