Simmer

Iterative refinement loop — take an artifact (single file or workspace) and hone it repeatedly against user-defined criteria until it's as good as it can get.

Related skills (test-kitchen family):

• test-kitchen:omakase-off — don't know what you want → parallel designs → react → pick
• test-kitchen:cookoff — know what you want, it's code → parallel implementations → fixed criteria → steal the best
• simmer — know what you want, it's anything → user-defined criteria → iterate until good

Flow

"Simmer this" / "Refine this" / "Optimize this pipeline"
    ↓
┌─────────────────────────────────────┐
│  SETUP (identify + criteria)        │
│  Load simmer-setup subskill         │
│                                     │
│  Output: artifact, rubric, N iters, │
│  evaluator (optional),              │
│  background (optional)              │
└─────────────────────────────────────┘
    ↓
┌─────────────────────────────────────┐
│  LOOP (default 3 iterations)        │
│                                     │
│  Each iteration:                    │
│  1. Dispatch generator subagent     │
│  2. Run evaluator (if present)      │
│  3. Dispatch judge subagent         │
│  4. Load reflect subskill           │
│                                     │
│  Generator gets: candidate + ASI    │
│           + background              │
│  Judge gets: candidate + rubric     │
│       + evaluator output (if any)   │
│  Reflect gets: full score history   │
└─────────────────────────────────────┘
    ↓
┌─────────────────────────────────────┐
│  OUTPUT                             │
│  Best candidate → result file       │
│  Score trajectory displayed         │
└─────────────────────────────────────┘

When to Use

Trigger when user wants iterative refinement of any kind:

• "Simmer this", "refine this", "hone this", "iterate on this"
• "Make this better", "improve this over a few rounds"
• "Polish this", "tighten this up"
• "Optimize this pipeline", "find the best model for this task"
• "Tune this configuration", "improve these prompts against this test suite"
• Any request to iteratively improve an artifact or workspace

Judge mode is auto-selected by setup based on problem complexity:

Plateau upgrade: If the loop started with a single judge and detects a plateau (3 iterations without improvement), offer: "Scores have plateaued. Switch to judge board for deeper diagnosis?" If the user accepts, switch to JUDGE_MODE: board for remaining iterations.

Not simmer: If the artifact is code and the user wants parallel implementations, use cookoff instead.

Orchestration

Announce: "I'm using the simmer skill to set up iterative refinement."

Track progress (TodoWrite if available, otherwise inline):

1. Setup — identify artifact, elicit criteria, determine evaluation method
2. Refinement loop (N iterations)
3. Output best version with score trajectory

Phase 1: Setup

Invoke simmer:simmer-setup.

Do not attempt to identify the artifact or ask about criteria yourself — that is the setup subskill's job.

Shortcut: If the user (or calling system) has already provided artifact, criteria (each with at least one sentence describing what a high score looks like), iteration count, mode, and optionally evaluator/background, skip the setup subskill entirely. Construct the setup brief directly and proceed to Phase 2.

Setup returns a brief:

ARTIFACT: [content, file path, or directory path]
ARTIFACT_TYPE: [single-file | workspace]
CRITERIA:
  - [criterion 1]: [what better looks like]
  - [criterion 2]: [what better looks like]
  - [criterion 3]: [what better looks like]
PRIMARY: [criterion name — omit if equally weighted]
EVALUATOR: [command to run — omit for judge-only mode]
BACKGROUND: [constraints, available resources, domain knowledge — omit if not needed]
OUTPUT_CONTRACT: [valid output format description — omit for text/creative]
VALIDATION_COMMAND: [quick check command — omit if no cheap validation exists]
SEARCH_SPACE: [what's in scope to explore — omit if unconstrained]
JUDGE_MODE: [single | board — auto-selected by setup based on complexity. User can override]
JUDGE_PANEL: [optional custom judge definitions — omit to use defaults for problem class]
ITERATIONS: [N]
MODE: [seedless | from-file | from-paste | from-workspace]
OUTPUT_DIR: [path, default: docs/simmer]

Phase 2: Refinement Loop

For single-file mode:

mkdir -p {OUTPUT_DIR}

For workspace mode:

# Create initial commit to snapshot the seed state
cd {ARTIFACT}
git add -A && git commit -m "simmer: iteration 0 — seed state"

Iteration counting:

"N iterations" means N generate-judge-reflect cycles AFTER the initial seed judgment. The seed judgment is iteration 0 (not counted toward N). So ITERATIONS: 3 means:

• Iteration 0: Judge the seed (no generator)
• Iteration 1: Generate → Judge → Reflect
• Iteration 2: Generate → Judge → Reflect
• Iteration 3: Generate → Judge → Reflect
• Total: 3 generation passes + 1 seed judgment = 4 judge rounds

For seedless mode: iteration 1 generates the initial candidate AND judges it. ITERATIONS: 3 means 3 generation passes total.

Iteration 0 (seed):

Single-file mode:

• Write the seed artifact to {OUTPUT_DIR}/iteration-0-candidate.md
• If seedless: dispatch generator subagent to produce initial candidate from description + criteria, then judge it
• If from-file or from-paste: the seed IS the starting artifact — judge it directly (no generator)

Workspace mode:

• The seed is the current state of the workspace directory
• If from-workspace: judge the current state directly (no generator)
• If seedless: dispatch generator to scaffold the initial workspace, then judge it

Each iteration:

Step 1: Generator (subagent)

Invoke simmer:simmer-generator as a subagent.

Single-file subagent prompt:

You are the generator in a simmer refinement loop.

Invoke the skill: simmer:simmer-generator

ITERATION: [N]
ARTIFACT_TYPE: single-file
CRITERIA:
[rubric from setup]

CURRENT CANDIDATE:
[full text of current best candidate]

JUDGE FEEDBACK (ASI from previous round):
[ASI text, or "First iteration — generate initial candidate" if seedless iteration 1]

Write your improved candidate to: {OUTPUT_DIR}/iteration-[N]-candidate.md
(or appropriate extension matching artifact type)

Report: what specifically changed and why (2-3 sentences).

Workspace subagent prompt:

You are the generator in a simmer refinement loop.

Invoke the skill: simmer:simmer-generator

ITERATION: [N]
ARTIFACT_TYPE: workspace
WORKSPACE: [directory path]
CRITERIA:
[rubric from setup]

BACKGROUND:
[constraints, available resources, domain knowledge from setup]

OUTPUT_CONTRACT:
[valid output format — omit if not specified in setup]

VALIDATION_COMMAND:
[quick check command — omit if not specified in setup]

SEARCH_SPACE:
[what's in scope to explore — omit if not specified in setup]

JUDGE FEEDBACK (ASI from previous round):
[ASI text — may describe coordinated changes across multiple files]

EXPLORATION STATUS:
[from reflect: what's been tried vs untried — omit on iteration 1 or if no search space]

Make your changes directly in the workspace directory.
You may edit multiple files in a single iteration when the ASI calls for coordinated changes.
If making infrastructure changes, run VALIDATION_COMMAND (if available) before reporting success.

Report: what specifically changed and why (2-3 sentences).

Step 2: Run Evaluator (if present)

If the setup brief includes an EVALUATOR command: ``