harness-generation

The full skill.

Original instructions from the publisher’s SKILL.md

# Harness Generation

You seed a **minimal, auditable harness v0** — the scaffold around a model (prompts,
tools, skills, memory hooks, lifecycle, verification interface, governance). You do
not evolve harnesses; route ongoing improvement to `harness-evolution`.

## Trigger Discipline

**Auto-invoke** when chained from `project-setup` 6c, `retroactive-project-setup`, `harness-engineering` Step 0, or `setup-evaluation` harness FAIL. See `harness-engineering/references/harness-readiness-gate.md`.

## Hard Rules

Never generate a harness without a versioned **component manifest** (`docs/harness/manifest.json`).
Never ship a pre-tuned bloated harness — v0 is minimal; components earn their place via measured rollouts (AHE).
Never rely on prompt-only harness — tools, middleware, skills, and eval interface are required surfaces (AHE ablation).
Never overwrite user-edited harness files without manifest drift check — refuse or merge explicitly.
Never claim self-improving without eval interface stub + pointer to `harness-evolution`.
Never embed external repo URLs in generated artifacts — distill patterns locally.

---

## Workflow

### Step 1 — Classify delivery context

| Context | v0 focus |
|---------|----------|
| agent-loom skill library project | Skill routing, AGENTS.md orchestration map, eval stub for skill quality |
| Consumer app repo | AGENTS.md, `.agents/skills/`, forbidden paths, key commands |
| Legacy repo (no AGENTS.md) | Gap-fill only — pair with `retroactive-project-setup` first |
| Multi-agent chain planned | Manifest only — topology is `agent-builder`, not this skill |

### Step 2 — Inventory repo (silent)

Read: manifests, existing `AGENTS.md`, `.agents/skills/`, CI configs, `docs/memory/`,
`docs/evals/`, `docs/harness/`. Auto-extract commands per `project-setup` Step 1b.

### Step 3 — Emit component manifest

Write `docs/harness/manifest.json` per `references/component-manifest.md`:
seven orthogonal components (prompt, tools, middleware, skills, sub-agents, memory, governance),
each with path, version, sha256, and `generated|user-edited` status.

### Step 4 — Scaffold artifacts

Apply patterns from `references/scaffold-patterns.md`:

1. **Prompt / routing** — merge into `AGENTS.md` or create harness section; keep ≤150 lines total.
2. **Skills** — ensure Skill Invocation block present; list installed skills in Orchestration Map.
3. **Tools** — document MCP/tool surfaces in manifest; stub `docs/harness/tools.md` if needed.
4. **Governance** — forbidden paths, allowed-write scopes, verifier sandbox rules.
5. **Eval interface stub** — `docs/harness/eval-interface.md` + empty `docs/harness/tasks.json` shape
   (file_phrase + command checks per metaharness pattern).
6. **Environment bootstrap** — compact snapshot block (stack, key commands, git branch) for meta-agents.

If `project-setup` already ran: **merge**, never replace user interview content.

### Step 5 — Drift gate

Document `harness sync --check` equivalent: compare manifest hashes to disk; flag user-edited files
skipped on re-run. CI recommendation in manifest notes.

### Step 6 — Hand off

| Next need | Route |
|-----------|-------|
| Full AGENTS.md interview missing | `project-setup` |
| Eval rubric + regression suite | `eval-rubric-design` → `eval-pipeline` |
| Improve harness from failures | `harness-evolution` (requires eval harness) |
| Multi-agent design | `agent-builder` (orthogonal) |

Append to `docs/skill-outputs/SKILL-OUTPUTS.md`. Log harness version `v0` in `docs/memory/current-state.md` if memory suite installed.

---

## Gotchas

- **Minimal seed is mandatory.** Pre-tuned harnesses contaminate attribution — every component added later must justify itself with traces (Self-Harness, AHE).
- **AGENTS.md must stay lean.** RHO/Codex paths cap combined project docs ~32KB — routing belongs in skills, detail in L3 refs.
- **Harness ≠ agent topology.** `agent-builder` designs who talks to whom; this skill designs what files/tools/prompts wrap the model.
- **Deterministic scaffold beats one-shot LLM init.** Inspect → plan → staged writes → manifest (harnessforge pattern); LLM fill is optional fallback only.
- **Blueprint validators that shell out are a trust boundary** — document, never auto-run untrusted commands.

---

## Output Format

```
Harness generation complete
Version: v0
Context: [library | consumer | legacy-gap-fill]
Manifest: docs/harness/manifest.json
Artifacts: [list paths]
Eval stub: docs/harness/eval-interface.md
Drift check: [documented command]
Next: [eval-pipeline | harness-evolution | project-setup]
```

---

## Example

<examples>
  <example>
    <input>Generate a harness for this React monorepo — we have AGENTS.md from project-setup.</input>
    <output>
Harness generation complete
Version: v0 | Context: consumer
Manifest: docs/harness/manifest.json (7 components, all generated)
Merged: Skill Invocation + Orchestration Map preserved from interview
Created: docs/harness/eval-interface.md, docs/harness/tasks.json (stub), docs/harness/governance.md
Next: eval-rubric-design to define harness regression dimensions
    </output>
  </example>
</examples>

## Common Rationalizations

| Excuse | Reality |
|--------|---------|
| "AGENTS.md is enough" | No manifest, eval stub, or governance = not a harness v0 |
| "Skip eval stub for now" | harness-evolution hard-fails without it |
| "Copy external harness README" | Distill patterns; secure-scan; no URL embed |
| "Let LLM write the whole harness" | Deterministic manifest + merge beats opaque generation |
| "Agent-builder already ran" | Topology ≠ harness files — run both |

## Verification

- [ ] `docs/harness/manifest.json` exists with 7 components and hashes
- [ ] Eval interface stub + tasks.json shape present
- [ ] AGENTS.md ≤150 lines; user content preserved on merge
- [ ] Governance forbidden paths documented
- [ ] SKILL-OUTPUTS.md appended

## Red Flags

- Harness v0 bloated with speculative prompts/tools
- User-edited files overwritten without merge
- No eval interface stub when evolution is planned
- External SKILL.md vendored wholesale

## Prune Log
Last pruned: 2026-07-05
- Deep learn-from: scaffold-patterns L3 — drift CI, interface validation, AHE sandbox

## Impact Report

```
Harness v0 generated: [context]
Manifest: docs/harness/manifest.json | Components: 7
Eval stub: [yes/no] | Merged AGENTS.md: [yes/no]
Files created: [count] | Next route: [skill]
```

## Reference Files

- `references/component-manifest.md` — seven components, JSON schema, ETCLOVG map
- `references/scaffold-patterns.md` — inspect→render, drift CI, bootstrap snapshot
- `references/examples.md` — library project + consumer repo worked examples