harness-creator
- Repo stars 7,591
- Author updated Live
- Author repo learn-harness-engineering
- Domain
- Other
- Compatible agents
-
- Claude Code
- Cursor
- Cline
- Codex
- Windsurf
- Gemini CLI
- +20
- Trust score
- 88 / 100 · community maintained
- Author / version / license
- @walkinglabs · no license declared
- Token usage
- Lean
- Setup complexity
- Plug-and-play
- External API key
- Not required
- Operating systems
- macOS · Linux · Windows
- Runtime requirements
- Node.js
- Permissions
-
- Read-only
- Write / modify
- Network behavior
- Local-only
- Install commands
- 26 variants
Profile is derived at build time from SKILL.md and install vectors. Subject to drift from author intent.
Heads up: 未限定 allowed-tools,默认拥有全部工具权限。
---
name: harness-creator
description: >- Use when the user wants a shareable assessment:. Use this skill to make a repository easier f…
category: other
runtime: Node.js
---
# harness-creator output preview
## PART A: Task fit
- Use case: >- Use when the user wants a shareable assessment:. Use this skill to make a repository easier for coding agents to start, stay in scope, verify work, and resume across sessions. Keep the harness small enough that agents actually follow it. runs entirely locally; runs on Node.js. Works with Claude Code, Cursor, Cline and 23 more..
- Inputs: target material, constraints, expected output, and acceptance criteria.
- Evidence boundary: follow “Core Model / First Move / Common Tasks” and do not present inference as author intent.
## PART B: Execution result
- **01** The card summarizes the use case; runtime output centers on “>- Use when the user wants a shareable assessment:. Use this skill to make a repository easier for coding agents to start, stay in scope, verify work, and resume across sessions. Keep the harness small enough that agents actually follow it. runs entirely locally; runs on Node.js. Works with Claude Code, Cursor, Cline and 23 more.”.
- **02** When the source has headings, the agent prioritizes “Core Model / First Move / Common Tasks” so the result follows the author’s structure.
- **03** Typical output includes task judgment, concrete steps, required commands or file edits, validation, and follow-up options.
- **04** Risk context follows the fingerprint: read files, write/modify files; mostly runs locally; usually needs no extra API key.
## Running Rules
- read files, write/modify files; mostly runs locally; usually needs no extra API key.
- Validate with a small sample before expanding scope.
- Return the result, validation criteria, and next iteration options. The source mentions slash commands such as `/path`; use them first when your agent supports command triggers.
Name target files or source material, expected output, forbidden changes, and whether network or shell access is allowed. Permission fingerprint: read files, write/modify files.
Start with a small task and check whether the result follows “Core Model / First Move / Common Tasks”. Inspect diffs, logs, previews, or tests before expanding scope.
Confirm the final output includes a concrete result, evidence, and next action. If it stays generic, tighten inputs, boundaries, and acceptance criteria.
---
name: harness-creator
description: >- Use when the user wants a shareable assessment:. Use this skill to make a repository easier f…
category: other
source: walkinglabs/learn-harness-engineering
---
# harness-creator
## When to use
- >- Use when the user wants a shareable assessment:. Use this skill to make a repository easier for coding agents to st…
- Use it when the task has clear inputs, repeatable steps, and validation criteria.
## What to provide
- Target material, scope, expected result, and forbidden changes.
- Whether network, commands, file writes, or external services are allowed.
## Execution rules
- Organize steps around “Core Model / First Move / Common Tasks” and keep inference separate from source facts.
- read files, write/modify files; mostly runs locally; usually needs no extra API key.
- Validate with a small sample before expanding the task.
## Output requirements
- Return the deliverable, key evidence, validation method, and next action.
- Mark missing information as unknown; do not invent commands, platforms, or dependencies. The author source anchors workflow facts; repository files anchor sources and commands; Fluxly only adds fit, limitations, and quality judgment.
skill "harness-creator" {
input -> user goal + target files + boundaries + acceptance criteria
context -> Core Model / First Move / Common Tasks
rules -> SKILL.md triggers / order / output contract
runtime -> Node.js | read files, write/modify files | mostly runs locally
guardrails -> usually needs no extra API key + small-sample validation + diff/log review
output -> copyable result + checklist + next iteration
} Harness Creator
Use this skill to make a repository easier for coding agents to start, stay in scope, verify work, and resume across sessions. Keep the harness small enough that agents actually follow it.
Not for model selection, prompt tuning in isolation, chat UI design, or general app architecture.
Core Model
Every useful coding-agent harness has five subsystems:
| Subsystem | Minimal artifact | Purpose |
|---|---|---|
| Instructions | AGENTS.md or CLAUDE.md |
Startup path, working rules, definition of done |
| State | feature_list.json, progress.md |
Current feature, status, evidence, next step |
| Verification | init.sh or documented commands |
Tests/checks the agent must run before claiming done |
| Scope | Feature dependencies and done criteria | Prevents overreach and half-finished work |
| Lifecycle | session-handoff.md, end-of-session routine |
Makes the next session restartable |
First Move
- Inspect what already exists: instruction files, feature/state files, verification commands, docs, package manifests.
- Ask only for missing context that cannot be inferred safely: target agent, desired file name, tolerance for structure, and whether overwriting is allowed.
- Prefer a minimal harness first. Add memory, tool safety, multi-agent, or benchmark details only when the user's problem calls for them.
Common Tasks
Create a harness
Use the bundled script when working on a local repository:
node skills/harness-creator/scripts/create-harness.mjs --target /path/to/project
Options:
--agent-file CLAUDE.mdfor Claude-oriented projects.--package-manager npm|pnpm|yarn|bunwhen detection is wrong.--commands "cmd one,cmd two"for custom verification.--forceonly after confirming overwrites are acceptable.
Then explain what was created and how the user should replace placeholder feature entries.
Audit an existing harness
Run:
node skills/harness-creator/scripts/validate-harness.mjs --target /path/to/project
Report the five subsystem scores, the lowest-scoring area, and the first 2-3 changes that would improve reliability. Treat the lowest score as a candidate bottleneck; confirm with failures, logs, or task outcomes before claiming causality.
Produce a report
Use when the user wants a shareable assessment:
node skills/harness-creator/scripts/render-assessment-html.mjs --target /path/to/project
node skills/harness-creator/scripts/run-benchmark.mjs --target /path/to/project --html /path/to/report.html
Be clear that this is a structural benchmark. Real effectiveness still needs before/after agent sessions on representative tasks.
When to Read References
Load only the reference needed for the user's problem:
- Memory across sessions: Memory Persistence
- Reusable workflows as skills: Skill Runtime
- Permissions, tools, concurrency: Tool Registry & Safety
- Context budget and progressive disclosure: Context Engineering
- Delegation and parallel agents: Multi-Agent Coordination
- Hooks, startup, long-running work: Lifecycle & Bootstrap
- Non-obvious failure modes: Gotchas
Design Rules
- Keep the root instruction file short: routing and invariants, not a full manual.
- Put project facts in project docs, not in the skill.
- Make verification commands explicit and runnable.
- Require evidence before marking a feature done.
- Use one active feature unless the harness has explicit multi-agent ownership boundaries.
- Prefer append/update state files over relying on chat history.
- Never hide destructive behavior in scripts; overwrites require explicit user approval.
Deliverable Checklist
For a usable minimal harness, leave the target project with:
-
AGENTS.mdorCLAUDE.md -
feature_list.json -
progress.md -
init.sh - Optional
session-handoff.mdfor multi-session work - Documented verification evidence or next action
If you cannot create files, provide exact file contents and commands instead.
Decide Fit First
Design Intent
How To Use It
Boundaries And Review