BeClaude

claude-code-harness

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2.2kCommunity RegistryGeneralby Chachamaru · MIT

A harness for solo developers (Vibecoders) to handle full-cycle contract development.

First seen 5/22/2026

Summary

Claude Code Harness provides a disciplined plan-work-review-ship loop for solo developers using Claude Code, turning ad-hoc agent sessions into repeatable, evidence-driven delivery cycles.

  • It enforces spec writing, structured planning, testable work, review gates, and release evidence so that vibecoders can handle full-cycle contract development with confidence.

Overview

<p align="center"> <img src="docs/images/claude-harness-logo-with-text.png" alt="Claude Harness" width="400"> </p>

<p align="center"> <strong>Plan. Work. Review. Ship.</strong><br> <em>A disciplined delivery loop for Claude Code, with bounded paths for Codex and OpenCode.</em> </p>

<p align="center"> <a href="https://github.com/Chachamaru127/claude-code-harness/releases/latest"><img src="https://img.shields.io/github/v/release/Chachamaru127/claude-code-harness?display_name=tag&sort=semver" alt="Latest Release"></a> <a href="LICENSE.md"><img src="https://img.shields.io/badge/License-MIT-green.svg" alt="License"></a> <a href="docs/CLAUDE_CODE_COMPATIBILITY.md"><img src="https://img.shields.io/badge/Claude_Code-v2.1+-purple.svg" alt="Claude Code"></a> <img src="https://img.shields.io/badge/Skills-5_Verbs-orange.svg" alt="Skills"> <img src="https://img.shields.io/badge/Core-Go_Native-00ADD8.svg" alt="Go Core"> </p>

<p align="center">

</p>

<p align="center"> <img src="docs/images/readme/hero-operating-loop-en.png" alt="Claude Code Harness operating loop: Spec, Plan, Work, Review, Release" width="900"> </p>

Claude Code is powerful, but raw agent work drifts: plans live in chat, tests become optional, review happens too late, and release evidence gets rebuilt by memory. Harness turns that into one repeatable operating path.

After install, the default changes from "ask the agent to code" to:

  1. write the spec and plan,
  2. implement only the approved slice,
  3. verify the result,
  4. review independently,
  5. package evidence for PR or release.

Quickstart

New users should start from the tool they already use. Existing users should run the migration report before cleanup or reinstall.

PathStart
New userTool-first onboarding
Existing userMigration check
Claude Code fast pathInstall in 30 seconds
Trigger proofSkill trigger gate

Install in 30 Seconds

bash
claude
/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install claude-code-harness@claude-code-harness-marketplace
/harness-setup

Next command: run /harness-plan with one small request.

bash
/harness-plan Improve the README onboarding flow

First 15 Minutes

  1. Install through your tool route.
  2. Run /harness-setup or the equivalent setup script.
  3. Run /harness-plan with a small request; Harness writes the spec.md and

Plans.md drafts for you to check. Small typo, docs, and status updates stay lightweight.

  1. Approve the generated contract or reply with the correction you want.
  2. Run the smallest approved task, for example /harness-work 1.1.1.
  3. Run /harness-review and keep the verification output.

Your job is not to hand-write the plan. It is to approve or correct the generated contract before execution continues.

How It Works

Harness adds a source-of-truth loop around agent work. The 5 verb skills keep that surface small: plan, work, review, sync, release.

  1. You describe the outcome in normal language.
  2. /harness-plan drafts or updates spec.md and Plans.md with scope,

acceptance criteria, unknowns, and stop conditions.

  1. Non-trivial planning records team_validation_mode and validates the plan

through team/sub-agent or manual-pass perspectives for spec/Plans alignment, memory reuse, product fit, security fit, and works-in-practice.

  1. Harness treats those files as the source of truth. Data the agent has not

seen stays unknown instead of being silently invented.

  1. /harness-work implements the approved slice with TDD and verification.
  2. /harness-review separates review from implementation.
  3. /harness-release packages only verified evidence.

Commands

CommandWhat happens inside
/harness-setupInstalls project guidance, command surfaces, hooks, and checks so the workflow starts from one known baseline.
/harness-planTurns intent into spec.md and Plans.md, including scope, acceptance criteria, dependencies, unknowns, stop conditions, and non-trivial planning validation.
/harness-workExecutes one approved task or range, adds tests when required, runs verification, and keeps work inside the plan.
/harness-work allRuns the approved plan through implementation and review paths; use after the plan is clear and the repo baseline is known.
/harness-reviewReviews the result separately from implementation and treats major findings as blockers.
/harness-releaseChecks release readiness, CHANGELOG/tag boundaries, and evidence packaging after implementation and review are complete.
bin/harness doctor --migration-reportInventories old plugin caches, Codex skills, OpenCode files, symlinks, and memory state without deleting data.

Basic Workflow

StageOutputGate
InvestigateEvidence and unknownsDo not promote unobserved data into claims.
Planspec.md + Plans.mdUser approves or corrects the generated contract.
WorkCode and testsTDD required when the task says so.
ReviewIndependent verdictMajor findings block completion.
PREvidence packPR ready is not release ready.
ReleaseTag/release artifactsRelease preflight must pass on the release path.

Install By Tool

ToolTierRoute
Claude CodesupportedClaude plugin marketplace, then /harness-setup.
Codex CLIinternal-compatiblescripts/setup-codex.sh --user; direct plugin smoke is tracked separately.
Codex appcandidateCandidate smoke only; do not reuse Codex CLI proof.
OpenCodeinternal-compatiblescripts/setup-opencode.sh; runtime parity is not claimed.
Cursorinternal-compatiblescripts/setup-cursor.sh real-directory local install; top support tier still gated on workflow smoke.
GitHub Copilot CLIcandidateManual profile research only.
Antigravity CLIfuture/unsupportedNo end-user install route in this phase.

Existing User Migration

Run bin/harness doctor --migration-report before changing an existing setup. The report inventories stale Claude plugin caches, duplicate Codex skills, old symlinks, OpenCode backup paths, and harness-mem state without deleting anything.

Support Boundary

Harness can describe candidate paths, but it does not inherit support claims from Superpowers, Hermes Agent, or any other project. A host only moves up when Harness has its own bootstrap, trigger, runtime, and release evidence.

not_observed != absent: missing local proof means "not proven here", not "impossible" and not "supported".

Requirements

  • Claude Code v2.1+ for the supported Claude path.
  • A project repository with write access for local setup.
  • No Node.js is required for the Go-native guardrail engine.
  • Optional harness-mem for

cross-session memory when configured and healthy.

Advanced

Use these after the basic trigger path is visible.

CapabilityWhat it addsBoundary
BreezingPlanner/Critic/Worker style team execution for larger task lists.Still gated by plan quality and review.
Codex companion reviewSchema-backed Codex second opinion through scripts/codex-companion.sh.Raw codex exec is not the Harness companion path.
OpenCode bootstrapMirrors Harness guidance into OpenCode-compatible surfaces.Real runtime parity is not claimed.
harness-memProject-scoped memory and recall across sessions.Optional companion; purge remains explicit.

Documentation

ResourceDescription
Tool-first onboardingWhere to start by host tool.
Install routesPer-tool setup and support-tier boundaries.
Migration checkExisting-user impact, compatibility, and rollback path.
Skill trigger gateHow install success is verified.
Capability matrixSupported, internal-compatible, candidate, and unsupported host claims.
Claude Code CompatibilityCurrent Claude Code requirements and compatibility notes.
Cursor IntegrationCursor handoff boundary and internal-compatible adapter notes.
Distribution ScopeIncluded vs compatibility vs development-only paths.
Hardening parityRuntime safety differences between Claude hooks and Codex gates.
Work All Evidence PackSuccess/failure verification contract for full-plan execution.
ChangelogUser-facing version history.

Contributing

Issues and PRs welcome. See CONTRIBUTING.md.

Acknowledgments

  • AI Masao - Hierarchical skill design
  • Beagle - Test tampering prevention patterns

License

MIT License. See LICENSE.md.

Install & Usage

1
Add a marketplace
/plugin marketplace add <org/repo>
2
Install the plugin

Add the configuration to /plugin install claude-code-harness@<marketplace>

3
Manage with /plugin
/plugin

Use Cases

A solo developer uses Harness to write a formal spec before starting any coding, ensuring client requirements are captured and agreed upon.
During a sprint, a developer runs the 'Plan' verb to break down a feature into actionable tasks with acceptance criteria before writing code.
After implementing a feature, the developer triggers 'Review' to automatically run tests, check code coverage, and generate a review summary.
When releasing a milestone, the developer uses 'Release' to produce a changelog, tag the version, and gather all evidence for client delivery.
A developer onboarding a new project runs 'Spec' to create a project charter and initial backlog from a client brief.
While debugging a production issue, the developer uses 'Work' with a focused plan to ensure the fix is tested and reviewed before deployment.

Usage Examples

1

/claude-code-harness spec --init --project 'E-commerce API' --client 'Acme Corp'

2

/claude-code-harness plan --feature 'user authentication' --from-spec spec.md

3

/claude-code-harness review --all --output review-summary.md

View source on GitHub
claude-codepluginvibecoderworkflowplan-work-review

Security Audits

LicensePassSourceWarnRepositoryPass

Frequently Asked Questions

What is claude-code-harness?

Claude Code Harness provides a disciplined plan-work-review-ship loop for solo developers using Claude Code, turning ad-hoc agent sessions into repeatable, evidence-driven delivery cycles. It enforces spec writing, structured planning, testable work, review gates, and release evidence so that vibecoders can handle full-cycle contract development with confidence.

How to install claude-code-harness?

To install claude-code-harness: add a marketplace (/plugin marketplace add <org/repo>), then add the config to /plugin install claude-code-harness@<marketplace>. Finally, /plugin in Claude Code.

What is claude-code-harness best for?

claude-code-harness is a plugin categorized under General. It is designed for: claude-code, plugin, vibecoder, workflow, plan-work-review. Created by Chachamaru.

What can I use claude-code-harness for?

claude-code-harness is useful for: A solo developer uses Harness to write a formal spec before starting any coding, ensuring client requirements are captured and agreed upon.; During a sprint, a developer runs the 'Plan' verb to break down a feature into actionable tasks with acceptance criteria before writing code.; After implementing a feature, the developer triggers 'Review' to automatically run tests, check code coverage, and generate a review summary.; When releasing a milestone, the developer uses 'Release' to produce a changelog, tag the version, and gather all evidence for client delivery.; A developer onboarding a new project runs 'Spec' to create a project charter and initial backlog from a client brief.; While debugging a production issue, the developer uses 'Work' with a focused plan to ensure the fix is tested and reviewed before deployment..