Chachamaru

via GitHub · Posted Jul 12, 2026 · 1 min read

Claude Code Harness

Claude Skill

Claude Code Dedicated Development Harness - Achieving High-Quality Development Through an Autonomous Plan→Work→Review Cycle

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Shell MIT v5.0.0 Updated 1 month ago

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At a glance

Shell 24 skills Actively maintained Commercial OK

A structured development framework that orchestrates Claude Code through repeatable planning, implementation, review, and release phases with machine-checked specifications and CI gates. Designed for teams and individual developers who want autonomous AI-assisted coding with verifiable output and clear decision surfaces at each stage.

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README

Claude Code Harness

The problem

Agent coding drifts. Plans live in chat and disappear. Tests become optional under deadline. Review happens after the code is already merged. Release evidence gets reconstructed from memory.

Harness replaces "ask the agent to code" with one repeatable path:

write the spec → implement only the approved slice → verify → review independently → package evidence.

It does not make the model smarter. It fixes the procedure and the boundary around the model — so it keeps working when the model changes.

Claims in this README are machine-checked. CI gates verify that described components are actually wired, that the task ledger stays consistent, and that shipped binaries rebuild from source. A feature appears here only after a gate proves it is reachable. Written is not working.

Install in 30 seconds

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

Then hand it something small:

/harness-plan Improve the README onboarding flow

Harness drafts spec.md and Plans.md for you. Your job is not to write the plan — it is to approve or correct it before execution continues.

Using a different tool? See install by tool below.

The loop

The 5 verb skills keep that surface small: plan, work, review, sync, release. (/harness-setup runs once at install time, above.)

Command	What happens
`/harness-plan`	Turns intent into `spec.md` + `Plans.md`: scope, acceptance criteria, dependencies, unknowns, stop conditions.
`/harness-work`	Implements one approved task or the whole plan. Adds tests when the task requires them.
`/harness-work all`	Runs the whole approved plan. Use once the plan is clear and the repo baseline is known.
`/harness-review`	Reviews the result separately from implementation. Major findings block completion.
`/harness-sync`	Compares the plan against what is actually implemented and reports drift.
`/harness-release`	Packages only verified evidence into CHANGELOG, tag, and release.

Each stage leaves the material the next stage needs.

Stage	Output	Gate
Plan	`spec.md` + `Plans.md`	You approve or correct the generated contract.
Work	Code and tests	TDD required when the task says so.
Review	Independent verdict	Major findings block completion.
PR	Evidence pack	PR-ready is not release-ready.
Release	Tag and artifacts	Release preflight must pass.

Data the agent has not seen stays unknown instead of being quietly invented.

The safety layer

This is what separates Harness from a prompt template. Every tool call is adjudicated by a Go engine before it runs — not reviewed after the fact, because a file diff cannot see a network send or a deletion.

Two layers, deliberately different in strength.

Layer	Decides	Overridable
Runtime floor — 5 categories	Denies outright	No. Not by any config, env var, or permission mode
Guardrails — R01–R15	Deny / confirm / warn	Partly, by project config

The floor covers billing, network egress, secret reads, production deploys, and destruction outside the task worktree. It sits on an isolated code path with no disable switch, so an autonomous run cannot talk itself past it.

Guardrails are the layer you tune. Direct pushes to main, writes to protected paths, forced pushes, history rewrites — each has a defined verdict, and some are configurable per project.

Confirmations move to plan time. Instead of interrupting a run, Harness collects the risky operations a plan will need and asks once, up front. Approvals carry an expiry, a task scope, and a use limit — so one approval never becomes a permanent hole.

Every stop is recorded. Rule id, category, and verdict land in a JSONL log. Command text is never written; only a hash and a length, and for secret-read and billing not even that. You can count what actually blocked you instead of guessing.

Decision surfaces for non-engineers

Three single-screen HTML views let a non-engineer sponsor judge without reading code.

Surface	When	Shows
Plan Brief	Plan finalized	Understanding, options, risks, acceptance criteria
Progress	During work	WIP/TODO/done counts and drift alerts, auto-regenerated
Acceptance	Before release	Per-criterion pass/fail with ship / wait / reject

Install by tool

Four install routes are not four identical guarantees. A setup script means a tool has an entry path, not a shared product promise.

Tool	Tier	Route
Claude Code	`supported`	Plugin marketplace, then `/harness-setup`
Codex CLI	`supported`	`scripts/setup-codex.sh --user`
Cursor	`supported`	`scripts/setup-cursor.sh` — containment is harness-side, see notes
Grok	`supported`	`scripts/setup-grok.sh`
Codex app	`candidate`	Candidate smoke only; CLI proof is not reused
OpenCode	`internal-compatible`	`scripts/setup-opencode.sh`; runtime parity not claimed
Hermes Agent	`candidate`	Manual symlink research route
GitHub Copilot CLI	`candidate`	Manual profile research
Antigravity CLI	`future/unsupported`	No end-user install route yet

EN tier	Japanese public wording
`supported`	正式対応
`internal-compatible`	互換利用可 / 制限付き対応
`candidate`	試験対応 / プレビュー
`future/unsupported`	非対応 / 将来検討

Claude Code, Codex CLI, Cursor, and Grok passed H1–H8 on their verified claim paths (live H4 2026-07-17; H7 release-preflight fail-closed wiring 2026-07-19). Every other row stays at its listed tier until it passes its own H1–H8 (docs/spec/planning-and-host-adapter.md, Phase 111).

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

not_observed != absent — missing local proof means "not proven here". It does not mean impossible, and it does not mean supported.

bin/harness doctor --migration-report

It inventories stale Claude plugin caches, duplicate Codex skills, old symlinks, OpenCode backup paths, and harness-mem state — without deleting anything.

Reach for these after the basic path is working.

Capability	What it adds	Boundary
Breezing	Planner / Critic / Worker team execution for larger task lists	Still gated by plan quality and review
Codex companion review	Schema-backed second opinion via `scripts/codex-companion.sh`	Raw `codex exec` is not the companion path
harness-mem	Project-scoped memory and recall across sessions	Optional; purge stays explicit
OpenCode bootstrap	Mirrors guidance into OpenCode-compatible surfaces	Runtime parity not claimed
auto-approve (experimental)	`HARNESS_AUTO_APPROVE=on` records the gate result in the orchestration ledger	Default OFF. Approval prompts are not skipped yet

Requirements

Claude Code v2.1+ for the supported Claude path
A repository with write access
No Node.js is required for the Go-native guardrail engine
Optional: harness-mem for cross-session memory

Documentation

Resource	Description
Tool-first onboarding	Where to start, by host tool
Install routes	Per-tool setup and tier boundaries
Migration check	Existing-user impact and rollback
Skill trigger gate	How install success is verified
Capability matrix	Full host claim table
Claude Code compatibility	Version requirements and notes
Cursor integration	Handoff boundary and containment
Distribution scope	Included vs compatibility vs dev-only
Hardening parity	Safety differences between hosts
Work All evidence pack	Verification contract for full-plan runs
Language / i18n	Switching output language
Changelog	User-facing version history

Contributing

Issues and PRs welcome. See CONTRIBUTING.md.

Acknowledgments

AI Masao — hierarchical skill design
Beagle — test tampering prevention patterns

License

MIT. See LICENSE.md.

24 skills in this repo

Plugin marketplace

Agent Browser

Browser automation through the repo agent-browser CLI. Explicit helper for navigation, forms, screenshots, scraping, and web-app checks. Prefer Browser Use or Playwright when available. Do NOT load for: sharing URLs, embedding links, or edi...

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install agent-browser

Breezing

Team execution mode (Codex host) — backward-compatible alias for harness-work with backend selection, including opt-in Cursor worker delegation. Composer/composer 2.5 maps to the cursor backend.

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install breezing

Breezing

Team execution mode — backward-compatible alias for harness-work with team orchestration. Composer/composer 2.5 maps to the cursor backend.

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install breezing-skillsbreezing

Cc Update Review

Quality guardrail for Claude/Codex update integration. Detects doc-only Feature Table additions and requires implementation or explicit planning. Internal use only.

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install cc-update-review

CI red? Call us. Pipeline fire brigade deploys. Use when user mentions CI failures, build errors, test failures, or pipeline issues. Do NOT load for: local builds, standard implementation work, reviews, or setup.

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install ci

Cursor Ask

Read-only delegate to cursor-agent (Composer) for questions, investigation, design discussion, and adversarial sanity checks. No worktree, no cherry-pick, no Lead diff review — cursor-agent is locked to ask mode and cannot write. Use when u...

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install cursor-ask

Cursor Do

Delegate a single write task to Cursor Composer via cursor-companion.sh inside an isolated worktree, then Lead-review the diff and cherry-pick. Use when user invokes cursor:do, says delegate to cursor, have composer write it, refactor with...

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install cursor-do

Cursor Review

Run a Cursor Composer review as an advisory second opinion while keeping the primary review verdict on the host brain. Use when user invokes cursor:review, asks Cursor to review, or wants composer to sanity-check a diff. Cursor never owns A...

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install cursor-review

Cursor Setup

Configure and verify the Cursor backend for Claude Code Harness. Use when user invokes cursor:setup, wants Cursor as the local default implementation backend, or asks to check Cursor plugin/agent readiness. Distribution default remains opt-...

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install cursor-setup

Failure Codifier

Extract recurring failure patterns from breezing orchestration logs and Judgment Ledger, emit failure-rule.v1 proposals with confidence scores. SSOT promotion to patterns.md or decisions.md is proposal-only — human-approval-required. Use wh...

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install failure-codifier

Harness Accept

Generate an Acceptance Demo HTML for non-engineer vibecoders right before ship/wait/reject decision. Reads back the acceptance_criteria that were stored as personal-preference.v1 by harness-plan-brief (joined by user_request_hash), then ren...

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install harness-accept

Harness Loop

HAR: Codex-native long-running loop runner. Uses a real background runner that executes one ready batch per cycle through Breezing by default, with status/stop controls. Trigger: long-running, loop, autonomous, background, Codex. Do NOT loa...

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install harness-loop

Harness Loop

Long-running task loop using /loop (Claude Code dynamic mode) and ScheduleWakeup to re-enter with fresh context on each wake-up. Internally invokes harness-work through Agent. Trigger: long-running, loop, wake-up, autonomous. Do NOT load fo...

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install harness-loop-skillsharness-loop

Harness Plan

HAR: Research-backed, team-validated task planning, Plans.md management, progress sync. Trigger: create a plan, add tasks, update Plans.md, mark complete, check progress. Do NOT load for: implementation, review, release.

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install harness-plan

Harness Plan Brief

Generate a Plan Brief HTML for non-engineer vibecoders before implementation starts. Searches harness-mem (project-only) for relevant past decisions, patterns, and Plans archive entries, then renders a single-file HTML artifact summarizing...

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install harness-plan-brief

Harness Progress

Generate a Progress Tracker HTML for non-engineer vibecoders to glance at session progress (cc:WIP / cc:TODO / cc:完了 counts, percentage, elapsed/estimated minutes, cost so far/estimate, drift alerts). Uses Plans.md as source of truth, ren...

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install harness-progress

Harness Release

Generic release automation for projects using Keep a Changelog + GitHub. Single confirmation gate then end-to-end automation: bump detection, CHANGELOG promotion, PR/main merge, tag, GitHub Release. Trigger: release, version bump, publish....

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install harness-release

Harness Review

HAR: Multi-angle code, plan, scope review. Security/quality check. Trigger: review, code review, plan review, scope analysis. Do NOT load for: implementation, new features, bugfix, setup, release.

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install harness-review

Harness Setup

HAR: Project init, tool setup, agent config, memory setup, skill mirror sync. Trigger: setup, init, new project, CI/Codex setup, harness-mem, mirror. Do NOT load for: implementation, review, release, planning.

Install

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

Harness Sync

HAR: Sync Plans.md with implementation. Drift detect, marker update, retrospective. Trigger: sync-status, where am I, check progress. --snapshot for snapshots. Do NOT load for: planning, implementation, review, release.

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install harness-sync

Harness Work

HAR: Execute Plans.md tasks from single task to full parallel team run. Trigger: implement, execute, do everything, breezing, team run, parallel, composer, composer 2.5. Do NOT load for: planning, review, release, setup.

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install harness-work

Harness Work

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install harness-work-skillsharness-work

Maintenance

File cleanup and archiving. Tidies up bloated Plans.md, session-log.md, old logs, and state files. Trigger: /maintenance, cleanup, archive, organize, split session-log. Do NOT load for: implementation, review, release, new feature developme...

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install maintenance

Memory

Manage SSOT, memory, and cross-tool memory search. Guardian of decisions.md and patterns.md. Use when user mentions memory, SSOT, decisions.md, patterns.md, merging, migration, SSOT promotion, sync memory, save learnings, memory search, har...

Install

/plugin marketplace add Chachamaru127/claude-code-harness
/plugin install memory

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