How do I install the Add Harness skill?

Run npx skillmds@latest add rachidchabane/add-harness in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Add Harness safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Add Harness?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Add Harness free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Add Harness?

RachidChabane (@rachidchabane) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Add Harness by rachidchabane — Agent Skill

Name: Add Harness
Author: RachidChabane

Add Harness

Add support for a new AI coding harness (Cursor, Windsurf, Zed, Aider, …) to agentsync. Use when a tool you want to manage isn't in core/adapters/. Reads the harness's docs, scaffolds the adapter, and verifies it.

RachidChabane 7330ad0 2 files · 5.9 KB Updated Sep 17, 2026

File contents

Add a harness to agentsync

Adding a harness is judgment work (mapping the harness's config concepts) wrapped around a deterministic scaffold. Do the steps in order; don't skip the doc-reading.

1. Check it isn't already handled

Look in core/adapters/__init__.py (ADAPTERS) and config/profile.json. If the harness is there, stop — there's nothing to add.

2. Scaffold the adapter (deterministic)

python3 skills/add-harness/scaffold-adapter.py <name>

This writes core/adapters/<name>.py (stubbed) and registers it. It does NOT know the harness — you fill that in next.

3. Read the harness's docs (the judgment — do not guess)

Find and confirm, from the harness's own documentation:

Instructions — does it read a user-scope instructions/rules file? Where? (If only inline in settings, mirror VS Code's approach.)
MCP — its MCP config format and file location (or that it has none).
Skills/permissions — any skill-availability control (or none).
Enforcement (hooks) — the tricky part: can it run a command before a tool call? What JSON does the hook get on stdin (the command field name)? How does it signal "block"? If it has no hook surface but has a plugin system, mirror OpenCode's plugin. If it can't enforce at all, leave enforcement out of capabilities().

4. Fill the adapter

Implement capabilities() (honestly — only what the harness actually supports) and targets() using the existing target types (Link, Json, Merge, HookSpec). Reuse the shared core/enforcement/guard-commit.sh and session-nudge.sh — point the harness's hook at them per its contract; don't re-implement the gate. Keep extra_owned/extra_hooks from self._passthrough(ctx) so settings passthrough works.

5. Detection + test + verify

Add a detection line for it in init.sh.
Add assertions to tests/test_apply.py (its files render correctly in the sandbox).
Run make verify. It must pass before you're done.

Reference

core/adapters/claude.py (full-featured) and vscode.py (instructions-only, reuses another harness's hooks) are the two ends of the spectrum to copy from.

---name: add-harnessdescription: Add support for a new AI coding harness (Cursor, Windsurf, Zed, Aider, …) to agentsync. Use when a tool you want to manage isn't in core/adapters/. Reads the harness's docs, scaffolds the adapter, and verifies it.---# Add a harness to agentsyncAdding a harness is **judgment work** (mapping the harness's config concepts) wrappedaround a **deterministic scaffold**. Do the steps in order; don't skip the doc-reading.## 1. Check it isn't already handledLook in `core/adapters/__init__.py` (`ADAPTERS`) and `config/profile.json`. If theharness is there, stop — there's nothing to add.## 2. Scaffold the adapter (deterministic)```python3 skills/add-harness/scaffold-adapter.py <name>```This writes `core/adapters/<name>.py` (stubbed) and registers it. It does NOT know theharness — you fill that in next.## 3. Read the harness's docs (the judgment — do not guess)Find and confirm, from the harness's own documentation:- **Instructions** — does it read a user-scope instructions/rules file? Where? (If only inline in settings, mirror VS Code's approach.)- **MCP** — its MCP config format and file location (or that it has none).- **Skills/permissions** — any skill-availability control (or none).- **Enforcement (hooks)** — *the* tricky part: can it run a command before a tool call? What JSON does the hook get on stdin (the command field name)? How does it signal "block"? If it has no hook surface but has a plugin system, mirror OpenCode's plugin. If it can't enforce at all, leave `enforcement` out of `capabilities()`.## 4. Fill the adapterImplement `capabilities()` (honestly — only what the harness actually supports) and`targets()` using the existing target types (`Link`, `Json`, `Merge`, `HookSpec`). Reusethe shared `core/enforcement/guard-commit.sh` and `session-nudge.sh` — point theharness's hook at them per its contract; don't re-implement the gate. Keep`extra_owned`/`extra_hooks` from `self._passthrough(ctx)` so settings passthrough works.## 5. Detection + test + verify- Add a detection line for it in `init.sh`.- Add assertions to `tests/test_apply.py` (its files render correctly in the sandbox).- Run `make verify`. It must pass before you're done.## Reference`core/adapters/claude.py` (full-featured) and `vscode.py` (instructions-only, reusesanother harness's hooks) are the two ends of the spectrum to copy from.

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