Agent harness guide

Every agent harness type gets the same passive Cratis skills; only the install mechanics differ. This page walks each harness with the exact commands. Running several harnesses against the same repository is a separate topic: Multiple harnesses.

What every harness receives is identical in content: roughly fifty skills — a SKILL.md plus references and assets per skill, no hooks, no executable code, no MCP server. Skills are passive markdown; your assistant loads the matching one from the task, or you invoke it by name.

Harness	Install status
Claude Code	Installable today
OpenAI Codex	Installable today
GitHub Copilot	Installable today
Cursor	Installable today
Pi via npm	Published package today
Kiro, Junie, Gemini CLI	Pending per-host review

All marketplace installs resolve the real skills/ directory on the Cratis/AI default branch — what you install is exactly what a reviewer reads (Cratis/AI#264).

Claude Code

1. Add the Cratis marketplace:

   /plugin marketplace add Cratis/AI

2. Install the public plugin:

   /plugin install cratis@cratis

3. Verify: list installed plugins and confirm cratis appears, then ask your assistant something Cratis-shaped (“add a projection for order events”) and watch it load the matching skill.

4. Uninstall with /plugin uninstall cratis@cratis. Skills are passive — nothing is left in your project.

Cratis maintainers install the maintainer bundle the same way: /plugin install cratis-engineering@cratis. Grok and Junie read the same Claude-compatible manifests.

OpenAI Codex

codex plugin marketplace add Cratis/AI
codex plugin install cratis@cratis

The plugin carries the whole public bundle. Uninstall reverses it.

GitHub Copilot / VS Code

copilot plugin marketplace add Cratis/AI
copilot plugin install cratis@cratis

List and remove work the same way (copilot plugin list, copilot plugin uninstall cratis@cratis).

Cursor

Cursor resolves the same skills through its committed marketplace manifest (.cursor-plugin/marketplace.json at the repository root) — add the marketplace source in Cursor’s plugin settings and the skills appear. The manifest carries the identical canonical skill bytes; there is no Cursor-specific fork of the content.

Pi via npm

Pi installs ordinary npm packages. Today the published package is the unsupported @cratis/ai-fundamentals 0.x evaluation — the Fundamentals concept guidance, not the whole bundle:

# Project-scoped, exact pin recorded in .pi/settings.json
pi install -l npm:@cratis/ai-fundamentals@0.10.0

# User-wide
pi install npm:@cratis/ai-fundamentals@0.10.0

Commit .pi/settings.json after review; uninstalling removes the package and touches nothing else.

Pending: Kiro, Junie, Gemini CLI

• Kiro — skills-only Agent Plugins 1.0 packaging is prepared and byte-identical; manifest delivery and host review are pending.
• Junie — the skills-only Junie extension is prepared; host review is pending.
• Gemini CLI — an isolated install/list/remove smoke has passed, but the host wants a manifest at the repository root and this repository’s root carries none, so there is no working install today.

Status

All installs are an unsupported 0.x evaluation until the governed release gates pass. The versioned per-profile package flow (exact pins arriving as reviewed pull requests) is designed but not published — today the marketplace follows the Cratis/AI default branch and npm carries only @cratis/ai-fundamentals. Being listed in a vendor’s own marketplace UI is a separate, still-pending manual submission per host (Cratis/AI#147).