Capa

The package manager and MCP gateway for AI coding agents

Why · Features · Install · Quick start · Wrap · Web UI · Docs

Declare skills, tools, rules, sub-agents, MCP servers, hooks, and plugins once in capabilities.yaml. Run capa install. CAPA writes them into Cursor, Claude Code, Codex, Windsurf, GitHub Copilot, and 35+ other agents — native formats, pinned SHAs, zero manual sync. At runtime it is also the MCP gateway: every agent talks to one local endpoint; CAPA proxies upstream servers, lazy-loads tools, and scopes what each sub-agent can call.

https://github.com/user-attachments/assets/200a8cf9-7236-4cc0-a9e4-332bb6664b41

Why CAPA?

Agent config today is scattered across CLAUDE.md, .cursor/rules/, AGENTS.md, MCP JSON, hooks, and skill folders. No two teammates match. Nothing is pinned. Cloning the repo does not clone the agent setup.

CAPA collapses that into one version-controlled file next to your code — and a local MCP gateway in front of every tool:

• capabilities.yaml — source of truth for every capability
• capabilities.lock — SHA pins so tomorrow's clone gets the same bytes
• Marker blocks — surgical writes that leave hand-edited content alone
• MCP gateway — one endpoint per project; CAPA proxies stdio / HTTP / SSE servers, applies formatters, and records activity

The teammate who clones tomorrow gets the exact setup you have today.

Features

• One file → 35+ agents — write once; CAPA fans out to each provider's native layout (.cursor/rules/, .claude/agents/, AGENTS.md, …)
• MCP gateway — one local endpoint per agent; CAPA proxies upstream MCP servers, lazy-loads tools on demand, and filters tools per sub-agent
• Cheaper inference, same quality — on-demand tool loading instead of front-loading the whole catalog (19–40% fewer tokens across 150 trials on claude-opus-4-8)
• capa wrap — run Cursor, Claude, Codex, and more from a shadow workspace so provider dirs never touch your real repo
• Local Web UI — interactive capabilities editor with live YAML sync, registry browse, OAuth setup, and drag-to-reorder
• Activity traces — live feed of every MCP call, shell tool, and agent span on the project page
• Plugins that unpack — Claude and Cursor plugins decompose into skills, MCP, rules, sub-agents, and hooks
• Registries — browse skills.sh, Cursor Marketplace, Claude plugins, and Claude marketplace catalogs
• capa add --passthrough — write provider-native files directly when you want unmanaged one-offs
• Sub-agent isolation — each sub-agent gets a filtered MCP endpoint, so research agents never inherit a git push tool

Installation

macOS and Linux:

curl -LsSf https://capa.sh/install.sh | sh

Windows:

powershell -ExecutionPolicy ByPass -c "irm https://capa.sh/install.ps1 | iex"

Quick start

1. Initialize

cd your-project
capa init

Creates capabilities.yaml and registers the project with the local CAPA server (default http://localhost:5912).

2. Add capabilities

capa add vercel-labs/agent-skills@web-researcher
capa add --server --id brave --cmd npx --arg @brave/brave-search-mcp
capa registry search skills-sh "research"

3. Install