Multi-agent
One repository serves Claude Code, GitHub Copilot, OpenAI Codex and Cursor. The plugin content is shared across all of them.
AGent Marketplace Kit
Ship a plugin marketplace for every AI coding agent.
agmk scaffolds and manages plugin marketplaces for
Claude Code, GitHub Copilot, OpenAI Codex
and Cursor — one canonical catalog, distributed through
any Git forge with a plain git push.
npm install -g @agmkit/cli
- MIT license
- Node ≥ 22
- Zero lock-in
npx @agmkit/cli— nothing to install
One repo serves
- Claude Code
- GitHub Copilot
- OpenAI Codex
- Cursor
Distributed via
- GitHub
- GitLab
- Bitbucket
- Gitea
- self-hosted
Why agmk
Like ng for Angular — but for agent plugin marketplaces
init gives you a push-ready repository; add, build, sync, bump and validate cover the whole life of the project afterwards.
Forge-agnostic
Distribute via GitHub, GitLab, Bitbucket, Gitea or self-hosted — with a plain git push. No registry account, no lock-in.
One source of truth
A single canonical .claude-plugin/marketplace.json. Generated registries derive from it — and never drift.
Full lifecycle
init · add · build · sync · bump · validate · list — from first scaffold to versioned releases with changelogs.
Reference, vendor, or scaffold
Catalog a remote plugin by reference (no clone), vendor a template into your repo with --vendor, or scaffold from built-in templates.
CI-ready
Generated GitHub Actions / GitLab CI out of the box, with validate and build --check gates that fail on drift.
How it works
One canonical catalog → every agent → any forge
agmk always writes one canonical catalog plus your plugins. How each agent reads it falls into three groups: native, generated by agmk build, or not supported yet. New to this? Start with what a plugin marketplace is.
Native — no build step
Claude Code and GitHub Copilot read .claude-plugin/marketplace.json directly. Push the repo and it installs.
Generated — agmk build
Codex and Cursor install from their own committed registry, derived from the same catalog. Run build once; add / bump / sync keep it fresh automatically.
Not supported yet
Gemini, OpenCode, Windsurf and Kiro can be passed to --agents, but nothing is generated for them — a marketplace is not installable from these agents today. They have no registry concept, so supporting them means a different distribution model, not just another generator.
Quick start
Your first marketplace in four steps
Requires Node.js ≥ 22. Run it on demand with npx — nothing to install.
$ npx @agmkit/cli init my-marketplace # 1 · scaffold a push-ready repo
◆ marketplace.json · plugins/ · AGENTS.md · CI — ready to push
$ cd my-marketplace && agmk add skill tdd-coach # 2 · add a plugin
◆ plugins/tdd-coach scaffolded · catalog + README updated
$ agmk validate # 3 · check the catalog
✔ catalog valid — 1 plugin, 0 errors
$ git push -u origin main # 4 · distribute via git
🎉 anyone can now install your plugins straight from the repo
claude> /plugin install tdd-coach@my-marketplace
init targets Claude Code and GitHub Copilot by default; add --agents codex,cursor to serve more. --agents also accepts gemini, opencode, windsurf and kiro, but those are recorded as intent only — nothing is generated and consumers cannot install from them yet.
Commands
Seven commands, the whole lifecycle
agmk init
Scaffolds a git-first marketplace: catalog, plugins/, per-agent README, team settings, CI. --plugin scaffolds a standalone plugin instead.
agmk add
Registers a plugin: reference a remote repo (no clone), vendor it with --vendor, or scaffold from a template — skill, command, agent, hook, mcp.
agmk build
Generates the Codex and Cursor registries from the catalog. --check fails on drift — made for CI.
agmk sync
Reconciles the catalog with what's on disk: adds missing entries, fixes drift, flags orphans, regenerates docs and registries.
agmk bump
Bumps a plugin version from conventional commits, prepends a dated CHANGELOG.md entry, and can commit + tag with --tag.
agmk validate
Local checks plus delegation to claude plugin validate when available. Non-zero exit on error — CI-ready.
agmk list
Lists the available plugin templates, built-in and local.
Adding plugins
Reference. Vendor. Scaffold.
A plugin can live inside your marketplace or stay in its own repo, fetched at install time. agmk add handles every case.
Reference default
Catalog a remote plugin by reference — nothing is cloned; the agent fetches it at install time. Pin with --ref / --sha.
agmk add acme/deploy-plugin deployVendor
Clone a remote template into your repo so the plugin lives — and releases — with your marketplace.
agmk add gh:org/templates/kata kata --vendorScaffold
Start from a built-in or local template — or create a standalone plugin, no marketplace, with init --plugin.
agmk add skill tdd-coachFAQ
Questions, answered
What is agmk?
agmk is an open-source CLI (npm package) that scaffolds and manages plugin marketplaces for AI coding agents. Think ng for Angular, but for agent plugin marketplaces: init gives you a push-ready repository, and add, build, sync, bump and validate cover the whole life of the project afterwards.
Which AI coding agents does agmk support?
One repository serves Claude Code, GitHub Copilot, OpenAI Codex and Cursor. Claude Code and GitHub Copilot read the canonical catalog natively; for Codex and Cursor, agmk build generates their committed registries from the same catalog. Gemini, OpenCode, Windsurf and Kiro are accepted by --agents but recorded as intent only — no artifacts are generated, so a marketplace is not installable from these agents yet.
Do I need a build step?
Not for Claude Code or GitHub Copilot — they read .claude-plugin/marketplace.json as-is. For OpenAI Codex and Cursor, run agmk build once; after that, add, bump and sync keep the generated registries fresh automatically.
Can I distribute my marketplace outside GitHub?
Yes. agmk is forge-agnostic by design: distribute via GitHub, GitLab, Bitbucket, Gitea or any self-hosted Git forge with a plain git push. On github.com it uses the owner/repo shorthand; everywhere else it emits the git URL form, which every supported agent accepts.
How do consumers install my plugins?
With their agent's own command. Claude Code: /plugin marketplace add owner/repo then /plugin install name@marketplace. GitHub Copilot: copilot plugin marketplace add. OpenAI Codex: codex plugin marketplace add. Cursor: add the marketplace, then install the plugin by name.
Is agmk free?
Yes — agmk is MIT-licensed and free to use. It requires Node.js ≥ 22, and you can run it without installing via npx @agmkit/cli. It is an unofficial community tool, not affiliated with Anthropic, GitHub, OpenAI or Cursor.