Claude Code Plugin Marketplace Template

Start your team's (or your product's) Claude Code plugin marketplace in minutes: a ready-to-push repository with three working example plugins, a .claude/settings.json that auto-registers it for teammates, a GitHub Actions check, and mpcheck, an offline checker that catches the mistakes that make installs fail, including the ones claude plugin validate lets through.

• template/: copy it to a new repo. .claude-plugin/marketplace.json (name, owner, description, 3 entries), plugins/pr-helper (skill + slash command), plugins/team-conventions (skill), plugins/team-guardrails (read-only reviewer subagent + a PreToolUse hook that blocks force-pushes to main/master, exit code 2), .claude/settings.json (extraKnownMarketplaces + enabledPlugins), .github/workflows/validate-marketplace.yml, a README for your users, and tools/mpcheck.py.
• examples/broken-marketplace/: 11 entries with 27 planted errors, to see every check.
• tests/: 7 tests, including the template staying clean and in sync, and the hook's block/allow cases.

python3 tools/mpcheck.py check .            # errors and warnings, exit 1 on errors (--strict: on warnings too, --json)
python3 tools/mpcheck.py sync .             # add/update entries from plugins/*/.claude-plugin/plugin.json
python3 tools/mpcheck.py archive plugins/x --url-base https://files.example.com   # zip + sha256 + archive entry

It checks, per the Claude Code marketplace and manifest references (checked Nov 9, 2026):

• Marketplace: required name/owner/plugins, name characters, reserved and look-alike names (official names, other spellings such as claude.code.plugins, claude-plugins-v2, npm/gh, inline, claudeai-), missing description, unknown keys (Claude Code ignores typos silently), metadata.pluginRoot, renames chains.
• Entries: name rules and duplicates, reserved plugin names (claude-, anthropic-, cc-plugin- prefixes), ./ paths without .. or backslashes, folders that don't exist (validate passes, install fails), entry name vs plugin.json name (installing by the manifest name fails), version conflicts, hooks written as a path (never runs), strict: false conflicts, headers/headersHelper rules, directory-listing fields in entries.
• Sources: github owner/repo, 40-char lowercase sha, url/git-subdir fields, npm packages Claude Code refuses, archive https:// and sha256, command sources (ASCII, 500 chars, no 4-space runs, timeout 1-600, copy/link).
• Plugins: plugin.json JSON and name, component paths (./, no .., exist; agents must be files), homepage must parse as a URL, folders with no plugin content.

Use it alongside claude plugin validate, which is the authority for what Claude Code accepts; mpcheck runs without Claude Code installed (CI, pre-commit) and adds the install-time checks.

1. cp -r template ~/code/claude-plugins && cd ~/code/claude-plugins && git init 2. Rename acme-tools, the owner and the example plugins; edit the skills. 3. python3 tools/mpcheck.py sync . && python3 tools/mpcheck.py check . 4. Test locally: claude plugin marketplace add ./ then claude plugin install pr-helper@acme-tools. 5. Push to GitHub; teammates run claude plugin marketplace add <owner>/<repo>.

Run ./demo.sh for a tour and ./run_tests.sh for the tests. Python 3.9+, no dependencies.

• mpcheck doesn't fetch remote sources (github/npm/archive), so wrong repos or paths there show up at install time.
• Claude Code's rules change between versions; the checks match the documentation on Nov 9, 2026.
• Not affiliated with Anthropic.

Pairs with the Claude Code Subagents Pack and Claude Code Safety Hooks (both installable as plugins). License: LICENSE.txt.