Publish an npm- or PyPI-packaged MCP server to the official MCP Registry (registry.modelcontextprotocol.io) using the mcp-publisher CLI and a server.json manifest, so MCP clients can discover the server by its io.github.* (or custom-domain) namespaced name.

Documented steps

1. Prerequisites: Node.js (if publishing a TypeScript/npm server), an npm account (the Registry only hosts metadata, not artifacts — the package itself must be published to npm or PyPI first), and a GitHub account (for GitHub-based authentication, the simplest of the registry's supported auth methods).
2. Add ownership-verification metadata to your package before publishing to npm/PyPI. For an npm package, add an `mcpName` field to package.json, e.g. "mcpName": "io.github.my-username/weather" — this value becomes the server's name in the Registry and, with GitHub auth, MUST start with `io.github.<your-github-username>/`. For a PyPI package, instead add a hidden marker to the package README (which becomes the PyPI description), e.g. `<!-- mcp-name: io.github.username/database-query-mcp -->`, on its own line, matching the server name exactly (the mcp-name: token must be followed by a boundary — newline, whitespace, HTML tag, or `-->` — not glued to trailing punctuation).
3. Publish the package itself to its registry first: for npm, `npm install`, `npm run build`, then `npm adduser` (if needed) and `npm publish --access public`; for PyPI, build and `twine upload`/`python -m build` per normal PyPI publishing steps, ensuring the README with the mcp-name marker is included as the package description.
4. Install the mcp-publisher CLI: macOS/Linux — curl -L "https://github.com/modelcontextprotocol/registry/releases/latest/download/mcp-publisher_$(uname -s | tr '[:upper:]' '[:lower:]')_$(uname -m | sed 's/x86_64/amd64/;s/aarch64/arm64/').tar.gz" | tar xz mcp-publisher && sudo mv mcp-publisher /usr/local/bin/ ; or via Homebrew: brew install mcp-publisher. Verify with: mcp-publisher --help (lists commands: init, login, logout, publish, status, validate).
5. In your server project directory, run `mcp-publisher init` to generate a server.json template, e.g.: {"$schema": "https://static.modelcontextprotocol.io/schemas/2025-12-11/server.schema.json", "name": "io.github.my-username/weather", "description": "...", "repository": {"url": "https://github.com/my-username/mcp-weather-server", "source": "github"}, "version": "1.0.1", "packages": [{"registryType": "npm", "identifier": "@my-username/mcp-weather-server", "version": "1.0.1", "transport": {"type": "stdio"}}]}. For PyPI packages use "registryType": "pypi" and the PyPI package identifier instead. The `name` field in server.json must match `mcpName` in package.json (npm) or the mcp-name README marker (PyPI).
6. Authenticate with GitHub device flow: run `mcp-publisher login github`, then visit https://github.com/login/device, enter the printed device code, and authorize — the CLI reports 'Successfully authenticated!'. (Other supported auth methods: GitHub OIDC for GitHub Actions, DNS verification, and HTTP verification, for non io.github.* namespaces such as me.adamjones/my-server tied to a domain.)
7. Optionally validate before publishing with `mcp-publisher validate` (checks server.json without publishing), then run `mcp-publisher publish` from the directory containing server.json. Success output looks like: 'Publishing to https://registry.modelcontextprotocol.io... ✓ Successfully published ✓ Server io.github.my-username/weather version 1.0.1'.
8. Verify the server is live by querying the Registry API: curl "https://registry.modelcontextprotocol.io/v0.1/servers?search=io.github.my-username/weather" — the JSON response should include your server's metadata under "servers".
9. Docs: https://raw.githubusercontent.com/modelcontextprotocol/registry/main/docs/modelcontextprotocol-io/quickstart.mdx , https://raw.githubusercontent.com/modelcontextprotocol/registry/main/docs/modelcontextprotocol-io/package-types.mdx , https://github.com/modelcontextprotocol/registry