# Publishing to the MCP Registry
The [MCP Registry](https://registry.modelcontextprotocol.io/) lists MCP servers so users can discover and install them. To publish **Unity MCP Server** to the registry, follow the steps below.
## Prerequisites
- **npm account** — [Sign up](https://www.npmjs.com/signup) if needed. The registry verifies ownership via the published npm package.
- **GitHub account** — Authentication with GitHub is required so the registry can verify `io.github.rachitkumarrastogi/unity-mcp-server`.
## Step 1: Publish the package to npm
The registry only stores metadata; the actual package must be published to npm first.
```bash
cd /path/to/unity-mcp-server
npm install
npm run build
npm login # if not already logged in
npm publish --access public
```
If the name `unity-mcp-server` is already taken on npm, use a scoped name in `package.json` (e.g. `"name": "@rachitkumarrastogi/unity-mcp-server"`) and set the same value in `server.json` → `packages[0].identifier`. Keep `mcpName` in `package.json` as `io.github.rachitkumarrastogi/unity-mcp-server`.
## Step 2: Install the MCP Publisher CLI
**macOS / Linux:**
```bash
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/
```
**Homebrew:**
```bash
brew install mcp-publisher
```
**Windows:** See [Registry releases](https://github.com/modelcontextprotocol/registry/releases/latest) for the Windows binary.
Verify:
```bash
mcp-publisher --help
```
## Step 3: Log in to the registry (GitHub)
Authenticate as the GitHub user that owns the repository:
```bash
mcp-publisher login github
```
Follow the prompts (open the URL, enter the code, authorize). When the CLI reports success, login is complete.
## Step 4: Publish to the MCP Registry
From the repo root (where `server.json` lives):
```bash
mcp-publisher publish
```
Expected output is similar to:
```text
Publishing to https://registry.modelcontextprotocol.io...
✓ Successfully published
✓ Server io.github.rachitkumarrastogi/unity-mcp-server version 1.0.0
```
## Step 5: Confirm the listing
- Browse [registry.modelcontextprotocol.io](https://registry.modelcontextprotocol.io/) and search for “Unity” or “unity-mcp-server”.
- Or query the API:
```bash
curl "https://registry.modelcontextprotocol.io/v0.1/servers?search=unity-mcp-server"
```
## Updating the listing
After releasing a new version:
1. Bump `version` in `package.json` and in `server.json` (top-level and `packages[0].version`).
2. Run `npm run build` and `npm publish`.
3. Run `mcp-publisher publish` again.
## Troubleshooting
| Issue | What to do |
|-------|------------|
| “Registry validation failed for package” | Ensure `package.json` has `mcpName` exactly matching `server.json` → `name` (e.g. `io.github.rachitkumarrastogi/unity-mcp-server`). |
| “You do not have permission to publish this server” | With GitHub login, the server `name` must start with `io.github.<your-github-username>/`. Use the GitHub account that owns the repository. |
| “Invalid or expired Registry JWT token” | Run `mcp-publisher login github` again. |
## Official docs
- [Quickstart: Publish an MCP Server](https://github.com/modelcontextprotocol/registry/blob/main/docs/modelcontextprotocol-io/quickstart.mdx)
- [Package types (npm, PyPI, etc.)](https://github.com/modelcontextprotocol/registry/blob/main/docs/modelcontextprotocol-io/package-types.mdx)
- [Authentication options](https://github.com/modelcontextprotocol/registry/blob/main/docs/modelcontextprotocol-io/authentication.mdx)
