# Publish Your MCP Server

Complete guide to publishing an MCP server to the registry.

## What You'll Learn

By the end of this tutorial, you'll have:
- Created a server.json file for your MCP server
- Authenticated with the registry
- Successfully published your server
- Verified your server appears in the registry

## Prerequisites

- An MCP server you've already built ([follow this guide if you don't have one already](https://modelcontextprotocol.io/quickstart/server))
- Your server published to a package registry (npm, PyPI, Docker Hub, etc.)

## Step 1: Install the Publisher CLI

<!-- TODO: update once #358 solved -->

Download and build the MCP publisher tool:

```bash
# Clone the registry repository (requires Go 1.24+)
git clone https://github.com/modelcontextprotocol/registry
cd registry
make publisher

# The binary will be at cmd/publisher/bin/mcp-publisher
export PATH=$PATH:$(pwd)/cmd/publisher/bin
```

## Step 2: Initialize Your server.json

Navigate to your server's directory and create a template:

```bash
cd /path/to/your/mcp-server
mcp-publisher init
```

This creates a `server.json` with auto-detected values. You'll see something like:

```json
{
  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-07-09/server.schema.json",
  "name": "io.github.yourname/your-server",
  "description": "A description of your MCP server",
  "version_detail": {
    "version": "1.0.0"
  },
  "packages": [
    {
      "registry_type": "npm",
      "identifier": "your-package-name",
      "version": "1.0.0"
    }
  ]
}
```

## Step 3: Configure Your Server Details

Edit the generated `server.json`:

### Choose Your Namespace

The `name` field determines authentication requirements:

- **`io.github.yourname/*`** - Requires GitHub authentication
- **`com.yourcompany/*`** - Requires DNS or HTTP domain verification

### Add Package Validation

Your package must include validation metadata to prove ownership.


<details>
<summary><strong>📦 NPM Packages</strong></summary>

### Requirements
Add an `mcpName` field to your `package.json`:

```json
{
  "name": "your-npm-package",
  "version": "1.0.0",
  "mcpName": "io.github.username/server-name"
}
```

### How It Works
- Registry fetches `https://registry.npmjs.org/your-npm-package`
- Checks that `mcpName` field matches your server name
- Fails if field is missing or doesn't match

### Example server.json
```json
{
  "name": "io.github.username/server-name",
  "packages": [
    {
      "registry_type": "npm",
      "identifier": "your-npm-package",
      "version": "1.0.0"
    }
  ]
}
```

The official MCP registry currently only supports the NPM public registry (`https://registry.npmjs.org`).

</details>

<details>
<summary><strong>🐍 PyPI Packages</strong></summary>

### Requirements
Include your server name in your package README file using this format:

**MCP name format**: `mcp-name: io.github.username/server-name`

Add it to your README.md file (which becomes the package description on PyPI).

### How It Works
- Registry fetches `https://pypi.org/pypi/your-package/json`
- Passes if `mcp-name: server-name` is in the README content

### Example server.json
```json
{
  "name": "io.github.username/server-name",
  "packages": [
    {
      "registry_type": "pypi",
      "identifier": "your-pypi-package",
      "version": "1.0.0"
    }
  ]
}
```

The official MCP registry currently only supports the official PyPI registry (`https://pypi.org`).

</details>

<details>
<summary><strong>📋 NuGet Packages</strong></summary>

### Requirements
Include your server name in your package's README using this format:

**MCP name format**: `mcp-name: io.github.username/server-name`

Add a README file to your NuGet package that includes the server name.

### How It Works
- Registry fetches README from `https://api.nuget.org/v3-flatcontainer/{id}/{version}/readme`
- Passes if `mcp-name: server-name` is found in the README content

### Example server.json
```json
{
  "name": "io.github.username/server-name",
  "packages": [
    {
      "registry_type": "nuget",
      "identifier": "Your.NuGet.Package",
      "version": "1.0.0"
    }
  ]
}
```

The official MCP registry currently only supports the official NuGet registry (`https://api.nuget.org`).

</details>

<details>
<summary><strong>🐳 Docker/OCI Images</strong></summary>

### Requirements
Add an annotation to your Docker image:

```dockerfile
LABEL io.modelcontextprotocol.server.name="io.github.username/server-name"
```

### How It Works
- Registry authenticates with Docker Hub using public token
- Fetches image manifest using Docker Registry v2 API
- Checks that `io.modelcontextprotocol.server.name` annotation matches your server name
- Fails if annotation is missing or doesn't match

### Example server.json
```json
{
  "name": "io.github.username/server-name", 
  "packages": [
    {
      "registry_type": "oci",
      "identifier": "yourusername/your-mcp-server",
      "version": "1.0.0"
    }
  ]
}
```

The identifier is `namespace/repository`, and version is the tag and optionally digest.

The official MCP registry currently only supports the official Docker registry (`https://docker.io`).

</details>

<details>
<summary><strong>📁 MCPB Packages</strong></summary>

### Requirements
**MCP reference** - MCPB package URLs must contain "mcp" somewhere within them, to ensure the correct artifact has been uploaded. This may be with the `.mcpb` extension or in the name of your repository.

### Example server.json
```json
{
  "name": "io.github.username/server-name",
  "packages": [
    {
      "registry_type": "mcpb",
      "identifier": "https://github.com/you/your-repo/releases/download/v1.0.0/server.mcpb"
    }
  ]
}
```

The official MCP registry currently only supports artifacts hosted on GitHub or GitLab releases.

</details>

## Step 4: Authenticate

Choose your authentication method based on your namespace:

### GitHub Authentication (for io.github.* namespaces)

```bash
mcp-publisher login github
```

This opens your browser for OAuth authentication.

### DNS Authentication (for custom domains)

```bash
# Generate keypair
openssl genpkey -algorithm Ed25519 -out key.pem

# Get public key for DNS record
echo "_mcp-registry.yourcompany.com. IN TXT \"v=MCPv1; k=ed25519; p=$(openssl pkey -in key.pem -pubout -outform DER | tail -c 32 | base64)\""

# Add the TXT record to your DNS, then login
mcp-publisher login dns --domain yourcompany.com --private-key $(openssl pkey -in key.pem -noout -text | grep -A3 "priv:" | tail -n +2 | tr -d ' :\n')
```

## Step 5: Publish Your Server

With authentication complete, publish your server:

```bash
mcp-publisher publish
```

You'll see output like:
```
✓ Validating server.json
✓ Checking package ownership
✓ Publishing to registry
✓ Server published successfully!

Your server is now available at:
https://registry.modelcontextprotocol.io/servers/io.github.yourname/weather-server
```

## Step 6: Verify Publication

Check that your server appears in the registry:

```bash
curl https://registry.modelcontextprotocol.io/servers/io.github.yourname/weather-server
```

You should see your server metadata returned as JSON.

## Troubleshooting

**"Package validation failed"** - Ensure your package includes the required validation metadata (mcpName field, README mention, or Docker label).

**"Authentication failed"** - Verify you've correctly set up DNS records or are logged into the right GitHub account.

**"Namespace not authorized"** - Your authentication method doesn't match your chosen namespace format.

## Next Steps

- **Update your server**: Publish new versions with updated server.json files
- **Set up CI/CD**: Automate publishing with [GitHub Actions](github-actions.md)
- **Learn more**: Understand [server.json format](../../reference/server-json/generic-server-json.md) in depth

## What You've Accomplished

You've successfully published your first MCP server to the registry! Your server is now discoverable by MCP clients and can be installed by users worldwide.