Publishing Remote Servers

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# Publishing Remote Servers ## Transport Type ## URL Template Variables ## HTTP Headers ## Supporting Remote and Non-remote Installation

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# Publishing Remote Servers

<Note>
  The MCP Registry is currently in preview. Breaking changes or data resets may occur before general availability. If you encounter any issues, please report them on [GitHub](https://github.com/modelcontextprotocol/registry/issues).
</Note>

The MCP Registry supports remote MCP servers via the `remotes` property in `server.json`:

```json server.json highlight={7-12} theme={null}
{
  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-12-11/server.schema.json",
  "name": "com.example/acme-analytics",
  "title": "ACME Analytics",
  "description": "Real-time business intelligence and reporting platform",
  "version": "2.0.0",
  "remotes": [
    {
      "type": "streamable-http",
      "url": "https://analytics.example.com/mcp"
    }
  ]
}
```

A remote server **MUST** be publicly accessible at its specified URL.

## Transport Type

Remote servers should use the Streamable HTTP transport. The SSE transport is [deprecated](/specification/draft/deprecated), so publish an `"sse"` remote only to support existing clients. Remote servers can also support both transports simultaneously at different URLs.

Specify the transport by setting the `type` property of the `remotes` entry to either `"streamable-http"` or `"sse"`:

```json server.json highlight={9,13} theme={null}
{
  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-12-11/server.schema.json",
  "name": "com.example/acme-analytics",
  "title": "ACME Analytics",
  "description": "Real-time business intelligence and reporting platform",
  "version": "2.0.0",
  "remotes": [
    {
      "type": "streamable-http",
      "url": "https://analytics.example.com/mcp"
    },
    {
      "type": "sse",
      "url": "https://analytics.example.com/sse"
    }
  ]
}
```

## URL Template Variables

Remote servers can define URL template variables using `{curly_braces}` notation. This enables multi-tenant deployments where a single server definition can support multiple endpoints with configurable values:

```json server.json highlight={10-17} theme={null}
{
  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-12-11/server.schema.json",
  "name": "com.example/acme-analytics",
  "title": "ACME Analytics",
  "description": "Real-time business intelligence and reporting platform",
  "version": "2.0.0",
  "remotes": [
    {
      "type": "streamable-http",
      "url": "https://{tenant_id}.analytics.example.com/mcp",
      "variables": {
        "tenant_id": {
          "description": "Your tenant identifier (e.g., 'us-cell1', 'emea-cell1')",
          "isRequired": true
        }
      }
    }
  ]
}
```

When configuring this server, users provide their `tenant_id` value, and the URL template gets resolved to the appropriate endpoint (e.g., `https://us-cell1.analytics.example.com/mcp`).

Variables support additional properties like `default`, `choices`, and `isSecret`:

```json server.json highlight={12-22} theme={null}
{
  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-12-11/server.schema.json",
  "name": "com.example/multi-region-mcp",
  "title": "Multi-Region MCP",
  "description": "MCP server with regional endpoints",
  "version": "1.0.0",
  "remotes": [
    {
      "type": "streamable-http",
      "url": "https://api.example.com/{region}/mcp",
      "variables": {
        "region": {
          "description": "Deployment region",
          "isRequired": true,
          "choices": [
            "us-east-1",
            "eu-west-1",
            "ap-southeast-1"
          ],
          "default": "us-east-1"
        }
      }
    }
  ]
}
```

## HTTP Headers

MCP clients can be instructed to send specific HTTP headers by adding the `headers` property to the `remotes` entry:

```json server.json highlight={11-18} theme={null}
{
  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-12-11/server.schema.json",
  "name": "com.example/acme-analytics",
  "title": "ACME Analytics",
  "description": "Real-time business intelligence and reporting platform",
  "version": "2.0.0",
  "remotes": [
    {
      "type": "streamable-http",
      "url": "https://analytics.example.com/mcp",
      "headers": [
        {
          "name": "X-API-Key",
          "description": "API key for authentication",
          "isRequired": true,
          "isSecret": true
        }
      ]
    }
  ]
}
```

## Supporting Remote and Non-remote Installation

The `remotes` property can coexist with the `packages` property in `server.json` in order to allow MCP host applications to choose the preferred method of installation.

```json server.json highlight={7-22} theme={null}
{
  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-12-11/server.schema.json",
  "name": "io.github.username/email-integration-mcp",
  "title": "Email Integration",
  "description": "Send emails and manage email accounts",
  "version": "1.0.0",
  "remotes": [
    {
      "type": "streamable-http",
      "url": "https://email.example.com/mcp"
    }
  ],
  "packages": [
    {
      "registryType": "npm",
      "identifier": "@example/email-integration-mcp",
      "version": "1.0.0",
      "transport": {
        "type": "stdio"
      }
    }
  ]
}
```