# Source: https://modelcontextprotocol.io/registry/remote-servers.md

> ## Documentation Index
> Fetch the complete documentation index at: https://modelcontextprotocol.io/llms.txt
> Use this file to discover all available pages before exploring further.

# 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 can use the Streamable HTTP transport (recommended) or the SSE transport. 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"
      }
    }
  ]
}
```