feat: mcp server support in the router

[StarpTech]

Motivation and Context

This PR adds the Model Context Protocol (MCP) server implementation to the Cosmo Router, enabling seamless integration between GraphQL APIs and AI models like Claude, ChatGPT, and other LLMs.

Key Features

• MCP Server Implementation: Adds a dedicated MCP server implementation in the router
• Persisted Operations Integration: Leverages existing persisted operations to expose secure GraphQL operations to AI models
• Configurable Settings:
  • Enable/disable MCP server
  • Control port settings
  • Option to exclude mutations
  • Control schema exposure
  • Configure arbitrary operations execution
• Comprehensive Test Coverage: Added tests for all MCP functionality

How It Works

The MCP server exposes GraphQL operations as AI-callable tools, allowing AI models to:

1. Discover available operations
2. Understand input requirements through JSON schemas
3. Execute operations with appropriate parameters
4. Process returned data in natural language responses

Use Cases

• AI chatbots that query application data
• Voice assistants integrated with business systems
• Autonomous agents making data-informed decisions
• AI-powered data analysis and content generation

Security Considerations

• Respects existing authentication mechanisms
• Built on persisted operations for controlled access
• Optional flags to control mutation operations and schema exposure

Related PRs

Engine wundergraph/graphql-go-tools#1124
Docs wundergraph/cosmo-docs#48
Website https://github.com/wundergraph/website/pull/529

Checklist

• I have discussed my proposed changes in an issue and have received approval to proceed.
• I have followed the coding standards of the project.
• Tests or benchmarks have been added or updated.
• Documentation has been updated on https://github.com/wundergraph/cosmo-docs.
• I have read the Contributors Guide.

[github-actions]

Router image scan passed

✅ No security vulnerabilities found in image:

ghcr.io/wundergraph/cosmo/router:sha-f271d3719acbc2820b5885b424e182b320c50c97

[victoriris]

Hi @StarpTech, is the mcp gateway already supported in the router setup with docker-compose?
Ran a local experiment, but even after seeing it start in the logs and exposing the port the service does not handle HTTP requests to it

[StarpTech]

Hi @victoriris, to what exact setup are you referring to?

[victoriris]

@StarpTech I tried with the local docker examples + the MCP settings from the docs:

1. router-only and exposing the default MCP port: https://cosmo-docs.wundergraph.com/router/download-and-install#docker
2. full example, adding same mcp values to router config https://github.com/wundergraph/cosmo/blob/main/docker-compose.full.yml

Got both cases to run and load the operations, but the connection gets refused for the port 5025

[StarpTech]

Hi @victoriris, this has been addressed in #1825. After this, you can set mcp.server.listen_addr to 0.0.0.0:5025 to make it work with docker.