feat: add health check endpoint to mcp server

[ashwin-ranade]

Summary

Adds a simple /health endpoint that returns HTTP 200 for Kubernetes/Docker health checks.

Motivation

Container orchestration platforms need a basic HTTP endpoint for readiness probes. The existing /mcp endpoint expects MCP protocol requests and authentication, making it unsuitable for standard health checks.

Changes

• Added GET /health endpoint returning {"status": "healthy", "service": "mongodb-mcp"}
• Placed before authentication middleware to work with all configurations
• Added test coverage in existing streamableHttp test suite

Testing

All existing tests pass (13/13 in streamableHttp test suite), including new health endpoint tests with and without custom headers configured.

Manual verification:

Run mongodb-mcp-server via Node:

mongodb-mcp-server % npm start

Verify health endpoint works by curl-ing it in a different terminal:

ashwin.ranade@SGMDXFQXMK4K3 ~ % curl http://localhost:3000/health
{"status":"healthy","service":"mongodb-mcp"}%

[Copilot]

Pull Request Overview

This PR adds a health check endpoint to the MCP server's HTTP transport layer to support container orchestration and monitoring systems. The endpoint is designed to be accessible without authentication.

Key changes:

• Added a /health GET endpoint that returns a JSON response with status and service information
• Positioned the health endpoint before authentication middleware to ensure it's always accessible

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/transports/streamableHttp.ts	Implements the /health endpoint before authentication middleware
tests/integration/transports/streamableHttp.test.ts	Adds integration test verifying the health endpoint works without authentication

[nirinchev]

Hey, thank you so much for this contribution! The code looks good to me, but we would need you to sign the MongoDB Contributor Agreement before we can merge it.

[fmenezes]

it looks good to me 🎉

[fmenezes]

@ashwin-ranade let us know when you've signed https://www.mongodb.com/legal/contributor-agreement