Example Mcp Sse

migration-focused starter for building MCP servers on Streamable HTTP, replacing the deprecated SSE transport. uses TypeScript SDK v2 pre-alpha.

part of a series: stdio · stateless · stateful · sse (you are here)

what it does

• runnable Streamable HTTP server with session management, event replay, and graceful shutdown
• scaffold CLI (create-mcp-streamable-starter / create-mcp-sse-starter) to generate new projects from a proven template
• calculator demo with tools, resources, prompts, and structured output to exercise all MCP primitives
• vendored SDK v2 alpha tarballs for reproducible installs without npm registry dependency
• smoke tests for both the root project and scaffolded output
• CI workflow that validates root build, lint, typecheck, and generated project end-to-end

quick start

npm install
npm run dev

the server starts at http://127.0.0.1:3000 with these endpoints:

endpoint	method	purpose
/mcp	POST	JSON-RPC request/response
/mcp	GET	notification stream (stateful SSE)
/mcp	DELETE	session termination
/health	GET	health check with active session list
/	GET	server metadata

configure with environment variables or CLI flags:

PORT=4000 npm run dev
# or
npm run dev -- --port 4000

scaffold cli

generate a new MCP Streamable HTTP project:

npm run create -- --name my-server --target ./my-server
cd my-server
npm install
npm run dev

the generated project includes the full server module structure, vendored SDK tarballs, and its own smoke test. see docs/03-scaffold-cli.md for the complete reference.

documentation

doc	description
docs/README.md	documentation hub and reading order
docs/01-getting-started.md	prerequisites, install, run, verify
docs/02-architecture.md	module layout, request lifecycle, design rationale
docs/03-scaffold-cli.md	CLI reference, generated structure, extension workflow
docs/04-sdk-v2-notes.md	v2 packages, migration checklist, vendoring strategy
docs/05-validation.md	root and generated project validation, release checklist

sdk v2 context

this project targets the MCP TypeScript SDK v2 pre-alpha (2.0.0-alpha.0). v2 splits the monolithic @modelcontextprotocol/sdk into @modelcontextprotocol/server, @modelcontextprotocol/client, and @modelcontextprotocol/node. the server-side SSEServerTransport is removed; NodeStreamableHTTPServerTransport from @modelcontextprotocol/node is the replacement. v1.x remains the stable production recommendation from the upstream project. vendored tarballs in vendor/ pin the exact alpha artifacts for reproducible builds.

license

MIT