Remove SSE transport support (breaking change from upstream rmcp)

Context

The upstream rmcp crate has removed SSE (Server-Sent Events) transport support in PR modelcontextprotocol/rust-sdk#562. SSE has been removed from the MCP specification in favor of the more capable StreamableHttp transport.

This project must be updated to reflect this breaking change.

Files to Delete (13)

Source

  • src/transport/sse_server.rs - Entire SSE implementation

Examples

  • examples/counter_sse.rs
  • examples/authorization_proxy_sse_example.rs
  • examples/composition_sse_example.rs

Tests

  • tests/test_authorization_forwarding_sse.rs
  • tests/test_with_python.rs
  • tests/test_with_js/client.js
  • tests/test_with_js/server.js
  • tests/test_with_python/ (entire directory)

Snapshots

  • tests/snapshots/test_with_js__js_sse_client_responses.snap
  • tests/snapshots/test_with_python__python_sse_client_responses.snap

Files to Modify (5)

Cargo.toml

  • Remove transport-sse feature
  • Remove actix-rt dependency
  • Remove tokio-util dependency
  • Remove transport-sse-server from dev-dependencies rmcp features

src/transport/mod.rs

  • Remove SSE module documentation
  • Remove SSE module declaration and re-exports

src/lib.rs

  • Remove SSE references from documentation

tests/test_scope_composition.rs

  • Remove 3 SSE-specific tests
  • Update imports and documentation

tests/test_with_js.rs

  • Change feature gate to only require transport-streamable-http
  • Remove SSE test function

Breaking Change

This is a breaking change that removes the SseService, SseServerTransport, and SseServiceBuilder public types.