Add SSE transport support

[MathiasPaulenko]

Add SSE transport support

Context

WaveXisMCP currently supports two transports:

• stdio (default) — for local MCP clients like Claude Desktop, Cursor
• http — for CI/CD, shared instances, Docker

The MCP spec also defines SSE (Server-Sent Events) as a transport. Some MCP clients (notably older versions of some tools) prefer SSE over HTTP streaming. Adding SSE support would improve compatibility with a wider range of MCP clients.

What needs to happen

In wavexis-mcp

1. Add sse as a valid --transport option in wavexis_mcp/server.py
2. Implement SSE transport using the mcp library's SSE server (if available) or a custom implementation:
   • GET /sse — opens SSE stream, sends MCP messages as events
   • POST /messages — receives client messages
3. Add --sse-port flag (default: same as --port)
4. Update CLI help text
5. Update docs (docs/http-transport.md or new docs/sse-transport.md)

Implementation notes

• Check if the mcp Python SDK already provides an SSE transport (it may — check mcp.server.sse)
• If yes, just wire it up as a third transport option
• If no, implement using aiohttp or starlette SSE response
• SSE should work with the same --allow-remote and --port flags as HTTP
• Rate limiting should apply to SSE connections too

Getting started

1. Read wavexis_mcp/server.py to see how stdio and http transports are wired
2. Check the mcp package for SSE support: python -c "from mcp.server import sse; print(dir(sse))"
3. If SSE is available in the SDK, follow the same pattern as the HTTP transport
4. If not, implement a minimal SSE endpoint
5. Add tests
6. Update docs

References

• MCP transport spec
• Our HTTP transport docs
• mcp Python SDK