Support HTTP/SSE transport (mcpplay connect) #12
Description
Problem
mcpplay only supports stdio transport today. Many production MCP servers use HTTP (Streamable HTTP) or SSE transport. Users who want to test remote or HTTP-based servers have no way to connect.
Proposed solution
Add a mcpplay connect subcommand:
mcpplay connect http://localhost:3000/mcp # Streamable HTTP
mcpplay connect http://localhost:3000/sse # SSE (deprecated but still in use)This requires:
- A new transport adapter in the proxy layer alongside the existing stdio transport
- Using the MCP SDK's HTTP client instead of
stdio_client - Updating the CLI to accept a URL argument
- Showing the transport type (stdio/http/sse) in the UI server info badge
Alternatives considered
Users can wrap HTTP servers behind a stdio shim, but this defeats the purpose of a frictionless playground.