1.1 KiB
| @modelcontextprotocol/client |
|---|
| patch |
Probe stdio servers on a disposable sibling process. Some stdio servers exit on any pre-initialize request (servers built on the official Rust SDK, rmcp, behave this way), so under versionNegotiation: { mode: 'auto' } the server/discover probe previously killed the server and connect() hard-failed. The probe now runs on a short-lived sibling spawned from the same parameters — its stderr is discarded and it is reaped once the era is known — and the caller's transport spawns exactly once, afterwards: a legacy verdict connects with the plain initialize handshake (byte-identical to mode: 'legacy'), a modern verdict is adopted directly, and the session wire never carries server/discover. Closing the caller's transport during the probe aborts connect() with the typed SdkError(EraNegotiationFailed) and the session child is never spawned. On HTTP — and on custom stdio-shaped transports, which probe in place — a mid-probe connection close keeps rejecting with the typed connect error, now naming the close in pin-mode and modern-only diagnostics.