Skip to content

fix: Handle SSE controller closed state in error logging #795

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
jirispilka merged 2 commits into from
May 6, 2026
+4 −1
Merged

fix: Handle SSE controller closed state in error logging #795

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
376ca88
fix: Downgrade SSE controller-closed write errors to softFail
claude May 5, 2026
493556f
chore: Drop the SSE softFail unit test
claude May 5, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 4 additions & 1 deletion src/mcp/server.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -535,8 +535,11 @@ export class ActorsMcpServer {
// - "Failed to send response: Error: Not connected" (client vanished mid-flight)
// - "Conflict: Only one SSE stream is allowed per session" (duplicate GET on the
// streamable-http transport, e.g. tab refresh before the old SSE controller is GC'd)
// - "Invalid state: Controller is already closed" (ERR_INVALID_STATE from
// WebStandardStreamableHTTPServerTransport.writeSSEEvent when the SSE ReadableStream
// controller was closed by client cancellation before a queued event was flushed)
// All are expected; log as softFail so they don't flood Mezmo error alerts.
if (/Not connected|No connection established|Only one SSE stream/i.test(error.message ?? '')) {
if (/Not connected|No connection established|Only one SSE stream|Controller is already closed/i.test(error.message ?? '')) {
// Mezmo (logDNA) promotes log entries to errors when the message contains "error".
// Use errMessage key and sanitize the string to preserve the soft-fail log level.
const errMessage = (error.message ?? '').replace(/ error:/gi, ' failure:');
Expand Down