fix(stdio): close server transport on stdin EOF#1613
Open
rcdailey wants to merge 1 commit intomodelcontextprotocol:mainfrom
Open
fix(stdio): close server transport on stdin EOF#1613rcdailey wants to merge 1 commit intomodelcontextprotocol:mainfrom
rcdailey wants to merge 1 commit intomodelcontextprotocol:mainfrom
Conversation
Listen for the stdin "end" event so StdioServerTransport detects client disconnection as defined in step 1 of the MCP spec's stdio shutdown sequence. Previously the transport had no "end" listener, leaving servers unable to react to stdin closure without waiting for SIGTERM escalation. A guard flag prevents onclose from firing more than once when an explicit close() races with a late EOF event. Tests cover: EOF triggers close, duplicate-close guard, and clean EOF after a partial message.
@modelcontextprotocol/client
@modelcontextprotocol/server
@modelcontextprotocol/express
@modelcontextprotocol/hono
@modelcontextprotocol/node
commit: |
🦋 Changeset detectedLatest commit: afc81fa The changes in this PR will be included in the next version bump. This PR includes changesets to release 4 packages
Not sure what this means? Click here to learn what changesets are. Click here if you're a maintainer who wants to add another changeset to this PR |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
StdioServerTransportnever listened for theendevent on stdin. When a client initiates shutdown by closing stdin (step 1 of the MCP spec's stdio shutdown sequence), the server transport didn't detect it. The connection hung in a zombie state until the client escalated to SIGTERM (2 seconds later perStdioClientTransport.close()).This adds an
endlistener instart()that callsclose()on EOF, and an idempotency guard (_closedflag) to prevent doubleoncloseinvocation when explicitclose()and stdin EOF race.Related: #579