fix(transcript-server): normalize Accept header for lenient MCP compatibility#287
Draft
fix(transcript-server): normalize Accept header for lenient MCP compatibility#287
Conversation
@modelcontextprotocol/ext-apps
@modelcontextprotocol/server-basic-react
@modelcontextprotocol/server-basic-vanillajs
@modelcontextprotocol/server-budget-allocator
@modelcontextprotocol/server-cohort-heatmap
@modelcontextprotocol/server-customer-segmentation
@modelcontextprotocol/server-map
@modelcontextprotocol/server-pdf
@modelcontextprotocol/server-scenario-modeler
@modelcontextprotocol/server-shadertoy
@modelcontextprotocol/server-sheet-music
@modelcontextprotocol/server-system-monitor
@modelcontextprotocol/server-threejs
@modelcontextprotocol/server-transcript
@modelcontextprotocol/server-video-resource
@modelcontextprotocol/server-wiki-explorer
commit: |
…tibility - Patch rawHeaders (not just req.headers) for @hono/node-server compatibility - The SDK reads from rawHeaders which is normally immutable - Add HTTP logging middleware for debugging - Use app.post() with explicit 405 for GET/DELETE (per SDK examples)
ochafik
force-pushed
the
ochafik/fix-accept-header-normalization
branch
from
cf885fe to
a5d117f
Compare
Apply the same Accept header normalization fix to all example servers: - Patch rawHeaders for @hono/node-server compatibility - Use app.post() with explicit 405 for GET/DELETE - Fixes 406 errors when clients send Accept: */* or no Accept header
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
1 participant
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Problem
The MCP SDK's
StreamableHTTPServerTransportreturns 406 Not Acceptable when clients send:Accept: */*This happens because:
@hono/node-serverto convert Node.js requests to Web Standard Requests@hono/node-serverreads fromreq.rawHeaders(immutable array), notreq.headersreq.headers.acceptin middleware doesn't affect the SDK's header checkSolution
Patch
rawHeadersusingObject.defineProperty()to normalize the Accept header before the SDK processes the request.Changes
normalizeAcceptHeadermiddleware that patches bothreq.headersandrawHeadersapp.post()with explicit 405 handlers for GET/DELETE (per SDK examples)Testing
Next Steps
Will copy
main.tsto other example servers that use the same pattern.