fix(mcp): build well-known OAuth body before writing 200 status#2465
Merged
bflad merged 1 commit intoMay 1, 2026
Merged
Conversation
https://linear.app/speakeasy/issue/AGE-1970/bug-well-known-oauth-handlers-send-200-ok-before-error-paths-masking The two .well-known OAuth metadata handlers called WriteHeader(200) before constructing the JSON body. If body construction failed (marshal error or unrecognized result kind), oops.ErrHandle's second WriteHeader was silently dropped by net/http, so clients saw 200 OK with an error JSON body. Extract the body-build-then-write logic into two package-level helpers and add a regression test that asserts the helper does not touch the ResponseWriter when the result kind is unrecognized.
|
The latest updates on your projects. Learn more about Vercel for GitHub.
|
![claude[bot]](https://avatars.githubusercontent.com/in/1236702?s=60&v=4){kind=small}
There was a problem hiding this comment.
Claude Code Review
This repository is configured for manual code reviews. Comment @claude review to trigger a review and subscribe this PR to future pushes, or @claude review once for a one-time review.
Tip: disable this comment in your organization's Code Review settings.
🦋 Changeset detectedLatest commit: 1171755 The changes in this PR will be included in the next version bump. This PR includes changesets to release 1 package
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 |
qstearns
approved these changes
Apr 28, 2026
bflad
deleted the
bflad/age-1970-bug-well-known-oauth-handlers-send-200-ok-before-error-paths
branch
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 subscribe to this conversation on GitHub.
Already have an account?
Sign in.
2 participants
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
.well-knownOAuth metadata handlers inserver/internal/mcp/impl.gocalledw.WriteHeader(http.StatusOK)before building the JSON body. If body construction failed (json.Marshalerror or an unrecognizedOAuthServerMetadataResultKind), the handler returned an error tooops.ErrHandle, whose subsequentWriteHeader(code)was silently dropped bynet/http— clients saw200 OKwith an error JSON body shaped like{"name":"unexpected","message":"..."}.writeOAuthServerMetadataResponse,writeOAuthProtectedResourceMetadataResponse) so the body is fully built before any header is committed. Each helper documents the ordering invariant.server/internal/mcp/wellknown_oauth_test.gowith happy-path coverage plus a regression test that passes a bogus result kind and asserts the helper returns an error and leaves theResponseWriteruntouched (noContent-Type, empty body) — catches reintroductions of the original ordering.Notes
TestService_HandleWellKnownOAuth*tests still pass.