fix: omit OAuth resource on token refresh - #2590
Closed
he-yufeng wants to merge 1 commit into
Closed
Conversation
This was referenced May 27, 2026
Author
|
Closing this during backlog cleanup. The python-sdk queue has too many open PRs, and this older/no-human-signal item is lower priority than the remaining PRs that have recent validation, review discussion, or clearer current value. I can reopen or refresh it if maintainers want this specific change. |
9 tasks
fede-kamel
added a commit
to fede-kamel/python-sdk
that referenced
this pull request
Aug 19, 2026
…railing slash from PRM resource Two compounding bugs broke silent token refresh against Microsoft Entra ID v2.0 (AADSTS9010010), causing MCP servers using Entra OAuth to lose authentication after ~1 hour: - _refresh_token() sent the RFC 8707 resource parameter on refresh_token grants, which Entra v2.0 strictly rejects since March 2026. The parameter is now omitted from refresh requests. - Pydantic's AnyHttpUrl normalizes bare-domain PRM resource URLs to include a trailing slash, so the resource audience never matched the IdP app registration. get_resource_url() now strips the slash, but only when the path is exactly "/" with no query or fragment - RFC 9728 requires exact-string identity, so intentional trailing slashes on deeper paths are preserved. Implements the approach maintainers endorsed when consolidating earlier attempts (modelcontextprotocol#2590, since closed unmerged; see discussion on modelcontextprotocol#2645/modelcontextprotocol#2646). Fixes modelcontextprotocol#2578
fede-kamel
added a commit
to fede-kamel/python-sdk
that referenced
this pull request
Aug 20, 2026
…railing slash from PRM resource Two compounding bugs broke silent token refresh against Microsoft Entra ID v2.0 (AADSTS9010010), causing MCP servers using Entra OAuth to lose authentication after ~1 hour: - _refresh_token() sent the RFC 8707 resource parameter on refresh_token grants, which Entra v2.0 strictly rejects since March 2026. The parameter is now omitted from refresh requests. - Pydantic's AnyHttpUrl normalizes bare-domain PRM resource URLs to include a trailing slash, so the resource audience never matched the IdP app registration. get_resource_url() now strips the slash, but only when the path is exactly "/" with no query or fragment - RFC 9728 requires exact-string identity, so intentional trailing slashes on deeper paths are preserved. Implements the approach maintainers endorsed when consolidating earlier attempts (modelcontextprotocol#2590, since closed unmerged; see discussion on modelcontextprotocol#2645/modelcontextprotocol#2646). Fixes modelcontextprotocol#2578
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.
Summary
resourcefromrefresh_tokenrequestsresourceon authorization and initial token exchange requestsFixes #2578.
To verify
python -m py_compile src\mcp\client\auth\oauth2.py tests\client\test_auth.pyuv run pytest tests\client\test_auth.py -q --basetemp .tmp\pytest -p no:cacheprovideruv run ruff check src\mcp\client\auth\oauth2.py tests\client\test_auth.pyuv run ruff format --check src\mcp\client\auth\oauth2.py tests\client\test_auth.pyuv run pyright src\mcp\client\auth\oauth2.py tests\client\test_auth.pygit diff --check