René's URL Explorer Experiment


Title: fix: stop the standalone GET stream reconnecting forever on empty connections by heyhayes · Pull Request #3087 · modelcontextprotocol/python-sdk · GitHub

Open Graph Title: fix: stop the standalone GET stream reconnecting forever on empty connections by heyhayes · Pull Request #3087 · modelcontextprotocol/python-sdk

X Title: fix: stop the standalone GET stream reconnecting forever on empty connections by heyhayes · Pull Request #3087 · modelcontextprotocol/python-sdk

Description: Summary Split out from #2122. Since that PR was opened, its core fix — propagating an error to a waiting request when an SSE stream ends without a response — has landed upstream independently via the _resolve_abandoned_request helper (introduced in #3047), which resolves an abandoned request with a synthesized error both when an id-bearing stream ends unresumably and when reconnection attempts are exhausted. This PR carries forward only the two fixes from #2122 that are not covered by that work. Relates to #1401. What changed Stop the standalone GET stream reconnecting forever on empty connections. handle_get_stream reset its attempt counter to 0 whenever a connection ended "normally" — i.e. the async for over the SSE events completed without raising. A server that accepts the GET but immediately closes the stream with no events hits exactly this path, so the counter never advances and the client reconnects in an unbounded loop (throttled only by the reconnect delay). The counter now resets only when events were actually received; empty connections count toward MAX_RECONNECTION_ATTEMPTS, so the loop gives up. That give-up branch was previously marked unreachable (# pragma: no cover) — it is now reachable and covered by a test. Log unhandled exceptions in the default message handler. Transport-level errors not tied to a specific pending request (e.g. a GET stream failure) reach _default_message_handler as an Exception item and were silently discarded. It now logs a warning as an observability safety net. Testing New regression test drives repeated empty GET streams and asserts the loop terminates after MAX_RECONNECTION_ATTEMPTS rather than reconnecting forever. New test asserts _default_message_handler logs a warning for an Exception item. Full suite green; both changed files at 100% branch coverage.

Open Graph Description: Summary Split out from #2122. Since that PR was opened, its core fix — propagating an error to a waiting request when an SSE stream ends without a response — has landed upstream independently via t...

X Description: Summary Split out from #2122. Since that PR was opened, its core fix — propagating an error to a waiting request when an SSE stream ends without a response — has landed upstream independently via t...

Opengraph URL: https://github.com/modelcontextprotocol/python-sdk/pull/3087

X: @github

direct link

Domain: github.com

route-pattern/:user_id/:repository/pull/:id/files(.:format)
route-controllerpull_requests
route-actionfiles
fetch-noncev2:789bf967-8d6c-e0a5-a8e2-f06efcaf30a3
current-catalog-service-hashae870bc5e265a340912cde392f23dad3671a0a881730ffdadd82f2f57d81641b
request-idB724:1FBD82:19CC6B5:21E563C:6A5C786C
html-safe-nonce325a3335107538b455c14a8c835cd002c8531b3428a48e1250e1a352b0efdbf9
visitor-payloadeyJyZWZlcnJlciI6IiIsInJlcXVlc3RfaWQiOiJCNzI0OjFGQkQ4MjoxOUNDNkI1OjIxRTU2M0M6NkE1Qzc4NkMiLCJ2aXNpdG9yX2lkIjoiNjYyMzY2MzkwOTU4NDUzMzYxMiIsInJlZ2lvbl9lZGdlIjoiaWFkIiwicmVnaW9uX3JlbmRlciI6ImlhZCJ9
visitor-hmac06c1f75af66cc9a71d1c4a847674414c37b5c939d302bcc7edfdec935a406d1f
hovercard-subject-tagpull_request:4031886296
github-keyboard-shortcutsrepository,pull-request-list,pull-request-conversation,pull-request-files-changed,copilot
google-site-verificationApib7-x98H0j5cPqHWwSMm6dNU4GmODRoqxLiDzdx9I
octolytics-urlhttps://collector.github.com/github/collect
analytics-location///pull_requests/show/files
fb:app_id1401488693436528
apple-itunes-appapp-id=1477376905, app-argument=https://github.com/modelcontextprotocol/python-sdk/pull/3087/files
twitter:imagehttps://avatars.githubusercontent.com/u/39026099?s=400&v=4
twitter:cardsummary_large_image
og:imagehttps://avatars.githubusercontent.com/u/39026099?s=400&v=4
og:image:altSummary Split out from #2122. Since that PR was opened, its core fix — propagating an error to a waiting request when an SSE stream ends without a response — has landed upstream independently via t...
og:site_nameGitHub
og:typeobject
hostnamegithub.com
expected-hostnamegithub.com
None5290d7e14309ad1e76106a9c4237bd1041517e83ea182c8ab756752cb0c6940b
turbo-cache-controlno-preview
diff-viewunified
go-importgithub.com/modelcontextprotocol/python-sdk git https://github.com/modelcontextprotocol/python-sdk.git
octolytics-dimension-user_id182288589
octolytics-dimension-user_loginmodelcontextprotocol
octolytics-dimension-repository_id862584018
octolytics-dimension-repository_nwomodelcontextprotocol/python-sdk
octolytics-dimension-repository_publictrue
octolytics-dimension-repository_is_forkfalse
octolytics-dimension-repository_network_root_id862584018
octolytics-dimension-repository_network_root_nwomodelcontextprotocol/python-sdk
turbo-body-classeslogged-out env-production page-responsive full-width
disable-turbotrue
browser-stats-urlhttps://api.github.com/_private/browser/stats
browser-errors-urlhttps://api.github.com/_private/browser/errors
release9c975978430e9ad293956f2bbdaf153b1bd84a99
ui-targetfull
theme-color#1e2327
color-schemelight dark

Links:

Skip to contenthttps://github.com/modelcontextprotocol/python-sdk/pull/3087/files#start-of-content
https://github.com/
Sign in https://github.com/login?return_to=https%3A%2F%2Fgithub.com%2Fmodelcontextprotocol%2Fpython-sdk%2Fpull%2F3087%2Ffiles
GitHub CopilotWrite better code with AIhttps://github.com/features/copilot
GitHub Copilot appDirect agents from issue to mergehttps://github.com/features/ai/github-app
MCP RegistryNewIntegrate external toolshttps://github.com/mcp
ActionsAutomate any workflowhttps://github.com/features/actions
CodespacesInstant dev environmentshttps://github.com/features/codespaces
IssuesPlan and track workhttps://github.com/features/issues
Code ReviewManage code changeshttps://github.com/features/code-review
GitHub Advanced SecurityFind and fix vulnerabilitieshttps://github.com/security/advanced-security
Code securitySecure your code as you buildhttps://github.com/security/advanced-security/code-security
Secret protectionStop leaks before they starthttps://github.com/security/advanced-security/secret-protection
Why GitHubhttps://github.com/why-github
Documentationhttps://docs.github.com
Bloghttps://github.blog
Changeloghttps://github.blog/changelog
Marketplacehttps://github.com/marketplace
View all featureshttps://github.com/features
Enterpriseshttps://github.com/enterprise
Small and medium teamshttps://github.com/team
Startupshttps://github.com/enterprise/startups
Nonprofitshttps://github.com/solutions/industry/nonprofits
App Modernizationhttps://github.com/solutions/use-case/app-modernization
DevSecOpshttps://github.com/solutions/use-case/devsecops
DevOpshttps://github.com/solutions/use-case/devops
CI/CDhttps://github.com/solutions/use-case/ci-cd
View all use caseshttps://github.com/solutions/use-case
Healthcarehttps://github.com/solutions/industry/healthcare
Financial serviceshttps://github.com/solutions/industry/financial-services
Manufacturinghttps://github.com/solutions/industry/manufacturing
Governmenthttps://github.com/solutions/industry/government
View all industrieshttps://github.com/solutions/industry
View all solutionshttps://github.com/solutions
AIhttps://github.com/resources/articles?topic=ai
Software Developmenthttps://github.com/resources/articles?topic=software-development
DevOpshttps://github.com/resources/articles?topic=devops
Securityhttps://github.com/resources/articles?topic=security
View all topicshttps://github.com/resources/articles
Customer storieshttps://github.com/customer-stories
Events & webinarshttps://github.com/resources/events
Ebooks & reportshttps://github.com/resources/whitepapers
Business insightshttps://github.com/solutions/executive-insights
GitHub Skillshttps://skills.github.com
Documentationhttps://docs.github.com
Customer supporthttps://support.github.com
Community forumhttps://github.com/orgs/community/discussions
Trust centerhttps://github.com/trust-center
Partnershttps://github.com/partners
View all resourceshttps://github.com/resources
GitHub SponsorsFund open source developershttps://github.com/open-source/sponsors
Security Labhttps://securitylab.github.com
Maintainer Communityhttps://maintainers.github.com
Acceleratorhttps://github.com/open-source/accelerator
GitHub Starshttps://stars.github.com
Archive Programhttps://archiveprogram.github.com
Topicshttps://github.com/topics
Trendinghttps://github.com/trending
Collectionshttps://github.com/collections
Enterprise platformAI-powered developer platformhttps://github.com/enterprise
GitHub Advanced SecurityEnterprise-grade security featureshttps://github.com/security/advanced-security
Copilot for BusinessEnterprise-grade AI featureshttps://github.com/features/copilot/copilot-business
Premium SupportEnterprise-grade 24/7 supporthttps://github.com/enterprise/premium-support
Pricinghttps://github.com/pricing
Search syntax tipshttps://docs.github.com/search-github/github-code-search/understanding-github-code-search-syntax
documentationhttps://docs.github.com/search-github/github-code-search/understanding-github-code-search-syntax
Sign in https://github.com/login?return_to=https%3A%2F%2Fgithub.com%2Fmodelcontextprotocol%2Fpython-sdk%2Fpull%2F3087%2Ffiles
Sign up https://github.com/signup?ref_cta=Sign+up&ref_loc=header+logged+out&ref_page=%2F%3Cuser-name%3E%2F%3Crepo-name%3E%2Fpull_requests%2Fshow%2Ffiles&source=header-repo&source_repo=modelcontextprotocol%2Fpython-sdk
Reloadhttps://github.com/modelcontextprotocol/python-sdk/pull/3087/files
Reloadhttps://github.com/modelcontextprotocol/python-sdk/pull/3087/files
Reloadhttps://github.com/modelcontextprotocol/python-sdk/pull/3087/files
Please reload this pagehttps://github.com/modelcontextprotocol/python-sdk/pull/3087/files
modelcontextprotocol https://github.com/modelcontextprotocol
python-sdkhttps://github.com/modelcontextprotocol/python-sdk
Notifications https://github.com/login?return_to=%2Fmodelcontextprotocol%2Fpython-sdk
Fork 3.7k https://github.com/login?return_to=%2Fmodelcontextprotocol%2Fpython-sdk
Star 23.7k https://github.com/login?return_to=%2Fmodelcontextprotocol%2Fpython-sdk
Code https://github.com/modelcontextprotocol/python-sdk
Issues 259 https://github.com/modelcontextprotocol/python-sdk/issues
Pull requests 307 https://github.com/modelcontextprotocol/python-sdk/pulls
Actions https://github.com/modelcontextprotocol/python-sdk/actions
Projects https://github.com/modelcontextprotocol/python-sdk/projects
Models https://github.com/modelcontextprotocol/python-sdk/models
Security and quality 6 https://github.com/modelcontextprotocol/python-sdk/security
Insights https://github.com/modelcontextprotocol/python-sdk/pulse
Code https://github.com/modelcontextprotocol/python-sdk
Issues https://github.com/modelcontextprotocol/python-sdk/issues
Pull requests https://github.com/modelcontextprotocol/python-sdk/pulls
Actions https://github.com/modelcontextprotocol/python-sdk/actions
Projects https://github.com/modelcontextprotocol/python-sdk/projects
Models https://github.com/modelcontextprotocol/python-sdk/models
Security and quality https://github.com/modelcontextprotocol/python-sdk/security
Insights https://github.com/modelcontextprotocol/python-sdk/pulse
Sign up for GitHub https://github.com/signup?return_to=%2Fmodelcontextprotocol%2Fpython-sdk%2Fissues%2Fnew%2Fchoose
terms of servicehttps://docs.github.com/terms
privacy statementhttps://docs.github.com/privacy
Sign inhttps://github.com/login?return_to=%2Fmodelcontextprotocol%2Fpython-sdk%2Fissues%2Fnew%2Fchoose
heyhayeshttps://github.com/heyhayes
modelcontextprotocol:mainhttps://github.com/modelcontextprotocol/python-sdk/tree/main
heyhayes:fix/get-stream-empty-reconnect-loophttps://github.com/heyhayes/python-sdk/tree/fix/get-stream-empty-reconnect-loop
Conversation 3 https://github.com/modelcontextprotocol/python-sdk/pull/3087
Commits 2 https://github.com/modelcontextprotocol/python-sdk/pull/3087/commits
Checks 28 https://github.com/modelcontextprotocol/python-sdk/pull/3087/checks
Files changed 4 https://github.com/modelcontextprotocol/python-sdk/pull/3087/files
fix: stop the standalone GET stream reconnecting forever on empty connections https://github.com/modelcontextprotocol/python-sdk/pull/3087/files#top
Show all changes 2 commits https://github.com/modelcontextprotocol/python-sdk/pull/3087/files
b3a8a7e fix: stop infinite GET stream reconnection on repeated empty connections heyhayes Feb 21, 2026 https://github.com/modelcontextprotocol/python-sdk/pull/3087/commits/b3a8a7e4a47bbae53bc65a90404c9f5edec9958b
85b6fed Log warning for unhandled exceptions in default message handler heyhayes Feb 21, 2026 https://github.com/modelcontextprotocol/python-sdk/pull/3087/commits/85b6fed3210ceb2f7f0874aaf39ee882ece46540
Clear filters https://github.com/modelcontextprotocol/python-sdk/pull/3087/files
Please reload this pagehttps://github.com/modelcontextprotocol/python-sdk/pull/3087/files
Please reload this pagehttps://github.com/modelcontextprotocol/python-sdk/pull/3087/files
session.py https://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-634d1abcb8bda1a784f31e3431a10124e387f487dd243a54244515b4972aa0ee
streamable_http.py https://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-e8c18a3067a9b157c5c39a947f53d395afeb00e7026dad2d5a279011da943b5e
test_session.py https://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-623490a9c2dd576cc59e89f8d51f64acfffdeaad940e0bd4a0a51a50bc30d92d
test_streamable_http.py https://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-09ecebf3cb1cb198a43bd3159ecf388a4dfdc38f93c9812b671f40fc2c83ec29
src/mcp/client/session.pyhttps://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-634d1abcb8bda1a784f31e3431a10124e387f487dd243a54244515b4972aa0ee
View file https://github.com/modelcontextprotocol/python-sdk/blob/85b6fed3210ceb2f7f0874aaf39ee882ece46540/src/mcp/client/session.py
Open in desktop https://desktop.github.com
https://github.co/hiddenchars
https://github.com/modelcontextprotocol/python-sdk/pull/3087/{{ revealButtonHref }}
https://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-634d1abcb8bda1a784f31e3431a10124e387f487dd243a54244515b4972aa0ee
https://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-634d1abcb8bda1a784f31e3431a10124e387f487dd243a54244515b4972aa0ee
src/mcp/client/streamable_http.pyhttps://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-e8c18a3067a9b157c5c39a947f53d395afeb00e7026dad2d5a279011da943b5e
View file https://github.com/modelcontextprotocol/python-sdk/blob/85b6fed3210ceb2f7f0874aaf39ee882ece46540/src/mcp/client/streamable_http.py
Open in desktop https://desktop.github.com
https://github.co/hiddenchars
https://github.com/modelcontextprotocol/python-sdk/pull/3087/{{ revealButtonHref }}
https://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-e8c18a3067a9b157c5c39a947f53d395afeb00e7026dad2d5a279011da943b5e
https://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-e8c18a3067a9b157c5c39a947f53d395afeb00e7026dad2d5a279011da943b5e
https://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-e8c18a3067a9b157c5c39a947f53d395afeb00e7026dad2d5a279011da943b5e
tests/client/test_session.pyhttps://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-623490a9c2dd576cc59e89f8d51f64acfffdeaad940e0bd4a0a51a50bc30d92d
View file https://github.com/modelcontextprotocol/python-sdk/blob/85b6fed3210ceb2f7f0874aaf39ee882ece46540/tests/client/test_session.py
Open in desktop https://desktop.github.com
https://github.co/hiddenchars
https://github.com/modelcontextprotocol/python-sdk/pull/3087/{{ revealButtonHref }}
https://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-623490a9c2dd576cc59e89f8d51f64acfffdeaad940e0bd4a0a51a50bc30d92d
https://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-623490a9c2dd576cc59e89f8d51f64acfffdeaad940e0bd4a0a51a50bc30d92d
https://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-623490a9c2dd576cc59e89f8d51f64acfffdeaad940e0bd4a0a51a50bc30d92d
https://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-623490a9c2dd576cc59e89f8d51f64acfffdeaad940e0bd4a0a51a50bc30d92d
tests/client/test_streamable_http.pyhttps://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-09ecebf3cb1cb198a43bd3159ecf388a4dfdc38f93c9812b671f40fc2c83ec29
View file https://github.com/modelcontextprotocol/python-sdk/blob/85b6fed3210ceb2f7f0874aaf39ee882ece46540/tests/client/test_streamable_http.py
Open in desktop https://desktop.github.com
https://github.co/hiddenchars
https://github.com/modelcontextprotocol/python-sdk/pull/3087/{{ revealButtonHref }}
https://github.com/modelcontextprotocol/python-sdk/pull/3087/files#diff-09ecebf3cb1cb198a43bd3159ecf388a4dfdc38f93c9812b671f40fc2c83ec29
Please reload this pagehttps://github.com/modelcontextprotocol/python-sdk/pull/3087/files
https://github.com
Termshttps://docs.github.com/site-policy/github-terms/github-terms-of-service
Privacyhttps://docs.github.com/site-policy/privacy-policies/github-privacy-statement
Securityhttps://github.com/security
Statushttps://www.githubstatus.com/
Communityhttps://github.community/
Docshttps://docs.github.com/
Contacthttps://support.github.com?tags=dotcom-footer

Viewport: width=device-width


URLs of crawlers that visited me.