NewYour coding agent can read the release notes before it upgrades.Set up the MCP server →
PyPI · #47 most downloaded on PyPI
The lightning-fast ASGI server.
Last release 4 days ago
25 Sep 2026
Ships fairly regularly
a new release about every 3 weeks
Nearly every release is documented
notes for 60 of the last 60 stable releases
1 version withdrawn
withdrawn after publishing
9 years old
204 releases · first in 2017
Support Python 3.11 (#1652) 16/09/22
httptools version to 0.5.0 (#1645) 13/09/22py.typed to comply with PEP 561 (#1687) 07/10/22propagate to False on "uvicorn" logger (#1288) 08/10/22UvicornWorker. (#1565) 26/08/22WebSockets logs (#1385) 11/09/22--debug flag (#1640) 14/09/22DebugMiddleware (#1697) 07/10/22Support Python 3.11 (#1652)
Bump minimal httptools version to 0.5.0 (#1645)
Ignore HTTP/2 upgrade and optionally ignore WebSocket upgrade (#1661)
Add py.typed to comply with PEP 561 (#1687)
Set propagate to False on "uvicorn" logger (#1288)
USR1 signal is now handled correctly on UvicornWorker . (#1565)
Use path with query string on WebSockets logs (#1385)
Fix behavior on which "Date" headers were not updated on the same connection (#1706)
Remove the --debug flag (#1640)
Remove the DebugMiddleware (#1697)
One column per quarter.
Remove cyclic references on HTTP implementations. (#1604) 24/08/22
reload_delay default changed from None to 0.25 on uvicorn.run() and Config. None is not an acceptable value anymore. (#1545) 02/07/22Full Changelog: https://github.com/encode/uvicorn/compare/0.18.2...0.18.3
Add default log_config on uvicorn.run() #1541 24/06/22
log_config on uvicorn.run() #1541 24/06/22logging file name modification #1543 27/06/22Full Changelog: https://github.com/encode/uvicorn/compare/0.18.1...0.18.2
Add default log_config on uvicorn.run() (#1541)
Revert logging file name modification (#1543)
Use DEFAULT_MAX_INCOMPLETE_EVENT_SIZE as default to h11_max_incomplete_event_size on the CLI (#1534) 23/06/22
DEFAULT_MAX_INCOMPLETE_EVENT_SIZE as default to h11_max_incomplete_event_size on the CLI (#1534) 23/06/22Full Changelog: https://github.com/encode/uvicorn/compare/0.18.0...0.18.1
The reload flag prioritizes watchfiles instead of the deprecated watchgod (#1437) 18/06/22
reload flag prioritizes watchfiles instead of the deprecated watchgod (#1437) 18/06/22uvicorn.run() function (#1423) 10/05/22max_incomplete_event_size for h11 implementation (#1514) 22/06/22asgiref dependency (#1532) 22/06/22raw_path into bytes on both websockets implementations (#1487) 16/05/22asyncio.WindowsSelectorEventLoopPolicy() when using multiple workers to avoid "WinError 87" (#1454) 22/06/22Full Changelog: https://github.com/encode/uvicorn/compare/0.17.6...0.18.0
The reload flag prioritizes watchfiles instead of the deprecated watchgod (#1437)
Annotate uvicorn.run() function (#1423)
Allow configuring max_incomplete_event_size for h11 implementation (#1514)
Turn raw_path into bytes on both websockets implementations (#1487)
Revert log exception traceback in case of invalid HTTP request (#1518)
Set asyncio.WindowsSelectorEventLoopPolicy() when using multiple workers to avoid "WinError 87" (#1454)
Change httptools range to >=0.4.0 (#1400) 11/03/22
httptools range to >=0.4.0 (#1400) 11/03/22Fix case where url is fragmented in httptools protocol (#1263) 2/16/22
Full Changelog: https://github.com/encode/uvicorn/compare/0.17.4...0.17.5
Fix case where url is fragmented in httptools protocol (#1263)
Fix WSGI middleware not to explode quadratically in the case of a larger body (#1329)
Replace create_server by create_unix_server (#1362) 04/02/22
create_server by create_unix_server (#1362) 04/02/22Drop wsproto version checking. (#1359) 03/02/22
Revert #1332. While trying to solve the memory leak, it introduced an issue (#1345) when the server receives big chunks of data using the httptools im
httptools implementation. (#1354) 03/02/22Move all data handling logic to protocol and ensure connection is closed. (#1332) 28/01/22
spec_version field from "2.1" to "2.3", as Uvicorn is compliant with that version of the ASGI specifications. (#1337) 25/01/22Add the python_requires version specifier (#1328) 17/01/22
python_requires version specifier (#1328) 17/01/22Allow configurable websocket per-message-deflate setting (#1300) 29/12/21
root_path from logs (#1294) 25/12/21Allow configurable websocket per-message-deflate setting (#1300)
Support extra_headers for WS accept message (#1293)
Add missing http version on websockets scope (#1309)
Drop Python 3.6 support (#1261)
Fix reload process behavior when exception is raised (#1313)
Remove root_path from logs (#1294)
Enable read of uvicorn settings from environment variables (#1279) 06/12/21
websockets to 10.0. (#1180) 13/09/21httptools version range from "==0.2.*" to ">=0.2.0,<0.4.0". (#1243) 8/11/21HttpToolsProtocol.pipeline type from list to deque. (#1213) 10/10/21WSGIResponder.send_queue type from list to deque. (#1214) 10/10/21WebSocketProtocol.asgi_receive on which we returned a close frame even if there were data messages before that frame in the read queue. (#1252) 25/11/21--reload-dirs was splitting a string into single character directories. (#1267) 25/11/21Enable read of uvicorn settings from environment variables (#1279)
Bump websockets to 10.0. (#1180)
Ensure non-zero exit code when startup fails (#1278)
Increase httptools version range from "==0.2.*" to ">=0.2.0,<0.4.0". (#1243)
Override default asyncio event loop with reload only on Windows (#1257)
Replace HttpToolsProtocol.pipeline type from list to deque . (#1213)
Replace WSGIResponder.send_queue type from list to deque . (#1214)
Main process exit after startup failure on reloader classes (#1177)
Fix the need of httptools on minimal installation (#1135)
Fix ping parameters annotation in Config class (#1127)
Change reload to be configurable with glob patterns. Currently only .py files are watched, which is different from the previous default behavior. (#82
.py files are watched, which is different from the previous default behavior. (#820) 08/08/21asyncio.run which will: start a fresh asyncio event loop, on shutdown cancel any background tasks rather than aborting them, aexit any remaining async generators, and shutdown the default ThreadPoolExecutor. (#1070) 30/07/21SIGTERM supervisors now terminate their processes before joining them (#1069) 30/07/21httptools on minimal installation (#1135) 30/07/21Change reload to be configurable with glob patterns. Currently only .py files are watched, which is different from the previous default behavior. (#820)
Add Python 3.10-rc.1 support. Now the server uses asyncio.run which will: start a fresh asyncio event loop, on shutdown cancel any background tasks rather than aborting them, aexit any remaining async generators, and shutdown the default ThreadPoolExecutor . (#1070)
Exit with status 3 when worker starts failed (#1077)
Add option to set websocket ping interval and timeout (#1048)
Adapt bind_socket to make it usable with multiple processes (#1009)
Add existence check to the reload directory(ies) (#1089)
Add missing trace log for websocket protocols (#1083)
Support disabling default Server and Date headers (#818)
Add PEP440 compliant version of click (#1099)
Bump asgiref to 3.4.0 (#1100)
When receiving a SIGTERM supervisors now terminate their processes before joining them (#1069)
Fix httptools range to >=0.4.0 (#1400)
Defaults ws max_size on server to 16MB (#995) 5/29/21
Defaults ws max_size on server to 16MB (#995)
Improve user feedback if no ws library installed (#926 and #1023)
Support 'reason' field in 'websocket.close' messages (#957)
Implemented lifespan.shutdown.failed (#755)
Upgraded websockets requirements (#1065)
Switch to asyncio streams API (#869)
Update httptools from 0.1.* to 0.2.* (#1024)
Allow Click 8.0, refs #1016 (#1042)
Add search for a trusted host in ProxyHeadersMiddleware (#591)
Up wsproto to 1.0.0 (#892)
Force reload_dirs to be a list (#978)
Fix gunicorn worker not running if extras not installed (#901)
Fix socket port 0 (#975)
Prevent garbage collection of main lifespan task (#972)
Fixed wsgi middleware PATH_INFO encoding (#962) 2/20/21
Fixed wsgi middleware PATH_INFO encoding (#962)
Fixed uvloop dependency (#952) then (#959)
Relax watchgod up bound (#946)
Return 'connection: close' header in response (#721)
Docs: Nginx + websockets (#948)
Document the default value of 1 for workers (#940) (#943)
Enabled permessage-deflate extension in websockets (#764)
Prevent swallowing of return codes from subprocess when running with Gunicorn by properly resetting signals. (Pull #895)
subprocess when running with Gunicorn by properly resetting signals. (Pull #895)--factory flag. (Pull #914)--ws websockets. (Pull #921)Log full exception traceback in case of invalid HTTP request. (Pull #886 and #888)
Prevent exceptions when the ASGI application rejects a connection during the WebSocket handshake, when running on both --ws wsproto or --ws websockets
--ws wsproto or --ws websockets. (Pull #704 and #881)scope doesn't leak in logs when using JSON log formatters. (Pull #859 and #884)Add --factory flag to support factory-style application imports. (#875) 2020-12-07 50fc0d1c
--factory flag to support factory-style application imports. (#875) 2020-12-07 50fc0d1cServer in multithreaded contexts without having to override .install_signal_handlers(). (#871) 2020-12-07 ce2ef45aFix race condition that leads Quart to hang with uvicorn (#848) 11/18/20 de213614
Fix race condition that leads Quart to hang with uvicorn (#848)
Use latin1 when decoding X-Forwarded-* headers (#701)
Rework IPv6 support (#837)
Cancel old keepalive-trigger before setting new one. (#832)
Adding ability to decrypt ssl key file (#808) 10/12/20 90dbb6e0
Adding ability to decrypt ssl key file (#808)
Support .yml log config files (#799)
Added python 3.9 support (#804)
Fixes watchgod with common prefixes (#817)
Fix reload with ipv6 host (#803)
Added cli support for headers containing colon (#813)
Sharing socket across workers on windows (#802)
Note the need to configure trusted "ips" when using unix sockets (#796)
Improve changelog by pointing out breaking changes (#792) 9/29/20 e2b75064
Pinning h11 and python-dotenv to min versions (#789)
Get docs/index.md in sync with README.md (#784)
Make reload delay configurable (#774) 9/28/20 98010027
--reload or multiprocessing (#620)" (#756) 8/28/20 ff4af12dMake reload delay configurable (#774)
Upgrade maximum h11 dependency version to 0.10 (#772)
Allow .json or .yaml --log-config files (#665)
Add ASGI dict to the lifespan scope (#754)
Upgrade wsproto to 0.15.0 (#750)
Use optional package installs (#666)
Don't set log level for root logger (#767) 8/28/20 df81b168
Uvicorn no longer ships extra dependencies uvloop , websockets and httptools as default. To install these dependencies use uvicorn[standard] .
Revert "Improve shutdown robustness when using --reload or multiprocessing (#620)" (#756)
Fix terminate error in windows (#744)
Fix bug where --log-config disables uvicorn loggers (#512)
Fix a regression that caused Uvicorn to crash when using --interface=wsgi. (Pull #730)
--interface=wsgi. (Pull #730)SECURITY FIX: Prevent sending invalid HTTP header names and values.
SECURITY FIX: Prevent sending invalid HTTP header names and values. (#725)
SECURITY FIX: Ensure path value is escaped before logging to the console. (#724)
Fix --proxy-headers client IP and host when using a Unix socket. (#636)
Fix overriding the root logger.
Revert "Watch all files, not just .py" due to unexpected side effects.
Use watchgod, if installed, for watching code changes.
watchgod, if installed, for watching code changes..py files.Use watchgod , if installed, for watching code changes.
Watch all files, not just .py.
Pass through gunicorn timeout config.
- Update dependencies.
Don't open socket until after application startup.
Don't open socket until after application startup.
Support --backlog .
Use a more liberal h11 dependency. Either 0.8.* or 0.9.*`.
Fix reload/multiprocessing on Windows with Python 3.8.
Fix reload/multiprocessing on Windows with Python 3.8.
Drop IOCP support. (Required for fix above.)
Add uvicorn --version flag.
Add --use-colors and --no-use-colors flags.
Display port correctly, when auto port selection isused with --port=0 .
Nothing published for this version
Fix reload/multiprocessing error.
Use resource_sharer.DupSocket to resolve socket sharing on Windows.
Exit if workers or reload are use without an app import string style.
Exit if workers or reload are use without an app import string style.
Reorganise supervisor processes to properly hand over sockets on windows.
Update uvloop dependency to 0.14+
Error clearly when workers= is used with app instance, instead of an app import string.
Error clearly when workers=<NUM> is used with app instance, instead of an app import string.
Switch --reload-dir to current working directory by default.
- Add `--log-level trace
Enable --proxy-headers by default.
Resolve issues with logging when using --reload or --workers .
Resolve issues with logging when using --reload or --workers .
Setup up root logger to capture output for all logger instances, not just uvicorn.error and uvicorn.access .
Separated out uvicorn.error and uvicorn.access logs.
Support for Python 3.8
Separated out uvicorn.error and uvicorn.access logs.
Coloured log output when connected to a terminal.
Dropped logger= config setting.
Added --log-config [FILE] and log_config=[str|dict] . May either be a Python logging config dictionary or the file name of a logging configuration.
Added --forwarded_allow_ips and forwarded_allow_ips . Defaults to the value of the $FORWARDED_ALLOW_IPS environment variable or "127.0.0.1". The --proxy-headers flag now defaults to True , but only trusted IPs are used to populate forwarding info.
The --workers setting now defaults to the value of the $WEB_CONCURRENCY environment variable.
Added support for --env-file . Requires python-dotenv .
Back to top
Nothing published for this version
Nothing published for this version
Nothing published for this version
Nothing published for this version
Nothing published for this version
Nothing published for this version
Nothing published for this version
Nothing published for this version
Nothing published for this version
Nothing published for this version
Nothing published for this version
Nothing published for this version
Nothing published for this version
Nothing published for this version
Nothing published for this version
Nothing published for this version
Your coding agent can read these notes before it upgrades. Set up the MCP server →