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celery

5.6.344M downloads/mocelery/celery ↗New releases in your daily digest, changelog included.

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Last release 12 days ago
22 Sep 2026
Release timing varies
gaps range from 2 weeks to 6 months
Some releases are documented
notes for 27 of the last 60 stable releases
2 versions withdrawn
withdrawn after publishing
17 years old
225 releases · first in 2009

Release timeline

225 releases since 2009

2009201120132015

Releases

5.7.0a122 Sept 2026pre-releaseDeprecated
Remove deprecated args from redis get_connection call by @JaeHyuckSa in #10036
What's Changed

Fix Django worker recursion bug + defensive checks for pool_cls.module by @maycuatroi1 in #10048

Update elasticsearch requirement from <=9.1.2 to <=9.2.1 by @dependabot[bot] in #10053

Revert "Update elasticsearch requirement from <=9.1.2 to <=9.2.1" by @auvipy in #10054

Docs: Update user_preload_options example to use click. by @jorsyk in #10056

Fix invalid configuration key "bootstrap_servers" in Kafka demo by @jorsyk in #10060

Fix broken images on PyPI page by @Timour-Ilyas in #10066

Remove broken reference. in #10071

Removed --dist=loadscope from smoke tests by @Nusnus in #10073

Docs: Clarify task_retry signal args may be None by @GangEunzzang in #10076

Update example for Django by @sbc-khacnha in #10081

Update CI matrix to exclude Python 3.9 by @auvipy in #9980

Update default Python versions in Integration test by @auvipy in #10088

Update default Python versions in smoke-tests.yml by @auvipy in #10089

Remove Python 3.9 from tox configuration by @auvipy in #10087

Update Python and OS versions in Read the Docs config by @auvipy in #10090

Make tests compatible with pymongo >= 4.16 by @cjwatson in #10074

Remove Python 3.9 from Dockerfile by @auvipy in #10092

Revise Python compatibility for Celery versions by @auvipy in #10093

Update Python version requirement to 3.10 by @auvipy in #10091

fix: source install of cassandra-driver by @Izzette in #10105

fix: register task cross-reference role in Sphinx extension by @veeceey in #10100

fix: avoid cycle detection in native delayed delivery by @Izzette in #10095

fix(asynpool): avoid AttributeError when proc lacks _sentinel_poll by @mriddle in #10086

Update elastic-transport requirement from <=9.1.0 to <=9.2.1 by @dependabot[bot] in #10052

fix dusk_astronomical horizon sign (+18 -> -18) by @Mr-Neutr0n in #10121

Bump pytest from 8.4.2 to 9.0.2 by @dependabot[bot] in #10055

Fix#10106 onupdate col use lambda func by @ChickenBenny in #10108

Fix warm shutdown RuntimeError with eventlet>=0.37.0 (#10083) by @ChickenBenny in #10123

Fix 10109 db backend connection health by @ChickenBenny in #10124

Bump grpcio from 1.75.1 to 1.76.0 by @dependabot[bot] in #9962

Bump cryptography from 46.0.3 to 46.0.5 by @dependabot[bot] in #10132

Database Backend filter unsupport sql engine arguments with nullpool #7355 by @ChickenBenny in #10134

fix(beat): correct argument order in Service.reduce by @bysiber in #10137

ci: declare explicit read-only token permissions in workflow jobs by @Rohan5commit in #10139

chore: 'boto3to' to 'boto3 to' by @cuiweixie in #10133

Database Backend: Add missing index on date_done (Fixes #10097) by @ChickenBenny in #10098

docs: fix typo in CONTRIBUTING.rst by @Rohan5commit in #10141

Refer to Flower / Prometheus for monitoring by @WilliamDEdwards in #10140

[pre-commit.ci] pre-commit autoupdate by @pre-commit-ci[bot] in #10143

docs: remove duplicated words in broker and routing docs by @Rohan5commit in #10146

docs: fix stale version reference and grammar in README by @kelsonbrito50 in #10145

docs: fix wording in Celery 5.3 worker pool notes by @Rohan5commit in #10149

docs: fix duplicated wording in 3.1 changelog entry by @Rohan5commit in #10152

feat(task): decouple acks_on_failure and acks_on_timeout by @abdullahmujahidali in #10150

docs: fix changelog typo in context manager wording by @Rohan5commit in #10144

Fix/10096 worker fails to reconnect after redis failover by @ChickenBenny in #10151

Add __class_getitem__ to generic classes by @brianhelba in #10038

Improve on_after_finalize signal documentation by @Br1an67 in #10155

Database Backend Should Support the retry config parameters #6540 by @ChickenBenny in #10130

Add non-commutative example to clarify partial arg ordering in canvas docs by @Br1an67 in #10157

Bump google-cloud-firestore from 2.22.0 to 2.23.0 by @dependabot[bot] in #10126

Remove redundant test_isa_mapping test (fixes #10077) by @daniel7an in #10103

Upgrade pytest-celery to >=1.3.0 and adopt PYTEST_CELERY_PKG build arg by @Nusnus in #10162

Chore(deps): Update elasticsearch requirement from <=9.1.2 to <=9.3.0 by @dependabot[bot] in #10164

[pre-commit.ci] pre-commit autoupdate by @pre-commit-ci[bot] in #10161

Bump isort from 6.1.0 to 7.0.0 by @dependabot[bot] in #10051

Bump sphinx-click from 6.0.0 to 6.1.0 by @dependabot[bot] in #10050

Add redis-py DriverInfo support to Redis backend by @vchomakov in #10040

Remove deprecated args from redis get_connection call by @JaeHyuckSa in #10036

Fix #6912 rpc backend reconnection error by @ChickenBenny in #10179

Fix NameError with TYPE_CHECKING annotations on Python 3.14+ (PEP 649) by @drichardson in #10165

docs: Add elaboration on prefetch multiplier settings (worker_prefetch_multiplier) and worker_eta_task_limit by @tsangwailam in #10181

Fix O(K²) message bloat in a chain of chords by @Borzik in #10171

Fix mock connection interfaces to prevent TypeError during exception handling by @ChickenBenny in #10178

fix(trace): dispatch chain/callbacks on dedup fast-path for redelivered tasks by @aurangzaib048 in #10159

Extract reconnect_on_error to BaseResultConsumer by @ChickenBenny in #10189

pep 649 by @ericbuehl in #10187

[pre-commit.ci] pre-commit autoupdate by @pre-commit-ci[bot] in #10186

Fix#9722 friendly status errors for CLI by @ChickenBenny in #10190

docs: clarify after_return behavior for retried tasks by @KianAnbarestani in #10192

Add exists() method to AsyncResult by @veeceey in #10142

Add compression header to message protocol docs by @Br1an67 in #10156

docs: fix duplicated word in bootsteps comment by @Rohan5commit in #10153

Remove outdated autoreloader section from extending docs by @Br1an67 in #10154

Fix: prioritize request ignore_result over task definition by @patri27826 in #10184

Add Google Cloud PubSub dependency group by @dpgraham4401 in #10216

Chore(deps): Bump nick-fields/retry from 3 to 4 by @dependabot[bot] in #10213

fix: clear the timer while catch the exception by @ChickenBenny in #10218

fix(worker): add hub.reset() to synloop on connection error by @antonio-mello-ai in #10204

Replace remaining deprecated datetime.utcnow() calls by @as567-code in #10224

Fix#10022 request time limits by @ChickenBenny in #10206

fix: send the task failure in hard timeout by @ChickenBenny in #10226

Add engine_callback to database backend SessionManager by @avolant in #10135

feat(redis): support configuring additional connection errors by @abdullahmujahidali in #10158

fix: move dedup integration tests to smoke tests by @aurangzaib048 in #10232

fix: move prefork shutdown test to smoke tests by @aurangzaib048 in #10236

fix: move remaining start_worker() integration tests to smoke tests by @aurangzaib048 in #10239

fix: prevent graceful shutdown regression in connection recovery (GH-9705) by @aurangzaib048 in #10242

perf(examples): set a timeout on tasks HTTP calls by @EhteshamSid in #10244

docs: document return value of AsyncResult.get() and ResultSet.join() by @antonio-mello-ai in #10240

docs: clarify broker-specific semantics of task priority by @antonio-mello-ai in #10238

fix(base): add timeout to broker pool acquisition to prevent indefinite blocking by @aurangzaib048 in #10174

fix#4834 (canvas): fix chord error handling when body is a chain by @aurangzaib048 in #10247

[pre-commit.ci] pre-commit autoupdate by @pre-commit-ci[bot] in #10249

Fix warm shutdown not cancelling prefetched tasks in thread pool by @Aamirofficiall in #10183

chore: add Python 3.14 trove classifier by @sk- in #10176

Replace archived blacksmith python action with upstream python action by @c32-4e3-844-41ed9dc5d in #10265

Update apt-get install command in integration tests by @auvipy in #10267

Adjust retry settings in integration-tests.yml by @auvipy in #10268

Update apt-get install command in workflow by @auvipy in #10266

Bump codecov actions 5 -> 6 by @c32-4e3-844-41ed9dc5d in #10264

docs: clarify .delay() usage with signatures in the user guide section by @kittywaresz in #10258

[pre-commit.ci] pre-commit autoupdate by @pre-commit-ci[bot] in #10261

Add all integration tests to the CI matrix by @Izzette in #10259

Add libev-dev to Dockerfile dependencies by @auvipy in #10270

Using patching.modules after module test fixture leaks across test cases by @treszkai in #10256

docs: clarify Django settings with the CELERY namespace by @angelojbgama in #10272

fix(consumer): skip prefetch reduction when per-consumer QoS is in effect by @aurangzaib048 in #10253

fix(events): skip publish when producer is None to stop memory leak after broker reconnect by @Song-Junho97 in #10277

Bump grpcio from 1.76.0 to 1.78.0 by @dependabot[bot] in #10136

chore(deps): update sphinx-autobuild requirement from !=2024.9.3,>=2021.3.14 to !=2024.9.3,>=2024.10.3 by @dependabot[bot] in #10279

fix#8542: honour per-task serializer and execution options (send_task). by @Krishnachaitanyakc in #10217

fix(events): stop leaking exceptions and cancel stale Heart timers by @Song-Junho97 in #10280

Deferred ack synloop bug by @jberclaz in #10263

Fix head_from_fun following wrapped on Python 3.14+ by @dannon in #10281

Add missing stacklevel=2 to 12 warnings.warn() calls by @stef41 in #10260

Chore(deps): Bump pytest-github-actions-annotate-failures from 0.3.0 to 0.4.0 by @dependabot[bot] in #10168

fix(defaults): default to exclusive queues for RabbitMQ 4.3.0 compatibility by @Nusnus in
Note truncated.

5.6.326 Mar 2026Deprecated

Remove deprecated args from redis get_connection call by @JaeHyuckSa in #10036

What's Changed

Fix Django worker recursion bug + defensive checks for pool_cls.module by @maycuatroi1 in #10048
Docs: Update user_preload_options example to use click. by @jorsyk in #10056
Fix invalid configuration key "bootstrap_servers" in Kafka demo by @jorsyk in #10060
Fix broken images on PyPI page by @Timour-Ilyas in #10066
Remove broken reference. by @sueannioanis in #10071
Removed --dist=loadscope from smoke tests by @Nusnus in #10073
Docs: Clarify task_retry signal args may be None by @GangEunzzang in #10076
Update example for Django by @sbc-khacnha in #10081
Make tests compatible with pymongo >= 4.16 by @cjwatson in #10074
fix: source install of cassandra-driver by @Izzette in #10105
fix: register task cross-reference role in Sphinx extension by @veeceey in #10100
fix: avoid cycle detection in native delayed delivery by @Izzette in #10095
fix(asynpool): avoid AttributeError when proc lacks _sentinel_poll by @mriddle in #10086
fix dusk_astronomical horizon sign (+18 -> -18) by @Mr-Neutr0n in #10121
Fix/10106 onupdate col use lambda func by @ChickenBenny in #10108
Fix warm shutdown RuntimeError with eventlet>=0.37.0 (#10083) by @ChickenBenny in #10123
Fix 10109 db backend connection health by @ChickenBenny in #10124
Database Backend filter unsupport sql engine arguments with nullpool #7355 by @ChickenBenny in #10134
fix(beat): correct argument order in Service.reduce by @bysiber in #10137
ci: declare explicit read-only token permissions in workflow jobs by @Rohan5commit in #10139
chore: 'boto3to' to 'boto3 to' by @cuiweixie in #10133
Database Backend: Add missing index on date_done (Fixes #10097) by @ChickenBenny in #10098
docs: fix typo in CONTRIBUTING.rst by @Rohan5commit in #10141
Refer to Flower / Prometheus for monitoring by @WilliamDEdwards in #10140
docs: remove duplicated words in broker and routing docs by @Rohan5commit in #10146
docs: fix stale version reference and grammar in README by @kelsonbrito50 in #10145
docs: fix wording in Celery 5.3 worker pool notes by @Rohan5commit in #10149
docs: fix duplicated wording in 3.1 changelog entry by @Rohan5commit in #10152
docs: fix changelog typo in context manager wording by @Rohan5commit in #10144
Fix/10096 worker fails to reconnect after redis failover by @ChickenBenny in #10151
Improve on_after_finalize signal documentation by @Br1an67 in #10155
Add non-commutative example to clarify partial arg ordering in canvas docs by @Br1an67 in #10157
Remove redundant test_isa_mapping test (fixes #10077) by @daniel7an in #10103
Upgrade pytest-celery to >=1.3.0 and adopt PYTEST_CELERY_PKG build arg by @Nusnus in #10162
Remove deprecated args from redis get_connection call by @JaeHyuckSa in #10036
Fix #6912 rpc backend reconnection error by @ChickenBenny in #10179
Fix NameError with TYPE_CHECKING annotations on Python 3.14+ (PEP 649) by @drichardson in #10165
docs: Add elaboration on prefetch multiplier settings (worker_prefetch_multiplier) and worker_eta_task_limit by @tsangwailam in #10181
Fix O(K²) message bloat in a chain of chords by @Borzik in #10171
Fix mock connection interfaces to prevent TypeError during exception handling by @ChickenBenny in #10178
fix(trace): dispatch chain/callbacks on dedup fast-path for redelivered tasks by @aurangzaib048 in #10159
Extract reconnect_on_error to BaseResultConsumer by @ChickenBenny in #10189
pep 649 by @ericbuehl in #10187
Fix#9722 friendly status errors for CLI by @ChickenBenny in #10190
docs: clarify after_return behavior for retried tasks by @KianAnbarestani in #10192
Add compression header to message protocol docs by @Br1an67 in #10156
docs: fix duplicated word in bootsteps comment by @Rohan5commit in #10153
Remove outdated autoreloader section from extending docs by @Br1an67 in #10154
Fix: prioritize request ignore_result over task definition by @patri27826 in #10184
fix: clear the timer while catch the exception by @ChickenBenny in #10218
Prepare for release: v5.6.3 by @Nusnus in #10221

New Contributors

@maycuatroi1 made their first contribution in #10048
@jorsyk made their first contribution in #10056
@Timour-Ilyas made their first contribution in #10066
@sueannioanis made their first contribution in #10071
@GangEunzzang made their first contribution in #10076
@sbc-khacnha made their first contribution in #10081
@veeceey made their first contribution in #10100
@mriddle made their first contribution in #10086
@Mr-Neutr0n made their first contribution in #10121
@ChickenBenny made their first contribution in #10108
@bysiber made their first contribution in #10137
@Rohan5commit made their first contribution in #10139
@cuiweixie made their first contribution in #10133
@kelsonbrito50 made their first contribution in #10145
@Br1an67 made their first contribution in #10155
@daniel7an made their first contribution in #10103
@drichardson made their first contribution in #10165
@tsangwailam made their first contribution in #10181
@Borzik made their first contribution in #10171
@aurangzaib048 made their first contribution in #10159
@ericbuehl made their first contribution in #10187
@KianAnbarestani made their first contribution in #10192
@patri27826 made their first contribution in #10184

Full Changelog: v5.6.2...v5.6.3

Open source →

Additional notes

release-date : 2026-03-26 release-by : Tomer Nosrati

What’s Changed

Fix Django worker recursion bug + defensive checks for pool_cls.module (#10048)

Docs: Update user_preload_options example to use click. (#10056)

Fix invalid configuration key “bootstrap_servers” in Kafka demo (#10060)

Fix broken images on PyPI page (#10066)

Remove broken reference. (#10071)

Removed –dist=loadscope from smoke tests (#10073)

Docs: Clarify task_retry signal args may be None (#10076)

Update example for Django (#10081)

Make tests compatible with pymongo >= 4.16 (#10074)

fix: source install of cassandra-driver (#10105)

fix: register task cross-reference role in Sphinx extension (#10100)

fix: avoid cycle detection in native delayed delivery (#10095)

fix(asynpool): avoid AttributeError when proc lacks _sentinel_poll (#10086)

fix dusk_astronomical horizon sign (+18 -> -18) (#10121)

Fix/10106 onupdate col use lambda func (#10108)

Fix warm shutdown RuntimeError with eventlet>=0.37.0 (#10083) (#10123)

Fix 10109 db backend connection health (#10124)

Database Backend filter unsupport sql engine arguments with nullpool #7355 (#10134)

fix(beat): correct argument order in Service.reduce (#10137)

ci: declare explicit read-only token permissions in workflow jobs (#10139)

chore: ‘boto3to’ to ‘boto3 to’ (#10133)

Database Backend: Add missing index on date_done (Fixes #10097) (#10098)

docs: fix typo in CONTRIBUTING.rst (#10141)

Refer to Flower / Prometheus for monitoring (#10140)

docs: remove duplicated words in broker and routing docs (#10146)

docs: fix stale version reference and grammar in README (#10145)

docs: fix wording in Celery 5.3 worker pool notes (#10149)

docs: fix duplicated wording in 3.1 changelog entry (#10152)

docs: fix changelog typo in context manager wording (#10144)

Fix/10096 worker fails to reconnect after redis failover (#10151)

Improve on_after_finalize signal documentation (#10155)

Add non-commutative example to clarify partial arg ordering in canvas docs (#10157)

Remove redundant test_isa_mapping test (fixes #10077) (#10103)

Upgrade pytest-celery to >=1.3.0 and adopt PYTEST_CELERY_PKG build arg (#10162)

Remove deprecated args from redis get_connection call (#10036)

Fix #6912 rpc backend reconnection error (#10179)

Fix NameError with TYPE_CHECKING annotations on Python 3.14+ (PEP 649) (#10165)

docs: Add elaboration on prefetch multiplier settings (worker_prefetch_multiplier) and worker_eta_task_limit (#10181)

Fix O(K²) message bloat in a chain of chords (#10171)

Fix mock connection interfaces to prevent TypeError during exception handling (#10178)

fix(trace): dispatch chain/callbacks on dedup fast-path for redelivered tasks (#10159)

Extract reconnect_on_error to BaseResultConsumer (#10189)

pep 649 (#10187)

Fix#9722 friendly status errors for CLI (#10190)

docs: clarify after_return behavior for retried tasks (#10192)

Add compression header to message protocol docs (#10156)

docs: fix duplicated word in bootsteps comment (#10153)

Remove outdated autoreloader section from extending docs (#10154)

Fix: prioritize request ignore_result over task definition (#10184)

fix: clear the timer while catch the exception (#10218)

Prepare for release: v5.6.3 (#10221)

5.6.129 Dec 2025

Fix Redis Sentinel ACL authentication support by @anthonykuzmich7 in #10013

What's Changed

Fix Redis Sentinel ACL authentication support by @anthonykuzmich7 in #10013
Fix: Broker heartbeats not sent during graceful shutdown by @weetster in #9986
docs #5410 -- Document confirm_publish broker transport option by @JaeHyuckSa in #10016
close DB pools only in prefork mode by @petrprikryl in #10020
Fix: Avoid unnecessary Django database connection creation during cleanup by @snopoke in #10015
reliable prefork detection by @petrprikryl in #10023
better coverage by @petrprikryl in #10029
Docs: clarify result_extended vs periodic task metadata and show headers["periodic_task_name"] example by @SpaceShaman in #10030
Stop importing pytest_subtests by @cjwatson in #10032
Only use exceptiongroup backport for Python < 3.11 by @cjwatson in #10033
Prepare for release: v5.6.1 by @Nusnus in #10037

New Contributors

@anthonykuzmich7 made their first contribution in #10013
@weetster made their first contribution in #9986
@JaeHyuckSa made their first contribution in #10016
@snopoke made their first contribution in #10015
@SpaceShaman made their first contribution in #10030

Full Changelog: v5.6.0...v5.6.1

Open source →

Additional notes2 sources agree

What's Changed

Fix Redis Sentinel ACL authentication support (#10013)
Fix: Broker heartbeats not sent during graceful shutdown (#9986)
docs #5410 -- Document confirm_publish broker transport option (#10016)
close DB pools only in prefork mode (#10020)
Fix: Avoid unnecessary Django database connection creation during cleanup (#10015)
reliable prefork detection (#10023)
better coverage (#10029)
Docs: clarify result_extended vs periodic task metadata and show headers["periodic_task_name"] example (#10030)
Stop importing pytest_subtests (#10032)
Only use exceptiongroup backport for Python < 3.11 (#10033)
Prepare for release: v5.6.1 (#10037)

Open source →

5.6.030 Nov 2025Security

Security Fix: Broker Credential Leak Prevention

Celery v5.6.0 is now available.

Key Highlights

See What's new in Celery 5.6 for a complete overview or read the main highlights below.

Python 3.9 Minimum Version

Celery 5.6.0 drops support for Python 3.8 (EOL). The minimum required Python version is now 3.9. Users still on Python 3.8 must upgrade their Python version before upgrading to Celery 5.6.0.

Additionally, this release includes initial support for Python 3.14.

SQS: Reverted to `pycurl` from `urllib3`

The switch from pycurl to urllib3 for the SQS transport (introduced in Celery 5.5.0 via Kombu) has been reverted due to critical issues affecting SQS users.

Contributed by @auvipy in #9620.

Security Fix: Broker Credential Leak Prevention

Fixed a security issue where broker URLs containing passwords were being logged in plaintext by the delayed delivery mechanism. Broker credentials are now properly sanitized in all log output.

Contributed by @giancarloromeo in #9997.

Memory Leak Fixes

Two significant memory leaks have been fixed in this release:

Exception Handling Memory Leak: Fixed a critical memory leak in task exception handling that was particularly severe on Python 3.11+ due to enhanced traceback data. The fix properly breaks reference cycles in tracebacks to allow garbage collection.

Contributed by @jaiganeshs21 in #9799.

Pending Result Memory Leak: Fixed a memory leak where AsyncResult subscriptions were not being cleaned up when results were forgotten.

Contributed by @tsoos99dev in #9806.

ETA Task Memory Limit

New configuration option worker_eta_task_limit to prevent out-of-memory crashes when workers fetch large numbers of ETA or countdown tasks. Previously, workers could exhaust available memory when the broker contained many scheduled tasks.

Example usage:

app.conf.worker_eta_task_limit = 1000

Contributed by @sashu2310 in #9853.

Queue Type Selection for Auto-created Queues

New configuration options allow specifying the queue type and exchange type when Celery auto-creates missing queues. This is particularly useful for RabbitMQ users who want to use quorum queues with auto-created queues.

Configuration options:

task_create_missing_queue_type: Sets the queue type for auto-created queues (e.g., quorum, classic)
task_create_missing_queue_exchange_type: Sets the exchange type for auto-created queues

Example usage:

app.conf.task_create_missing_queue_type = 'quorum'

Contributed by @ghirailghiro in #9815.

What's Changed

Prepare for release: v5.6.0 by @Nusnus in #10010

Full Changelog: v5.6.0rc2...v5.6.0

Open source →

Additional notes2 sources agree

Celery v5.6.0 is now available.

Key Highlights

See whatsnew-5.6 for a complete overview or read the main highlights below.

Python 3.9 Minimum Version

Celery 5.6.0 drops support for Python 3.8 (EOL). The minimum required Python version is now 3.9. Users still on Python 3.8 must upgrade their Python version before upgrading to Celery 5.6.0.

Additionally, this release includes initial support for Python 3.14.

SQS: Reverted to pycurl from urllib3

The switch from pycurl to urllib3 for the SQS transport (introduced in Celery 5.5.0 via Kombu) has been reverted due to critical issues affecting SQS users:

Processing throughput dropped from ~100 tasks/sec to ~3/sec in some environments
UnknownOperationException errors causing container crash loops
Silent message processing failures with no error logs

Users of the SQS transport must ensure pycurl is installed. If you removed pycurl after upgrading to Celery 5.5.0, you will need to reinstall it.

Contributed by @auvipy in #9620.

Security Fix: Broker Credential Leak Prevention

Fixed a security issue where broker URLs containing passwords were being logged in plaintext by the delayed delivery mechanism. Broker credentials are now properly sanitized in all log output.

Contributed by @giancarloromeo in #9997.

Memory Leak Fixes

Two significant memory leaks have been fixed in this release:

Contributed by @jaiganeshs21 in #9799.

Pending Result Memory Leak: Fixed a memory leak where AsyncResult subscriptions were not being cleaned up when results were forgotten.

Contributed by @tsoos99dev in #9806.

ETA Task Memory Limit

New configuration option worker_eta_task_limit to prevent out-of-memory crashes when workers fetch large numbers of ETA or countdown tasks. Previously, workers could exhaust available memory when the broker contained many scheduled tasks.

Example usage:

app.conf.worker_eta_task_limit = 1000

Contributed by @sashu2310 in #9853.

Queue Type Selection for Auto-created Queues

Configuration options:

task_create_missing_queue_type: Sets the queue type for auto-created queues (e.g., quorum, classic)
task_create_missing_queue_exchange_type: Sets the exchange type for auto-created queues

Example usage:

app.conf.task_create_missing_queue_type = 'quorum'

Contributed by @ghirailghiro in #9815.

What's Changed

Prepare for release: v5.6.0 (#10010)

5.6.0rc11 Nov 2025pre-release

Celery v5.6.0 Release Candidate 1 is now available for testing. Please help us test this version and report any issues.

Celery v5.6.0 Release Candidate 1 is now available for testing.
Please help us test this version and report any issues.

What's Changed

Add support for Django Connection pool by @petrprikryl in #9953
Pin tblib to ==3.1.0 by @kernelshard in #9967
fix(worker): continue to attempt to bind other queues after a native delayed delivery binding failure has occurred by @Izzette in #9959
Handle UnpicklingError in persistent scheduler initialization by @pakallis in #9952
Bug Fix: Nested Chords Fail When Using django-celery-results with a Redis Backend by @kumuthu53 in #9950
Add support pymongo 4.12 by @kidoz in #9665
Make tests compatible with pymongo >= 4.14 by @cjwatson in #9968
tblib updated from 3.1.0 to 3.2.0 by @MehrazRumman in #9970
Fix remaining function typing and docstring by @wcislo-saleor in #9971
Fix regex pattern in version parsing and remove duplicate entry in all by @sagar1343 in #9978
Bump Kombu to v5.6.0 and removed <5.7 limit on kombu by @Nusnus in #9981
Prepare for (pre) release: v5.6.0rc1 by @Nusnus in #9982

New Contributors

@petrprikryl made their first contribution in #9953
@kernelshard made their first contribution in #9967
@Izzette made their first contribution in #9959
@kumuthu53 made their first contribution in #9950
@wcislo-saleor made their first contribution in #9971
@sagar1343 made their first contribution in #9978

Full Changelog: v5.6.0b2...v5.6.0rc1

Open source →

Additional notes2 sources agree

Celery v5.6.0 Release Candidate 1 is now available for testing. Please help us test this version and report any issues.

What's Changed

Add support for Django Connection pool (#9953)
Pin tblib to ==3.1.0 (#9967)
fix(worker): continue to attempt to bind other queues after a native delayed delivery binding failure has occurred (#9959)
Handle UnpicklingError in persistent scheduler initialization (#9952)
Bug Fix: Nested Chords Fail When Using django-celery-results with a Redis Backend (#9950)
Add support pymongo 4.12 (#9665)
Make tests compatible with pymongo >= 4.14 (#9968)
tblib updated from 3.1.0 to 3.2.0 (#9970)
Fix remaining function typing and docstring (#9971)
Fix regex pattern in version parsing and remove duplicate entry in __all__ (#9978)
Bump Kombu to v5.6.0 and removed <5.7 limit on kombu (#9981)
Prepare for (pre) release: v5.6.0rc1 (#9982)

Open source →

5.6.0b220 Oct 2025pre-release

Celery v5.6.0 Beta 2 is now available for testing. Please help us test this version and report any issues.

Celery v5.6.0 Beta 2 is now available for testing.
Please help us test this version and report any issues.

What's Changed

GitHub Actions: Test on Python 3.14 release candidate 2 by @cclauss in #9891
Update pypy to python 3.11 by @cclauss in #9896
Feature: Add support credential_provider to Redis Backend by @alaminopu in #9879
Celery.timezone: try tzlocal.get_localzone() before using LocalTimezone by @woutdenolf in #9862
Run integration tests on Python 3.14 by @cclauss in #9903
Fix arithmetic overflow for MSSQL result backend by @vladborovtsov in #9904
Add documentation for task_id param for apply_async function by @sumo1998 in #9906
Support redis client name by @mdalp in #9900
Bump Kombu to v5.6.0rc1 by @Nusnus in #9918
Fix broker connection retry attempt counter in the error log by @sumo1998 in #9911
fix: restrict disable-prefetch feature to Redis brokers only by @Dkhodos in #9919
fix(): preserve group order in replaced signature by @simonepozzoli-pix4d in #9910
Remove Python 3.8 from CI workflow by @auvipy in #9930
Update default Python versions in integration tests by @auvipy in #9931
Update tox.ini to remove Python 3.8 by @auvipy in #9932
Remove Python 3.8 from Dockerfile by @auvipy in #9933
Update Python version requirement to 3.9 by @auvipy in #9935
Update pypy version from 3.10 to 3.11 in Dockerfile by @auvipy in #9934
Flake8 fixes by @auvipy in #9955
Remove test-pypy3.txt from Dockerfile dependencies by @auvipy in #9939
Remove backports.zoneinfo for Python 3.9 compatibility by @auvipy in #9956
Update pytest-cov version for Python compatibility by @auvipy in #9957
Update pytest-rerunfailures and pre-commit versions by @auvipy in #9958
Prepare for (pre) release: v5.6.0b2 by @Nusnus in #9938

New Contributors

@vladborovtsov made their first contribution in #9904
@sumo1998 made their first contribution in #9906
@mdalp made their first contribution in #9900
@simonepozzoli-pix4d made their first contribution in #9910

Full Changelog: v5.6.0b1...v5.6.0b2

Open source →

Additional notes2 sources agree

Celery v5.6.0 Beta 2 is now available for testing. Please help us test this version and report any issues.

What's Changed

GitHub Actions: Test on Python 3.14 release candidate 2 (#9891)
Update pypy to python 3.11 (#9896)
Feature: Add support credential_provider to Redis Backend (#9879)
Celery.timezone: try tzlocal.get_localzone() before using LocalTimezone (#9862)
Run integration tests on Python 3.14 (#9903)
Fix arithmetic overflow for MSSQL result backend (#9904)
Add documentation for task_id param for apply_async function (#9906)
Support redis client name (#9900)
Bump Kombu to v5.6.0rc1 (#9918)
Fix broker connection retry attempt counter in the error log (#9911)
fix: restrict disable-prefetch feature to Redis brokers only (#9919)
fix(): preserve group order in replaced signature (#9910)
Remove Python 3.8 from CI workflow (#9930)
Update default Python versions in integration tests (#9931)
Update tox.ini to remove Python 3.8 (#9932)
Remove Python 3.8 from Dockerfile (#9933)
Update Python version requirement to 3.9 (#9935)
Update pypy version from 3.10 to 3.11 in Dockerfile (#9934)
Flake8 fixes (#9955)
Remove test-pypy3.txt from Dockerfile dependencies (#9939)
Remove backports.zoneinfo for Python 3.9 compatibility (#9956)
Update pytest-cov version for Python compatibility (#9957)
Update pytest-rerunfailures and pre-commit versions (#9958)
Prepare for (pre) release: v5.6.0b2 (#9938)

Open source →

5.6.0b115 Sept 2025pre-releaseDeprecated

Update setup.py to fix deprecation warning by @auvipy in #9771

Celery v5.6.0 Beta 1 is now available for testing.
Please help us test this version and report any issues.

What's Changed

docs: mention of json serializer recursive reference message size blowup (#5000) by @chrisbarber in #9743
docs: typo in canvas.rst by @chrisbarber in #9744
Makes _on_retry return a float as required to be used as errback on retry_over_time by @maccinza in #9741
Update canvas.rst doc calculation order for callback by @auvipy in #9758
Updated Blacksmith logo by @Nusnus in #9763
Made the Sponsors logos link to their website by @Nusnus in #9764
add missing cloudamqp logo by @auvipy in #9767
Improve sponsor visibility by @auvipy in #9768
fix: (#9773) task_id must not be empty with chain as body of a chord by @dfm88 in #9774
Update setup.py to fix deprecation warning by @auvipy in #9771
Adds integration test for chord_unlock bug when routed to quorum/topic queue by @maccinza in #9766
Add xfail test for default queue/exchange fallback ignoring task_default_* settings by @maccinza in #9765
Add xfail test for RabbitMQ quorum queue global QoS race condition by @maccinza in #9770
fix: (#8786) time out when chord header fails with group body by @dfm88 in #9788
Fix #9738 : Add root_id and parent_id to .apply() by @dfm88 in #9784
Replace DelayedDelivery connection creation to use context manger by @bityob in #9793
Fix #9794: Pydantic integration fails with future.annotations. by @davidt in #9795
add go and rust implementation in docs by @darixsamani in #9800
Fix memory leak in exception handling (Issue #8882) by @jaiganeshs21 in #9799
Fix handlers docs (Issue #9787) by @jaiganeshs21 in #9804
Remove importlib_metadata leftovers by @cjwatson in #9791
Update timeout minutes for smoke tests CI by @auvipy in #9807
Revert "Remove dependency on pycurl" by @auvipy in #9620
Add Blacksmith Docker layer caching to all Docker builds by @Nusnus in #9840
Bump Kombu to v5.6.0b1 by @Nusnus in #9839
Disable pytest-xdist for smoke tests and increase retries (CI ONLY) by @Nusnus in #9842
Fix Python 3.13 compatibility in events dumper by @Nusnus in #9826
Dockerfile Build Optimizations by @Nusnus in #9733
Migrated from useblacksmith/build-push-action@v1 to useblacksmith/setup-docker-builder@v1 in the CI by @Nusnus in #9846
Remove incorrect example by @YuppY in #9854
Revert "Use Django DB max age connection setting" by @danlamanna in #9824
Fix pending_result memory leak by @tsoos99dev in #9806
Update python-package.yml by @auvipy in #9856
Bump actions/checkout from 4 to 5 by @dependabot[bot] in #9857
Bump Kombu to v5.6.0b2 by @Nusnus in #9858
Refactor integration and smoke tests CI by @Nusnus in #9855
Fix AsyncResult.forget() with couchdb backend method raises TypeError: a bytes-like object is required, not 'str' by @temaxuck in #9865
Improve Docs for SQS Authentication by @BlaiseMuhirwa in #9868
Added .github/copilot-instructions.md for GitHub Copilot by @Nusnus in #9874
misc: credit removal by @0asys in #9877
Choose queue type and exchange type when creating missing queues (fix #9671) by @ghirailghiro in #9815
fix: prevent celery from hanging due to spawned greenlet errors in greenlet drainers by @linusphan in #9371
Feature/disable prefetch fixes by @Dkhodos in #9863
Add worker_eta_task_limit configuration to manage ETA task memory usage by @sashu2310 in #9853
Update runner version in Docker workflow by @auvipy in #9884
Prepare for (pre) release: v5.6.0b1 by @Nusnus in #9890

New Contributors

@chrisbarber made their first contribution in #9743
@dfm88 made their first contribution in #9774
@davidt made their first contribution in #9795
@darixsamani made their first contribution in #9800
@YuppY made their first contribution in #9854
@danlamanna made their first contribution in #9824
@tsoos99dev made their first contribution in #9806
@temaxuck made their first contribution in #9865
@BlaiseMuhirwa made their first contribution in #9868
@ghirailghiro made their first contribution in #9815
@linusphan made their first contribution in #9371
@Dkhodos made their first contribution in #9863
@sashu2310 made their first contribution in #9853

Full Changelog: v5.5.3...v5.6.0b1

Open source →

Additional notes2 sources agree

Celery v5.6.0 Beta 1 is now available for testing. Please help us test this version and report any issues.

What's Changed

docs: mention of json serializer recursive reference message size blowup (#5000) (#9743)
docs: typo in canvas.rst (#9744)
Makes _on_retry return a float as required to be used as errback on retry_over_time (#9741)
Update canvas.rst doc calculation order for callback (#9758)
Updated Blacksmith logo (#9763)
Made the Sponsors logos link to their website (#9764)
add missing cloudamqp logo (#9767)
Improve sponsor visibility (#9768)
fix: (#9773) task_id must not be empty with chain as body of a chord (#9774)
Update setup.py to fix deprecation warning (#9771)
Adds integration test for chord_unlock bug when routed to quorum/topic queue (#9766)
Add xfail test for default queue/exchange fallback ignoring task_default_* settings (#9765)
Add xfail test for RabbitMQ quorum queue global QoS race condition (#9770)
fix: (#8786) time out when chord header fails with group body (#9788)
Fix #9738 : Add root_id and parent_id to .apply() (#9784)
Replace DelayedDelivery connection creation to use context manager (#9793)
Fix #9794: Pydantic integration fails with __future__.annotations. (#9795)
add go and rust implementation in docs (#9800)
Fix memory leak in exception handling (Issue #8882) (#9799)
Fix handlers docs (Issue #9787) (#9804)
Remove importlib_metadata leftovers (#9791)
Update timeout minutes for smoke tests CI (#9807)
Revert "Remove dependency on pycurl" (#9620)
Add Blacksmith Docker layer caching to all Docker builds (#9840)
Bump Kombu to v5.6.0b1 (#9839)
Disable pytest-xdist for smoke tests and increase retries (CI ONLY) (#9842)
Fix Python 3.13 compatibility in events dumper (#9826)
Dockerfile Build Optimizations (#9733)
Migrated from useblacksmith/build-push-action@v1 to useblacksmith/setup-docker-builder@v1 in the CI (#9846)
Remove incorrect example (#9854)
Revert "Use Django DB max age connection setting" (#9824)
Fix pending_result memory leak (#9806)
Update python-package.yml (#9856)
Bump Kombu to v5.6.0b2 (#9858)
Refactor integration and smoke tests CI (#9855)
Fix AsyncResult.forget() with couchdb backend method raises TypeError: a bytes-like object is required, not 'str' (#9865)
Improve Docs for SQS Authentication (#9868)
Added .github/copilot-instructions.md for GitHub Copilot (#9874)
misc: credit removal (#9877)
Choose queue type and exchange type when creating missing queues (fix #9671) (#9815)
fix: prevent celery from hanging due to spawned greenlet errors in greenlet drainers (#9371)
Feature/disable prefetch fixes (#9863)
Add worker_eta_task_limit configuration to manage ETA task memory usage (#9853)
Update runner version in Docker workflow (#9884)
Prepare for (pre) release: v5.6.0b1 (#9890)

5.5.31 Jun 2025

make the tests run on python 3.13 for gcs backend by @auvipy in #9677

What's Changed

make the tests run on python 3.13 for gcs backend by @auvipy in #9677
Added DeepWiki to README by @Nusnus in #9683
Limit redis to <=v5.2.1 to match Kombu by @Nusnus in #9693
Use EX_OK instead of literal zero by @Nusnus in #9684
Make wheel metadata reproducible by @cjwatson in #9687
let celery install from kombu dependencies for better align by @auvipy in #9696
Fix stamping documentation to clarify stamped_headers key is optional in visitor methods by @Nusnus in #9697
Support apply_async without queue argument on quorum queues by @bityob in #9686
Updated rabbitmq doc about using quorum queues with task routes by @bityob in #9707
Add: Dumper Unit Test by @yiyu0x in #9711
Add unit test for event.group_from by @rogerforlife in #9709
refactor: add beat_cron_starting_deadline documentation warning by @alirafiei75 in #9712
fix: resolve issue #9569 by supporting distinct broker transport options for workers by @yiyu0x in #9695
Fixes issue with retry callback arguments in DelayedDelivery by @maccinza in #9708
get_exchange-unit-test by @rogerforlife in #9710
ISSUE-9704: Update documentation of result_expires, filesystem backend is supported by @MattiasDC in #9716
update to blacksmith ubuntu 24.04 by @auvipy in #9717
Added unit tests for celery.utils.iso8601 by @jaiganeshs21 in #9725
Update introduction.rst docs by @auvipy in #9728
Prepare for release: v5.5.3 by @Nusnus in #9732

New Contributors

@bityob made their first contribution in #9686
@yiyu0x made their first contribution in #9711
@rogerforlife made their first contribution in #9709
@alirafiei75 made their first contribution in #9712
@maccinza made their first contribution in #9708
@MattiasDC made their first contribution in #9716
@jaiganeshs21 made their first contribution in #9725

Full Changelog: v5.5.2...v5.5.3

Open source →

Additional notes2 sources agree

What's Changed

make the tests run on python 3.13 for gcs backend (#9677)
Added DeepWiki to README (#9683)
Limit redis to <=v5.2.1 to match Kombu (#9693)
Use EX_OK instead of literal zero (#9684)
Make wheel metadata reproducible (#9687)
let celery install from kombu dependencies for better align (#9696)
Fix stamping documentation to clarify stamped_headers key is optional in visitor methods (#9697)
Support apply_async without queue argument on quorum queues (#9686)
Updated rabbitmq doc about using quorum queues with task routes (#9707)
Add: Dumper Unit Test (#9711)
Add unit test for event.group_from (#9709)
refactor: add beat_cron_starting_deadline documentation warning (#9712)
fix: resolve issue #9569 by supporting distinct broker transport options for workers (#9695)
Fixes issue with retry callback arguments in DelayedDelivery (#9708)
get_exchange-unit-test (#9710)
ISSUE-9704: Update documentation of result_expires, filesystem backend is supported (#9716)
update to blacksmith ubuntu 24.04 (#9717)
Added unit tests for celery.utils.iso8601 (#9725)
Update introduction.rst docs (#9728)
Prepare for release: v5.5.3 (#9732)

Open source →