3.5.1.dev4: Nightly Development Release

What's Changed

Documentation 📓

• fix link in ECS worker docs by @mattiamatrix in #19364

Uncategorized

• Add @chrisguidry as a CODEOWNER by @desertaxle in #19368
• Fix automation deletion deadlock by enforcing consistent lock ordering by @zzstoatzz in #19369
• Migrate RedisStorageContainer from sync_compatible to async_dispatch by @devin-ai-integration[bot] in #19363
• Auto-update documentation by @github-actions[bot] in #19371
• Sync UI v2 OpenAPI schema with node v20.19.0 by @zzstoatzz in #19373

New Contributors

• @mattiamatrix made their first contribution in #19364

Full Changelog: 3.5.1.dev3...3.5.1.dev4

3.5.1.dev3: Nightly Development Release

What's Changed

Enhancements ➕➕

• Fix import order dependency and circular import issues by @zzstoatzz in #19344
• emit events for each deployment pull step execution by @zzstoatzz in #19339

Bug Fixes 🐞

• Fix EventsWorker singleton leak in prefect_test_harness by @zzstoatzz in #19343
• Fix run_deployment execution graph display when called from tasks by @desertaxle in #19361

Development & Tidiness 🧹

• chore(deps): bump helm/kind-action from 1.12.0 to 1.13.0 by @dependabot[bot] in #19340
• Remove legacy settings imports from CLI by @desertaxle in #19353
• clean up root directory by @zzstoatzz in #19355

Documentation 📓

• Add Pulumi section to Infrastructure as Code documentation by @bdalpe in #19352

Uncategorized

• chore(deps): bump @prefecthq/vue-compositions from 1.12.1 to 1.12.2 in /ui by @dependabot[bot] in #19323
• chore(deps-dev): bump vue-tsc from 3.0.4 to 3.1.2 in /ui by @dependabot[bot] in #19283
• Chore: Update prefect-ui-library to latest by @znicholasbrown in #19350
• Auto-update documentation by @github-actions[bot] in #19351
• Auto-update documentation by @github-actions[bot] in #19356
• Replace Optional with pipe syntax in _trim_traceback function by @devin-ai-integration[bot] in #19358
• auto-close superseded documentation PRs by @zzstoatzz in #19357

New Contributors

• @devin-ai-integration[bot] made their first contribution in #19358

Full Changelog: 3.5.1.dev2...3.5.1.dev3

3.5.1.dev2: Nightly Development Release

What's Changed

Bug Fixes 🐞

• Fix missing required parameters in run_task API Call by @desertaxle in #19335

Full Changelog: 3.5.1.dev1...3.5.1.dev2

3.5.1.dev1: Nightly Development Release

What's Changed

Bug Fixes 🐞

• fix deployment.parameters in subprocess flows by @zzstoatzz in #19331
• Fix event filter in Kubernetes observer by @desertaxle in #19333
• Fix misleading pyright error when calling async task with wrong argument types by @zzstoatzz in #19327

Uncategorized

• Auto-update documentation by @github-actions[bot] in #19336

Full Changelog: 3.5.0...3.5.1.dev1

3.5.0 - 🎃 The Exorcism of Python 3.9 👻

Released on October 31, 2025

With the removal of Python 3.9 support, Prefect now requires Python 3.10 or later. This means you can finally say goodbye to from __future__ import annotations in your workflow code—native type annotations are now standard! This release also removes several long-deprecated features, including Runner functionality and system Blocks. Check the Breaking Changes section below for details.

Enhancements ➕➕

• Add on_running hook support for tasks by @zzstoatzz in #19277
• Allow using Field descriptions directly in Flow parameters (#13912) by @jmesterh in #19281
• Add PREFECT_SERVER_UI_SHOW_PROMOTIONAL_CONTENT setting by @zzstoatzz in #19299

Breaking Changes ⚠️

• Remove Python 3.9 support by @desertaxle in #19273
• Remove deprecated Runner functionality and system Blocks by @desertaxle in #19307

Bug Fixes 🐞

• Fix forward reference resolution in ValidatedFunction by @desertaxle in #19289
• Fix datetime parameter serialization in run_deployment by @zzstoatzz in #19278
• Fix time zone normalization bug in interval schedules by @zzstoatzz in #19301
• Fix multiprocessing deadlock after using prefect_test_harness on Linux by @zzstoatzz in #19116

Development & Tidiness 🧹

• Update typer minimum to 0.16.0 for click>=8.2 compatibility by @zzstoatzz in #19269
• Remove weird language by @zzstoatzz in #19271
• Update just recipes to use 3.10 for lowest python by @zzstoatzz in #19297
• Fix duration in generate_deprecation_message by @desertaxle in #19314
• Fix RRuleSchedule test flakiness from DST-dependent date by @zzstoatzz in #19305
• Add debug log for fork handler registration failure by @zzstoatzz in #19311

Documentation 📓

• Add global concurrency limits concept doc and refactor how-to guide by @desertaxle in #19231

Full Changelog: 3.4.25...3.5.0

3.4.26.dev6: Nightly Development Release

What's Changed

Bug Fixes 🐞

• Fix multiprocessing deadlock after using prefect_test_harness on Linux by @zzstoatzz in #19116

Uncategorized

• Call pods containers in ECS by @leetrout in #19310

Full Changelog: 3.4.26.dev5...3.4.26.dev6

3.4.26.dev5: Nightly Development Release

What's Changed

Enhancements ➕➕

• Allow using Field descriptions directly in Flow parameters (#13912) by @jmesterh in #19281

Bug Fixes 🐞

• Fix time zone normalization bug in interval schedules by @zzstoatzz in #19301
• fix: RRuleSchedule test flakiness from DST-dependent date by @zzstoatzz in #19305

Uncategorized

• Auto-update documentation by @github-actions[bot] in #19303
• add option to disable the Kubernetes worker observer and pod event replication by @levzem in #19282

New Contributors

• @jmesterh made their first contribution in #19281

Full Changelog: 3.4.26.dev4...3.4.26.dev5

3.4.26.dev4: Nightly Development Release

What's Changed

Development & Tidiness 🧹

• update just recipes to use 3.10 for lowest python by @zzstoatzz in #19297

Uncategorized

• Add PREFECT_SERVER_UI_SHOW_PROMOTIONAL_CONTENT setting by @zzstoatzz in #19299
• Auto-update documentation by @github-actions[bot] in #19300

Full Changelog: 3.4.26.dev3...3.4.26.dev4

3.4.26.dev3: Nightly Development Release

What's Changed

Enhancements ➕➕

• Add on_running hook support for tasks by @zzstoatzz in #19277

Bug Fixes 🐞

• Fix forward reference resolution in ValidatedFunction by @desertaxle in #19289
• Fix datetime parameter serialization in run_deployment by @zzstoatzz in #19278

Documentation 📓

• Remove Python 3.9 support by @desertaxle in #19273

Uncategorized

• Auto-update documentation by @github-actions[bot] in #19291

Full Changelog: 3.4.26.dev2...3.4.26.dev3

3.4.26.dev2: Nightly Development Release

What's Changed

Development & Tidiness 🧹

• rm weird language by @zzstoatzz in #19271

Uncategorized

• Auto-update documentation by @github-actions[bot] in #19272
• chore(cicd): Update Dockerhub token for prefect-aws image builds by @jamiezieziula in #19274

Full Changelog: 3.4.26.dev1...3.4.26.dev2