3.6

3.6.21 - {"cli": { "speaks_json": true } }

Released on March 05, 2026

Enhancements ➕➕

• Add --output json support to flow ls command by @Br1an67 in #20907
• Fix match_related type hints and add Python examples for DeploymentEventTrigger by @devin-ai-integration[bot] in #20902
• Support multihost Postgres connection strings in LISTEN/NOTIFY listener by @devin-ai-integration[bot] in #20926
• Move event trimming from EventPersister to docket-based db_vacuum service by @tom21100227 in #20811
• Add --output json to task-run ls, work-pool ls, and concurrency-limit ls by @zzstoatzz in #20967
• Add --output json support to block inspect and block type inspect by @zzstoatzz in #20981
• Add --output json support to flow-run logs and task-run logs by @zzstoatzz in #20982
• Add --output json support to server services ls by @jellyfish0316 in #20983
• Add --output json support to cloud workspace and webhook commands by @zzstoatzz in #20984
• Add --output json support to work-queue ls and preview by @zzstoatzz in #20985
• Add --output json support to work-pool preview by @zzstoatzz in #20986
• Add --output json support to profile ls and config view by @zzstoatzz in #20987
• Add composite index on task_run(state_type, start_time) by @desertaxle in #20940
• Defer task worker import in CLI task command by @zzstoatzz in #20925
• Lazy-load top-level CLI command registration by @zzstoatzz in #20930
• Add centralized exit code hint registry by @desertaxle in #20959
• Add PREFECT_CLIENT_SERVER_VERSION_CHECK_ENABLED setting by @devin-ai-integration[bot] in #20973
• Cache serialized context and env vars in ProcessPoolTaskRunner.submit() by @devin-ai-integration[bot] in #20972

Bug Fixes 🐞

• Fix postgres_listener to preserve Kerberos/GSSAPI and TLS connection params by @devin-ai-integration[bot] in #20890
• Fix non-deterministic flow scanning in prefect deploy by @ashwanth0110 in #20874
• Remove Panel border from work-pool create sample code output by @Br1an67 in #20906
• Fix broken link in PrefectHTTPStatusError message by @devin-ai-integration[bot] in #20938
• Prevent Rich console from word-wrapping CLI JSON output by @zzstoatzz in #20947
• Fix database reset failing on PostgreSQL with orphaned state_id references by @devin-ai-integration[bot] in #20941
• Mark followers as seen and clean up lost follower Redis keys by @devin-ai-integration[bot] in #20955
• Fix expiration check on in-memory cache hits in ResultStore._read/_aread by @devin-ai-integration[bot] in #20988

Development & Tidiness 🧹

• Add clearer CLI benchmark regression gating feedback by @zzstoatzz in #20916
• Fix flaky test: mock git_clone in pip_install_reqs test by @devin-ai-integration[bot] in #20949
• Add apt retry configuration to Dockerfile to handle transient network errors by @devin-ai-integration[bot] in #20943

Documentation 📓

• Document prebuilt integration images and version pinning for workers by @rcash in #20893
• Improve MCP discoverability in existing docs IA by @gabcoyne in #20660
• Update rate limit docs to match unified limits by @zangell44 in #20927
• Add pull_with_block YAML example to Bitbucket integration docs by @toroleapinc in #20935
• Add missing PREFECT_API_URL env var in the self-hosted Docker Compose file by @Kiskadee-dev in #20897
• Add note about server default limit for client queries by @audreydng in #20909
• Document that deployment steps are just Python functions by @Sagargupta16 in #20956
• Minor cleanup from custom steps clarification by @zzstoatzz in #20963

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.20…3.6.21

---

3.6.20 - new cli, who dis?

Released on February 27, 2026

Enhancements ➕➕

• Migrate CLI from typer to cyclopts, remove toggle and delegation machinery by @zzstoatzz in #20821
• Route ProcessPoolTaskRunner subprocess events and logs through a single parent queue, improving per-task performance by ~28% in log-heavy workloads by @desertaxle in #20864
• Add configurable subprocess message processors to ProcessPoolTaskRunner for custom event/log handling in the parent forwarder by @desertaxle in #20869
• Use distinct FK scan for orphaned log/artifact vacuum queries, reducing cycle time from ~3.6s to ~0.5s on large databases by @zzstoatzz in #20868

Bug Fixes 🐞

• Avoid None asset descriptions in events by @devin-ai-integration[bot] in #20840
• Lower default DB vacuum batch_size from 1000 to 200 to prevent query timeouts on Postgres by @zzstoatzz in #20857
• Fix subprocess events silently lost in ProcessPoolTaskRunner when task completes before async event forwarding by @devin-ai-integration[bot] in #20876
• Fix page header breadcrumb truncation for long entity names by @devin-ai-integration[bot] in #20870
• Add truncation to card breadcrumbs and locale format automation count by @devin-ai-integration[bot] in #20871

Development & Tidiness 🧹

• Promote _cyclopts/ to src/prefect/cli/, remove typer dependency by @zzstoatzz in #20838
• Prevent nvm from clobbering setup-node in pre-commit CI by @zzstoatzz in #20854
• Increase test timeout to fix flaky concurrency slot release test by @devin-ai-integration[bot] in #20843
• Replace inline SQLite compilation with pre-built Docker image for faster builds by @desertaxle in #20824

Documentation 📓

• Update rate limit docs for unified two-bucket system by @zangell44 in #20828
• Update docs logos and favicon by @znicholasbrown in #20858

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.19…3.6.20

---

3.6.19 - This release sucks in the best way possible

Released on February 24, 2026

This release introduces an optional database vacuum service that periodically deletes old flow runs and orphaned resources (logs, artifacts, artifact collections) to keep your database lean. It’s disabled by default — enable it with PREFECT_SERVER_SERVICES_DB_VACUUM_ENABLED=true. Once enabled, it runs hourly and removes terminal top-level flow runs older than 90 days. Both the retention period and frequency are configurable via PREFECT_SERVER_SERVICES_DB_VACUUM_RETENTION_PERIOD (in seconds, minimum 1 hour) and PREFECT_SERVER_SERVICES_DB_VACUUM_LOOP_SECONDS.

Enhancements ➕➕

• Add DB vacuum service in Docket by @tom21100227 in #20746
• Add Docker images for prefect-gcp and prefect-azure by @devin-ai-integration[bot] in #20771

Bug Fixes 🐞

• Add SSRF protection to CustomWebhookNotificationBlock by @devin-ai-integration[bot] in #20781
• Fix scheduler to check per-schedule run counts for multi-schedule deployments by @devin-ai-integration[bot] in #20699
• Fix FastAPI 0.132.0 compatibility by @devin-ai-integration[bot] in #20822

Development & Tidiness 🧹

• Add UI v2 unit tests and E2E tests to Devin flaky test workflow by @devin-ai-integration[bot] in #20774
• Migrate work-pool command to cyclopts by @zzstoatzz in #20766
• Migrate transfer command to cyclopts by @zzstoatzz in #20767
• Migrate cloud command to cyclopts by @zzstoatzz in #20780
• Migrate deploy command to cyclopts by @zzstoatzz in #20783
• Remove bogus alias from cyclopts deployment command by @zzstoatzz in #20793
• Add deploy to cyclopts routing and remove dead delegation code by @zzstoatzz in #20794
• Migrate automation command to cyclopts and register init at root level by @zzstoatzz in #20802
• Split database and orchestration tests into separate jobs by @desertaxle in #20803
• Clean up cyclopts phase 2 — server status, stdin handling, watch monkeypatch by @devin-ai-integration[bot] in #20807

Documentation 📓

• Add ImportString section to form-building guide by @zzstoatzz in #20768
• Fix MDX rendering issues in prefect-databricks API reference docs by @desertaxle in #20792

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.18…3.6.19

---

3.6.18 - The annotation that minds its own business

Released on February 19, 2026

Enhancements ➕➕

• Add opaque annotation to prevent recursive traversal of resolved task inputs by @devin-ai-integration[bot] in #20650
• Add PREFECT_WORKER_DEBUG_MODE for worker-only debug logging by @devin-ai-integration[bot] in #20653
• Support DateTimeDelta as interval option in IntervalSchedule by @devin-ai-integration[bot] in #20692

Bug Fixes 🐞

• Include duration fields in TaskRunResponse by @vyagubov in #20664
• Skip lease renewal and release when no concurrency limits exist by @zzstoatzz in #20666
• Fix order-dependent slug collisions in deployment schedule replaces handling by @chrisguidry in #20669
• Strip null bytes from log messages before database insert by @Mr-Neutr0n in #20677
• Fix uq_task_run__flow_run_id_task_key_dynamic_key constraint violation with multiple background workers by @devin-ai-integration[bot] in #20697
• Fix async listener for UNIX domain socket PostgreSQL connections by @devin-ai-integration[bot] in #20744

Integrations & Dependencies 🤝

• Bump pydocket minimum version to 0.17.7 by @devin-ai-integration[bot] in #20731

Development & Tidiness 🧹

• Update YAML templates to conform with yamllint standards by @veeceey in #20594
• Migrate server, worker, shell CLI commands to cyclopts by @zzstoatzz in #20603
• Add Claude Code SessionStart hook to symlink AGENTS.md files to CLAUDE.md files by @desertaxle in #20667
• Migrate flow CLI command to cyclopts by @zzstoatzz in #20672
• Migrate flow-run CLI command to cyclopts by @zzstoatzz in #20673
• Add regression gate to CLI startup benchmarks by @zzstoatzz in #20678
• Migrate deployment CLI command to cyclopts by @zzstoatzz in #20721
• Migrate dashboard, task, sdk CLI commands to cyclopts by @zzstoatzz in #20723
• Migrate concurrency-limit, events, experimental CLI commands to cyclopts by @zzstoatzz in #20724
• Migrate variable, artifact, task-run, api CLI commands to cyclopts by @zzstoatzz in #20740
• Migrate dev, global-concurrency-limit CLI commands to cyclopts by @zzstoatzz in #20745
• Migrate block CLI command to cyclopts and add command aliases by @zzstoatzz in #20749
• Migrate work-queue CLI command to cyclopts by @zzstoatzz in #20763

Documentation 📓

• Add comprehensive base job template examples for Kubernetes by @kingsley-123 in #20670
• Set up automatic API reference docs via mdxify for all integration packages by @devin-ai-integration[bot] in #20679, #20704–#20720
• Exclude analytics module from API reference docs by @devin-ai-integration[bot] in #20722
• Add documentation for logging inside hooks by @pblocz in #20734
• Clarify that primitive wait_for_input types generate a value field for programmatic resume by @desertaxle in #20741

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.17…3.6.18

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3.6.17 - Goodbye, Ghost in the WebSocket

Released on February 12, 2026

New Features 🎉

• Add prefect server status command by @devin-ai-integration[bot] in #20619

Enhancements ➕➕

• Make PrefectFutureList.result() fail-fast using as_completed by @desertaxle in #20592
• Improve CLI connection message for self-hosted server by @Kulkarnivaishnavi473 in #20623
• Add replaces field for renaming schedule slugs by @desertaxle in #20460
• Add attribution headers to SDK API requests by @zangell44 in #20508

Bug Fixes 🐞

• Fix flow timeout not retrying when retries are enabled by @devin-ai-integration[bot] in #20572
• Fix the flow run graph being hidden when a flow run is in AwaitingRetry state by @vyagubov in #20318
• Fix websocket timeout when watching long-running flow runs by @devin-ai-integration[bot] in #20590
• Handle missing resources gracefully in prefect transfer automations by @devin-ai-integration[bot] in #20639
• Fix prefect deploy stripping {{ ctx.flow.* }} templates from job variables by @desertaxle in #20611
• Add ResumeFlowRun action to automation events by @lordsoffallen in #20604
• Fix print_as_log so log formatters report the caller’s location by @devin-ai-integration[bot] in #20618

Development & Tidiness 🧹

• Deflake lease renewal failure tests: revoke via API to avoid FS race by @devin-ai-integration[bot] in #20576
• Fix flaky test_error_handling_on_cache_policies by increasing random range by @devin-ai-integration[bot] in #20566
• Fix flaky test_docker_deploy: add retry logic for transient Docker registry errors by @devin-ai-integration[bot] in #20580
• Add cyclopts CLI migration infrastructure by @zzstoatzz in #20584
• Migrate config, profile, version to cyclopts (wave 1) by @zzstoatzz in #20585
• Add CycloptsCliRunner for in-process CLI testing by @zzstoatzz in #20609
• Fix flaky threaded client lifespan test by using thread-safe counters by @devin-ai-integration[bot] in #20616
• Fix potential script injection in Docker build workflows by @RinZ27 in #20593
• Fix flaky concurrency timeout tests by @devin-ai-integration[bot] in #20568
• Add CLI subdirectories to EXCLUDE_FROM_CLEAR_DB_AUTO_MARK by @devin-ai-integration[bot] in #20578
• Replace UI_COMPONENTS_CONTENTS_PRS_RW with GITHUB_TOKEN in nightly release workflow by @jamiezieziula in #20602
• Use PAT token for nightly release workflow by @jamiezieziula in #20627
• Increase SQLite busy_timeout for better test concurrency by @devin-ai-integration[bot] in #20553

Documentation 📓

• Update manage workspace instructions by @rcash in #20569
• Add testing with caplog example by @rcash in #20570
• Remove deprecated GitHub Action reference by @seanpwlms in #20610
• Add docs/AGENTS.md and write-docs skill for AI agent guidance by @desertaxle in #20606
• Fix inconsistent deployment concurrency limit documentation by @devin-ai-integration[bot] in #20622
• Fix incorrect concurrency_options key in debouncing guide by @desertaxle in #20633
• Add Telegram notification example by @Rodrigorm33 in #20385
• Fix MDX OpenAPI frontmatter to match schema.json paths by @devin-ai-integration[bot] in #20620

Experimental 🧪

• Add include_files support to @ecs decorator for bundling non-Python files by @desertaxle in #20551

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.16…3.6.17

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3.6.16 - It’s Bulking Season

Released on February 05, 2026

New Features 🎉

• Add prefect cloud asset list and delete commands by @zzstoatzz in #20524
• Add bulk operation endpoints for flow runs, deployments, and flows by @bunchesofdonald in #20469
• Add SDK instrumentation module by @desertaxle in #20438

Enhancements ➕➕

• Allow infra name templating with flow and flow_run by @Rodrigorm33 in #20358
• Add max_scheduled_runs, parameters, and slug fields to deployment schedule methods by @devin-ai-integration[bot] in #20556

Bug Fixes 🐞

• Fix visit_collection to handle NamedTuples by @chuqCTC in #20517
• Use count endpoint for deployments page empty state check by @zzstoatzz in #20404
• Handle non-serializable objects in JsonFormatter for logging by @devin-ai-integration[bot] in #20482
• Fix env var template resolution in deploy --all console output by @devin-ai-integration[bot] in #20511
• Resolve circular import when plugins import from prefect by @desertaxle in #20514
• Fix stale TaskRunContext leaking into Pending event related resources by @bunchesofdonald in #20536

Development & Tidiness 🧹

• Remove old admin routes by @desertaxle in #20515
• Untrack analytics config file to fix build versioning by @devin-ai-integration[bot] in #20483
• Add regression test for fan-out sibling asset dependency isolation by @chrisguidry in #20478
• Fix flaky test: add thread completion check and increase timeout by @devin-ai-integration[bot] in #20505
• Use unique block type slugs in tests to prevent parallel test conflicts by @devin-ai-integration[bot] in #20496
• Exclude 10 test modules from clear_db auto-mark by @devin-ai-integration[bot] in #20487
• Add more test modules to EXCLUDE_FROM_CLEAR_DB_AUTO_MARK by @devin-ai-integration[bot] in #20490
• Add DB-LIGHT test modules to clear_db exclusion list by @devin-ai-integration[bot] in #20491
• Add test_flow_runs.py and telemetry/ to clear_db exclusion list by @devin-ai-integration[bot] in #20492
• Add input/, deployment/, experimental/ to clear_db exclusion list by @devin-ai-integration[bot] in #20493
• Add tests/results to clear_db exclusion list by @devin-ai-integration[bot] in #20495
• Add 5 test modules to EXCLUDE_FROM_CLEAR_DB_AUTO_MARK by @devin-ai-integration[bot] in #20504
• Add tests/events/client to clear_db exclusion list by @devin-ai-integration[bot] in #20506
• Add tests/infrastructure to clear_db exclusion list by @devin-ai-integration[bot] in #20507
• Add tests/blocks/ to EXCLUDE_FROM_CLEAR_DB_AUTO_MARK by @devin-ai-integration[bot] in #20512
• Add tests/test_task_runners.py and tests/test_variables.py to clear_db exclusion list by @devin-ai-integration[bot] in #20530
• Add tests/test_futures.py and tests/test_logging.py to clear_db exclusion list by @devin-ai-integration[bot] in #20531
• Add UUID-based randomization to top-level test files by @devin-ai-integration[bot] in #20539
• Add UUID-based randomization to CLI Cloud test files by @devin-ai-integration[bot] in #20546
• Add UUID-based randomization to CLI Deploy test files by @devin-ai-integration[bot] in #20552
• Add UUID-based randomization to CLI transfer test files by @devin-ai-integration[bot] in #20563

Documentation 📓

• Add Claude Code marketplace install instructions to MCP docs by @devin-ai-integration[bot] in #20545

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.15…3.6.16

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3.6.15 - Simply Authful

Released on January 30, 2026

Bug Fixes 🐞

• Fix PrefectCloudEventsClient auth handshake breaking Cloud connections by @desertaxle in #20472
• Cap concurrency limit retry-after to prevent excessive delays from burst traffic by @bunchesofdonald in #20470

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.14…3.6.15

---

3.6.14 - A Prefect Server for Every ::1

Released on January 29, 2026

Enhancements ➕➕

• Support parsing TOML 1.0 on Python 3.11+ by @zed in #20398
• Make runner cancellation observing critical to runner health by @joshuastagner in #20219
• Reload root settings after running plugins to enable environment variable updates to take effect by @desertaxle in #20393
• Support IPv6 addresses in prefect server start by @zzstoatzz in #20361
• Add authentication to /api/events/in WebSocket endpoint by @devin-ai-integration[bot] in #20372

Bug Fixes 🐞

• Add polling fallback in PrefectFlowRunFuture.wait_async by @devin-ai-integration[bot] in #20406
• Fix race condition in ephemeral consumer group cleanup by @devin-ai-integration[bot] in #20435
• Fix flow runs with parameter validation failures missing end_time by @devin-ai-integration[bot] in #20369
• Fix flow_run.id returning string "None" instead of None by @bnaul in #20425

Integrations & Dependencies 🤝

• Bump pydocket minimum version to 0.17.2 by @chrisguidry in #20405

Development & Tidiness 🧹

• Replace skipif(sys.platform != 'win32') with @pytest.mark.windows and remove skipif(sys.platform == 'win32') by @devin-ai-integration[bot] in #20327
• Fix flaky test: use pytest.approx for date_diff_seconds timing assertions by @devin-ai-integration[bot] in #20354
• Migrate deployments/runner.py from @sync_compatible to @async_dispatch by @zzstoatzz in #20359
• Fix flaky test_timeout_concurrency_slot_released tests by @devin-ai-integration[bot] in #20364
• Migrate Task.serve() from @sync_compatible to @async_dispatch by @zzstoatzz in #20374
• Migrate Flow.deploy() from @sync_compatible to @async_dispatch by @zzstoatzz in #20380
• Migrate Runner methods from @sync_compatible to @async_dispatch by @zzstoatzz in #20382
• Fix flaky docket task keys tests: use custom lifespan without worker by @devin-ai-integration[bot] in #20408
• Fix flaky test: use TestClient as context manager for proper lifespan cleanup by @devin-ai-integration[bot] in #20426
• Add CLI benchmark harness as external dependency by @zzstoatzz in #20439
• Add in-repo CLI benchmark workflow by @zzstoatzz in #20451

Documentation 📓

• Add accordion for logging pydantic-ai tool calls to Prefect by @zzstoatzz in #20410
• Expand task invocation methods documentation by @devin-ai-integration[bot] in #20403
• Add Docket URL configuration for HA background services by @devin-ai-integration[bot] in #20422
• Add Bluesky link to README by @zzstoatzz in #20413

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.13…3.6.14

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3.6.13 - The heartbeat is coming from inside the engine

Released on January 23, 2026

Enhancements ➕➕

• Add FlowRunFilterCreatedBy by @zzstoatzz in #20256
• Add retry logic for PrefectEventsClient.__aenter__() initial connection by @devin-ai-integration[bot] in #20328

Bug Fixes 🐞

• Move flow run heartbeat event emission to flow run engine by @zzstoatzz in #19641
• Fix websocket cleanup AttributeError in event clients by @devin-ai-integration[bot] in #20323
• Add warning when sync task with timeout runs in worker thread by @desertaxle in #20315
• Prevent GitHub token leakage in git error messages by @Rodrigorm33 in #20330
• Consolidate strip_auth_from_url into prefect._internal.urls by @zzstoatzz in #20331
• Fix git URL comparison when credentials are embedded in URL by @zzstoatzz in #20346
• Fix slot_decay_per_second None value causing 422 error in upsert_global_concurrency_limit_by_name by @devin-ai-integration[bot] in #20320
• Fix Windows-specific process termination bug in hosted_api_server fixture by @devin-ai-integration[bot] in #20322

Development & Tidiness 🧹

• Fix flaky docket task keys tests: include running tasks in key assertions by @devin-ai-integration[bot] in #20293
• Pin miniconda3 image to fix conda Docker build failure by @desertaxle in #20309
• Bump dependencies in lockfile by @zzstoatzz in #20205
• Push dev images to main repository with dev tags by @mitchnielsen in #20311
• Fix flaky test cleanup: use ignore_errors in rmtree for SQLite race condition by @devin-ai-integration[bot] in #20326
• Fix release workflows not triggering on prereleases by @mitchnielsen in #20332
• Fix conda Docker build by installing git from Trixie on Bookworm by @desertaxle in #20345
• Fix flaky test: add sys.path isolation fixture for importtools tests by @devin-ai-integration[bot] in #20347
• Migrate task_worker.py from @sync_compatible to @async_dispatch by @zzstoatzz in #20259
• Migrate testing fixtures from @sync_compatible to @async_dispatch by @zzstoatzz in #20313
• Migrate ResultStore from @sync_compatible to @async_dispatch by @zzstoatzz in #20314
• Migrate Flow.visualize from @sync_compatible to @async_dispatch by @zzstoatzz in #20353

Documentation 📓

• Update job variables page title to cover flow runs by @devin-ai-integration[bot] in #20351

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.12…3.6.13

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3.6.12 - It’s not a feature, it’s a bug!

Released on January 20, 2026

Enhancements ➕➕

• Add httpx.ConnectError to client retry exceptions by @joshuastagner in #20276

Bug Fixes 🐞

• Add build=False documentation to flow.deploy guide by @devin-ai-integration[bot] in #20269
• fix: display error details nicely in work-pool create command by @devin-ai-integration[bot] in #20277
• fix: remove CANCELLED from EnforceCancellingToCancelledTransition to allow retrying cancelled flows by @zzstoatzz in #20275
• Add retry logic to PrefectEventSubscriber.__aenter__() for initial connections by @devin-ai-integration[bot] in #20295
• fix: convert dynamic_key to str in sync client’s create_task_run by @zzstoatzz in #20302
• Fix wait() timeout not being respected when using WatcherThreadCancelScope by @devin-ai-integration[bot] in #20257

Development & Tidiness 🧹

• migrate RemoteFileSystem and SMB from @sync_compatible to @async_dispatch by @zzstoatzz in #20230
• Migrate notification blocks from @sync_compatible to @async_dispatch by @zzstoatzz in #20258
• Fix Devin flaky tests workflow API integration by @desertaxle in #20272
• Add GitHub Actions workflow to trigger Devin.ai on test failures by @desertaxle in #20255

Documentation 📓

• Add release notes for integration packages by @desertaxle in #20266

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.11…3.6.12

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3.6.11 - It’s my generation, baby

Released on January 15, 2026

This release introduces prefect sdk generate a new CLI command that generates fully-typed, custom Python SDKs from the deployments in your workspace or self-hosted server, making it easy to trigger your deployments from other workflows with confidence.

To see how it works, check out the Prefect docs. This functionality is currently in beta, so try it out and open a GitHub issue if you have feedback!

New Features 🎉

• Add prefect sdk generate CLI command for generating custom deployment SDKs from existing deployments by @desertaxle in #20150, #20158, #20167, #20172, #20173

Enhancements ➕➕

• Add JSON output to prefect variable ls CLI command by @xeniumcode in #20192
• Add JSON output to prefect global-concurrency-limit ls CLI command by @xeniumcode in #20194
• Add JSON output to prefect artifact CLI commands by @xeniumcode in #20193
• Add JSON output to prefect block ls CLI command by @xeniumcode in #20195
• Add JSON output to prefect block type ls CLI command by @xeniumcode in #20196
• Add JSON output to prefect deployment schedule CLI commands by @xeniumcode in #20197
• Add JSON output to prefect deployment CLI commands by @xeniumcode in #20198
• Migrate pause, suspend, resume, and run_input from @sync_compatible to @async_dispatch by @devin-ai-integration[bot] in #20178
• Add force parameter to ChangeFlowRunState and flow_run_id Jinja filter by @zzstoatzz in #20112
• Link automation.action.* events to automation.triggered event by @chrisguidry in #20227
• Add DISABLED to client DeploymentStatus enum for Cloud compatibility by @chrisguidry in #20244

Bug Fixes 🐞

• Fix flow run cancellation handling bugs by @joshuastagner in #20143
• Fix race condition in filesystem lease storage with atomic writes by @devin-ai-integration[bot] in #20153
• Add task keys to docket calls in API handlers to prevent duplicate execution by @desertaxle in #20210
• Support ISO 8601 duration strings for interval schedules in prefect.yaml by @zzstoatzz in #20238
• Disable Docket result storage to prevent memory bloat by @desertaxle in #20253
• Preserve the updated column value of deployments when marking them as ready by @vkrot-innio in #19936

Development & Tidiness 🧹

• Add arun_deployment and replace @sync_compatible with @async_dispatch by @desertaxle in #20160
• Patch correct method in test_concurrency_respects_timeout by @devin-ai-integration[bot] in #20185
• Fix flaky test by reducing slot_decay_per_second to prevent race condition by @devin-ai-integration[bot] in #20208
• Remove incorrect docstrings from CLI ls commands by @zzstoatzz in #20206
• Add Claude command frontmatter by @zzstoatzz in #20224
• Enable multi-checker type safety tests with mypy, pyright, and ty by @zzstoatzz in #20159
• Migrate concurrency/v1 from @sync_compatible to @async_dispatch by @zzstoatzz in #20225
• Migrate blocks/core.py from @sync_compatible to @async_dispatch by @devin-ai-integration[bot] in #20226
• Stale item cleanup enhancements by @bdalpe in #20145
• Add plan label to exclude from release notes by @zzstoatzz in #20182
• Auto-label PRs that touch plans/ directory by @zzstoatzz in #20183
• Disable migrations and block registration for multi-worker test by @devin-ai-integration[bot] in #20179
• Fix plan label to only apply when all changed files are in plans/ by @desertaxle in #20207

Documentation 📓

• Add ECS base job template customization guide by @zzstoatzz in #20249
• Fix MDX parsing error in events CLI documentation by @desertaxle in #20252
• Add documentation for prefect sdk generate CLI by @desertaxle in #20241

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.10…3.6.11

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3.6.10 - Five Bugs Walked Into A Bar And None Of Them Left

Released on January 08, 2026

Enhancements ➕➕

• Add prefect automation update CLI command by @devin-ai-integration[bot] in #20118
• Add upserting global concurrency limit decay by @cbrown1234 in #20124

Bug Fixes 🐞

• Fix AttributeError in Consumer.cleanup() for non-memory brokers by @devin-ai-integration[bot] in #20089
• Fix exception_to_crashed_state_sync failing without async backend by @zzstoatzz in #20139
• Fix MockValSer serialization error with StateDetails by @zzstoatzz in #20127
• Resolve race condition in compound trigger evaluation by @desertaxle in #20106
• Fix AttributeError for functools.partial hooks in Runner by @devin-ai-integration[bot] in #20136

Development & Tidiness 🧹

• Add UISettings model for /ui-settings endpoint by @desertaxle in #20103
• Fix flaky test_concurrency_respects_timeout test by @devin-ai-integration[bot] in #20138
• Update @prefecthq/prefect-ui-library to version 3.14.8 by @marvin-robot in #20147
• Run integration tests against PostgreSQL to prevent CI timeouts by @devin-ai-integration[bot] in #20080
• Use correct apt version syntax for git in Dockerfile by @devin-ai-integration[bot] in #20094

Documentation 📓

• Link to MCP server security FAQ by @zzstoatzz in #20120
• Fix broken ECS worker deployment guide links by @devin-ai-integration[bot] in #20119
• Clarify that base job template variables must be referenced in job_configuration by @zzstoatzz in #20133

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.9…3.6.10

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3.6.9 - Auld Lang Sync

Released on December 31, 2025

New Features 🎉

• Add worker-side cancellation for pending flow runs by @joshuastagner in #20022

Enhancements ➕➕

• Add JSON schema for prefect.yaml files by @zzstoatzz in #19996
• Send entrypoint pip install errors to Prefect logs by @jakekaplan in #20058
• Run read and count queries concurrently in paginate endpoints by @zzstoatzz in #20049

Bug Fixes 🐞

• Preserve symlinks in get_directory instead of following them by @majiayu000 in #19993
• Fix GitRepository name parameter preservation in pull step conversion by @devin-ai-integration[bot] in #20004
• Add explicit ruamel.yaml.clib dependency to fix Docker builds by @zzstoatzz in #20068

Development & Tidiness 🧹

• Update @prefecthq/prefect-ui-library to version 3.14.5 by @marvin-robot in #20003
• Add GitHub Actions workflow for UI v2 E2E tests by @devin-ai-integration[bot] in #20042

Documentation 📓

• Add link to Python AI Conference by @aaazzam in #20054

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.8…3.6.9

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3.6.8 - On Exception! On Timeout! On Error and Failure! 🦌

Released on December 24, 2025

New Features 🎉

• Add prefect flow-run retry command by @desertaxle in #19858

Enhancements ➕➕

• Add url property to server-side ReceivedEvent for automation templates by @devin-ai-integration[bot] in #19851

Bug Fixes 🐞

• Add timeout to Docket worker shutdown by @desertaxle in #19940
• Prevent dictionary mutation during iteration in preprocess_schema by @zzstoatzz in #19946
• Allow string form_data in CustomWebhookNotificationBlock by @zzstoatzz in #19953
• Bump pydocket version and remove background worker shutdown timeout by @desertaxle in #19969
• Fix TASK_SOURCE cache policy for remote execution with cloudpickle by @desertaxle in #19926

Development & Tidiness 🧹

• Run lint, build, and test in parallel for ui-v2 checks by @devin-ai-integration[bot] in #19884
• Fix docker deploy integration test failing due to uv import by @desertaxle in #19899
• Update kickoff-release schedule from Monday to Thursday by @devin-ai-integration[bot] in #19930

Documentation 📓

• Add security considerations to Prefect MCP server guide by @zzstoatzz in #19875
• Document AWS IAM role assumption by @seanpwlms in #19963

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.7…3.6.8

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3.6.7 - LoopService #OpenToWork: 3+ Years Experience Looping

Released on December 18, 2025

Enhancements ➕➕

• Add support for AWS IAM authentication for PostgreSQL database by @alaminopu in #19580
• Add generic typing support for Variable.get method by @devin-ai-integration[bot] in #19764
• Convert late_runs service to Docket perpetual function by @zzstoatzz in #19722
• Convert repossessor service to Docket perpetual function by @zzstoatzz in #19739
• Convert foreman service to Docket perpetual function by @zzstoatzz in #19741
• Convert telemetry service to Docket perpetual function by @zzstoatzz in #19754
• Convert scheduler and proactive triggers to Docket, remove LoopService by @zzstoatzz in #19756

Bug Fixes 🐞

• Update broken links in creating-automations docs by @devin-ai-integration[bot] in #19759
• Silence retryable SQLite lock errors from docket.worker logger by @devin-ai-integration[bot] in #19772
• Exclude unset grace_period_seconds from deployment concurrency_options by @zzstoatzz in #19784
• Correct docket_url setting path to server.docket.url by @zzstoatzz in #19791
• Fix Mattermost bot name issue by @tre-ert in #19780
• Restore netloc-based credential formatting for YAML deployments by @zzstoatzz in #19873

Development & Tidiness 🧹

• Add @chrisguidry as a CODEOWNER by @zzstoatzz in #19738

Documentation 📓

• Add negative matching documentation for automation triggers by @chrisguidry in #19760

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.6…3.6.7

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3.6.6 - The Eternal Docket of the Spotless Server

Released on December 08, 2025

Enhancements ➕➕

• Add client-side configuration for deployment concurrency grace period by @devin-ai-integration[bot] in #19489
• Add PostgreSQL search_path support via settings by @devin-ai-integration[bot] in #19620
• Add memory safeguards to event persister service by @desertaxle in #19651
• Add perpetual services infrastructure and convert cancellation_cleanup to perpetual Docket task by @zzstoatzz in #19715
• Convert pause_expirations service to perpetual Docket task by @zzstoatzz in #19719

Bug Fixes 🐞

• Prevent uvloop from setting global event loop policy in healthcheck by @zzstoatzz in #19660
• Clarify result_storage usage with @task and @flow decorators by @devin-ai-integration[bot] in #19671
• Exclude DEFAULT cache policy from triggering automatic persist_result by @devin-ai-integration[bot] in #19673
• Remove return type annotation from settings serializer to fix OpenAPI schema by @zzstoatzz in #19616
• Use history_interval_seconds as parameter name in OpenAPI schema by @desertaxle in #19659

Development & Tidiness 🧹

• Turn off dependabot for Vue UI package updates by @desertaxle in #19636
• Add weekly release kickoff workflow by @desertaxle in #19661
• Migrate prefect.input.actions from sync_compatible to async_dispatch by @zzstoatzz in #19632
• Remove auto-generate docs workflow by @desertaxle in #19665

Documentation 📓

• Fix incorrect Dockerfile example in “Deploy via Python” guide by @desertaxle in #19653

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.5…3.6.6

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3.6.5 - Batch Me If You Can

Released on December 04, 2025

Enhancements ➕➕

• Raise if event is too big by @jakekaplan in #19531
• Support Path objects in result_storage parameter by @zzstoatzz in #19533
• Hide “Join the Community” in air-gapped deployments by @zzstoatzz in #19540
• Parametrize xreadgroup batch size in consumer and add EventPersister service setting by @saschwartz in #19545
• Parametrize xautoclaim batch size by @saschwartz in #19557
• Parametrize TaskRunRecorder and Trigger service message read batch size by @saschwartz in #19559
• Add Slack GovCloud (slack-gov.com) webhook support to SlackWebhook block by @devin-ai-integration[bot] in #19565
• Support dot-delimited syntax for job_variables in workers by @devin-ai-integration[bot] in #19619
• Add client-side caching for concurrency limits by @devin-ai-integration[bot] in #19625

Bug Fixes 🐞

• Support username:password auth for self-hosted BitBucket instances by @zzstoatzz in #19516
• Optimize /api/task_runs/count endpoint performance by @naaa760 in #19548
• Fix docker compose file in self hosted docs by @rodeyfeld in #19551
• Fix performance issues with sync tasks on Windows by @desertaxle in #19595
• Fix dead thread hang by @zzstoatzz in #19601
• Allow Jinja templates in trigger enabled field during YAML loading by @zzstoatzz in #19610
• Fix compatibility with fastapi==0.123.7 by @desertaxle in #19626
• Allow EC2 task definitions to omit launchType for capacity providers by @zzstoatzz in #19630

Integrations & Dependencies 🤝

• Update sucrase to remove vulnerable glob dependency by @zzstoatzz in #19599

Development & Tidiness 🧹

• Add timeout to worker teardown to prevent test flakes by @zzstoatzz in #19465
• Update CODEOWNERS by @desertaxle in #19578
• Pin pytest-asyncio to fix 3.10 client tests by @desertaxle in #19609
• Fix flakes in TestReadTaskRunCountsByState::test_returns_all_state_types by @desertaxle in #19612

Documentation 📓

• Add per-worker task concurrency example by @zzstoatzz in #19541
• Improve database maintenance documentation and examples by @zzstoatzz in #19604
• Fix YAML key for Bitbucket repository by @desertaxle in #19607
• Add Google Tag Manager integration to docs by @zzstoatzz in #19629

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.4…3.6.5

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3.6.4 - No Deployment Left Unparametrized

Released on November 21, 2025

Bug Fixes 🐞

• fix: preserve event template parameters in deployment triggers by @zzstoatzz in #19504
• Fix truncating log behavior by @jakekaplan in #19496

Integrations & Dependencies 🤝

• Chore: Bump ui library by @znicholasbrown in #19492

Documentation 📓

• docs: Add migration note about unmapped mutable objects by @zzstoatzz in #19494

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.3…3.6.4

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3.6.3 - That’s JSON Bourne

Released on November 19, 2025

Enhancements ➕➕

• Add -o json output option to prefect flow-run ls command by @devin-ai-integration[bot] in #19484
• fix: allow pause_flow_run() to pause parent flow when called from task by @zzstoatzz in #19457

Bug Fixes 🐞

• Use acquisition service pattern for lease-based concurrency slots by @bunchesofdonald in #19451
• fix: respect subflow attributes (log_prints, result_storage) when running inside task by @zzstoatzz in #19450
• fix: defer forward reference resolution in ValidatedFunction by @zzstoatzz in #19452
• fix: validate deployment triggers after templating so jinja-based booleans work, should close #19348 by @iclectic in #19414
• fix: show detailed validation errors for top-level prefect.yaml fields by @zzstoatzz in #19468
• Clamp denied_slots decay rate to match retry-after calculation by @bunchesofdonald in #19466
• Fix: Enable parameter type checking for @task decorator by @zzstoatzz in #19459

Development & Tidiness 🧹

• add —build-arg to dev build-image command to allow direct passing of… by @conrade-ctc in #19473

Documentation 📓

• Add database cleanup example with human/AI approval by @zzstoatzz in #19456

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.2…3.6.3

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3.6.2 - The Missing Link

Released on November 13, 2025

Enhancements ➕

• Add causal link from automation action events to triggering events by @zzstoatzz in #19426

Bug Fixes 🐞

• cap retry-after for concurrency limits to prevent excessive delays by @zzstoatzz in #19428
• accept numeric values for PREFECT_API_SERVICES_LATE_RUNS_AFTER_SECONDS by @zzstoatzz in #19434
• add work_queue_id to DeploymentResponse by @zzstoatzz in #19417

Development & Tidiness 🧹

• correct GitHub Actions conditional syntax in integration release workflow by @zzstoatzz in #19439

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.1…3.6.2

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3.6.1 - Pop, Lock it, Docket

Released on November 10, 2025

Enhancements ➕

• Add logfire sampling configuration and fix boolean env var handling by @zzstoatzz in #19383

Bug Fixes 🐞

• Fix interactive deploy CLI selecting wrong flow when opting out by @zzstoatzz in #19392
• Fix deployment.parameters in nested flows using ContextVars by @zzstoatzz in #19366

Integrations & Dependencies 🤝

• Upgrade pydocket to stable 0.13.0 release by @zzstoatzz in #19401

Documentation 📓

• Add client methods for querying events via REST API by @zzstoatzz in #19382

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.0…3.6.1

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3.6.0 - Throw it on the docket and we’ll get to it in a jiffy

This release adds pydocket, a background task system, to replace FastAPI’s background_tasks. Background tasks now include automatic retries and can optionally use Redis as a backing layer for enhanced durable execution.

Released on November 07, 2025

Enhancements ➕➕

• Replace FastAPI background_task usage with pydocket by @desertaxle in #19377
• Emit events for deployment pull step execution by @zzstoatzz in #19339

Bug Fixes 🐞

• Fix import order dependency and circular import issues by @zzstoatzz in #19344
• Fix deployment.parameters in subprocess flows by @zzstoatzz in #19331
• Fix misleading pyright error when calling async task with wrong argument types by @zzstoatzz in #19327
• 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
• Fix automation deletion deadlock by enforcing consistent lock ordering by @zzstoatzz in #19369

Integrations & Dependencies 🤝

• Update prefect-ui-library to latest version by @znicholasbrown in #19350

Development & Tidiness 🧹

• Remove legacy settings imports from CLI by @desertaxle in #19353
• Clean up root directory by @zzstoatzz in #19355
• 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
• Add @chrisguidry as a CODEOWNER by @desertaxle in #19368
• Sync UI v2 OpenAPI schema with node v20.19.0 by @zzstoatzz in #19373
• Migrate RedisStorageContainer from sync_compatible to async_dispatch by @devin-ai-integration[bot] in #19363

Documentation 📓

• Add Pulumi section to Infrastructure as Code documentation by @bdalpe in #19352
• Fix link in ECS worker docs by @mattiamatrix in #19364

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.5.0…3.6.0

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