Breaking Changes

• ➖ Drop support for pydantic.v1. PR #14609 by @tiangolo.

Internal

• ✅ Run performance tests only on Pydantic v2. PR #14608 by @tiangolo.

Refactors

• 🔊 Add a custom FastAPIDeprecationWarning. PR #14605 by @tiangolo.

Docs

• 📝 Add documentary to website. PR #14600 by @tiangolo.

Translations

• 🌐 Update translations for de (update-outdated). PR #14602 by @nilslindemann.
• 🌐 Update translations for de (update-outdated). PR #14581 by @nilslindemann.

Internal

• 🔧 Update pre-commit to use local Ruff instead of hook. PR #14604 by @tiangolo.
• ✅ Add missing tests for code examples. PR #14569 by @YuriiMotov.
• 👷 Remove lint job from test CI workflow. PR #14593 by @YuriiMotov.
• 👷 Update secrets check. PR #14592 by @tiangolo.
• 👷 Run CodSpeed tests in parallel to other tests to speed up CI. PR #14586 by @tiangolo.
• 🔨 Update scripts and pre-commit to autofix files. PR #14585 by @tiangolo.

Breaking Changes

• 🔊 Add deprecation warnings when using pydantic.v1. PR #14583 by @tiangolo.

Translations

• 🔧 Add LLM prompt file for Korean, generated from the existing translations. PR #14546 by @tiangolo.
• 🔧 Add LLM prompt file for Japanese, generated from the existing translations. PR #14545 by @tiangolo.

Internal

• ⬆️ Upgrade OpenAI model for translations to gpt-5.2. PR #14579 by @tiangolo.

Upgrades

• ➖ Drop support for Pydantic v1, keeping short temporary support for Pydantic v2's pydantic.v1. PR #14575 by @tiangolo.
  • The minimum version of Pydantic installed is now pydantic >=2.7.0.
  • The standard dependencies now include pydantic-settings >=2.0.0 and pydantic-extra-types >=2.0.0.

Docs

• 📝 Fix duplicated variable in docs_src/python_types/tutorial005_py39.py. PR #14565 by @paras-verma7454.

Translations

• 🔧 Add LLM prompt file for Ukrainian, generated from the existing translations. PR #14548 by @tiangolo.

Internal

• 🔧 Tweak pre-commit to allow committing release-notes. PR #14577 by @tiangolo.
• ⬆️ Use prek as a pre-commit alternative. PR #14572 by @tiangolo.
• 👷 Add performance tests with CodSpeed. PR #14558 by @tiangolo.

Breaking Changes

• 🔧 Drop support for Python 3.8. PR #14563 by @tiangolo.
  • This would actually not be a breaking change as no code would really break. Any Python 3.8 installer would just refuse to install the latest version of FastAPI and would only install 0.124.4. Only marking it as a "breaking change" to make it visible.

Refactors

• ♻️ Upgrade internal syntax to Python 3.9+ 🎉. PR #14564 by @tiangolo.

Docs

• ⚰️ Remove Python 3.8 from CI and remove Python 3.8 examples from source docs. PR #14559 by @YuriiMotov and @tiangolo.

Translations

• 🌐 Update translations for pt (add-missing). PR #14539 by @tiangolo.
• 🔧 Add LLM prompt file for French, generated from the existing French docs. PR #14544 by @tiangolo.
• 🌐 Sync Portuguese docs (pages found with script). PR #14554 by @YuriiMotov.
• 🌐 Sync Spanish docs (outdated pages found with script). PR #14553 by @YuriiMotov.
• 🌐 Sync German docs. PR #14519 by @nilslindemann.
• 🔥 Remove inactive/scarce translations to Vietnamese. PR #14543 by @tiangolo.
• 🔥 Remove inactive/scarce translations to Persian. PR #14542 by @tiangolo.
• 🔥 Remove translation to emoji to simplify the new setup with LLM autotranslations. PR #14541 by @tiangolo.
• 🌐 Update translations for pt (update-outdated). PR #14537 by @tiangolo.
• 🌐 Update translations for es (update-outdated). PR #14532 by @tiangolo.
• 🌐 Update translations for es (add-missing). PR #14533 by @tiangolo.
• 🌐 Remove translations for removed docs. PR #14516 by @tiangolo.

Internal

• ⬆ Bump markdown-include-variants from 0.0.7 to 0.0.8. PR #14556 by @YuriiMotov.
• 🔧 Temporarily disable translations still in progress, being migrated to the new LLM setup. PR #14555 by @YuriiMotov.
• 🔧 Update test workflow config, remove commented code. PR #14540 by @tiangolo.
• 👷 Configure coverage, error on main tests, don't wait for Smokeshow. PR #14536 by @tiangolo.
• 👷 Run Smokeshow always, even on test failures. PR #14538 by @tiangolo.
• 👷 Make Pydantic versions customizable in CI. PR #14535 by @tiangolo.
• 👷 Fix checkout GitHub Action fetch-depth for LLM translations, enable cron monthly. PR #14531 by @tiangolo.
• 👷 Fix Typer command for CI LLM translations. PR #14530 by @tiangolo.
• 👷 Update LLM translation CI, add language matrix and extra commands, prepare for scheduled run. PR #14529 by @tiangolo.
• 👷 Update github-actions user for GitHub Actions workflows. PR #14528 by @tiangolo.
• ➕ Add requirements for translations. PR #14515 by @tiangolo.

Fixes

• 🐛 Fix parameter aliases. PR #14371 by @YuriiMotov.

Fixes

• 🐛 Fix support for tagged union with discriminator inside of Annotated with Body(). PR #14512 by @tiangolo.

Refactors

• ✅ Add set of tests for request parameters and alias. PR #14358 by @YuriiMotov.

Docs

• 📝 Tweak links format. PR #14505 by @tiangolo.
• 📝 Update docs about re-raising validation errors, do not include string as is to not leak information. PR #14487 by @tiangolo.
• 🔥 Remove external links section. PR #14486 by @tiangolo.

Translations

• 🌐 Sync Russian docs. PR #14509 by @YuriiMotov.
• 🌐 Sync German docs. PR #14488 by @nilslindemann.

Internal

• 👷 Tweak coverage to not pass Smokeshow max file size limit. PR #14507 by @tiangolo.
• ✅ Expand test matrix to include Windows and MacOS. PR #14171 by @svlandeg.

Fixes

• 🐛 Fix support for if TYPE_CHECKING, non-evaluated stringified annotations. PR #14485 by @tiangolo.

Fixes

• 🐛 Fix handling arbitrary types when using arbitrary_types_allowed=True. PR #14482 by @tiangolo.

Docs

• 📝 Add variants for code examples in "Advanced User Guide". PR #14413 by @YuriiMotov.
• 📝 Update tech stack in project generation docs. PR #14472 by @alejsdev.

Internal

• ✅ Add test for Pydantic v2, dataclasses, UUID, and __annotations__. PR #14477 by @tiangolo.

Features

• 🚸 Improve tracebacks by adding endpoint metadata. PR #14306 by @savannahostrowski.

Internal

• ✏️ Fix typo in scripts/mkdocs_hooks.py. PR #14457 by @yujiteshima.