Who contributed to FastAPI & Pydantic on August 19, 2026?

6 developers shipped this update, including pr-submit, tiangolo, latest-changes[bot], pr-submit[bot], Viicos, and wse114.

What were the notable FastAPI & Pydantic updates?

Allow any `CoreSchema` to be used as serialization, Improve performance of `GenerateSchema.generate_schema()` dispatching, and Fix Unix timestamp typo.

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Pydantic opens serialization to any core schema

By RepoJournal · Filed 07:00 UTC on August 19, 2026 · About FastAPI & Pydantic

6 people shipped this

latest-changes[bot] @latest-changes[bot] 2 cited

Viicos @Viicos 2 cited

wse114 @wse114 2 cited

pr-submit @pr-submit 1 cited

tiangolo @tiangolo 1 cited

pr-submit[bot] @pr-submit[bot]

Pydantic's latest PR lets any CoreSchema act as a serializer, closing a long-standing gap between validators and serializer function schemas.

Pydantic's "Allow any CoreSchema to be used as serialization" [1] unblocks a class of schemas that previously couldn't be serialized because the as_ser_schema() helper assumed the input wasn't a serializer function schema. The same contributor, Viicos, also shipped a performance pass on GenerateSchema.generate_schema() dispatching [2], doing a single get_origin() call early to decide whether to look for __get_pydantic_core_schema__(), which lands meaningful savings on hot paths. Two small housekeeping PRs round out the desk: a Unix timestamp typo fix [3] and its merge commit [4] correct the spelling of "since" in docs. Over on FastAPI, the action is translation automation and release notes: a ko translation update [5] comes with a note that PRs to the llm-prompt.md file are preferred for better LLM-generated translations, and branch updates [6] and release notes refreshes [7][8] keep the repo humming. All quiet on breaking changes. Ship with confidence.

Action items

→ Review pydantic PR 13680 and test serialization cases that previously failed pydantic/pydantic [plan]
→ Benchmark schema generation after PR 13614 to confirm performance gains pydantic/pydantic [monitor]
→ Check the ko translation flow and consider updating llm-prompt.md for better translations fastapi/fastapi [monitor]

References

[1] Allow any `CoreSchema` to be used as serialization ↗ pydantic/pydantic
[2] Improve performance of `GenerateSchema.generate_schema()` dispatching ↗ pydantic/pydantic
[3] Fix Unix timestamp typo ↗ pydantic/pydantic
[4] Fix Unix timestamp typo (#13679) pydantic/pydantic
[5] 🌐 Update translations for ko (update-outdated) ↗ fastapi/fastapi
[6] 👷 Update translation PR branches with PR Push ↗ fastapi/fastapi
[7] 📝 Update release notes fastapi/fastapi
[8] 📝 Update release notes fastapi/fastapi

Quick answers

What shipped in FastAPI & Pydantic on August 19, 2026?: Pydantic's latest PR lets any CoreSchema act as a serializer, closing a long-standing gap between validators and serializer function schemas. In total, 7 commits and 5 pull requests landed.
Who contributed to FastAPI & Pydantic on August 19, 2026?: 6 developers shipped this update, including pr-submit, tiangolo, latest-changes[bot], pr-submit[bot], Viicos, and wse114.
What were the notable FastAPI & Pydantic updates?: Allow any `CoreSchema` to be used as serialization, Improve performance of `GenerateSchema.generate_schema()` dispatching, and Fix Unix timestamp typo.

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