FastAPI has released version 0.157.0, a feature update that focuses on parameter handling and documentation clarity. The headline addition lets developers combine query, header and cookie parameter models in a single declaration, reducing boilerplate for endpoints that read from multiple request locations. The release also ships several documentation clarifications and a small internal cleanup.
The concrete changes in this release:
- Combined parameter models: added support for merging query, header and cookie parameter models, so a single declaration can pull values from different parts of the request (PR #16573, by @tiangolo).
- Boolean query parameter parsing: documentation now explicitly clarifies how boolean query parameters are parsed (PR #16569).
- Nullable and default values: docs clarify how nullable query parameters and path parameter defaults behave (PR #16568).
- Internal maintenance: translation notifications and approval labeling were removed from the project's workflow (PR #16570).
Why this matters: parameter models are one of FastAPI's most useful patterns for validating and documenting inputs, but until now they were typically tied to a single request location. Combining query, header and cookie models in one place should make handlers that depend on multiple sources (authentication cookies plus headers plus filters, for example) easier to write and less repetitive in their type annotations. The documentation updates are equally practical: boolean query parsing and nullable/default behaviour are frequent sources of confusion, and clearer guidance reduces the trial-and-error of debugging unexpected coercion. Teams pinned to earlier releases should review their parameter declarations before upgrading, since the new capability changes how models can be composed. The internal workflow changes have no runtime impact for application developers but keep the project's contribution process leaner.
Source: https://github.com/fastapi/fastapi/releases/tag/0.157.0.