MEP 2 - Building a Flask <> Pydantic autogeneration tool

• Author: Rodda John
• Status: Adopted
• Adopted: 2023-10-15

Decision

We chose to build a library (currently in utils/api) that:

• Uses route type annotations to parse args and construct responses
• Uses route type annotations to generate OpenAPI spec

Alternatives

• flask-pydantic
• spectree
• flask-pydantic-spec
• FastAPI

flask-pydantic

• Does not generate OpenAPI spec
• Much of the interface and some of the implementation is ripped from here

spectree & flask-pydantic-spec

• flask-pydantic-spec is a fork of spectree
• Few (< 500) stars on Github; limited community + support

FastAPI

• Flask is considerably more trusted + long-lived
  • Patrick & Rodda's experience is with Flask
• Reversible: can embed Flask routes within FastAPI
  • Perhaps important for async support