FastOpenAPI
Dev tools
api documentation library
SHOW HN2025
How HN took it
7 positive, 11 neutral or asking, 1 mixed, 4 critical, out of 23 comments about the project. Thread score +0.17.
Design: 4 for, 0 againstIdea: 0 for, 3 againstDocs: 1 for, 0 againstPerformance: 0 for, 1 against
The thread, comment by comment
Each row is a top-level comment and its replies, in HN's order. Select a cell to open that comment on HN.
positive neutral or mixed critical about another commenter or something else the maker
What HN said
What people liked
Clean, seamless FastAPI-style decorator and router design for Flask
From 3 comments
This is really cool - something I've been looking for with Flask. Cleanest implementation with just the decorator that I've seen. (As an aside, is there an open-source UI for…
memset on HNAwesome project! It looks so seamless for Flask! Just switch routers, and you model deserialization/serialization, and /docs. Really impressive work! Is there any way to not need…
odie5533 on HNfor someone that comes primarily from a .net background. This looks fantastic! Just one thing that I tried to find more information about is: are you suppose to rely on the…
asabla on HN
Fills a long-standing gap for docs in Flask and other frameworks
From 2 comments
Love Flask, but this has always been a missing tool. I have a question though - it seems like you're actually modifying the response data type for Flask routes so that it's a…
These335 on HNNice. This was one of the main shortcomings in Falcon that pushed me to switch some projects to FastAPI. That said FastAPI had many other benefits that went far beyond API specs.
Everdred2dx on HN
Objections
Requires returning Pydantic models for best docs, a big ask for existing APIs
From 1 comment
Love Flask, but this has always been a missing tool. I have a question though - it seems like you're actually modifying the response data type for Flask routes so that it's a…
These335 on HN
Response model must be specified explicitly rather than inferred from return type
From 1 comment
Awesome project! It looks so seamless for Flask! Just switch routers, and you model deserialization/serialization, and /docs. Really impressive work! Is there any way to not need…
odie5533 on HN
Requests
Django or DRF support
From 2 comments
No love for Django? I am looking for an alternative to DRF and Django-ninja that can optionally generate typed APIs and docs directly from the model definitions.
Onavo on HNWhy no Django?
raylad on HN
Automatic response type inference
From 1 comment
Awesome project! It looks so seamless for Flask! Just switch routers, and you model deserialization/serialization, and /docs. Really impressive work! Is there any way to not need…
odie5533 on HN
Streaming or chunked response documentation
From 1 comment
And would it document a streaming API? (With transfer-encoding: chunked) The support for that in OpenAPI is still in progress, I believe.
pamelafox on HN
Questions
Does the Flask extra also support Quart?
From 1 comment
Does the flask extra also support quart?
pamelafox on HN
How should API versioning be handled with prefixes?
From 1 comment
for someone that comes primarily from a .net background. This looks fantastic! Just one thing that I tried to find more information about is: are you suppose to rely on the…
asabla on HN
Alternatives named
Django Ninja
From 2 comments
No love for Django? I am looking for an alternative to DRF and Django-ninja that can optionally generate typed APIs and docs directly from the model definitions.
Onavo on HNDjango Ninja provides this already for Django, and it is great.
ensignavenger on HN
DRF-spectacular
From 1 comment
DRF-spectacular is an okay choice here, you have to manage consistency with return types yourself but the docs and customization options are well done.
sastraxi on HN
FastAPI or Litestar
From 1 comment
There is already plenty available that will do what you want. FastAPI or Litestar are two popular ones.
stackskipton on HN
RapiDoc
From 2 comments
Thanks a lot! Glad to hear it fits your needs. For a clean, documentation UI, the best open-source options right now are probably Swagger UI and ReDoc. FastOpenAPI uses both by…
mr_Fatalyst on HNMaybe Rapidoc?
ddorian43 on HN