flask-restx VS OpenAPI-Specification

For this project, we’ll use Flask and Flask-RESTX.

When it comes to Flask, in particular, there’re plenty of choices. And in fairness, not all frameworks are created equal. You’ve got flasgger, restx (successor of flask-restplus), flask-RESTful, and flask-smorest, to mention a few. How do you choose among those???

Flask-RESTX is an extension that adds support for quickly building REST APIs - GitHub - python-restx/flask-restx

Dependendo da linguagem, existem algumas ferramentas que auxiliam na geração automática das docs do Swagger. Por exemplo, no Python+flask existe o flask-restx

However, after following [the example](https://github.com/python-restx/flask-restx/tree/88497ced96674916403fa7829de693eaa3485a08/examples/zoo_app), [more complex tutorials](https://github.com/TheMorpheus407/Tutorials/tree/master/Flask/RestplusAPI) or other [basic tutorials](https://blog.ordix.de/rest), I still only receive 404s when calling get on /api or the endpoints I tried to define.

I have a flask app which is a REST API endpoint built using flask-restx. The APIs are organized neatly using namespaces. I now need to add a new set of API to access mysql data and flask-rest-jsonapi seems to be good fit for it. However I would like to add these new APIs implemented inside a flask-restx namespace.

But if you are using a Flask based app, I recently tried Flask-RESTX library which includes some great features:

Note: Support for hierarchical tags is expected to arrive in the OpenAPI specification 3.2.0 at the earliest, which is currently planned for August 2025. After that, FastAPI and Swagger UI / Redoc will also need to adopt the new version. I don't expect these changes to be available any time soon.

Given the prevalence of OpenAPI, and its use in API documentation platforms - here are examples of how to perform different types of deprecations, which most OpenAPI tooling should handle. One unfortunate missing feature in OpenAPI 3.1 is that there isn't a formal way to guide users to the latest version of your API - despite a spec being proposed years ago, so we'll have to hack that into the description.

gRPC A little more background on how our control-plane used to work: we had an HTTP-based API gateway that talked to our gRPC monolithic backend service.6 We thought about extending gRPC streaming from our backend to clients…but the API-gateway handled auth and connections for us and doing gRPC in our Javascript frontend wasn’t something we wanted to take on and in addition it meant that we wouldn’t be able to curl our endpoints easily. To me there’s nothing quite like curl localhost:8000 to begin understanding a service.7 Websockets Websockets would have been fun, but truthfully we didn’t need ‘em, the communication we wanted was really just getting output to our users quickly and we didn’t really need bi-directional communication. Server-Sent Events Server Sent Events (SSE) is pretty cool, enabling sending real-time updates to clients. SSE is well-supported by browsers and you can also “just curl it!”. One of the only drawbacks for us was the OpenAPI support wasn’t great at the time (see this), but our frontend team was able to work around it and in addition there wasn’t a tightly defined model for the logs output, so the benefits of using our spec (strict types) weren’t as big here compared to other parts of our API.

If we go to the OpenAPI's repository, we'll see that:

And I'll be using the OpenAPI Pet Store spec file as an example.

I saw your sibling comment about "keeping it simple," however that is a bit counter to "generates OpenAPI specifications" since those for sure are not limited to just application/json request/response bodies

I wanted to draw your attention to "normal" POST application/x-www-form-urlencoded <https://github.com/OAI/OpenAPI-Specification/blob/3.1.0/vers...> and its multipart/form-data friend <https://github.com/OAI/OpenAPI-Specification/blob/3.1.0/vers...>

The latter is likely problematic, but the former is in wide use still, including, strangely enough, the AWS API, although some of their newer services do have an application/json protocol

I know that's a lot of words, but the tl;dr would be that if you want your extension to be application/json only, then changing the description to say "OpenAPI specifications for application/json handshakes" would help the consumer be on the same page with your goals

Since FastAPI is based on OpenAPI, at this point you can also use the automatically generated docs. There are multiple options, and two are included by default. Try them out by accessing the following URLs:

This approach requires a constant context switch and is clearly not productive. Here, the OpenAPI Specification can help; you might already have it, but is it scalable? In this article, we’ll learn how to create an OpenAPI Specification document that is readable, scalable, and follows the principle of extension without modifying the existing document.

Phil Sturgeon, who along with Ben Hutton and Henry Andrews from the JSON Schema community, helped drive the push to full JSON Schema Draft 2020-12 compliance, has written a blog post for the official OpenAPIs.org website on how to transition your OAS documents from v3.0.x to v3.1.0.