OpenAPI-Specification VS openapi-generator

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.

In this article, we will be learning how to document API written in Node.js using a tool called Swagger. Swagger allows you to describe the structure of your APIs so that machines can read them. The ability of APIs to describe their own structure is the root of all awesomeness in Swagger. Why is it so great? Well, by reading our API’s structure, swagger can automatically build beautiful and interactive API documentation. It can also automatically generate client libraries for your API in many languages and explore other possibilities like automated testing. Swagger does this by asking our API to return a YAML or JSON that contains a detailed description of your entire API. This file is essentially a resource listing of our API which adheres to OpenAPI Specifications.

You may encounter APIs described as RESTful that do not meet these criteria. This is often the result of bottom-up coding, where top-down design should have been used. Another thing to watch out for is the absence of a schema. There are alternatives, but OpenAPI is a common choice with good tools support. If you don't have a schema, you can create one by building a Postman collection.

OpenAPI Generator is a versatile tool that emerged as a fork of Swagger Codegen, offering enhanced support and features. It allows developers to generate API client libraries, server stubs, and documentation for over 30 programming languages.

Since @tanstack/react-query and swr give all control of the request to the user, the API automation solution is provided by third-party request tools. For example, axios and fetch can automatically generate request codes through openapi-generator or @openapitools/openapi-generator-cli.

You would use OpenAPI (formerly Swagger) [1] for that, which includes JSONSchema for data types but also adds specs for defining REST apis. There are plenty of generators and other tools that work with OpenAPI [2]

[1] https://www.openapis.org/

[2] https://openapi-generator.tech/

I found some "tricks" to write less code, hence less code to maintain if there are any changes. Also less code with bugs just by changing the inputs.

For example, OpenAPI spec file + OpenAPI generator (https://github.com/OpenAPITools/openapi-generator). Any changes in the OpenAPI spec are reflected in the final code with a build step.

Another example: MapStruct (https://mapstruct.org/) to avoid passing data from Entity classes to DTO and back. Saves looots of boilerplate code.

Which are your tricks?

Disclaimer: We're an early adopter of Stainless at Mux.

I've spent more of my time than I'd like to admit managing both OpenAPi spec files [1] and fighting with openapi-generator [2] than any sane person should have to. While it's great having the freedom to change the templates an thus generated SDKs you get with using that sort of approach, it's also super time consuming, and when you have a lot of SDKs (we have 6 generated SDKs), in my experience it needs someone devoted to managing the process, staying up with template changes etc.

Excited to see more SDK languages come to Stainless!

[1] https://www.mux.com/blog/an-adventure-in-openapi-v3-api-code...

[2] https://github.com/OpenAPITools/openapi-generator

As a result, the following specification can be used to generate clients in a number of different languages via OpenAPI Generator.

Of course you can compile the server from source if you have Go and the OpenAPI generator JAR (https://github.com/OpenAPITools/openapi-generator?tab=readme...)

Follow these steps : https://github.com/c100k/rebootx-on-prem/blob/master/.github...

And then :

(cd ./impl/http-server-go && GOARCH=amd64 GOOS=openbsd go build -o /app/rebootx-on-prem-http-server-go-openbsd-amd64 -v)

By adapting the arch if needed. Not tested, but it should work.

TL;DR: Start generating your HTTP clients and all the DTOs of the requests and responses automatically from your API, using openapi-generator instead of writing your own.