openapi-generator VS openapi-typescript-codegen

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.

As an alternative, you can also use the official OpenAPI Generator, which is a more generic tool supporting a wide range of languages and frameworks.

I trialed generating SDKs using the OpenAPI Generator package, which was largely unsatisfactory.

If Swagger/OpenAPI is available, save yourself a lot of trouble and generate the client using OpenAPI Generator. If not, use a library like RestEase to make it significantly easier to create the client.

For a run of the mill REST API you should generate OpenAPI (Swagger) info for the API using a library like NSwag or Swashbuckle. You'd want to do this no matter what because it's documentation for the API, but the bonus is that you can use it with tools like OpenAPI Generator to create API client code and models in a variety of languages. You certainly can create an API client library manually, it would entail having a nuget package with a class library that contains the models and client code for calling the endpoints (which I'd create using a lib such as RestEase unless you just enjoy writing boilerplate code by hand). However 95% of the time it simply isn't worth creating your own lib when OpenAPI is available because once you've done it a time or two it takes less than 5 min to run the generator and create (or update) a lib.

Then you can use oapi-codegen or openapi-generator to generate the Go (or other language) SDK for it.

I’d also add that if you use Typescript with an OpenAPI client generator (https://github.com/ferdikoomen/openapi-typescript-codegen) it can immensely alleviate some of the biggest pain points of seperate backend and front-end. It always used to be a major pain in the ass with the amount of overhead an API change would incur - updating documentation, postman, constant communication between backend and front-end devs, etc. Now I just npm run generate, I see new API changes in my Git client and Typescript errors for code that needs updating.

Also, using a library like Tanstack Query or Rdtk Query can almost completely eliminate manual state management, and kinda makes the whole development experience feel almost like SSR.

I have been in love with Loopback.io since v2 even though it was a bit of a rollercoaster.. Loopback v4 is a beautiful library. Its been around longer than nestjs but that's the easiest thing to compare it too. I recently have been creating lb4 servers that interface nextjs and react native clients. Initially, I identify my entities and use cases that I want to build. I then use the lb4 cli to auto generate models, relations, controllers, datasources, interceptors (add logic on methods/classes). I can start testing them with the OpenAPI explorer. With the openapi-typescript-codegen library I can generate services from my lb4 OpenAPI spec that I can use on the client side. From there, you can really query data easily with the loopback filter (which can be used on the client too). I initially started doing this with angular1/2+ but its been pleasant using many clients. Even though I have been leveraging it for years in production, I am still learning and exploring. There are many other awesome things I can expand on or explain if you are interested!

https://loopback.io/doc/en/lb4/

https://github.com/ferdikoomen/openapi-typescript-codegen/tr...

In our current project with a TS frontend and Python backend, we use an OpenAPI schema as the source of truth and openapi-typescript-codegen [0] to interface with it on the client side. While not perfect, it provides a very nice interface to our API with request/response typings.

I also wrote a 10-line mock API wrapper that you can call as mockApi((request) => response), and it will type-check that your mock function implements the API correctly.

[0]: https://github.com/ferdikoomen/openapi-typescript-codegen

Second step is to generate typescript types from the backend's spec. You can use a library like this.

openapi-typescript-codegen Generates a Typescript client with interfaces from an OpenAPI spec.

I'm not familiar with all the options openapi-generator has. I tried it awhile ago and found it quite buggy, and more of a pain to run, especially if you're not already doing Java development. I ended up preferring OpenAPI Typescript Codegen, which is written in Typescript. One option it has which would solve the problem you're running into here, is that you can tell it to use union types instead of enums. So your interfaces would be generated as

I'm currently working on two separate projects, the first is a Django project with DRF and I codegen with drf-spectacular [1] and openapi-typescript-codegen [2]. The other project also uses Django, with the API through Hasura and codegen with graphql-codegen [3]. In both of these cases I've been able to largely avoid duplicating my models clientside, or at least it isn't manual.

1: https://github.com/ferdikoomen/openapi-typescript-codegen

2: https://drf-spectacular.readthedocs.io/en/latest/

3: https://github.com/dotansimha/graphql-code-generator

For typescript client code generation, I typically use something like openapi-typescript-codegen, but there are a lot more generators (like the openapi-generator project) that are imperfect in their own ways, I'm sure you can find one that works for you.