I think there's a few in this space but they're all kinda meh. I actually had this idea a while back but I'm working on something else now.

Done well, its a decent idea, I'd pay for it in my current company.

I actually got the idea because I was impressed that AWS internally has a really mature model first docs and SDK generation tech. They've actually opensourced parts of it (https://awslabs.github.io/smithy/) but it's not ready for use yet.

Seems like Smithy is mostly for internal use at AWS:

"Why not just use an existing IDL?" "Existing IDLs available outside of AWS were not extensible enough to meet our needs and not compatible with our existing services."

Their support also seems limited: https://awslabs.github.io/smithy/implementations.html

That's something that we are doing at APIMatic already.

APIMatic[1] is a Code-Generation-as-a-Service[2] that generates SDKs for C#, Python, PHP, Ruby, TypeScript and Java from OpenAPI specs (and more formats). We help companies create a better Developer Experience[3] for their APIs using SDKs and API Documentation that are always up-to-date with the API implementation. We have a pretty solid customer base[4] and SDKs generated using APIMatic have been downloaded millions of times.

PS: My email is in my profile.

[1] https://www.apimatic.io

[2] https://alpha.apimatic.io/continuous-code-generation/

[3] https://www.apimatic.io/developer-experience-portal

[4] https://alpha.apimatic.io/success-stories/

As someone who just released an OpenAPI spec for our API and struggled with building client libraries to test that the spec was correctly generated, I'd pay for this, especially if it integrated with the rubygems/packagists/nugets of the world.

Let me know if you want an alpha or beta tester. Our OpenAPI spec is here: https://github.com/fusionauth/fusionauth-openapi and my contact info is in my profile.

Swaggerhub does most of this

Seems Swaggerhub mostly deals with documentation, not SDK generation: https://swagger.io/tools/swaggerhub/features/

https://support.smartbear.com/swaggerhub/docs/apis/generatin....

TIL! It looks like it does support client lib generation: https://support.smartbear.com/swaggerhub/docs/apis/generatin...

It doesn't say which tier that is available in: https://swagger.io/tools/swaggerhub/pricing/ nor does it handle uploading the SDK to a dependency manager site (that I can see) but that gives you an indication of the pricing structure and possible demand.

It's opensource. I ran it in the past locally to test it, so it should still work i think.

It's quite easy to create a library to your own flavor. The default is kinda "meuh" for .net.

It downloads a .zip file that you can use then. Should be able to automate with some work/language.