I recently wrote a blog to help teams decide between writing the SDKs for their APIs by hand or generating them using a code generator: https://www.apimatic.io/blog/2021/09/the-great-sdk-battle-bu...

TLDR: There are a good many technical challenges to creating high-quality SDKs in multiple languages for a medium to large-sized REST API and most teams seem to underestimate the amount of effort required to build and maintain SDKs. The speed and savings from code generation is quite compelling and a modern commercial code generator like APIMatic has a wide-enough feature-set that most REST APIs don't require writing SDKs by hand anymore.

Disclaimer: I am a contributor to APIMatic Code Generator.

Does apimatic use the following open-source code generators or it builds a proprietary code generator from scratch?

Swagger Codegen: https://github.com/swagger-api/swagger-codegen

OpenAPI Generator: https://github.com/OpenAPITools/openapi-generator

AutoRest: https://github.com/Azure/AutoRest

NSwag: https://github.com/RicoSuter/NSwag

oapi-codegen: https://github.com/deepmap/oapi-codegen

go-swagger: https://github.com/go-swagger/go-swagger