Elm API SDK Generator

Generate an Elm SDK from an OpenAPI Spec (OAS).

Goal

To allow developers to generate an Elm module(s) from an OpenAPI Spec. This is primarily for developers wanting to integrate with a 3rd party service that doesn't provide an Elm SDK for their service. It can also be used within a company where the back end generates an OAS from the written code or an OAS is written and used to generate both the backend and Elm SDKs.

Example Usage

A RealWorld app using a generated SDK to demonstrate how to use it.

Getting Started

• npm install -D elm-open-api
• node elm-open-api ./page/to/oas.json

Arguments you can pass:

• <entryFilePath>: The path to the Open API Spec, either .json or .y[a]ml
  • Technically the OAS allows for parts of a spec to be in separate files, but this isn't supported yet.
• [--output-dir <output dir>]: The directory to output to. Defaults to generated/.
• [--module-name <module name>]: The Elm module name. Default to <OAS info.title>.
• [--generateTodos <generateTodos>]: Whether to generate TODOs for unimplemented endpoints, or fail when something unexpected is encountered. Defaults to no. To generate Debug.todo "" instead of failing use one of: yes, y, true.

Development

The general flow of the app is: parse args & read in the spec using elm-pages, generate the Elm code with elm-codegen, and write it to disk using elm-pages.

• Clone this repo
• Inside your cloned repo, run direnv allow
• Start coding!
• Run npm run dev <path to oas spec>.json
  • e.g. npm run dev ./example/github-spec.json will produce generated/GitHub_v3_REST_API.elm

Thank you

• miniBill for your many contributions
• elm-pages for making it easy to write a CLI app in Elm
• Elm for an easy to use & maintain language