Build a Typescript SDK using OpenAPI Generator CLI

There are many language templates to choose from. (Clojure, CSharp, Elixir, Go, Java, PHP, Python, Ruby, Typescript and more)

Typescript offers several flavors to generate either server-side or front-end SDKs.

Front-end

typescript-angular
typescript-aurelia
typescript-jquery
typescript-redux-query
typescript-rxjs

Server-side

typescript (experimental)
typescript-axios
typescript-fetch
typescript-inversify
typescript-nestjs (experimental)
typescript-node

Generate

For our exercise, let’s build our SDK with the Typescript Fetch template.

Start in an empty folder and run this command in your terminal.

docker run --rm -v ${PWD}:/local openapitools/openapi-generator-cli:v6.2.1 generate \
    -i https://raw.githubusercontent.com/apimatic/petstore/main/oas/petstore.yaml \
    -g typescript-fetch \
    -o /local/petstore_ts_fetch

We add ${PWD}:/local to our command so output can use a relative path. This is also useful when pointing to a local API specification file.

Below are the arguments we pass.

(-i) Input value is the petstore.json file on GitHub.
(-g) Generator value determines the template to use
(-o) Output value is where to write the new SDK locally.

There are many more arguments you can pass to customize the output from OpenAPI generator CLI.

Compile

Browse to the folder petstore_ts_fetch and sadly there isn’t a README. Lack of documentation around how to use generated SDKs can be a challenge when using OpenAPI Generator.

Experienced developers will notice package.json and tsconfig.json are also missing. Not sure why these are omitted, but the steps below will help install dependencies and configure TypeScript in order to build your SDK.