To use with JavaScript as an autocomplete tool you need to install TypeScript, run the Zeus CLI, and then transform the result to JS using tsc

$ npm i -D typescript
# OR
# yarn add -D typescript

Generate Zeus:

$ zeus schema.graphql ./

And transform it using Typescript:

$ npx tsc ./zeus/*.ts --declaration --target es5 --skipLibCheck
# OR
# yarn tsc ./zeus/*.ts --declaration --target es5 --skipLibCheck

This will generate an out.d.ts file so that you can have autocompletion.