Getting Started | Zeus GraphQL TypeScript generator

Use the Zeus CLI to generate types and GraphQL clients based on your schema, which you can then import into your projects to autocomplete, query and use GraphQL responses in a type-safe way.

Quick Start

Installation

$ npm i -g graphql-zeus
# OR
# yarn global add graphql-zeus

You can also install it locally to a project and then use it as an npm or yarn script command or with npx or yarn directly eg:

$ npx zeus schema.graphql ./
# OR
# yarn zeus schema.graphql ./

TypeScript

Zeus is TypeScript native, you can refer to imported types directly from the generated output of the CLI

$ zeus schema.graphql ./

Demo Endpoint

All demo code here is using the demo GraphQL endpoint of Olympus Cards{rel="nofollow"} built with GraphQL Editor. Feel free to check out the GraphiQL interface{rel="nofollow"} too.

Query With Zeus Chain Client

You can now use the Zeus Chain client from the generated output to make type-safe queries and mutations to your endpoint and receive type-safe responses.

import { Chain } from './zeus';

// Create a Chain client instance with the endpoint
const chain = Chain('https://faker.graphqleditor.com/a-team/olympus/graphql');

// Query the endpoint with Typescript autocomplete for arguments and response fields
const listCardsAndDraw = await chain('query')({
  cardById: [
    {
      cardId: 'da21ce0a-40a0-43ba-85c2-6eec2bf1ae21',
    },
    {
      name: true,
      description: true,
    },
  ],
  listCards: {
    name: true,
    skills: true,
    attack: [
      {
        cardID: [
          '66c1af53-7d5e-4d89-94b5-1ebf593508f6',
          'fc0e5757-4d8a-4f6a-a23b-356ce167f873',
        ],
      },
      {
        name: true,
      },
    ],
  },
  drawCard: {
    name: true,
    skills: true,
    Attack: true,
  },
});
// listCardsAndDraw is now typed as the response of the query.

When querying a GraphQL field that takes an argument like cardById above, the fields are defined in terms of a tuple for example: cardById: [ {...arguments} , {...response_selection_set} ] and the equivalent in gql syntax would be:

cardById (cardId: "da21ce0a-40a0-43ba-85c2-6eec2bf1ae21") {
  name
  description
}

For fields that have no argument, they receive only the response selection set object values.

Note: Chain will also accept a second argument of fetch-like options to configure the client with properties such as credentials, mode, headers etc...

Note: There is also an exported Zeus Gql convenience function in a Chain client, pre-configured with the endpoint specified in the CLI.

Listen on a WebSocket - GraphQL Subscriptions

Use the Zeus Subscription client creator in your generated output to create WebSocket connections to your GraphQL socket.

import { Subscription } from './zeus';

// Create a Subscription client instance with the endpoint
const sub = Subscription(
  'https://faker.graphqleditor.com/a-team/olympus/graphql',
);

// Call the client instance and listen for responses
sub('subscription')({
  deck: {
    id: true,
  },
}).on((response) => {
  console.log(response.deck);
});

Read more about subscriptions

Usage with NodeJS

Generates clients for use with Node.js

$ zeus schema.graphql ./  --node

Usage with React Native

This works as usual:

$ zeus schema.graphql ./

Other CLI Options

Specify the output folder with a second argument

$ zeus schema.graphql ./generated

Output Typescript Only with the --typescript flag

$ zeus schema.graphql ./ --typescript

Load your schema from a URL with a URL in the first argument

$ zeus https://faker.graphqleditor.com/a-team/olympus/graphql ./

Download and save your GraphQL schema to a local path with the --graphql=savePath flag

$ zeus https://faker.graphqleditor.com/a-team/olympus/graphql ./ --graphql=generated

Generate and save a JSON schema to a local path with the --jsonSchema=savePath flag

$ zeus https://faker.graphqleditor.com/a-team/olympus/graphql ./ --graphql=generated

Add a header value with the --header=value flag

$ zeus https://faker.graphqleditor.com/a-team/olympus/graphql ./ --header=Authorization:myNiceAuthHeader

Get help with the Zeus CLI by using this command:

$ zeus help

Tip:

Add a script entry in your package.json file for quickly calling Zeus generation:

"scripts": {
//...
"generate": "zeus https://faker.graphqleditor.com/a-team/olympus/graphql zeusGenerated --typescript --header='My-Auth-Secret:JsercjjJY5MmghtHww6UF' --apollo"
},