A test framework and CLI for running fully automated, randomized tests against any GraphQL API.

Usage no npm install needed!

<script type="module">
  import graphqlMonkey from '';


GraphQL Monkey

:monkey: A test framework and CLI for running fully automated, randomized tests against any GraphQL API.


npm i graphql-monkey -g


Testing a GraphQL API directly via command-line:

gqlm --url

See gqlm --help for more options.

Most use cases will need an options file with some preparation logic (authentication etc., see below for a detailed reference). For example:

const request = require('request-promise-native');

module.exports = { gqlm };

async function gqlm() {
  return {
    url: '',
    count: 30,
    requestOptions: await login()

async function login() {
  const response = await request({
    method: 'POST',
    url: '',
    body: {
      grant_type: 'password',
      client_id: 'xxxxx',
      client_secret: 'xxxxx',
      username: 'gibbon',
      password: 'bananas'
    json: true

  return {
    headers: {
      Authorization: `Bearer ${response.access_token}`

Run with gqlm example.js.


Options may be set using an options file. An options file is a JavaScript file exporting a default function or gqlm function returning an object containing the options. The exported function may be async. For TypeScript there's a TestOptionsInput interface which may be used as a return type.

Using the options file, you can implement preparation logic, like authentication.

Additionally, some options may be set via command-line.

Count (-n, --count)

count: number

Sets the number of queries to generate and test.

Exit (-e, --exit)

exit: boolean

If set, GQLM will exit after the first failed request. Useful to fix failures step-by-step.

Printing (-p, --print)

Defines what GQLM will print to the console. Multiple arguments may be specified. Possible values are:

  • requests: Print requests
  • responses: Print responses
  • errors: Print GraphQL errors
  • failures: Print requests and GraphQL errors for failed tests
  • memory: Print memory after all tests
  • types: Print a report for each type, including coverage

For example, gqlm example.ts -p failures -p memory will print failures and the data in memory after all tests.

Require (-r, --require)

Requires a Node.js module on startup. Multiple modules may be specified. Useful for transpilation, e.g when using TypeScript: gqlm example.ts --require ts-node/register

Seed (-s, --seed)

seed: string

Sets the seed for random number generation.

Setting the seed yields a deterministic, reproducible run of tests. Useful to reproduce failures during development.

The seed of the last run is printed at the end of every report.


data: any

Sets the initially known data for argument generation. The provided data may have any structure.

When generating arguments, GQLM will match argument names to keys in its knowledge base, and prefer using known values to guess arguments.

The knowledge is built from the given initial data as well as from recorded response bodies.

For example, if the GraphQL API has arguments or inputs named fruit anywhere, GQLM can be "helped" to guess input for these fields by providing:

function gqlm() {
  return {
    // ...
    data: {
      fruit: ['banana', 'apple', '...'],
      // ...


aliases: string[][]

Defines aliasing for data. Often, different field names have the same semantics, for example may be equivalent to Contract.customerId. GQLM will use aliases to match field names and known data more effectively.

  aliases: [
    ["id", "customerId", "contractId"],

Request Options

requestOptions: request.Options

Options for HTTP requests. See

Endpoint Callback

endpointCallback: (endpoint: TestEndpoint) => TestEndpoint | null

An optional callback that allows transforming (return endpoint) or omitting test endpoints (return null).

Error Callback

errorCallback: (error: GraphQLError) => boolean

An optional callback that determines whether an error is an unexpected error (return true) or not (return false).

Only unexpected errors will mark a test result as failed.

Result Callback

resultCallback: (result: TestResult) => TestResult | null

An optional callback that allows transforming (return result) or omitting test results (return null).