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Max Tokens

Limit the number of tokens in a GraphQL document.

It is used to prevent DOS attack, heap overflow or server overloading.

The token limit is often limited by the graphql parser, but this is not always the case and would lead to a fatal heap overflow.

Configuring for GraphQL Armor​

GraphQLArmorConfig({
  maxTokens: {
    // Toogle the plugin | default: true
    enabled?: boolean,
    
    // Tokens threshold | default: 1000
    n?: int,

    /* 
      If this is set to true, details about the configured limit are included in the GraphQLError message when errors occur.
      When set to false errorMessage is used as the GraphQLError message.

      default: true
    */
    exposeLimits?: boolean,

    // The error message used when exposeLimits is set to false | default: 'Query validation error.'
    errorMessage?: string,

    // Callbacks that are ran whenever a Query is accepted
    onAccept?: GraphQLArmorAcceptCallback[],

    // Callbacks that are ran whenever a Query is rejected
    onReject?: GraphQLArmorRejectCallback[],

    // Do you want to propagate the rejection to the client? | default: true
    propagateOnRejection?: boolean,
  }
})

Standalone usage​

Installation​

note

If you want to use the maxTokens plugin out of GraphQL Armor, you can install it from npm:

# npm
npm install @escape.tech/graphql-armor-max-tokens

# yarn
yarn add @escape.tech/graphql-armor-max-tokens

With @graphql/graphql-js​

You can directly use the maxTokens option:

import { parse } from '@graphql/graphql-js';
parse('{ foo }', { maxTokens: 2 }));

With @envelop/core from @the-guild-org​

import { envelop } from '@envelop/core';
import { maxTokensPlugin } from '@escape.tech/graphql-armor-max-tokens';

const getEnveloped = envelop({
  plugins: [
    // ... other plugins ...
    maxTokensPlugin({
        n: 1000,
    }),
  ]
});

References​