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GraphQL-JS is a very well written runtime implementation of the latest GraphQL spec. However, by compiling to JS, V8 is able to create optimized code which yields much better performance. graphql-jit leverages this behaviour of V8 optimization by compiling the queries into functions to significantly improve performance (See benchmarks below)


$ yarn benchmark skip-json
Starting introspection
graphql-js x 1,155 ops/sec ±1.55% (215 runs sampled)
graphql-jit x 5,961 ops/sec ±5.34% (216 runs sampled)
Starting fewResolvers
graphql-js x 14,313 ops/sec ±1.43% (224 runs sampled)
graphql-jit x 409,587 ops/sec ±1.08% (216 runs sampled)
Starting manyResolvers
graphql-js x 13,201 ops/sec ±1.50% (216 runs sampled)
graphql-jit x 229,025 ops/sec ±1.18% (216 runs sampled)
Starting nestedArrays
graphql-js x 108 ops/sec ±1.30% (216 runs sampled)
graphql-jit x 1,317 ops/sec ±2.38% (213 runs sampled)
Done in 141.94s.

Support for GraphQL spec

The goal is to support the June 2018 version of the GraphQL spec.

Differences to graphql-js

In order to achieve better performance, the graphql-jit compiler introduces some limitations. The primary limitation is that all computed properties must have a resolver and only these can return a Promise.


yarn add graphql-jit


For complete working examples, check the examples/ directory

Create a schema

const typedefs = `
type Query {
  hello: string
const resolvers = {
  Query: {
    hello() {
      return new Promise(resolve => setTimeout(() => resolve("World!"), 200));

const { makeExecutableSchema } = require("graphql");
const schema = makeExecutableSchema({ typedefs, resolvers });

Compile a Query

const query = `
const { parse } = require("graphql");
const document = parse(query);

const { compileQuery, isCompiledQuery } = require("graphql-jit");
const compiledQuery = compileQuery(schema, document);
// check if the compilation is successful

if (!isCompiledQuery(compiledQuery)) {
  throw new Error("Error compiling query");

Execute the Query

const executionResult = await compiledQuery.query(root, context, variables);

Subscribe to the Query

const result = await compiledQuery.subscribe(root, context, variables);
for await (const value of result) {


compiledQuery = compileQuery(schema, document, operationName, compilerOptions)

Compiles the document AST, using an optional operationName and compiler options.

  • schema {GraphQLSchema} - graphql schema object

  • document {DocumentNode} - document query AST ,can be obtained by parse from graphql

  • operationName {string} - optional operation name in case the document contains multiple operations(queries/mutations/subscription).

  • compilerOptions {Object} - Configurable options for the compiler

    • disableLeafSerialization {boolean, default: false} - disables leaf node serializers. The serializers validate the content of the field at runtime so this option should only be set to true if there are strong assurances that the values are valid.
    • customSerializers {Object as Map, default: {}} - Replace serializer functions for specific types. Can be used as a safer alternative for overly expensive serializers
    • customJSONSerializer {boolean, default: false} - Whether to produce also a JSON serializer function using fast-json-stringify. The default stringifier function is JSON.stringify

compiledQuery.query(root: any, context: any, variables: Maybe<{ [key: string]: any }>)

the compiled function that can be called with a root value, a context and the required variables.

compiledQuery.subscribe(root: any, context: any, variables: Maybe<{ [key: string]: any }>)

(available for GraphQL Subscription only) the compiled function that can be called with a root value, a context and the required variables to produce either an AsyncIterator (if successful) or an ExecutionResult (error).

compiledQuery.stringify(value: any)

the compiled function for producing a JSON string. It will be JSON.stringify unless compilerOptions.customJSONSerializer is true. The value argument should be the return of the compiled GraphQL function.