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GraphQL Code Generator

Generate anything from GraphQL schema / operations!

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Programmatic Usage#

GraphQL Code Generator also provides a complete programmatic API.

The programmatic API can be used if you need to customize the execution flow or write a tool that uses the codegen.

Basic Programmatic Usage#

In order to use the programmatic API, start by importing codegen from @graphql-codegen/core:

import { codegen } from '@graphql-codegen/core'

Then, create a configuration object (complete signature):

import { buildSchema, printSchema, parse, GraphQLSchema } from 'graphql' import * as fs from 'fs' import * as path from 'path' import * as typescriptPlugin from '@graphql-codegen/typescript' const schema: GraphQLSchema = buildSchema(`type A { name: String }`) const outputFile = 'relative/pathTo/filename.ts' const config = { documents: [], config: {}, // used by a plugin internally, although the 'typescript' plugin currently // returns the string output, rather than writing to a file filename: outputFile, schema: parse(printSchema(schema)), plugins: [ // Each plugin should be an object { typescript: {} // Here you can pass configuration to the plugin } ], pluginMap: { typescript: typescriptPlugin } }

The schema field be a valid GraphQLSchema object. If you need to load your GraphQL schema from an external source (file, URL), you can use loadSchema from @graphql-tools/load.

Notice that a plugin name key in pluginMap and plugins must match to identify a plugin and its configuration.

You need to import the plugin in your favorite way; you can also use await import to lazy load it.

Then, provide the config object to codegen:

const output = await codegen(config) fs.writeFile(path.join(__dirname, outputFile), output, () => { console.log('Outputs generated!') })

We are using this API in the live demo on the GraphQL Code Generator website. The code is here.

Loading schema and documents

You can use one of the tools from @graphql-tools for file loading, schema merging, transformations and more.

Using the CLI instead of core#

If you wish to have the benefits that cli package has (like loading schema and document files, parsing endpoints and more), you can use require() (or import) for @graphql-codegen/cli directly with Node.JS:

import { generate } from '@graphql-codegen/cli' async function doSomething() { const generatedFiles = await generate( { schema: 'http://127.0.0.1:3000/graphql', documents: './src/**/*.graphql', generates: { [process.cwd() + '/models/types.d.ts']: { plugins: ['typescript'] } } }, true ) }

The return value should be of type Promise<FileOutput[]>.