Registry / api / type-graphql

type-graphql

library2.0.0-rc.3jsnpmunverified

TypeGraphQL is a framework for building GraphQL APIs with TypeScript using classes and decorators. Current stable version is v2.0.0-rc.3, actively maintained with regular releases. It leverages TypeScript's decorators and type metadata to define GraphQL types, inputs, and resolvers, reducing boilerplate. Key differentiators include first-class integration with class-validator for input validation and graphql-scalars for custom scalar support. It supports both code-first and schema-first approaches, though decorator-based code-first is preferred. Requires GraphQL v16+, class-validator >=0.14.3, and graphql-scalars >=1.25.0. Beta releases occur every few months.

api devops

npm install type-graphql

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · TYPE-GRAPHQL

type-graphql

apijavascriptv2.0.0-rc.3

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

ObjectType

✓ import { ObjectType } from 'type-graphql'

✗ const { ObjectType } = require('type-graphql')

ESM-only since v2; CommonJS require is unsupported.

Resolver

✓ import { Resolver } from 'type-graphql'

✗ import { RootResolver } from 'type-graphql'

Named export, not default. 'RootResolver' does not exist.

buildSchema

✓ import { buildSchema } from 'type-graphql'

✗ import buildSchema from 'type-graphql'

Named export, not default.

Shows defining a GraphQL type with ObjectType and a resolver with Query, then building the schema and starting an Apollo server.

import 'reflect-metadata'; import { ObjectType, Field, ID, Resolver, Query, buildSchema } from 'type-graphql'; import { ApolloServer } from '@apollo/server'; import { startStandaloneServer } from '@apollo/server/standalone'; @ObjectType() class Recipe { @Field(type => ID) id: string; @Field() title: string; @Field({ nullable: true }) description?: string; } @Resolver(of => Recipe) class RecipeResolver { @Query(() => Recipe) async randomRecipe(): Promise<Recipe> { return { id: '1', title: 'Pizza', description: 'Delicious' }; } } async function main() { const schema = await buildSchema({ resolvers: [RecipeResolver] }); const server = new ApolloServer({ schema }); const { url } = await startStandaloneServer(server, { listen: { port: 4000 } }); console.log(`Server running at ${url}`); } main();

Debug

Known issues

breakingv2 drops CommonJS support; only ESM modules (import) are supported.

fix

Migrate import statements to ESM syntax and ensure package.json includes 'type': 'module'.

affects: >=2.0.0-alpha.0

breakingv2 requires Node.js >= 20.11.1

fix

Upgrade Node.js to at least version 20.11.1.

affects: >=2.0.0

breakingv2 requires Reflect.defineMetadata polyfill from 'reflect-metadata' to be imported at the entry point.

fix

Add import 'reflect-metadata' at the top of your main file.

affects: >=2.0.0

deprecatedDeprecated: 'buildTypeDefsAndResolvers' is removed in v2. Use 'buildSchema' instead.

fix

Replace calls to buildTypeDefsAndResolvers with buildSchema.

affects: >=2.0.0

gotchaField returns must be decorated with @Field. Missing @Field on a property leads to silent schema omission.

fix

Ensure all GraphQL-exposed properties have the @Field decorator.

affects: >=1.0.0

gotchaResolver class methods must be decorated with @Query, @Mutation, or @FieldResolver. Omitting decorator will not infer them.

fix

Always decorate resolver methods appropriately.

affects: >=1.0.0

gotchaInheriting from a base class does not automatically inherit @Field decorators; must redeclare on subclass.

fix

Add @Field on each subclass property that should appear in the schema.

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: Cannot read properties of undefined (reading 'prototype')

Missing 'reflect-metadata' import

fix

Add 'import "reflect-metadata"' at the top of your entry file.

NoExplicitTypeError: Unable to infer GraphQL type from Reflect metadata. You need to provide explicit type for argument.

Class-validator or type metadata not emitted

fix

Enable 'emitDecoratorMetadata' and 'experimentalDecorators' in tsconfig.json.

Cannot determine GraphQL type for argument named 'data' of mutation 'createRecipe'. Make sure to explicitly provide the type.

Parameter type is not decorator-friendly or missing decorator

fix

Use @Arg() decorator with explicit type, e.g., @Arg('data', () => RecipeInput) data: RecipeInput.

Duplicate directive: @ObjectType

Multiple decorators of same kind on same class

fix

Ensure each class uses only one @ObjectType() (or @InputType, etc.) decorator.

Upgrade

Version history

2.0.0-rc.3latest on npm

Audit

Dependencies

graphqlrequiredcore peer dependency for building GraphQL schemas

class-validatoroptionaldecorator-based input validation for resolvers

graphql-scalarsoptionalprovides custom scalar types like DateTime

Agent activity

34 hits · last 30 days

node

Resources

githubhttps://github.com/MichalLytek/type-graphql ↗

packagetype-graphql ↗

homepagehttps://typegraphql.com ↗