Overview

prisma-flat-graphql-generator is a prisma generator designed to automatically generate GraphQL schema and resolvers from a Prisma schema. This tool streamlines the process of setting up a GraphQL server by creating a comprehensive structure of resolvers, type definitions, and input types based on your Prisma models.

Key Features:

• ✅ Zero Dependencies: Generated code has no external runtime dependencies beyond Prisma Client and GraphQL
• ✅ N+1 Prevention: Built-in query optimization automatically prevents N+1 issues
• ✅ Standalone: No need for @paljs/plugins or graphql-type-json - everything is self-contained
• ✅ Type Safe: Full TypeScript support with generated types

Installation

To install, run:

npm install prisma-flat-graphql-generator

That's it! No additional dependencies required. The generated code is completely standalone.

In your Prisma schema file, add the following generator clause:

generator graphql {
    provider = "prisma-flat-graphql-generator"
    output   = "./generated/graphql"  // Optional: specify output directory
}

Usage

1. Generate GraphQL Schema and Resolvers

Run Prisma generate:

npx prisma generate

2. Use with Apollo Server

The generated code works directly with Apollo Server - no middleware or wrapping needed:

import { ApolloServer } from '@apollo/server';
import { startStandaloneServer } from '@apollo/server/standalone';
import { PrismaClient } from '@prisma/client';
import { typeDefs, resolvers } from './generated/graphql';

const prisma = new PrismaClient();

const server = new ApolloServer({
  typeDefs,
  resolvers,
});

const { url } = await startStandaloneServer(server, {
  context: async () => ({ prisma }),
  listen: { port: 4000 },
});

console.log(`🚀 Server ready at ${url}`);

That's it! The resolvers automatically optimize queries to prevent N+1 issues.

Example

For models User and Post:

query GetUserWithPosts($userId: String!) {
  user(where: { id: { equals: $userId } }) { 
    id
    displayName
    photoURL
    posts {
      id
      text
    }
  }
}

query GetAllUsers { 
  users {
    id
    displayName
    photoURL
  }
}

Generator Configurations

You can customize the generator output with the following configurations:

• models Specify models to generate typeDefs and resolvers for.
• excludeModels Exclude specific models from generating typeDefs and resolvers.
• excludeInputFields Exclude fields from filtering in GraphQL queries.
• excludeOutputFields Exclude fields from GraphQL outputs.
• output Set a custom output directory for the generator (Defaults to the same directory as schema.prisma file).

Testing

This library has comprehensive test coverage to ensure reliability:

npm test              # Run all tests
npm run test:watch    # Watch mode for development
npm run test:coverage # Generate coverage report

Test Suite:

• 51 passing tests across unit and integration tests
• Tests cover: generation, exclusions, enums, bug fixes, and edge cases
• Recent bug fixes verified with dedicated test coverage

Recent Improvements (v0.1.13):

• ✅ Fixed duplicate type definitions in generated GraphQL schemas
• ✅ Fixed GraphQL formatting to ensure consistent output
• ✅ Fixed nested relation handling to support deep query optimization
• ✅ Fixed _count and aggregate fields causing introspection failures
• ✅ Added 21 new tests specifically for bug fixes

See CHANGELOG.md for detailed release notes.

Acknowledgments

This library was inspired by Ahmed Elywa's work on paljs.

Limitations

Currently, this generator does not support mutations such as create, update, or delete.

Contributing

Contributions are welcome to extend the functionality, including support for mutations and more.

See CLAUDE.md for development guidelines and architecture details.