GQLSchemaGen

Generate GraphQL schemas from Go structs with annotations, generics support, and advanced field control.

📖 Full Documentation: https://pablor21.github.io/gqlschemagen

💡 VS Code Extension: gqlschemagen-vscode

What is GQLSchemaGen?

GQLSchemaGen generates GraphQL schema files (.graphqls) from your Go code using simple annotations. Designed to work seamlessly with gqlgen, it turns your Go structs into GraphQL types, inputs, and enums—keeping your schema in sync with your codebase.

Key Features

✨ Code-First Schema Generation - Annotate Go structs to generate types, inputs, and enums
🎯 Advanced Field Control - Fine-grained visibility with ro/wo/rw tags and field filtering
🔄 Auto-Discovery - Automatically generate schemas for referenced types
🧬 Full Generics Support - Works with Go 1.18+ generic types (Response[T], Connection[T])
🗂️ Namespace Organization - Organize schemas into folders/namespaces
🔧 Scalar Mappings - Map Go types to GraphQL scalars globally (UUID → ID, time.Time → DateTime)
🛡️ Schema Preservation - Keep manual edits with @GqlKeepBegin/@GqlKeepEnd markers
⚙️ gqlgen Integration - Generates @goModel, @goField directives automatically (requires Opt-in via config or --gqlgen flag)

Quick Start

Installation

go install github.com/pablor21/gqlschemagen@latest

Basic Usage

1. Annotate your Go structs:

package models

// @gqlType
type User struct {
    ID        string    `gql:"id,type:ID"`
    Name      string    `gql:"name"`
    Email     string    `gql:"email"`
    CreatedAt time.Time `gql:"createdAt,ro"` // Read-only (excluded from inputs)
}

// @gqlInput
type CreateUserInput struct {
    Name     string `gql:"name"`
    Email    string `gql:"email"`
    Password string `gql:"password,wo"` // Write-only (excluded from types)
}

// @gqlEnum
type UserRole string

const (
    UserRoleAdmin  UserRole = "admin"  // @gqlEnumValue(name:"ADMIN")
    UserRoleViewer UserRole = "viewer" // @gqlEnumValue(name:"VIEWER")
)

2. Create config file gqlschemagen.yml:

gqlschemagen init

This command generates a default gqlschemagen.yml configuration file in your current directory.

3. Generate schema:

gqlschemagen generate --gqlgen

4. Generated schema.graphqls:

type User @goModel(model: "your-module/models.User") {
  id: ID!
  name: String!
  email: String!
  createdAt: String!
}

input CreateUserInput {
  name: String!
  email: String!
  password: String!
}

enum UserRole {
  ADMIN
  VIEWER
}

Advanced Features

Multiple Types from One Struct

// @gqlType(name:"User")
// @gqlType(name:"PublicUser", ignoreAll:"true")
// @gqlInput(name:"CreateUserInput")
// @gqlInput(name:"UpdateUserInput")
type User struct {
    ID    string `gql:"id,type:ID,ro"`
    Name  string `gql:"name,include:*"`      // Include in all
    Email string `gql:"email,include:User"`  // Only in User type
}

Scalar Mappings

scalars:
  ID:
    model:
      - github.com/google/uuid.UUID
  DateTime:
    model:
      - time.Time

Auto-Generation

auto_generate:
  strategy: referenced  # none | referenced | all | patterns
  max_depth: 3

Documentation

• Getting Started
• Configuration
• Features
  • Types & Inputs
  • Field Filtering
  • Scalar Mappings
  • Auto-Generation
  • Generics Support
• CLI Reference

Contributing

We welcome contributions! To add new features or improvements, please follow these steps:

1. Update configuration Modify the Config struct in config.go to include any new settings required by your feature.

2. Add parsing logic Implement the necessary parsing in directives.go to handle any new directives or annotations.

3. Implement code generation Extend generator.go with the generation logic for your feature.

4. Update documentation Make sure to update this README or relevant docs to reflect your changes, including a brief explanation of the feature.

5. Add examples Provide usage examples or sample code demonstrating how to use your feature.

Following these steps ensures that your contribution is clear, well-documented, and easy for others to understand.

License

MIT License. See LICENSE for details.

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Made with ❤️ by Pablo Ramirez pablo@pramirez.dev | Website | GitHub