Build HTTP APIs from protobuf definitions

Transform your protobuf services into production-ready HTTP APIs with automatic documentation and helper functions.

🚀 Try it in 30 seconds

# Clone and run the working example
git clone https://github.com/SebastienMelki/sebuf.git
cd sebuf/examples/simple-api
make demo

This starts a working HTTP API with JSON endpoints, OpenAPI docs, and helper functions - all generated from a simple .proto file.

What you get

• HTTP handlers from protobuf services (JSON + binary support)
• Mock server generation with realistic field examples for rapid prototyping
• Automatic request validation using protovalidate with buf.validate annotations
• HTTP header validation with type checking and format validation (UUID, email, datetime)
• Structured error responses with field-level validation details in JSON or protobuf
• OpenAPI v3.1 docs that stay in sync with your code, one file per service for better organization
• Helper functions that eliminate protobuf boilerplate
• Zero runtime dependencies - works with any Go HTTP framework

How it works

From this protobuf definition:

service UserService {
  // Header validation at service level
  option (sebuf.http.service_headers) = {
    required_headers: [{
      name: "X-API-Key"
      type: "string"
      format: "uuid"
      required: true
    }]
  };
  
  rpc CreateUser(CreateUserRequest) returns (User);
}

message CreateUserRequest {
  // Automatic validation with buf.validate
  string name = 1 [
    (buf.validate.field).string = {
      min_len: 2, max_len: 100
    },
    (sebuf.http.field_examples) = {
      values: ["Alice Johnson", "Bob Smith", "Charlie Davis"]
    }
  ];
  string email = 2 [
    (buf.validate.field).string.email = true,
    (sebuf.http.field_examples) = {
      values: ["alice@example.com", "bob@example.com"]
    }
  ];
  
  oneof auth_method {
    EmailAuth email = 3;
    TokenAuth token = 4;
  }
}

sebuf generates:

// HTTP handlers with automatic validation (both headers and body)
api.RegisterUserServiceServer(userService, api.WithMux(mux))

// Mock server with realistic data (optional)
mockService := api.NewMockUserServiceServer()
api.RegisterUserServiceServer(mockService, api.WithMux(mux))

// Helper functions  
req := api.NewCreateUserRequestEmail("user@example.com", "secret")
req := api.NewCreateUserRequestToken("auth-token")

// Validation happens automatically:
// - Headers validated first (returns HTTP 400 for missing/invalid headers)
// - Then request body validated (returns HTTP 400 for invalid requests)
// OpenAPI docs (UserService.openapi.yaml) - includes validation rules, headers, and examples

Quick setup

# Install the tools
go install github.com/SebastienMelki/sebuf/cmd/protoc-gen-go-oneof-helper@latest
go install github.com/SebastienMelki/sebuf/cmd/protoc-gen-go-http@latest  
go install github.com/SebastienMelki/sebuf/cmd/protoc-gen-openapiv3@latest

# Try the complete example
cd examples/simple-api && make demo

Next steps

• Complete Tutorial - Full walkthrough with working code
• Documentation - Comprehensive guides and API reference
• More Examples - Additional patterns and use cases

What's this good for?

• Web & mobile APIs - JSON/HTTP endpoints from protobuf definitions
• API documentation - OpenAPI specs that never get out of sync
• Type-safe development - Leverage protobuf's type system for HTTP APIs
• Client generation - Generate clients for any language from your API spec

Built on Great Tools

sebuf stands on the shoulders of giants, integrating with an incredible ecosystem:

• Protocol Buffers by Google - The foundation for everything
• protovalidate by Buf - Powers our automatic validation
• Buf CLI - Modern protobuf tooling and dependency management
• OpenAPI 3.1 - Industry standard API documentation
• Common Expression Language (CEL) by Google - Flexible validation rules

We're grateful to all maintainers of these projects that make sebuf possible.

Contributing

We welcome contributions! See CONTRIBUTING.md for details.

License

MIT License - see LICENSE

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