Design Language

Explore Goa’s powerful domain-specific language (DSL) for API design, offering a declarative approach to service development with built-in code generation and validation.

Learn about Goa’s Design Language (DSL), a powerful domain-specific language that revolutionizes API design. The DSL is the cornerstone of Goa’s approach to service development, offering a unique blend of simplicity and sophistication that sets it apart from traditional API development methods.

Why Goa’s DSL?

Goa’s DSL empowers you to express your service design in a clear, declarative way while enforcing best practices and maintaining consistency. It acts as a single source of truth for your entire API, automatically generating everything from documentation to server code to client SDKs.

Key benefits include:

  • Type Safety: Define your types once, use them everywhere with complete confidence
  • Contract-First Design: Focus on your API’s design before diving into implementation details
  • Automatic Validation: Get built-in request and response validation without writing boilerplate
  • Code Generation: Transform your designs into production-ready code with a single command
  • Living Documentation: Keep your API documentation always in sync with your implementation

Getting Started

The DSL is organized into logical sections that guide you through the API design process:

  • Start with Data Modeling to define your service’s types and structures
  • Learn about Service Design to specify endpoints and their behaviors
  • Explore Security to implement authentication and authorization
  • Master Error Handling for robust API responses

Whether you’re building a simple REST API or a complex microservices architecture, Goa’s DSL provides the tools and abstractions you need to create professional, production-ready services.

Ready to dive in? Let’s start with data modeling, the foundation of any well-designed API.

In This Section

Data Modeling

Define your service’s data structures using Goa’s comprehensive type system. Create type definitions that match your domain model while ensuring data integrity through validation rules and constraints.

API Definition

Define your API’s global properties using Goa’s API DSL. Configure metadata, documentation, servers, and global settings.

Services & Methods

Define your API’s services and methods using Goa’s service definition DSL. Create clear, well-documented endpoints with strongly typed payloads and results.

HTTP Transport Mapping

Define how your service methods map to HTTP endpoints. Learn how to map payloads to HTTP requests and responses.

Transport Mapping

Define how your service communicates over different transport protocols. Map your service methods to HTTP and gRPC endpoints.

Security

Define authentication and authorization schemes for your services using Goa’s security DSL, including JWT, API keys, Basic Auth, and OAuth2.