@eventcatalog/language-server

Beta - This package is in active development and the DSL syntax may change between releases.

A language server and parser for the EventCatalog DSL (.ec files) - a human-readable, declarative language for defining event-driven architectures.

What is the EventCatalog DSL?

The EventCatalog DSL is a complementary language for EventCatalog that brings architecture-as-code to your event-driven systems. Write your domains, services, events, commands, channels, and their relationships in a concise, human-readable format.

The DSL is designed to work hand-in-hand with EventCatalog — import existing resources from your catalog into .ec files, design and iterate on your architecture as code, and push changes back into EventCatalog. It's a two-way workflow: catalog to code, code to catalog.

domain Payment {
  version 1.0.0
  owner payment-team

  service PaymentService {
    version 1.0.0

    sends event PaymentProcessed {
      version 1.0.0
      summary "Emitted when a payment completes successfully"
    }

    receives command ProcessPayment
    receives event OrderCreated
  }
}

Features

• Full language server with diagnostics, completions, and hover information
• Parses .ec files into a structured graph representation
• Supports all EventCatalog resource types: domains, services, events, commands, queries, channels, containers, data products, flows, users, and teams
• Inline and referenced resource definitions
• Formatter for consistent code style

Supported Resource Types

| Resource | Keyword | | --------------- | ----------------- | | Domain | domain | | Service | service | | Event | event | | Command | command | | Query | query | | Channel | channel | | Container | container | | Data Product | data-product | | Flow | flow | | User | user | | Team | team | | Actor | actor | | External System | external-system | | Visualizer | visualizer |

Roadmap

• Schema support (inline and referenced schemas for messages)
• Entities
• Schemas as first-class resources

Specification

See SPEC.md for the full language specification including grammar, syntax details, and examples.

License

See the root LICENSE file.