CQRS Handlers Reference

Command Query Responsibility Segregation patterns in Ever Gauzy.

Overview

Gauzy uses NestJS CQRS (@nestjs/cqrs) to separate write operations (commands) from read operations (queries). This provides:

• Clear separation of concerns
• Easy testing of business logic
• Event-driven side effects

Command Pattern

Defining a Command

export class CreateOrganizationSprintCommand implements ICommand {
  constructor(public readonly input: IOrganizationSprintCreateInput) {}
}

Handling a Command

@CommandHandler(CreateOrganizationSprintCommand)
export class CreateOrganizationSprintHandler implements ICommandHandler<CreateOrganizationSprintCommand> {
  constructor(private readonly sprintService: OrganizationSprintService) {}

  async execute(command: CreateOrganizationSprintCommand) {
    const { input } = command;
    return await this.sprintService.create(input);
  }
}

Dispatching a Command

@Post('/')
async create(@Body() entity: CreateSprintDTO) {
  return await this.commandBus.execute(
    new CreateOrganizationSprintCommand(entity)
  );
}

Command Flow

Common Patterns

Pattern	Description
Create commands	Entity creation with side effects
Update commands	Entity updates with validation
Composite commands	Multi-step operations
Event-emitting commands	Trigger events after execution

Related Pages

• Plugin Development Guide — creating plugins with CQRS
• Architecture Overview — system architecture