Overview

Signal tasks are the event broadcasters of Compozy's event-driven architecture. They enable workflows to send structured messages that coordinate between processes, trigger asynchronous actions, and implement sophisticated publish-subscribe patterns. When combined with wait tasks, signal tasks create powerful synchronization mechanisms that form the backbone of Compozy's event-driven signal system.

Core Capabilities

Signal tasks provide essential event-driven coordination features:

Task Structure

Signal tasks use a simple yet powerful configuration structure built on Compozy's task configuration system. Every signal task contains two essential components: the signal identification and payload data.

id: signal-task-name
type: signal
signal:
  id: "signal-identifier"
  payload:
    data: "{{ .workflow.input.value }}"
    timestamp: "{{ now }}"
outputs:
  signal_dispatched: "{{ .task.outputs.signal_dispatched }}"
  signal_id: "{{ .task.outputs.signal_id }}"

Integration with Wait Tasks

Signal tasks enable robust, event-driven communication between independent workflows. One workflow can notify or trigger actions in another, allowing for decoupled orchestration and real-time coordination across complex business processes. This mechanism is essential for building scalable systems where workflows need to interact, synchronize, or respond to events generated elsewhere in the platform.

id: complete-order-processing
type: signal
signal:
  id: "order-ready-for-fulfillment"
  payload:
    order_id: "{{ .workflow.input.order_id }}"
    customer_id: "{{ .workflow.input.customer_id }}"
    items: "{{ .task.output.processed_items }}"

    # Fulfillment instructions
    fulfillment_instructions:
      shipping_method: "{{ .workflow.input.shipping_method }}"
      priority: "{{ .workflow.input.priority }}"
      special_instructions: "{{ .workflow.input.special_instructions }}"

    # Order metadata
    order_metadata:
      total_amount: "{{ .task.output.total_amount }}"
      payment_confirmed: "{{ .task.output.payment_confirmed }}"
      processed_at: "{{ now }}"

id: wait-for-order
type: wait
wait_for: "order-ready-for-fulfillment"
condition: 'signal.payload.order_metadata.payment_confirmed == true'
timeout: 3600s  # 1 hour

processor:
  type: basic
  agent:
    id: fulfillment-processor
    instructions: "Process order for fulfillment"
  with:
    order_data: "{{ .signal.payload }}"
    fulfillment_center: "{{ .workflow.input.fulfillment_center }}"

outputs:
  fulfillment_initiated: "{{ .processor.output.initiated }}"
  estimated_shipping: "{{ .processor.output.estimated_shipping }}"

Best Practices

Follow these established patterns to build reliable and maintainable signal-driven workflows. These practices ensure signal tasks integrate effectively with the broader event-driven architecture and support debugging, monitoring, and system reliability.

Summary

Signal tasks form the foundation of event-driven workflows in Compozy, enabling loose coupling, scalable coordination, and sophisticated inter-workflow communication patterns. Their immediate execution and flexible payload system make them ideal for creating responsive, event-driven applications.

References