Events Providers Overview

Introduction

Events Providers enable your digital worker to respond to external triggers beyond messaging. They handle:

Webhooks from external services
Scheduled tasks (timers/cron)
Email notifications
SMS notifications

Available Providers

Webhook Receive HTTP webhooks from external services

Timer Schedule tasks with cron expressions

Email (SendGrid) Send transactional emails via SendGrid

SMS (Twilio) Send SMS messages via Twilio

Architecture

External Service / Timer
    │
    ▼ HTTP / Schedule
┌─────────────────────────────────────────┐
│           Events Ingress                │
│     (Process incoming event)            │
└─────────────────────────────────────────┘
    │
    ▼ Normalized Event
┌─────────────────────────────────────────┐
│              NATS Bus                   │
│    greentic.events.{env}.{tenant}.{type}│
└─────────────────────────────────────────┘
    │
    ▼
┌─────────────────────────────────────────┐
│           Flow Executor                 │
│      (Process with event flows)         │
└─────────────────────────────────────────┘

Event Normalization

All events are normalized to a common format:

pub struct Event {
    pub id: String,
    pub event_type: String,
    pub source: String,
    pub timestamp: u64,
    pub payload: Value,
    pub metadata: Option<Value>,
}

Configuration

In Bundle

providers:
  events-webhook:
    pack: "providers/events/events-webhook.gtpack"

  events-timer:
    pack: "providers/events/events-timer.gtpack"

Event Flows

name: handle_event
version: "1.0"

nodes:
  - id: process
    type: script
    config:
      script: |
        // Process the event
        let payload = event.payload;
        process_payload(payload)
    next: respond

triggers:
  - type: event
    event_type: "order.created"
    target: process

NATS Subjects

Events flow through NATS:

Subject	Purpose
`greentic.events.{env}.{tenant}.{type}`	Event notifications
`greentic.events.{env}.{tenant}.{type}.result`	Event processing results

Common Patterns

Event-Driven Notifications

nodes:
  - id: on_order
    type: branch
    config:
      conditions:
        - expression: "event.event_type == 'order.created'"
          next: send_confirmation
        - expression: "event.event_type == 'order.shipped'"
          next: send_tracking

Scheduled Tasks

nodes:
  - id: daily_report
    type: http
    config:
      method: GET
      url: "https://api.example.com/reports/daily"
    next: send_email

triggers:
  - type: timer
    cron: "0 9 * * *"  # 9 AM daily
    target: daily_report