What Is a Trigger?

The concept of a "Trigger" doesn't originate from computer science.

It comes from the ancient physical action of pulling. The word traces back to the Dutch trekker, meaning "the one who pulls". By the 17th century, it evolved into the English word trigger, referring to the small component on a firearm that, when pulled, unleashes a much larger chain reaction.

From a physical "puller" to a digital "start signal," the essence of the Trigger has always remained the same:

It is the automated entry point of cause and effect.

Today, the Dify platform introduces its own Trigger — a core automation mechanism designed to unlock the full potential of AI applications.

From Manual Execution to Intelligent Automation

When building AI-native applications and sophisticated workflows, the ultimate goal is clear: real-time responsiveness and autonomous execution.

Historically, Dify applications relied on:

• Manual user input in the Webapp

• Programmatic calls from backend systems through the API

This request–response model is efficient, but when it comes to scheduled tasks or external event listeners, developers often had to build their own schedulers and services — increasing both system complexity and maintenance cost.

With the introduction of the Trigger node, Dify removes this burden entirely.

As one of the workflow's start nodes, a Trigger allows your workflow to run automatically based on predefined rules — transforming your AI application from passive execution to proactive intelligence.

In this guide, we will walk through the three Trigger types available in Dify and help you choose the right "lever" for seamless workflow automation.

From Cron to Events: How Dify Unifies Two Automation Paradigms

Dify Triggers bring together two foundational paradigms in computing automation:

Scheduled Automation

Represented by Unix Cron, solving the question: "When should something run?"

Its value lies in:

• Predictability

• Operational efficiency

Tasks such as maintenance, report generation, or recurring routines run reliably on schedule.

Dify Schedule Trigger inherits these capabilities.

Event-Driven Architecture (EDA)

Represented by Webhook systems, solving the question:

"What should happen when an event occurs?"

Its value lies in:

• Real-time responsiveness

• Automation driven by external signals

Dify Plugin Trigger and Webhook Trigger bring this paradigm into workflows.

Together, these three triggers provide complete coverage of automation scenarios — from time-based execution to real-time event reaction.

The Three Types of Triggers in Dify Workflows

Dify offers three types of triggers, each designed for a different automation need:

Through a unified design model, they support consistent building, debugging, and scaling across all automation scenarios.

We'll evaluate the three triggers from two perspectives:

1. When is it triggered?

2. What event causes the trigger?

Scheduled Trigger — Let Your Workflow Run on Time

The Scheduled Trigger is the most classic automation method. It is ideal for tasks that must follow a fixed timetable.

Perfect for:

• Daily industry news push, KPIs, or team digests

• Weekly cleanup tasks, data synchronization, or log checks

• Monthly reconciliation, audit workflows, or data archiving

• Recurring background jobs such as cache refresh or state polling

If your task is predictable and repetitive, the Scheduled Trigger is the right choice.

How to Use

On the Dify workflow canvas:

• Select the Start Node

• Switch to Scheduled Trigger

• Configure the run time using the visual interface

You can also use Cron expressions for precise schedule control, ideal for users familiar with Unix cron.

Best Practice: Daily Industry Intelligence Digest

Many teams need a consistent stream of industry insights, but manually collecting, filtering, and summarizing news every morning is time-consuming and unreliable. Scheduled Triggers solve this by turning a repetitive research task into a fully automated routine that delivers insights at the exact same time every day — ensuring your team never misses important updates while eliminating manual overhead.

• Goal: Automatically generate a daily industry brief using AI and deliver it to the team.

• Setup: Run every weekday at 9:00 AM.

• Workflow:

[Dify DSL: Daily News for Slack Channel.yml]

• Value: Eliminates hours of manual research and ensures consistent delivery.

Event-Driven Automation: Plugin Triggers & Webhook Triggers

Event-driven automation enables workflows to respond instantly to changes in external systems.

Dify provides two options, depending on how you want to integrate external events.

Plugin Trigger — The Easiest Integration Path

If the external system you rely on (GitHub, Slack, Outlook, Zendesk, calendar services, etc.) already provides a Trigger in the Dify Plugin Marketplace, this is the recommended choice.

The Plugin Trigger handles:

• Event listening

• Authentication

• Data structures

• Common event types (e.g., GitHub PR opened, Slack mention, Email received)

With just a few clicks, events flow into your workflow — no code required.

Best Practice: Tech News Assistant in Slack

In fast-paced teams, waiting for someone to search for news, gather context, and share updates slows communication. Plugin Triggers allow workflows to react instantly when users mention an assistant inside Slack. This creates a fluid, conversational interface where team members can request insights naturally in their day-to-day communication environment — no switching tools, no extra steps.

• Goal: Build an interactive tech-news assistant inside Slack.

• Trigger: When the assistant is mentioned in the channel.

• Workflow:

[Dify DSL Example: Slack Trigger a news researcher.yml]

• Value: Acts like a digital teammate, providing instant industry insights.

Webhook Trigger — "Here's a URL. Call me when something happens."

When:

• No plugin trigger exists, or

• You need to handle custom events

The Webhook Trigger becomes the most flexible and universal option.

Key Characteristics

• Universal compatibility

  - Any system capable of sending an HTTP POST request can trigger Dify.

• Highly customizable

  - You control the payload format, signature model, and authorization scheme.

• Fits any architecture

  - From enterprise backends to edge scripts, niche SaaS tools, automation platforms, or a Raspberry Pi task — if it speaks HTTP, it works.

How to Use

Dify generates a Webhook URL for you:

You can freely define:

• The input schema for the webhook request

• The output schema returned by the webhook

Summary: How to Choose Your Trigger

Selecting the right Trigger is the first step toward building an efficient automated workflow.

Here's a quick decision guide:

Security Tip

When using Webhook Triggers, always implement signature verification (e.g., HMAC) in downstream nodes such as a Code node to ensure requests are legitimate.

Enter the Fully Automated, Event-Driven Era of AI Workflows

Triggers mark Dify's transition into a new era of autonomous, event-driven AI applications.

Whether your workflow needs:

• Scheduled execution

• Real-time integration with external systems

• Flexible ingestion of custom events

Triggers provide the fundamental "cause" that initiates your automated "effect."

Now is the perfect time to adopt these powerful levers in your workflows — and unlock the full automation potential of your AI applications.

References

[1] https://en.wikipedia.org/wiki/Cron Wikipedia. "Cron." Accessed November 11, 2025.

[2] https://docs.dify.ai/en/guides/workflow/node/trigger Dify Docs. "Trigger." Accessed November 11, 2025.