Triggers
How patterns start — webhooks, schedules, pattern calls, and manual runs.
A trigger is the event that starts a pattern's execution. Every pattern has exactly one trigger node, placed at the beginning of the execution flow. The trigger you choose determines how and when your pattern runs.
Trigger types at a glance
| Trigger | Starts when | Output data | Requires deployment |
|---|---|---|---|
| On Webhook | An HTTP request arrives at the pattern's URL | Request body, headers, query parameters, HTTP method | Yes (but URL is available immediately) |
| On Schedule | A cron schedule fires | None | Yes |
| On Pattern Call | Another pattern invokes it with the Call Pattern node | Caller-provided input values | Yes |
| On Start | You select Run in the editor or execute via the API | None | No |
When to use each trigger
On Webhook
Use On Webhook when an external service needs to notify your pattern that something happened. Webhooks are the foundation of event-driven automation — services like GitHub, Slack, Stripe, and Jira push events to your pattern's URL in real time.
Each pattern with a webhook trigger receives a unique, stable URL that survives undeploy and redeploy. You can register this URL with external services before you even deploy the pattern.
On Schedule
Use On Schedule when your pattern needs to run at regular intervals. Cron expressions give you precise control over timing — from every five minutes to once a month to weekdays at 9 AM.
Scheduled patterns are ideal for polling APIs, generating reports, running health checks, and performing periodic cleanup.
On Pattern Call
Use On Pattern Call when you want to build reusable logic that other patterns invoke. This makes your pattern behave like a function: it accepts typed inputs, runs its logic, and returns typed outputs to the caller.
Pattern composition lets you break complex workflows into focused, testable pieces that you maintain independently.
On Start
Use On Start for patterns you trigger manually from the editor or the dashboard. This is the simplest trigger — it takes no configuration and has no external event source. Every new pattern starts with an On Start node by default.
On Start is well suited for one-off scripts, data migrations, and patterns you run on demand.
Deep dive
Webhooks
Stable URLs, HTTP methods, output pins, HMAC validation, custom responses, and tap mode.
Schedules
Cron expressions, common patterns, catch-up behavior, and timezone considerations.
Pattern calls
Typed inputs and outputs, the Call Pattern node, Respond With, and composition patterns.
Related
- Triggers concept -- high-level overview of trigger types
- Patterns -- the workflows that triggers start
- Deployments -- triggers only fire on deployed patterns
- Executions -- the runs that triggers create