---
title: Setting Cron Triggers
description: Set a Cron Trigger for your Worker.
image: https://developers.cloudflare.com/dev-products-preview.png
---

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# Setting Cron Triggers

Set a Cron Trigger for your Worker.

* [  JavaScript ](#tab-panel-11967)
* [  TypeScript ](#tab-panel-11968)
* [  Python ](#tab-panel-11969)
* [  Hono ](#tab-panel-11970)

JavaScript

```
export default {  async scheduled(controller, env, ctx) {    console.log("cron processed");  },};
```

TypeScript

```
interface Env {}export default {  async scheduled(    controller: ScheduledController,    env: Env,    ctx: ExecutionContext,  ) {    console.log("cron processed");  },};
```

Python

```
from workers import WorkerEntrypoint, Response
class Default(WorkerEntrypoint):    async def scheduled(self, controller, env, ctx):        print("cron processed")
```

TypeScript

```
import { Hono } from "hono";
interface Env {}
// Create Hono appconst app = new Hono<{ Bindings: Env }>();
// Regular routes for normal HTTP requestsapp.get("/", (c) => c.text("Hello World!"));
// Export both the app and a scheduled functionexport default {  // The Hono app handles regular HTTP requests  fetch: app.fetch,
  // The scheduled function handles Cron triggers  async scheduled(    controller: ScheduledController,    env: Env,    ctx: ExecutionContext,  ) {    console.log("cron processed");
    // You could also perform actions like:    // - Fetching data from external APIs    // - Updating KV or Durable Object storage    // - Running maintenance tasks    // - Sending notifications  },};
```

## Set Cron Triggers in Wrangler

Refer to [Cron Triggers](https://developers.cloudflare.com/workers/configuration/cron-triggers/) for more information on how to add a Cron Trigger.

If you are deploying with Wrangler, set the cron syntax (once per hour as shown below) by adding this to your Wrangler file:

* [  wrangler.jsonc ](#tab-panel-11971)
* [  wrangler.toml ](#tab-panel-11972)

JSONC

```
{  "$schema": "./node_modules/wrangler/config-schema.json",  "name": "worker",  // ...  "triggers": {    "crons": [      "0 * * * *"    ]  }}
```

TOML

```
"$schema" = "./node_modules/wrangler/config-schema.json"name = "worker"
[triggers]crons = [ "0 * * * *" ]
```

You also can set a different Cron Trigger for each [environment](https://developers.cloudflare.com/workers/wrangler/environments/) in your [Wrangler configuration file](https://developers.cloudflare.com/workers/wrangler/configuration/). You need to put the `[triggers]` table under your chosen environment. For example:

* [  wrangler.jsonc ](#tab-panel-11973)
* [  wrangler.toml ](#tab-panel-11974)

JSONC

```
{  "env": {    "dev": {      "triggers": {        "crons": [          "0 * * * *"        ]      }    }  }}
```

TOML

```
[env.dev.triggers]crons = [ "0 * * * *" ]
```

## Test Cron Triggers using Wrangler

The recommended way of testing Cron Triggers is using Wrangler.

Cron Triggers can be tested using Wrangler by passing in the `--test-scheduled` flag to [wrangler dev](https://developers.cloudflare.com/workers/wrangler/commands/general/#dev). This will expose a `/__scheduled` (or `/cdn-cgi/handler/scheduled` for Python Workers) route which can be used to test using a HTTP request. To simulate different cron patterns, a `cron` query parameter can be passed in.

Terminal window

```
npx wrangler dev --test-scheduled
curl "http://localhost:8787/__scheduled?cron=0+*+*+*+*"
curl "http://localhost:8787/cdn-cgi/handler/scheduled?cron=*+*+*+*+*" # Python Workers
```

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