Setting Cron Triggers

JavaScript

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

TypeScript

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

Set Cron Triggers in Wrangler

Refer to 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.toml file:

wrangler.toml

name = "worker"

# ...

[triggers]
crons = ["0 * * * *"]

wrangler.json

{
  "name": "worker",
  "triggers": {
    "crons": [
      "0 * * * *"
    ]
  }
}

You also can set a different Cron Trigger for each environment in your wrangler.toml. You need to put the [triggers] table under your chosen environment. For example:

wrangler.toml

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

wrangler.json

{
  "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. This will expose a /__scheduled route which can be used to test using a HTTP request. To simulate different cron patterns, a cron query parameter can be passed in.

npx wrangler dev --test-scheduled

curl "http://localhost:8787/__scheduled?cron=0+*+*+*+*"

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