Writing tasks: Introduction

Tasks are the core of Trigger.dev. They are long-running processes that are triggered by events.

Before digging deeper into the details of writing tasks, you should read the fundamentals of tasks to understand what tasks are and how they work.

Writing tasks

Topic	Description
Logging	View and send logs and traces from your tasks.
Errors & retrying	How to deal with errors and write reliable tasks.
Wait	Wait for periods of time or for external events to occur before continuing.
Concurrency & Queues	Configure what you want to happen when there is more than one run at a time.
Versioning	How versioning works.
Machines	Configure the CPU and RAM of the machine your task runs on
Idempotency	Protect against mutations happening twice.
Reattempting & Replaying	You can reattempt a task that has failed all of its attempts. You can also replay a task with a new version of your code.
Notifications	Send realtime notifications from your task that you can subscribe to from your backend or frontend.
Rollbacks	Rollback code inside a task when errors happen to provide transactional guarantees.
Using APIs	How to use APIs from within your tasks.
Trigger filters	Prevent unwanted filters where the payload doesn’t match your filter.
Middleware	Middleware can wrap the task run function.
Automated tests	Write automated tests in code.