---
title: "How to trigger an Airflow DAG from another DAG"
description: "How to trigger another DAG from an Airflow DAG"
author: "Bartosz Mikulski"
author_bio: "Principal AI Engineer & MLOps Architect. I bridge the gap between \"it works in a notebook\" and \"it works for 200 million users.\""
author_url: https://mikulskibartosz.name
author_linkedin: https://www.linkedin.com/in/mikulskibartosz/
author_github: https://github.com/mikulskibartosz
canonical_url: https://mikulskibartosz.name/trigger-an-airflow-dag-from-another-dag
---

I wondered how to use the `TriggerDagRunOperator` operator since I learned that it exists. I had a few ideas.

There is a concept of SubDAGs in Airflow, so extracting a part of the DAG to another and triggering it using the `TriggerDagRunOperator` does not look like a correct usage.

The next idea was using it to trigger a compensation action in case of a DAG failure. We can use the `BranchPythonOperator` to define two code execution paths, choose the first one during regular operation, and the other path in case of an error. In the other branch, we can trigger another DAG using the trigger operator. However, that does not make any sense either. I could put all of the compensation tasks in the other code branch and not bother using the trigger operator and defining a separate DAG.

On the other hand, if I had a few DAGs that require the same compensation actions in case of failures, I could extract the common code to a separate DAG and add only the `BranchPythonOperator` and the `TriggerDagRunOperator` to all of the DAGs that must fix something in a case of a failure.

The next idea I had was extracting an expansive computation that does not need to run every time to a separate DAG and trigger it only when necessary. For example, when the input data contains some values.

Still, all of those ideas a little bit exaggerated and overstretched. Perhaps, most of the time, the `TriggerDagRunOperator` is just overkill.

## Usage

The usage of `TriggerDagRunOperator` is quite simple. All we need is this code:

```python
trigger = TriggerDagRunOperator(
    task_id="trigger_id",
    trigger_dag_id="the_id_of_another_dag",
    dag=dag,
)
```