Amazon CodeCatalyst is no longer open to new customers. Existing customers can continue to use the service as normal. For more information, see [How to migrate from CodeCatalyst](migration.md).

# Determining which predefined variables your workflow emits
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Use the following procedure to determine which predefined variables a workflow emits when it runs. You can then reference these variables within the same workflow. 

For more information about predefined variables, see [Using predefined variables](workflows-using-predefined-variables.md).

**To determine the predefined variables that your workflow emits**
+ Do one of the following:
  + **Run the workflow once**. After the run finishes, the variables emitted by the workflow are displayed on the **Variables** tab of the run details page. For more information, see [Viewing workflow run status and details](workflows-view-run.md).
  + **Consult the [List of predefined variables](workflow-ref-action-variables.md)**. This reference lists the variable name (key) and value for each predefined variable.

**Note**  
The maximum total size of a workflow's variables is listed in [Quotas for workflows in CodeCatalyst](workflows-quotas.md). If the total size exceeds the maximum, the action that occurs after the maximum is reached may fail.