Variables

Variables enable you to store and reuse non-sensitive bits of data, such as configuration information. They are:

• named, mutable values of any JSON type
• scoped to a self-hosted Prefect server instance or a single workspace in a Prefect Cloud account
• meant for values with infrequent writes and frequent reads (but you can create or modify variables at any time)
• cacheable for quicker retrieval
• most commonly loaded during flow runtime (but you can load them in other contexts to pass configuration information to Prefect configuration files, such as deployment steps)

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Manage variables

Create, read, edit, and delete variables through the Prefect UI, API, and CLI. Names must adhere to these traditional variable naming conventions:

• Have no more than 255 characters
• Only contain lowercase alphanumeric characters ([a-z], [0-9]) or underscores (_). Spaces are not allowed.
• Be unique

Values must have less than or equal to 5000 characters.

Optionally, you can add tags to a variable.

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Through the Prefect UI

View all the variables in your self-hosted Prefect server instance or Prefect Cloud account workspace in the Variables page of the Prefect UI. Both the name and value of all variables are visible to anyone with access to the server or workspace.

To create a new variable:

1. Select the + button next to the header of the Variables page.
2. Enter the name and value of the variable.

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Through the REST API

You can manage variables with the Prefect API.

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Through the CLI

You can manage variables with the Prefect CLI.

• prefect variable set creates or updates a variable.
• prefect variable get retrieves a variable’s value.
• prefect variable unset deletes a variable.
• prefect variable ls lists all variables.
• prefect variable inspect shows a variable’s details.

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Through Terraform

You can manage variables with the Terraform provider for Prefect.