Transform tool

When to use it

When you need to remap an API response, extract a specific field, format a date, build a message from variables, or clean data before using it.

Steps

1. 1Create a tool → choose type «Transform».
2. 2Define the output: a JSON object with the keys you want to generate.
3. 3In the value of each key, use {{...}} expressions to reference flow variables.
4. 4Save and test with a sample payload to verify the output.

Reference

{{...}} expressions

Access any flow variable. Support dot notation: {{previous_node.data.name}}

Helper functions

Available inside expressions: .toUpperCase(), .toLowerCase(), .trim(), .split(), .join(), .slice(), parseInt(), parseFloat().

Ternary conditional

{{condition ? true_value : false_value}} for simple logic without a condition tool.

Output

The full object the tool returns. Available in downstream nodes as {{node_name.output}}.

Common errors

Variable undefined

The variable you reference doesn't exist in the flow context at that point. Check the name and that the upstream node generates it.

Empty or null output

If the expression fails silently, the field is null. Test the tool with real data to verify.

Next step

Learn Tool Condition to branch the flow based on a condition.