Overview
The "Request Mapper" node allows users to transform and map input data items by setting or modifying fields according to specified rules. It supports two modes: manual mapping, where fields are edited one by one, and JSON mode, where fields can be set from a JSON object. This node is useful in workflows that require reshaping or enriching data before sending it to other services or nodes.
Common scenarios include:
- Mapping API response fields to a desired format.
- Adding or updating specific fields in each item.
- Filtering or including only certain fields from the input.
- Preparing data for downstream processing or integration.
For example, you might use this node to rename fields, add calculated values, or remove unwanted fields from incoming data.
Properties
| Name | Meaning |
|---|---|
| Mode | Choose between "Manual Mapping" (edit fields individually) or "From JSON" (set fields from a JSON object). |
| Fields to Set | In Manual Mapping mode, specify individual field assignments to set or update on each item. |
| Include Other Input Fields | Whether to include all original input fields along with the newly set fields in the output. |
| Input Fields to Include | When including other input fields, select how to filter them: "All", "Selected" fields, or "All Except" some fields. |
| Fields to Include | Comma-separated list of field names to include if "Selected" option is chosen for input fields inclusion. |
| Fields to Exclude | Comma-separated list of field names to exclude if "All Except" option is chosen for input fields inclusion. |
Output
The node outputs an array of items where each item contains JSON data representing the transformed fields as per the mapping rules. The output JSON includes:
- Fields explicitly set or modified by the user.
- Optionally, other input fields depending on the "Include Other Input Fields" setting and filtering options.
No binary data output is produced by this node.
Dependencies
- No external services or API keys are required.
- The node relies on internal helper modules for execution logic but does not require additional n8n credentials or environment variables.
Troubleshooting
Issue: Output missing expected fields.
- Cause: The "Include Other Input Fields" option may be disabled, or fields are excluded via filters.
- Resolution: Enable "Include Other Input Fields" or adjust the "Input Fields to Include" settings accordingly.
Issue: Fields not updated as expected.
- Cause: Incorrect field names or assignment syntax in "Fields to Set".
- Resolution: Verify field names and ensure correct usage of manual mapping or JSON mode.
Issue: Errors related to JSON parsing when using "From JSON" mode.
- Cause: Malformed JSON input.
- Resolution: Validate JSON syntax before inputting.