---
sourceDocument: Australia API Reference
sourceDocumentLink: https://servicenow-prod.fluidtopics.net/r/api-reference

 Release :

    - australia

ft:locale :

    - en-US

ft:publication_title :

    - Australia API Reference

ft:clusterId :

    - crapiref

bundleId :

    - crapiref

workflow :

    - Creator


---

# Generate variables

# Generate REST message variables {#ariaid-title1}

Release version: Australia  
Updated March 12, 2026  
![](https://www.servicenow.com/docs/portal-asset/ico-clock) 1 minute to read  
Populate the list of variable substitutions automatically based on variables defined in several REST message HTTP method fields.

## Before you begin

Before starting this procedure, create a REST Message record with at least one HTTP method that uses variables.

Role required: web_service_admin

## Procedure

1. Navigate to AllSystem Web ServicesREST Message.
2. Select a REST Message record.
3. Select a method from the HTTP Methods related list.
4. Click the Auto-generate variables related link.  
   The Variable Substitutions related list is automatically populated for any variables defined in the HTTP Method Endpoint field and the HTTP Headers and HTTP Query Parameters embedded lists. For POST and PUT messages, variables defined in the Content field are also used.
{#t_GenerateMessageVariables__steps_gyf_bfd_cs}

## What to do next

You can use the REST Message workflow activity to send the message, or click Preview Script Usage to get a sample script. The sample script includes a setStringParameter call for each defined variable substitution that allows you to assign a value to the variable in your script.

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