REST API Developer Guide

Introduction to REST API
Quick Start
Examples
Getting Information About My Organization
Working with Object Metadata
Working with Records
Delete Lightning Experience Event Series
Working with Searches and Queries
Get an Image from a Rich Text Area Field
Insert or Update Blob Data
Get Blob Data
Working with Recently Viewed Information
Managing User Passwords
Working with Approval Processes and Process Rules
Get a List of All Approval Processes
Submit a Record for Approval
Approve a Record
Reject a Record
Bulk Approvals
Get a List of Process Rules
Get a Particular Process Rule
Trigger Process Rules
Using Event Monitoring
Using Composite Resources
Generating an OpenAPI 3.0 Document for sObjects REST API (Beta)
Reference
PDF

Reject a Record

Use the Process Approvals resource to reject a record or a collection of records. Each call takes an array of requests. The current user must be an assigned approver.
Example usage
Example request body reject.json file
Example JSON response body