Configuring an HTTP Callout Action

Connect Flow Builder to an HTTP-based API without using code. To establish a connection between the API and Salesforce, you create an external credential and a named credential in Setup. Then, HTTP Callout guides you through describing the functionality of your API and the endpoint that you’re connecting to. Based on the information that you enter, Flow Builder generates an external service with a corresponding invocable action that you can use across Salesforce.

• Guidelines for Authenticating HTTP Callout Actions
  Before you configure an HTTP Callout action within Flow Builder, set up a named credential to authenticate requests to the external system. From Setup, follow these guidelines to create a permission set, auth provider, external credential, and named credential, in that order; then grant users access to the User Credentials object.
• Configure an HTTP Callout Action
  HTTP Callout guides you through entering the details about the HTTP web-based service or REST API endpoint that you're connecting to. After you complete the configuration, you invoke the action in a flow. HTTP Callout assumes that you're familiar with the API that you want to call.
• Manage External Inventory with HTTP Callout Action Example
  This example reviews your store's inventory levels and make an HTTP callout to your supplier's API to place orders when inventory is low.