Set Up a Connected App for Headless Identity

A connected app is a framework that allows your off-platform app to request data from Salesforce APIs. To integrate your single-page app with Headless Identity APIs, create a connected app and configure its settings and access policies.
Available in: both Salesforce Classic (not available in all orgs) and Lightning Experience
Available in: Enterprise, Unlimited, and Developer Editions

As part of the connected app setup, you enable the Authorization Code and Credentials Flow. With this flow, you can set up headless login. Enabling this flow is also a prerequisite for enabling headless registration. You also define what Salesforce data your app can access with scopes and configure additional security settings and access policies. And you define a callback URL, which you use as the redirect_uri parameter during headless flows.

After you create a connected app, you get a consumer key, or client_id. During headless flows, your app passes the consumer key to Salesforce to identify itself.