Retell uses the OAuth 2.0 Client Credentials flow for server-to-server authentication. This means no interactive login is required — Retell authenticates directly using the credentials you provide.
Prerequisites
- A Salesforce edition with API access (Enterprise, Unlimited, Developer, or Performance)
- System Administrator permissions in Salesforce
- A dedicated integration user account (recommended)
Step 1: Create a Connected App
Open App Manager
Log in to Salesforce as an administrator. Click the gear icon in the top-right corner, then select Setup.In the Quick Find box, type External Client App and click on it.
Step 2: Enable OAuth Settings
Enable OAuth
Scroll down to the API (Enable OAuth Settings) section and check Enable OAuth Settings.
Set callback URL
Enter a placeholder Callback URL such as:The Client Credentials flow does not use a callback URL, but the field is required.
Enable Client Credentials Flow
Check Enable Client Credentials Flow. This is the critical setting that allows Retell to authenticate without interactive login.
Select OAuth scopes
Under Selected OAuth Scopes, add the following scopes from the Available list:
- Manage user data via APIs (api) — required for REST API calls
- Perform requests at any time (refresh_token, offline_access)

Step 3: Get Consumer Key and Consumer Secret
View consumer details
After saving, you’ll be taken to the Connected App detail page. Click Consumer Key and Secret.You may be prompted to verify your identity via an email verification code.
Step 4: Configure App Policies
Set the Run-As user
Under the Client Credentials Flow section, select a Run As user. This is the Salesforce user whose permissions the integration will use for all API calls.



