Invoke a deployed Salesforce Agentforce agent from an external system using the Agent API

In-depth guide

Steps

1. Register an external client app in Salesforce Setup with OAuth scopes: chatbot_api, sfap_api, api, and refresh_token; configure the Client Credentials flow for server-to-server calls.
2. Obtain an access token via the OAuth 2.0 client credentials flow: POST to https://<instance>.salesforce.com/services/oauth2/token with grant_type=client_credentials.
3. Start an agent session: POST https://api.salesforce.com/einstein/ai-agent/v1/agents/<agentId>/sessions with a JSON body containing externalSessionKey (a UUID), instanceConfig.endpoint (your org URL), and streamingCapabilities.
4. Send a message to the agent within the session: POST https://api.salesforce.com/einstein/ai-agent/v1/sessions/<sessionId>/messages with body {"message": {"role": "user", "content": [{"type": "text", "text": "<user input>"}]}.
5. Parse the streaming or synchronous response to extract the agent's reply text and any action outputs; handle the sequenceId to maintain conversation order.
6. End the session when the conversation is complete: DELETE https://api.salesforce.com/einstein/ai-agent/v1/sessions/<sessionId>.