AgentLine can connect a live caller to the agent's configured owner_phone when a human is needed. This is an owner-only transfer, not a general destination-routing API or a warm handoff with a private briefing. If your requirement is to brief a sales representative before joining the caller, evaluate a platform with an explicit warm-transfer feature.
Configure the destination
Use an owner-controlled E.164 phone number. Set owner_phone on agent creation or update it with PATCH /v1/agents/{id}. Leave transfer_number unset: the service derives it from owner_phone. If supplied, transfer_number must match owner_phone; a different destination is rejected.
In Bash, set AGENTLINE_API_KEY privately and replace AGENT_ID and OWNER_PHONE before running:
curl --fail-with-body -X PATCH https://api.agentline.cloud/v1/agents/AGENT_ID -H "Authorization: Bearer $AGENTLINE_API_KEY" -H "Content-Type: application/json" -d '{"owner_phone":"OWNER_PHONE"}'The API also uses owner_phone for owner-related task behavior. Treat changing it as a routing change and confirm the correct person controls the destination. Read back the agent configuration before testing.
Give the assistant a clear escalation rule
Keep the ordinary support instructions in the full agent prompt. Add a rule such as: answer routine questions from approved information; if the caller asks for a person or the request cannot be handled, connect them to the owner. Tell the caller what is happening before the handoff. Updating system_prompt replaces the previous instructions, so preserve the rest of your prompt.
The hosted voice path handles the transfer signal. Your webhook should not invent a new transfer endpoint or return a caller-selected destination. The owner destination is configured ahead of time. Calls already involving the owner are protected against transferring back to that same person.
Test success and failure separately
- Provision and configure a test agent using the REST walkthrough.
- Call its number from a different phone while the owner is available. Ask to speak with a human and check that the owner receives the call.
- Repeat while the owner does not answer. Confirm the caller hears the failure response rather than a claim that someone has joined.
- Ask an ordinary question that the agent can answer. Confirm it stays in the conversation.
- Inspect the transcript and call status. Keep test observations separate from configuration validation.
These are suggested acceptance tests, not results of a published call benchmark. A configured owner number alone does not guarantee pickup, availability, or a successful bridge.
When a warm transfer is required
Retell documents cold, warm and agentic warm transfers, including recipient briefing options. That is a different workflow from AgentLine's direct owner handoff. Evaluate who receives the call, whether they hear a summary first, and what the caller experiences when nobody answers. For qualification workflows, see AgentLine vs Retell for lead follow-up.
Configuration reviewed against AgentLine API schema and agent skill and AgentLine's owner-transfer implementation.