Create Phone Call

Authentication header containing API key (find it in dashboard). The format is "Bearer YOUR_API_KEY"

The number you own in E.164 format. Must be a Retell managed number.

The number you want to call, in E.164 format. Right now only US numbers are officially supported.

For this particular call, override the agent used with this agent id. This does not bind the agent to this number, this is for one time override.

An arbitrary object for storage purpose only. You can put anything here like your internal customer id associated with the call. Not used for processing. You can later get this field from the call object.

Add optional dynamic variables in key value pairs of string that injects into your Retell LLM prompt and tool description. Only applicable for Retell LLM.

Type of the call. Used to distinguish between web call and phone call.

The caller number.

The callee number.

Direction of the phone call.

Unique id of the call. Used to identify in LLM websocket and used to authenticate in audio websocket.

Corresponding agent id of this call.

Status of call.

• registered: Call id issued, starting to make a call using this id.

• ongoing: Call connected and ongoing.

• ended: The underlying websocket has ended for the call. Either user or agent hanged up, or call transferred.

• error: Call encountered error.

An arbitrary object for storage purpose only. You can put anything here like your internal customer id associated with the call. Not used for processing. You can later get this field from the call object.

Add optional dynamic variables in key value pairs of string that injects into your Retell LLM prompt and tool description. Only applicable for Retell LLM.

Whether this call opts out of sensitive data storage like transcript, recording, logging.

Begin timestamp (milliseconds since epoch) of the call. Available after call starts.

End timestamp (milliseconds since epoch) of the call. Available after call ends.

Transcription of the call. Available after call ends.

Transcript of the call in the format of a list of utterance, with timestamp. Available after call ends.

Transcript of the call weaved with tool call invocation and results. It precisely captures when (at what utterance, which word) the tool was invoked and what was the result. Available after call ends.

Recording of the call. Available after call ends.

Public log of the call, containing details about all the requests and responses received in LLM WebSocket, latency tracking for each turntaking, helpful for debugging and tracing. Available after call ends.

End to end latency (from user stops talking to agent start talking) tracking of the call, available after call ends. This latency does not account for the network trip time from Retell server to user frontend. The latency is tracked every time turn change between user and agent.

LLM latency (from issue of LLM call to first token received) tracking of the call, available after call ends. When using custom LLM. this latency includes LLM websocket roundtrip time between user server and Retell server.

LLM websocket roundtrip latency (between user server and Retell server) tracking of the call, available after call ends. Only populated for calls using custom LLM.

The reason for the disconnection of the call. Read details desciption about reasons listed here at Disconnection Reason Doc.

Post call analysis that includes information such as sentiment, status, summary, and custom defined data to extract. Available after call ends. Subscribe to call_analyzed webhook event type to receive it once ready.