# Function Call Response

Voice Agent

The `FunctionCallResponse` message contains the result of a function call. It is usually sent by the client in response to a `FunctionCallRequest`, but may also be sent by the server if the function was handled internally (When a request contained `client_side: false`).

## Purpose

This message completes a function call flow. It provides the output of the function to the agent, regardless of where it was executed.

- If the [request](/guides/self-hosted-deployments-3-voice-agent-function-call-request) was marked `client_side: true`, the client sends the `FunctionCallResponse`.
- If the request had `client_side: false`, the server sends this message after processing the function.
- Send no response for a call named in a [`FunctionCallCancelled`](/guides/self-hosted-deployments-3-voice-agent-function-call-cancelled). The turn resumed, the call is void, and a late response is dropped.

## Fields

- `type`: Always `"FunctionCallResponse"`.
- `id`: The ID of the original function call (optional but recommended for traceability).
- `name`: The name of the function that was called.
- `content`: A text summary or result of the function's output. This is often passed to the next step in the conversation, or parsed if it contains encoded text (i.e. JSON).

## Example payload

```json
{
  "type": "FunctionCallResponse",
  "id": "fc_12345678-90ab-cdef-1234-567890abcdef",
  "name": "get_weather",
  "content": "{\"location\": \"Fremont, CA 94539\", \"temperature_c\": 21, \"condition\": \"Sunny\", \"humidity\": 40, \"wind_kph\": 14}"
}
```

In this example, the client (or server) returns the result of calling the `get_weather` function.

## Related messages

- [`FunctionCallRequest`](/guides/self-hosted-deployments-3-voice-agent-function-call-request): The message that triggers a function to be called.
- [`FunctionCallCancelled`](/guides/self-hosted-deployments-3-voice-agent-function-call-cancelled): Tells you a request is void and needs no response.

## Related pages

- [Function Calling](./self-hosted-deployments-3-voice-agents-function-calling.md)
- [Build A Function Call](./self-hosted-deployments-3-build-a-function-call.md)
- [Function Call Request](./self-hosted-deployments-3-voice-agent-function-call-request.md)
- [Function Call Context](./self-hosted-deployments-3-voice-agent-function-call-context.md)

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