# Vapi

> Inspect call audio and transcripts alongside the execution that produced them.

Connect Vapi to listen to a call alongside its recorded agent activity. Radiant uses the call ID attached to an operation to retrieve its audio and transcript in the **Recording** tab.

## Connect Vapi

An owner or admin opens **Settings → Integrations**, chooses **Configure** on Vapi, and enters a private Vapi API key with access to the calls to inspect. Radiant encrypts the saved key and does not display it again.

After setup, **Manage** lets you test the connection or replace the key. A failed test keeps the saved key and shows **Disconnected**, so you can retry after resolving access or availability. **Disconnect** removes the key.

## Associate a call with a span

In your application’s instrumentation, record the Vapi call ID as the string attribute `vapi.call.id` on the span representing the call:

```json
{ "vapi.call.id": "00000000-0000-4000-8000-000000000001" }
```

Open that span’s details and select **Recording**. The association is specific to the selected span: an ID on a parent span or in resource attributes does not enable playback for its children.

For the span-attribute API used by your application, follow its [connection guide](/docs/platform/connect-your-agent.md). The [OpenTelemetry attribute example](/docs/platform/connect-your-agent/opentelemetry.md#add-attributes) shows how to set a value on an invocation span.

If Recording is absent, inspect the selected span’s attributes. Update instrumentation to put the string attribute on the call span, then record another call.

## Listen alongside the transcript

Select a transcript message to seek to its timestamp, or seek on the waveform. **Follow playback** keeps the current message visible as the call plays. Playback also supports speed changes and downloading; stereo recordings show separate user and assistant waveforms.

[![Appointment assistant span details with Recording selected, separate user and assistant waveforms, playback controls, and a timestamped four-turn transcript.](/docs/images/platform/vapi-transcript-dark.png)](/docs/images/platform/vapi-transcript-dark.png)

Call recording and synchronized transcript.

A waveform-loading error does not necessarily prevent audio playback, and you can retry the waveform separately. When audio is unavailable, read the transcript. **Open in Vapi** opens the original call, including recordings exceeding Radiant’s playback limit; your browser must be signed into Vapi.

## Resolve a retrieval error

Confirm that the call belongs to the Vapi organization accessible to the saved key. Test the connection under **Settings → Integrations → Vapi → Manage**, and replace the key if its permissions changed. Use **Open in Vapi** to confirm the original call and recording are available.