> ## Documentation Index
> Fetch the complete documentation index at: https://documentation.uponai.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Check Actual Latency

> Monitor per-call latency metrics from the dashboard or via the API.

Monitor the latency of individual calls in the **Call History** section of the dashboard.

## Understanding Latency Metrics

**End-to-end latency** measures total time from when the user stops speaking until the agent begins responding — including processing time, network delays, and model inference.

| Metric           | Description                                     |
| ---------------- | ----------------------------------------------- |
| **P90**          | 90% of calls have latency below this value      |
| **Median (P50)** | Half of all calls have latency below this value |
| **Min**          | Fastest response time achieved                  |

## Retrieve Latency via API

Use the Get Call API to retrieve detailed latency breakdowns after a call ends:

```bash theme={null}
curl -X GET "https://api.uponai.com/v2/get-call/CALL_ID" \
  -H "Authorization: Bearer YOUR_API_KEY"
```

## Latency Breakdown Fields

| Field                       | Description                                                                                           |
| --------------------------- | ----------------------------------------------------------------------------------------------------- |
| `e2e`                       | End-to-end: user stops talking → agent starts talking (excludes network trip to frontend)             |
| `asr`                       | Transcription latency                                                                                 |
| `llm`                       | LLM latency: start of LLM call → first speakable chunk. Includes websocket roundtrip for custom LLMs. |
| `llm_websocket_network_rtt` | Websocket roundtrip between your server and UponAI. Custom LLM only.                                  |
| `tts`                       | Text-to-speech: trigger → first audio byte                                                            |
| `knowledge_base`            | Knowledge base retrieval latency. Only when agent uses knowledge base.                                |
| `s2s`                       | Speech-to-speech: request → first byte. Only for S2S models.                                          |

Each component includes: `p50`, `p90`, `p95`, `p99`, `min`, `max`, `num`, `values`.

## Example Response

```json theme={null}
{
  "latency": {
    "e2e": {
      "p50": 800,
      "p90": 1200,
      "p95": 1500,
      "p99": 2500,
      "min": 500,
      "max": 2700,
      "num": 10,
      "values": [500, 620, 780, 800, 850, 900, 1100, 1200, 1500, 2700]
    },
    "llm": {
      "p50": 400,
      "p90": 650,
      "p95": 800,
      "p99": 1200,
      "min": 250,
      "max": 1300,
      "num": 10,
      "values": [250, 310, 380, 400, 420, 500, 600, 650, 800, 1300]
    },
    "tts": {
      "p50": 150,
      "p90": 250,
      "p95": 300,
      "p99": 400,
      "min": 80,
      "max": 420,
      "num": 10,
      "values": [80, 100, 130, 160, 200, 230, 250, 300, 420]
    }
  }
}
```