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

# Update Span

> Complete a span with output and metrics

Update a span with its output, timing, and metrics after the operation completes.

<ParamField path="span_id" type="string" required>
  Span identifier
</ParamField>

<ParamField body="output" type="object" required>
  Span output data

  <Expandable title="properties">
    <ParamField body="content" type="string">
      For LLM spans: response content
    </ParamField>

    <ParamField body="tool_calls" type="array">
      For LLM spans: tool calls made
    </ParamField>

    <ParamField body="documents" type="array">
      For retrieval spans: retrieved documents
    </ParamField>

    <ParamField body="result" type="any">
      For tool spans: tool result
    </ParamField>
  </Expandable>
</ParamField>

<ParamField body="end_time" type="string" required>
  ISO 8601 timestamp when span completed
</ParamField>

<ParamField body="tokens_input" type="integer">
  Input tokens used (LLM spans)
</ParamField>

<ParamField body="tokens_output" type="integer">
  Output tokens generated (LLM spans)
</ParamField>

<ParamField body="cost_usd" type="number">
  Estimated cost in USD
</ParamField>

<ParamField body="status" type="string" required>
  Span status: `completed` or `error`
</ParamField>

<ParamField body="error_message" type="string">
  Error message if status is `error`
</ParamField>

<ResponseField name="span_id" type="string" required>
  Updated span identifier
</ResponseField>

<ResponseField name="duration_ms" type="integer" required>
  Calculated duration in milliseconds
</ResponseField>

<RequestExample>
  ```bash cURL theme={null}
  curl -X PATCH https://api.playgent.com/v1/spans/span_mno345 \
    -H "Authorization: Bearer your-api-key" \
    -H "Content-Type: application/json" \
    -d '{
      "output": {
        "content": "Our refund policy allows returns within 30 days...",
        "tool_calls": []
      },
      "end_time": "2024-12-16T10:00:02.456Z",
      "tokens_input": 234,
      "tokens_output": 156,
      "cost_usd": 0.0089,
      "status": "completed"
    }'
  ```
</RequestExample>

<ResponseExample>
  ```json Response theme={null}
  {
    "span_id": "span_mno345",
    "duration_ms": 2333
  }
  ```
</ResponseExample>