> ## 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.

# Create Trace

> Start a new trace for agent execution

Start a new trace to capture detailed execution spans. Called by the SDK at agent invocation start.

<ParamField body="agent_id" type="string" required>
  Agent being traced
</ParamField>

<ParamField body="run_id" type="string">
  Link trace to a test run (optional)
</ParamField>

<ParamField body="input" type="object" required>
  Initial input to the agent

  <Expandable title="properties">
    <ParamField body="messages" type="array">
      Input messages
    </ParamField>
  </Expandable>
</ParamField>

<ParamField body="metadata" type="object">
  Additional metadata

  <Expandable title="properties">
    <ParamField body="session_id" type="string">
      Session identifier
    </ParamField>

    <ParamField body="user_id" type="string">
      User identifier
    </ParamField>
  </Expandable>
</ParamField>

<ResponseField name="trace_id" type="string" required>
  Unique trace identifier
</ResponseField>

<ResponseField name="root_span_id" type="string" required>
  Root span identifier for the trace
</ResponseField>

<RequestExample>
  ```bash cURL theme={null}
  curl -X POST https://api.playgent.com/v1/traces \
    -H "Authorization: Bearer your-api-key" \
    -H "Content-Type: application/json" \
    -d '{
      "agent_id": "agent_abc123",
      "run_id": "run_def456",
      "input": {
        "messages": [{ "role": "user", "content": "What is your refund policy?" }]
      },
      "metadata": {
        "session_id": "sess_123",
        "user_id": "user_456"
      }
    }'
  ```
</RequestExample>

<ResponseExample>
  ```json Response theme={null}
  {
    "trace_id": "trace_ghi789",
    "root_span_id": "span_jkl012"
  }
  ```
</ResponseExample>