curl --request GET \
  --url https://api.agentmark.co/v1/traces/{traceId}/spans/{spanId} \
  --header 'Authorization: Bearer <token>' \
  --header 'X-Agentmark-App-Id: <api-key>'

{
  "data": {
    "input": "<string>",
    "output": "<string>",
    "output_object": "<string>",
    "tool_calls": "<string>"
  }
}