curl --request POST \
  --url https://api.arize.com/v2/evaluators \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "space_id": "U3BhY2U6NDkzOkJaSkc=",
  "name": "Hallucination Eval",
  "description": "Detects hallucinated content in LLM responses",
  "type": "template",
  "version": {
    "commit_message": "Initial version",
    "template_config": {
      "name": "hallucination",
      "template": "You are an evaluation assistant. Given the following input and output, determine if the output contains hallucinated content.\n\nInput: {{input}}\nOutput: {{output}}\nReference: {{reference}}",
      "include_explanations": true,
      "use_function_calling_if_available": true,
      "classification_choices": {
        "hallucinated": 0,
        "factual": 1
      },
      "direction": "maximize",
      "data_granularity": "span",
      "llm_config": {
        "ai_integration_id": "TGxtSW50ZWdyYXRpb246MTI6YUJjRA==",
        "model_name": "gpt-4o",
        "invocation_parameters": {
          "temperature": 0
        },
        "provider_parameters": {}
      }
    }
  }
}
'

{
  "id": "RXZhbHVhdG9yOjEyOmFCY0Q=",
  "name": "Hallucination Eval",
  "description": "Detects hallucinated content in LLM responses",
  "type": "template",
  "space_id": "U3BhY2U6NDkzOkJaSkc=",
  "created_at": "2026-02-16T22:05:47.900Z",
  "updated_at": "2026-02-16T22:05:48.150Z",
  "created_by_user_id": "VXNlcjoxOm5OYkM=",
  "version": {
    "id": "RXZhbHVhdG9yVmVyc2lvbjoxMDpYeVp3",
    "evaluator_id": "RXZhbHVhdG9yOjEyOmFCY0Q=",
    "commit_hash": "a3b1c9e4f7d2a0518e6c3bb9217f87d1c4e810f2",
    "commit_message": "Initial version",
    "template_config": {
      "name": "hallucination",
      "template": "You are an evaluation assistant...",
      "include_explanations": true,
      "use_function_calling_if_available": true,
      "classification_choices": {
        "hallucinated": 0,
        "factual": 1
      },
      "direction": "maximize",
      "data_granularity": "span",
      "llm_config": {
        "ai_integration_id": "TGxtSW50ZWdyYXRpb246MTI6YUJjRA==",
        "model_name": "gpt-4o",
        "invocation_parameters": {
          "temperature": 0
        },
        "provider_parameters": {}
      }
    },
    "created_at": "2026-02-16T22:05:48.143Z",
    "created_by_user_id": "VXNlcjoxOm5OYkM="
  }
}