This is a very useful trick, but since the June update you can also use the “function calling” feature to extract structured data. I converted the example in the blog post (I used GPT-4 to convert the TypeScript type into a JSON schema):

curl https://api.openai.com/v1/chat/completions -u :$OPENAI_API_KEY -H 'Content-Type: application/json' -d '{
  "model": "gpt-3.5-turbo-0613",
  "messages": [
    {"role": "user", "content": "A user has performed the following searches and visited the following sites recently: weather in New York, NYC weather, NYC chance of rain today, is New York a rainy city (They may or may not have changed goals half way through this session.)"}
  ],
  "functions": [
    {
      "name": "report_browsing_goal_analysis",
      "description": "Reports the analysis the users recent browsing activity",
      "parameters": {
        "type": "object",
        "properties": {
            "goal": {
                "type": "string",
                "description": "The users consistent recent browsing goal"
            },
            "confidence": {
                "type": "string",
                "description": "How confident the analysis engine is in this goal",
                "enum": ["very low", "low", "med", "high", "very high"]
            },
            "switched": {
                "type": "boolean",
                "description": "Whether or not the user seems to have switched goals recently"
            },
            "advice": {
                "type": "array",
                "description": "An array of up to 3 creative, specific, non-obvious ways the system recommends for the user to meet their current goal. (Do not return generic suggestions like subscribe to a newsletter or do a Google search, instead recommend specific actions that the user should consider.)",
                "items": {
                    "type": "object",
                    "properties": {
                        "text": {
                            "type": "string"
                        },
                        "probabilityOfBeingUseful": {
                            "type": "string",
                            "enum": ["very low", "low", "med", "high", "very high"]
                        },
                        "creativity": {
                            "type": "string",
                            "enum": ["very low", "low", "med", "high", "very high"]
                        },
                        "funLevel": {
                            "type": "string",
                            "enum": ["very low", "low", "med", "high", "very high"]
                        }
                    },
                    "required": ["text", "probabilityOfBeingUseful", "creativity", "funLevel"]
                },
                "maxItems": 3
            }
        },
        "required": ["goal", "confidence", "switched", "advice"]
    }
    }
  ]
}'

This is what the API returned:

{
  "id": "chatcmpl-7Xd4BPsW9QBuk46BJRZRCNoFpJtV9",
  "object": "chat.completion",
  "created": 1688249351,
  "model": "gpt-3.5-turbo-0613",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": null,
        "function_call": {
          "name": "report_browsing_goal_analysis",
          "arguments": "{\n  \"goal\": \"weather in New York\",\n  \"confidence\": \"high\",\n  \"switched\": false,\n  \"advice\": [\n    {\n      \"text\": \"Check the hourly weather forecast for New York to plan your activities.\",\n      \"probabilityOfBeingUseful\": \"high\",\n      \"creativity\": \"high\",\n      \"funLevel\": \"low\"\n    },\n    {\n      \"text\": \"Subscribe to a weather alert service to stay updated on the weather in New York.\",\n      \"probabilityOfBeingUseful\": \"medium\",\n      \"creativity\": \"medium\",\n      \"funLevel\": \"low\"\n    },\n    {\n      \"text\": \"Join a local weather enthusiasts group to discuss weather patterns in New York.\",\n      \"probabilityOfBeingUseful\": \"low\",\n      \"creativity\": \"high\",\n      \"funLevel\": \"high\"\n    }\n  ]\n}"
        }
      },
      "finish_reason": "function_call"
    }
  ],
  "usage": {
    "prompt_tokens": 303,
    "completion_tokens": 194,
    "total_tokens": 497
  }
}

Here is just the JSON result extracted:

{
  "goal": "weather in New York",
  "confidence": "high",
  "switched": false,
  "advice": [
    {
      "text": "Check the hourly weather forecast for New York to plan your activities.",
      "probabilityOfBeingUseful": "high",
      "creativity": "high",
      "funLevel": "low"
    },
    {
      "text": "Subscribe to a weather alert service to stay updated on the weather in New York.",
      "probabilityOfBeingUseful": "medium",
      "creativity": "medium",
      "funLevel": "low"
    },
    {
      "text": "Join a local weather enthusiasts group to discuss weather patterns in New York.",
      "probabilityOfBeingUseful": "low",
      "creativity": "high",
      "funLevel": "high"
    }
  ]
}

Pretty cool, isn’t it?

(BTW this was GPT-3.5)