{
  "type": "object",
  "properties": {
    "model": {
      "type": "string",
      "description": "Specifies the model to use, e.g., 'openai/gpt-4' or 'meta-llama/llama-2-70b-chat'."
    },
    "messages": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "role": {
            "type": "string",
            "enum": ["user", "assistant", "system", "tool"],
            "description": "Defines who sends the message."
          },
          "content": {
            "type": ["string", "array"],
            "items": {
              "oneOf": [
                {
                  "type": "object",
                  "properties": {
                    "type": { "type": "string", "enum": ["text"] },
                    "text": { "type": "string" }
                  },
                  "required": ["type", "text"]
                },
                {
                  "type": "object",
                  "properties": {
                    "type": { "type": "string", "enum": ["image_url"] },
                    "image_url": {
                      "type": "object",
                      "properties": {
                        "url": { "type": "string", "format": "uri" },
                        "detail": { "type": "string", "default": "auto" }
                      },
                      "required": ["url"]
                    }
                  },
                  "required": ["type", "image_url"]
                }
              ]
            }
          },
          "tool_calls": {
            "type": ["array", "null"],
            "items": {
              "type": "object",
              "properties": {
                "id": { "type": "string" },
                "type": { "type": "string", "enum": ["function"] },
                "function": {
                  "type": "object",
                  "properties": {
                    "name": { "type": "string" },
                    "arguments": { "type": "string", "description": "JSON string of arguments." }
                  },
                  "required": ["name", "arguments"]
                }
              },
              "required": ["id", "type", "function"]
            }
          }
        },
        "required": ["role", "content"]
      }
    },
    "tools": {
      "type": ["array", "null"],
      "items": {
        "type": "object",
        "properties": {
          "type": { "type": "string", "enum": ["function"] },
          "function": {
            "type": "object",
            "properties": {
              "name": { "type": "string" },
              "description": { "type": "string" },
              "parameters": { "type": "object" }
            },
            "required": ["name", "parameters"]
          }
        }
      }
    },
    "route": {
      "type": "string",
      "description": "Specify 'fallback' for fallback models or leave blank for default routing."
    }
  },
  "required": ["messages"]
}