{
  "type": "object",
  "properties": {
    "messages": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "role": {
            "type": "string",
            "enum": ["system", "user", "assistant", "function"],
            "description": "Role of the message sender."
          },
          "content": {
            "type": ["string", "null"],
            "description": "Content of the message, or null if not applicable."
          },
          "name": {
            "type": ["string", "null"],
            "pattern": "^[a-zA-Z0-9_-]{1,64}$",
            "description": "Optional name for the message sender, such as a function name or user name. Must be 1-64 characters and match the pattern a-z, A-Z, 0-9, underscores or dashes."
          },
          "tool_calls": {
            "type": ["array", "null"],
            "items": {
              "type": "object",
              "properties": {
                "tool_name": {
                  "type": "string",
                  "description": "Name of the tool being called."
                },
                "parameters": {
                  "type": "object",
                  "description": "Parameters passed to the tool. The structure depends on the tool."
                }
              },
              "required": ["tool_name", "parameters"]
            },
            "description": "Calls to external tools made by the assistant, or null if none."
          },
          "image_url": {
            "type": ["string", "null"],
            "format": "uri",
            "description": "URL of an image if the message contains one, or null if none."
          }
        },
        "required": ["role"]
      },
      "description": "Array of messages exchanged in the conversation."
    },
    "tools": {
      "type": ["array", "null"],
      "description": "Optional list of tools available for the model to call. Currently, only functions are supported.",
      "items": {
        "type": "object",
        "properties": {
          "type": {
            "type": "string",
            "enum": ["function"],
            "description": "Specifies that the tool is a function."
          },
          "function": {
            "type": "object",
            "properties": {
              "name": {
                "type": "string",
                "pattern": "^[a-zA-Z0-9_-]{1,64}$",
                "description": "Name of the function to be called. Must be 1-64 characters long and match the pattern a-z, A-Z, 0-9, underscores, or dashes."
              },
              "description": {
                "type": ["string", "null"],
                "description": "Optional description of what the function does. Can be null if not provided."
              },
              "parameters": {
                "type": "object",
                "description": "Parameters the function accepts, described as a JSON Schema object."
              },
              "strict": {
                "type": "boolean",
                "default": false,
                "description": "Specifies if strict schema adherence is required for the function call. Default is false."
              }
            },
            "required": ["name"]
          }
        },
        "required": ["type", "function"]
      }
    }
  },
  "required": ["messages"],
  "additionalProperties": false
}