Tool

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://raw.githubusercontent.com/api-evangelist/letta/main/json-schema/letta-tool-schema.json",
  "title": "Tool",
  "description": "Representation of a tool, which is a function that can be called by the agent.",
  "properties": {
    "id": {
      "type": "string",
      "pattern": "^tool-[a-fA-F0-9]{8}",
      "title": "Id",
      "description": "The human-friendly ID of the Tool",
      "examples": [
        "tool-123e4567-e89b-12d3-a456-426614174000"
      ]
    },
    "tool_type": {
      "$ref": "#/$defs/ToolType"
    },
    "description": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Description",
      "description": "The description of the tool."
    },
    "source_type": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Source Type",
      "description": "The type of the source code."
    },
    "name": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Name",
      "description": "The name of the function."
    },
    "tags": {
      "items": {
        "type": "string"
      },
      "type": "array",
      "title": "Tags",
      "description": "Metadata tags.",
      "default": []
    },
    "source_code": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Source Code",
      "description": "The source code of the function."
    },
    "json_schema": {
      "anyOf": [
        {
          "additionalProperties": true,
          "type": "object"
        },
        {
          "type": "null"
        }
      ],
      "title": "Json Schema",
      "description": "The JSON schema of the function."
    },
    "args_json_schema": {
      "anyOf": [
        {
          "additionalProperties": true,
          "type": "object"
        },
        {
          "type": "null"
        }
      ],
      "title": "Args Json Schema",
      "description": "The args JSON schema of the function."
    },
    "return_char_limit": {
      "type": "integer",
      "maximum": 1000000,
      "minimum": 1,
      "title": "Return Char Limit",
      "description": "The maximum number of characters in the response.",
      "default": 50000
    },
    "pip_requirements": {
      "anyOf": [
        {
          "items": {
            "$ref": "#/$defs/PipRequirement"
          },
          "type": "array"
        },
        {
          "type": "null"
        }
      ],
      "title": "Pip Requirements",
      "description": "Optional list of pip packages required by this tool."
    },
    "npm_requirements": {
      "anyOf": [
        {
          "items": {
            "$ref": "#/$defs/NpmRequirement"
          },
          "type": "array"
        },
        {
          "type": "null"
        }
      ],
      "title": "Npm Requirements",
      "description": "Optional list of npm packages required by this tool."
    },
    "default_requires_approval": {
      "anyOf": [
        {
          "type": "boolean"
        },
        {
          "type": "null"
        }
      ],
      "title": "Default Requires Approval",
      "description": "Default value for whether or not executing this tool requires approval."
    },
    "enable_parallel_execution": {
      "anyOf": [
        {
          "type": "boolean"
        },
        {
          "type": "null"
        }
      ],
      "title": "Enable Parallel Execution",
      "description": "If set to True, then this tool will potentially be executed concurrently with other tools. Default False.",
      "default": false
    },
    "created_by_id": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Created By Id",
      "description": "The id of the user that made this Tool."
    },
    "last_updated_by_id": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Last Updated By Id",
      "description": "The id of the user that made this Tool."
    },
    "metadata_": {
      "anyOf": [
        {
          "additionalProperties": true,
          "type": "object"
        },
        {
          "type": "null"
        }
      ],
      "title": "Metadata",
      "description": "A dictionary of additional metadata for the tool."
    },
    "project_id": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Project Id",
      "description": "The project id of the tool."
    }
  },
  "additionalProperties": false,
  "type": "object",
  "$defs": {
    "ToolType": {
      "type": "string",
      "enum": [
        "custom",
        "letta_core",
        "letta_memory_core",
        "letta_multi_agent_core",
        "letta_sleeptime_core",
        "letta_voice_sleeptime_core",
        "letta_builtin",
        "letta_files_core",
        "external_langchain",
        "external_composio",
        "external_mcp"
      ],
      "title": "ToolType"
    },
    "PipRequirement": {
      "properties": {
        "name": {
          "type": "string",
          "minLength": 1,
          "title": "Name",
          "description": "Name of the pip package."
        },
        "version": {
          "anyOf": [
            {
              "type": "string"
            },
            {
              "type": "null"
            }
          ],
          "title": "Version",
          "description": "Optional version of the package, following semantic versioning."
        }
      },
      "type": "object",
      "required": [
        "name"
      ],
      "title": "PipRequirement"
    },
    "NpmRequirement": {
      "properties": {
        "name": {
          "type": "string",
          "minLength": 1,
          "title": "Name",
          "description": "Name of the npm package."
        },
        "version": {
          "anyOf": [
            {
              "type": "string"
            },
            {
              "type": "null"
            }
          ],
          "title": "Version",
          "description": "Optional version of the package, following semantic versioning."
        }
      },
      "type": "object",
      "required": [
        "name"
      ],
      "title": "NpmRequirement"
    }
  }
}