{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "description": "MCP Tasks Extension Schema. Contains only task-related definitions from the MCP 2025-11-25 specification. Base types (Result, JSONRPCRequest, JSONRPCNotification, etc.) are defined in the core MCP schema.",
  "$comment": "Extension Identifier: io.modelcontextprotocol/tasks. Core MCP types (Result, JSONRPCRequest, etc.) are structurally inlined in this schema for portability. The authoritative definitions are in the core schema at https://github.com/modelcontextprotocol/modelcontextprotocol/tree/main/schema/2025-11-25",
  "$defs": {
    "TaskStatus": {
      "description": "The status of a task.",
      "enum": ["working", "input_required", "completed", "failed", "cancelled"],
      "type": "string"
    },
    "TaskMetadata": {
      "description": "Metadata for augmenting a request with task execution.\nInclude this in the `task` field of the request parameters.",
      "properties": {
        "ttl": {
          "description": "Requested duration in milliseconds to retain task from creation.",
          "type": "integer"
        }
      },
      "type": "object"
    },
    "RelatedTaskMetadata": {
      "description": "Metadata for associating messages with a task.\nInclude this in the `_meta` field under the key `io.modelcontextprotocol/related-task`.",
      "properties": {
        "taskId": {
          "description": "The task identifier this message is associated with.",
          "type": "string"
        }
      },
      "required": ["taskId"],
      "type": "object"
    },
    "Task": {
      "description": "Data associated with a task.",
      "properties": {
        "taskId": {
          "description": "The task identifier.",
          "type": "string"
        },
        "status": {
          "$ref": "#/$defs/TaskStatus",
          "description": "Current task state."
        },
        "statusMessage": {
          "description": "Optional human-readable message describing the current task state.\nThis can provide context for any status, including:\n- Reasons for \"cancelled\" status\n- Summaries for \"completed\" status\n- Diagnostic information for \"failed\" status (e.g., error details, what went wrong)",
          "type": "string"
        },
        "createdAt": {
          "description": "ISO 8601 timestamp when the task was created.",
          "type": "string"
        },
        "lastUpdatedAt": {
          "description": "ISO 8601 timestamp when the task was last updated.",
          "type": "string"
        },
        "ttl": {
          "description": "Actual retention duration from creation in milliseconds, null for unlimited.",
          "type": ["integer", "null"]
        },
        "pollInterval": {
          "description": "Suggested polling interval in milliseconds.",
          "type": "integer"
        }
      },
      "required": ["taskId", "status", "createdAt", "lastUpdatedAt", "ttl"],
      "type": "object"
    },
    "CreateTaskResult": {
      "description": "A response to a task-augmented request.",
      "properties": {
        "_meta": {
          "additionalProperties": {},
          "description": "See the core MCP specification for notes on `_meta` usage.",
          "type": "object"
        },
        "task": {
          "$ref": "#/$defs/Task"
        }
      },
      "required": ["task"],
      "type": "object"
    },
    "TaskAugmentedRequestParams": {
      "description": "Common params for any task-augmented request.",
      "properties": {
        "_meta": {
          "additionalProperties": {},
          "description": "See the core MCP specification for notes on `_meta` usage.",
          "properties": {
            "progressToken": {
              "description": "If specified, the caller is requesting out-of-band progress notifications for this request (as represented by notifications/progress). The value of this parameter is an opaque token that will be attached to any subsequent notifications. The receiver is not obligated to provide these notifications.",
              "type": ["string", "integer"]
            }
          },
          "type": "object"
        },
        "task": {
          "$ref": "#/$defs/TaskMetadata",
          "description": "If specified, the caller is requesting task-augmented execution for this request.\nThe request will return a CreateTaskResult immediately, and the actual result can be retrieved later via tasks/result.\n\nTask augmentation is subject to capability negotiation - receivers MUST declare support for task augmentation of specific request types in their capabilities."
        }
      },
      "type": "object"
    },
    "GetTaskRequest": {
      "description": "A request to retrieve the state of a task.",
      "properties": {
        "id": {
          "description": "A unique identifier for the request.",
          "type": ["string", "integer"]
        },
        "jsonrpc": {
          "const": "2.0",
          "type": "string"
        },
        "method": {
          "const": "tasks/get",
          "type": "string"
        },
        "params": {
          "properties": {
            "taskId": {
              "description": "The task identifier to query.",
              "type": "string"
            }
          },
          "required": ["taskId"],
          "type": "object"
        }
      },
      "required": ["id", "jsonrpc", "method", "params"],
      "type": "object"
    },
    "GetTaskResult": {
      "description": "The response to a tasks/get request.",
      "allOf": [
        {
          "properties": {
            "_meta": {
              "additionalProperties": {},
              "description": "See the core MCP specification for notes on `_meta` usage.",
              "type": "object"
            }
          },
          "type": "object"
        },
        {
          "$ref": "#/$defs/Task"
        }
      ]
    },
    "GetTaskPayloadRequest": {
      "description": "A request to retrieve the result of a completed task.",
      "properties": {
        "id": {
          "description": "A unique identifier for the request.",
          "type": ["string", "integer"]
        },
        "jsonrpc": {
          "const": "2.0",
          "type": "string"
        },
        "method": {
          "const": "tasks/result",
          "type": "string"
        },
        "params": {
          "properties": {
            "taskId": {
              "description": "The task identifier to retrieve results for.",
              "type": "string"
            }
          },
          "required": ["taskId"],
          "type": "object"
        }
      },
      "required": ["id", "jsonrpc", "method", "params"],
      "type": "object"
    },
    "GetTaskPayloadResult": {
      "description": "The response to a tasks/result request.\nThe structure matches the result type of the original request.\nFor example, a tools/call task would return the CallToolResult structure.",
      "additionalProperties": {},
      "properties": {
        "_meta": {
          "additionalProperties": {},
          "description": "See the core MCP specification for notes on `_meta` usage.",
          "type": "object"
        }
      },
      "type": "object"
    },
    "CancelTaskRequest": {
      "description": "A request to cancel a task.",
      "properties": {
        "id": {
          "description": "A unique identifier for the request.",
          "type": ["string", "integer"]
        },
        "jsonrpc": {
          "const": "2.0",
          "type": "string"
        },
        "method": {
          "const": "tasks/cancel",
          "type": "string"
        },
        "params": {
          "properties": {
            "taskId": {
              "description": "The task identifier to cancel.",
              "type": "string"
            }
          },
          "required": ["taskId"],
          "type": "object"
        }
      },
      "required": ["id", "jsonrpc", "method", "params"],
      "type": "object"
    },
    "CancelTaskResult": {
      "description": "The response to a tasks/cancel request.",
      "allOf": [
        {
          "properties": {
            "_meta": {
              "additionalProperties": {},
              "description": "See the core MCP specification for notes on `_meta` usage.",
              "type": "object"
            }
          },
          "type": "object"
        },
        {
          "$ref": "#/$defs/Task"
        }
      ]
    },
    "ListTasksRequest": {
      "description": "A request to retrieve a list of tasks.",
      "properties": {
        "id": {
          "description": "A unique identifier for the request.",
          "type": ["string", "integer"]
        },
        "jsonrpc": {
          "const": "2.0",
          "type": "string"
        },
        "method": {
          "const": "tasks/list",
          "type": "string"
        },
        "params": {
          "properties": {
            "cursor": {
              "description": "An opaque token representing the current pagination position.",
              "type": "string"
            }
          },
          "type": "object"
        }
      },
      "required": ["id", "jsonrpc", "method"],
      "type": "object"
    },
    "ListTasksResult": {
      "description": "The response to a tasks/list request.",
      "properties": {
        "_meta": {
          "additionalProperties": {},
          "description": "See the core MCP specification for notes on `_meta` usage.",
          "type": "object"
        },
        "nextCursor": {
          "description": "An opaque token representing the pagination position after the last returned result.\nIf present, there may be more results available.",
          "type": "string"
        },
        "tasks": {
          "items": {
            "$ref": "#/$defs/Task"
          },
          "type": "array"
        }
      },
      "required": ["tasks"],
      "type": "object"
    },
    "TaskStatusNotificationParams": {
      "description": "Parameters for a `notifications/tasks/status` notification.",
      "allOf": [
        {
          "properties": {
            "_meta": {
              "additionalProperties": {},
              "description": "See the core MCP specification for notes on `_meta` usage.",
              "type": "object"
            }
          },
          "type": "object"
        },
        {
          "$ref": "#/$defs/Task"
        }
      ]
    },
    "TaskStatusNotification": {
      "description": "An optional notification from the receiver to the requestor, informing them that a task's status has changed. Receivers are not required to send these notifications.",
      "properties": {
        "jsonrpc": {
          "const": "2.0",
          "type": "string"
        },
        "method": {
          "const": "notifications/tasks/status",
          "type": "string"
        },
        "params": {
          "$ref": "#/$defs/TaskStatusNotificationParams"
        }
      },
      "required": ["jsonrpc", "method", "params"],
      "type": "object"
    },
    "TaskServerCapabilities": {
      "description": "Task-related server capabilities. Include this in the server's capabilities object during initialization.",
      "properties": {
        "tasks": {
          "properties": {
            "list": {
              "description": "Whether this server supports tasks/list.",
              "type": "object"
            },
            "cancel": {
              "description": "Whether this server supports tasks/cancel.",
              "type": "object"
            },
            "requests": {
              "properties": {
                "tools": {
                  "properties": {
                    "call": {
                      "description": "Whether the server supports task-augmented tools/call requests.",
                      "type": "object"
                    }
                  },
                  "type": "object"
                }
              },
              "type": "object"
            }
          },
          "type": "object"
        }
      },
      "type": "object"
    },
    "TaskClientCapabilities": {
      "description": "Task-related client capabilities. Include this in the client's capabilities object during initialization.",
      "properties": {
        "tasks": {
          "properties": {
            "list": {
              "description": "Whether this client supports tasks/list.",
              "type": "object"
            },
            "cancel": {
              "description": "Whether this client supports tasks/cancel.",
              "type": "object"
            },
            "requests": {
              "properties": {
                "sampling": {
                  "properties": {
                    "createMessage": {
                      "description": "Whether the client supports task-augmented sampling/createMessage requests.",
                      "type": "object"
                    }
                  },
                  "type": "object"
                },
                "elicitation": {
                  "properties": {
                    "create": {
                      "description": "Whether the client supports task-augmented elicitation/create requests.",
                      "type": "object"
                    }
                  },
                  "type": "object"
                }
              },
              "type": "object"
            }
          },
          "type": "object"
        }
      },
      "type": "object"
    },
    "ToolTaskSupport": {
      "description": "Task support declaration for individual tools.\n- \"forbidden\": Tool does not support task-augmented execution (default when absent)\n- \"optional\": Tool may support task-augmented execution\n- \"required\": Tool requires task-augmented execution",
      "enum": ["forbidden", "optional", "required"],
      "type": "string"
    }
  }
}