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x/async

Overview​

The IAsync.sol precompile enables EVM smart contracts to interact with the x/async module.

In this article, you'll find a full list of available methods, allowing you to query and manage the following components:

To learn how to use this precompile, refer to the following guides:

Code

You can find the x/async precompile code on GitHub: IAsync.sol

Precompile address​

To reference the IAsync precompile in your code, use the following precompile address:

0x0000000000000000000000000000000000000903

Tasks​

Create a new Task​

  • Method: addTask()
  • Description: Creates a Task. Emits the CreateTask event.
  • Code: 
    function addTask(
        string calldata plugin,
        bytes calldata input,
        address callback
    ) external returns (uint64 taskId);
  • Parameters: 
    @param plugin The unique name of the plugin
    @param input The plugin's input
    @param callback The address of callback contract
    Notes
    • The following Plugin types are currently available: pricepred, http. To learn more, see x/async: AVR Plugins.
    • The callback parameter is optional. The callback contract must have a cb() function, allowing it to be invoked once the Task is ready.
  • Output: 
    @return taskId The id of the task
  • Usage example: Create a new Task

Query Tasks​

  • Method: tasks()
  • Description: Returns a list of all Tasks in all states (including pending ones). See the TasksResponse struct.
  • Code: 
    function tasks(
        Types.PageRequest calldata pagination,
        address creator
    ) external view returns (TasksResponse memory response);
  • Parameters: 
    @param pagination The pagination details
    @param creator Optional creator address filter
  • Output: 
    @return response The paged tasks
  • Usage example: Query Tasks

Query pending Tasks​

  • Method: pendingTasks()
  • Description: Returns a list of all pending Tasks. See the PendingTasksResponse struct.
  • Code: 
    function pendingTasks(
        Types.PageRequest calldata pagination
    ) external view returns (PendingTasksResponse memory response);
  • Parameters: 
    @param pagination The pagination details
  • Output: 
    @return response The paged tasks
  • Usage example: Query pending Tasks

Query a Task by ID​

  • Method: taskById()
  • Description: Returns a Task by ID (pending Tasks included). See the TaskByIdResponse struct.
  • Code: 
    function taskById(
        uint64 taskId
    ) external view returns (TaskByIdResponse memory response);
  • Parameters: 
    @param taskId The task id
  • Output: 
    @return response The task response
  • Usage example: Query a Task by ID

Plugins​

Query Plugins​

  • Method: plugins()
  • Description: Returns a list of all available Plugins. See the PluginsResponse struct.
  • Code: 
    function plugins(
        Types.PageRequest calldata pagination
    ) external view returns (PluginsResponse memory response);
  • Parameters: 
    @dev Defines a method to query available plugins.
    @param pagination The pagination details
  • Output: 
    @return response The paged plugins
  • Usage example: Query Plugins

Structs​

Task​

  • Description: A struct representing a Task.
  • Code: 
    struct Task {
        uint64 id;
        address creator;
        string plugin;
        bytes input;
    }

TaskVote​

  • Description: A struct representing a vote on the results of a Task. Includes the TaskVoteType enum.
  • Code: 
    struct TaskVote {
        uint64 taskId;
        bytes Voter;
        TaskVoteType vote;
    }

TaskResult​

  • Description: A struct representing the result of a Task.
  • Code: 
    struct TaskResult {
        uint64 id;
        bytes output;
        bytes submitter;
    }

TaskResponse​

  • Description: A struct representing a Task and its data. Includes the Task, TaskVote, and TaskResult structs.
  • Code: 
    struct TaskResponse {
        Task task;
        TaskVote[] votes;
        TaskResult result;
    }

TasksResponse​

  • Description: A response returned when you query Tasks. Includes the TaskResponse struct.
  • Code: 
    struct TasksResponse {
        Types.PageResponse pagination;
        TaskResponse[] tasks;
    }

PendingTasksResponse​

  • Description: A response returned when you query pending Task. Includes the Task struct.
  • Code: 
    struct PendingTasksResponse {
        Types.PageResponse pagination;
        Task[] tasks;
    }

TaskByIdResponse​

Plugin​

  • Description: A struct representing a Plugin.
  • Code: 
    struct Plugin {
      string id;
      address creator;
      string description;
    }

PluginsResponse​

  • Description: A response returned when you query Plugins. Includes the Plugin struct.
  • Code: 
    struct PluginsResponse {
      Types.PageResponse pagination;
      Plugin[] plugins;
    }

Enums​

TaskVoteType​

  • Description: The Task vote type.
  • Code: 
    enum TaskVoteType {
       Unspecified,
       Verified,
       Rejected
    }

Events​

CreateTask​

  • Description: An event emitted when a Task is created.
  • Code: 
    event CreateTask(
        uint64 indexed taskId,
        address indexed creator,
        string plugin,
        address callbackAddress
    );
  • Parameters: 
    @param creator The address of the creator
    @param taskId The task Id
    @param plugin The name of the plugin
    @param callbackAddress The address of callback contract