Todoist

Creates tasks in Todoist by translating MCP protocol messages into REST API calls, handling task properties (title, description, due dates, priority, labels, project assignment) through a standardized message-passing interface. Implements bidirectional serialization between MCP's JSON-RPC format and Todoist's REST payload structure, enabling AI agents and tools to create tasks without direct API knowledge.

Retrieves tasks from Todoist with support for filtering by project, label, priority, due date, and completion status through MCP method calls that translate to REST API queries. Implements query parameter construction to leverage Todoist's server-side filtering, returning structured task objects with full metadata for downstream processing by AI agents.

Updates existing tasks in Todoist by accepting MCP method calls with task ID and modified fields (title, description, due date, priority, labels, project assignment), translating them into REST API PATCH/PUT requests. Implements field-level updates so agents can modify specific task properties without overwriting unspecified fields.

Marks tasks as complete or permanently deletes them from Todoist through MCP method calls that invoke REST API endpoints for task state transitions. Implements idempotent operations so repeated completion calls don't cause errors, and provides explicit deletion with confirmation semantics for destructive operations.

Retrieves and manages Todoist projects and sections through MCP, allowing agents to list projects, create new projects, and organize tasks into sections. Translates MCP method calls into REST API operations for project CRUD and section management, enabling hierarchical task organization through the protocol interface.

Manages task labels and metadata through MCP by providing methods to list available labels, create new labels, and assign/remove labels from tasks. Implements label discovery so agents understand available organizational tags, and supports label operations as part of task update workflows.

Handles Todoist API authentication by accepting an API token at MCP server initialization and managing session state server-side, so individual MCP clients never handle credentials directly. Implements token validation and error handling for authentication failures, translating Todoist API auth errors into MCP-compliant error responses.

Implements comprehensive error handling that translates Todoist REST API errors into MCP-compliant JSON-RPC error responses, including rate limiting, invalid parameters, and authentication failures. Maps HTTP status codes and Todoist error messages to standardized MCP error codes and descriptions, ensuring consistent error semantics across all capabilities.

Implements JSON-RPC 2.0 method dispatch that routes incoming MCP requests to appropriate Todoist API handlers based on method name. Uses a registry pattern to map method names (e.g., 'createTask', 'getTask') to handler functions, with parameter validation and type coercion before API calls.