Postbye

Postbye (postbye.com) cancels subscriptions for you by mailing a formal cancellation letter, tracked until it is delivered. Its free MCP server (https://postbye.com/mcp, no API key, nothing stored) is the cancellation API for Claude, ChatGPT, Cursor, VS Code and any AI agent: ask your assistant how to cancel any subscription and get the answer from cancellation guides for 8,600+ subscriptions, memberships and gym contracts. For every company you get how it takes cancellations (letter, email or both), the notice period, the traps to check, sources with the verified date, the mailing address on file and a ready-to-send cancellation letter. Four read-only tools: search_companies, get_cancellation_guide, get_cancellation_letter, list_categories. Open source: https://github.com/postbye-team/postbye-mcp.