Min, a newcomer to the Hacker News scene from Bangkok, has launched Flashpaper, a tool for self-destructing secret sharing. Inspired by spy movies and a desire for a dead man's switch, Flashpaper allows users to send information that is "burned after reading." Messages can be set to expire after a countdown timer, or a maximum of 24 hours if not opened.

Encryption occurs in the browser, with the key remaining in the URL fragment, ensuring the server never sees it. This provides a zero-knowledge approach for web users. To keep the service light and simple, Flashpaper operates in RAM-only, eschewing a database. This design choice was also motivated by a lack of funds for database maintenance.

For AI agents, Flashpaper offers a REST API and an MCP server for dead-drop style secret links that can only be claimed once. Subsequent claims result in a 404 error. However, this API flow is not zero-knowledge as the server briefly handles plaintext before encryption. Min acknowledges potential security concerns for the agent API and has detailed limitations in a SECURITY.md file. The project is open-source under the MIT license, with an honorware policy for enterprise use, such as self-hosted Docker instances. The repository can be found on GitHub, and a live demo is available at flashpaper.app.