ONCE

ONCE is an open source platform dedicated to temporary sharing of links and private information.

It comes from a simple idea: not everything we share needs to remain accessible forever. For this reason, ONCE offers tools that allow setting precise limits on content availability, without requiring accounts, registrations, or complex configurations.

LINK allows you to create temporary URLs that automatically redirect to a destination chosen by the user.

Each link is identified by a unique slug and can be configured by defining a maximum number of visits and a time expiration. When a recipient opens the link, the system verifies that it is still valid and, if so, immediately redirects them to the original destination. Once the visit limit is reached or the expiration has passed, the link becomes unusable.

Access management takes place through PostgreSQL and atomic functions that prevent simultaneous requests from exceeding the allowed number of uses. In this way, even in the presence of multiple concurrent openings, the configured limit is respected.

SECRETS is the tool dedicated to sharing private messages through an end-to-end encryption system.

The message is encrypted directly in the browser before being sent to the server, using AES-256-GCM. When a password is set, key derivation combines PBKDF2 and HKDF. The database stores exclusively the encrypted content and the metadata required for its management.

The recipient can request to view the message only once. The server verifies the availability of the secret and atomically records its consumption before returning the encrypted content, which is decrypted locally in the browser. It is also possible to add password protection and a time expiration.

The goal is to ensure that the server can manage and distribute messages without having access to their original content.