In Freenet, Delegates act like advanced representatives, similar to a human delegate, performing actions on Freenet on your behalf. Think of them as a more sophisticated version of a web browser's local storage, with similarities to Unix "Daemons". Operating within the Freenet kernel on your device, Delegates are a secure and flexible mechanism for managing private data, such as cryptographic keys, tokens, and passwords, and executing complex tasks.
Delegates interact with various components within Freenet, including Contracts, User Interfaces, and other Delegates. They can also communicate directly with the user, such as to request user permissions or notify the user of events.
Implemented in WebAssembly and adhering to the DelegateInterface trait, Delegates seamlessly integrate within the Freenet network, operating securely on your devices.
Delegates utilize a message passing system similar to the actor model to interact with Contracts, other Delegates, and Applications.
The Freenet kernel makes sure that for any incoming message, whether it's from another Delegate, a User Interface, or a Contract update, the receiver knows who the sender is. This allows delegates to verify the behavior of any component they interact with, and decide if they can be trusted.
Delegates have a wide variety of uses:
A key manager delegate manages a user's private keys. Other components can request that this Delegate sign messages or other data on their behalf.
An inbox delegate maintains an inbox of messages sent to the user in an email-like system. It retrieves messages from an inbox Contract, decrypts them, and stores them locally where they can be accessed by other components like a user interface.
A contacts delegate manages a user's contacts. It can store and retrieve contact information, and can be used by other components to send messages to contacts.
An alerts delegate watches for events on the network, such as a mention of the user's name in a discussion, and notifies the user of these events via an alert.
Moreover, Delegates can securely synchronize with identical Delegate instances running on other devices controlled by the user, such as a laptop, phone, or desktop PC. This synchronization, facilitated through a shared secret private key provided by the user, allows the Delegates to communicate securely, acting as both backups and replicas of each other through Freenet's peer-to-peer network.
Delegates have much in common with Service Workers in the web browser ecosystem. Both are self-contained software modules, running independently of the user interface and performing complex tasks on behalf of the user.
However, Delegates are even more powerful. While Service Workers can store data and interact with components within the scope of the web browser and its pages, Delegates can talk to other Delegates in the same device, or with other Delegates running elsewhere via Freenet's peer-to-peer network.