example

UCAN examples

This directory contains an example of UCAN usage across multiple agents, and their respective implementations.

Please note that UCAN in itself doesn't enforce any protocol, topology or transport, and as such what you have here is one possibility among many others. In particular:

• this example is really geared towards using UCAN for an HTTP API
• it uses a particular flavor of issuer protocol and token exchange. In particular, that issuer gives delegation tokens to anyone asking.

Your situation may be different from this, and would call for a different setup.

Remember that everything in /toolkit is essentially helpers, pre-made building blocks. You can use them, change them or make your own.

Scenario 1

Starting simple, if we run service, service-issuer and alice-client-server, we have the following scenario:

• service controls the access to the resource (it's the Executor in that diagram). You can think about it as a proxy with authentication.
• service-issuer gives a delegation tokens to clients. service and service-issuer share the same DID and keypair.
• alice-client-server ask for a token, and periodically makes request

Scenario 2

Building on the previous scenario, we are adding sub-delegation.

• alice-client-server still do the same thing, but also expose a similar token issuer with the same protocol (for simplicity in that example)
• bob-client request a delegation from Alice, and make direct request to the service

Note a few things:

• Alice can finely tune what Bob can do
• Bob receives two delegations: the original one Alice got and a second one delegating some of that original power to him
• Bob can make direct calls to the service without having to be proxied somewhere
• The service doesn't have to know beforehand about Bob or what power is given to him