HALO

HALO is identity management for local-first apps. It handles a user’s identity, the devices and credentials that act for it, and who can join a space.

An identity in HALO is a key pair. The client generates it on the device, and no server issues it or holds the private key. The identity signs the user’s changes, and peers check those signatures instead of asking a server who the user is.

HALO is built on Keyhive, a capability-based access control and group encryption system for local-first data. Keyhive records who may do what as signed delegations that every peer can check, and it keeps the keys that encrypt a space for its current members.

The @dxos/halo package

The package has three namespaces:

• Identity creates, reads and recovers the user’s identity, lists its devices, and invites a new device.
• Invitation drives one invitation once it exists: its code, its events, and the step where the guest enters the authorization code.
• Space creates spaces, invites people to them, and manages each member’s role.

Ways to establish an identity on a device

1. Create a new identity from the app.
2. Accept a device invitation from a device that already has the identity.
3. Recover the identity with a recovery code, sometimes called a paper key.
4. Recover the identity with a passkey.

How these pages relate to ECHO

ECHO stores and replicates the data in a space; HALO decides who may join it. The ECHO learning path creates an identity in one line so it can open a space, and its Sharing a space page invites a second person.

The HALO learning path builds an app of its own, a contact book: a name, a few named spaces, the people in them, a second device and a recovery code.