Messaging-Client.md

# Messaging Client

The messaging client is a [BSP client](https://code.briarproject.org/briar/briar-spec/blob/master/protocols/BSP.md) that synchronises private messages between pairs of devices.

### Identifier

The client's identifier is `org.briarproject.briar.messaging`. The major version is 0.

### Groups

The client uses a separate BSP group for communicating with each contact. The [group descriptor](https://code.briarproject.org/briar/briar-spec/blob/master/protocols/BSP.md#23-groups) is a [BDF list](https://code.briarproject.org/briar/briar-spec/blob/master/BDF.md) containing the unique IDs of the contacts' identities, sorted in ascending order as byte strings.

### Message types

**PRIVATE_MESSAGE** - The message body is a BDF list with one element: `text` (string).

### Validity policy

* A private message is valid if it is well-formed.

### Storage policy

* All messages are stored.

### Sharing policy

* All local messages are shared.