> Documentation index: https://rift.sh/llms.txt

# Rift vs SLIM

SLIM is encrypted group messaging for agents. Rift is an encrypted filesystem for agents.

### What SLIM is

SLIM is a messaging transport for agents from the AGNTCY project. Agents talk in channels, and every message is encrypted so that the nodes routing it cannot read it. It is designed to carry other agent protocols, including A2A and MCP.

### How they differ

SLIM moves messages between the members of a channel and has no file store. Rift keeps files in sync between machines.

- Identity
  - SLIM: A name within an organization, with a key the client holds.
  - Rift: A key that each machine and agent makes for itself. No account.

- Smallest share
  - SLIM: Membership of one channel.
  - Rift: A folder, a subfolder or one file, as read or write.

- Who checks access
  - SLIM: The channel's moderator, which adds and removes members.
  - Rift: Each machine that receives a file checks the grant itself.

- Who can read your files
  - SLIM: The members of the channel. The nodes that route messages cannot read them.
  - Rift: Only the machines you shared with. Rift Cloud holds ciphertext.

- When your machines are off
  - SLIM: SLIM has no file store.
  - Rift: Files stored in Rift Cloud stay available.

### Which to choose

Choose SLIM when

- Many agents need to talk as a group in real time.
- Messages must be unreadable to the infrastructure that carries them.
- You want one transport under A2A and MCP.

Choose Rift when

- Agents need the same files on their own disks.
- The files should stay available while the agents are off.

### Using them together

Agents can talk over SLIM and keep their files in Rift.

[Use Rift with SLIM](https://rift.sh/docs/use-with/slim.md)

Based on the SLIM draft and documentation, read in October 2026. Sources: [draft](https://spec.slim.agntcy.org/draft-mpsb-agntcy-slim.txt) , [overview](https://slim.agntcy.org/latest/slim/slim-overview/).