Collaboration

Active contributors: ConradIrwin, maxdeviant, mikayla-maki

Purpose

Zed's headline collaboration features: shared projects, calls with audio, persistent channels, presence, and notifications. Two or more users can edit the same files in real time, follow each other's cursors, and talk over LiveKit-powered audio.

Crates

Crate	Role
crates/collab	Backend service (separate binary)
crates/client	High-level client driving collab + cloud
crates/collab_ui	The collab panel, contacts, channels UI
crates/call	Real-time call orchestration
crates/livekit_api, crates/livekit_client	LiveKit SDK integration
crates/channel	Channel model (membership, topics, threads)
crates/notifications	In-app notifications surface
crates/proto	Shared protobuf schema
crates/rpc	Transport / message routing

How it works

sequenceDiagram
    participant A as Zed (User A)
    participant S as collab::Server
    participant B as Zed (User B)
    A->>S: WebSocket connect (auth)
    A->>S: ShareProject(project)
    S->>B: ProjectShared(...)
    B->>S: JoinProject(project_id)
    S-->>B: Project snapshot + worktree state
    A->>S: BufferEdited(...)
    S->>B: BufferEdited(...)
    B->>S: BufferEdited(...)
    S->>A: BufferEdited(...)

Shared projects

Sharing a project sends the worktree, open buffers, language-server state, and presence info to other participants. Edits are CRDT-flavored (replica IDs in crates/text), so concurrent edits merge without conflict.

Calls

Calls are signaled through crates/call and use LiveKit for media. Each call has a room ID minted by collab; clients exchange tokens before connecting to the LiveKit room.

Channels

A channel is a persistent room with members, threads, and a notes document. The state lives server-side in Postgres; clients sync via the same RPC channel as everything else.

Presence

The collab server tracks who is online and what project they're working in. The collab panel renders contacts with status and lets you join their projects (subject to permissions).

Notifications

crates/notifications shows in-app toasts for incoming calls, channel events, and follow requests. Schema in crates/proto.

Entry points for modification

• New RPC message — crates/proto/proto/..., then handlers on both sides.
• Backend behaviour — crates/collab/src/rpc/.
• UI — crates/collab_ui/src/.
• Audio — crates/livekit_client (and crates/audio, crates/denoise, crates/media).

Related pages

• collab — the deployed backend
• RPC — wire format
• Remote development — shares the same RPC plumbing