See also: UI guide · Sessions · Backends · How-to: Set up an AI team
Sessions open in the same IDE can message each other. One assistant can delegate work to others, review their results and be told when a peer has gone quiet. Settings covers the default communication permissions.
In ⚙ > Session Configuration > MCP Tools, enable the Peer messaging group. Its Peer Messaging Config contains Allow inter-AI communication, Auto-notify on incoming messages, and Allow important messages, interrupt this session. The first setting is required; the latter two use the defaults in Settings. The Idle watchers group has an Idle Watchers Config containing Allow idle AI watcher timer, which enables notices when a peer has been idle for a while.
Every messaging and idle-watcher tool is in the MCP tool reference. How long inbox entries are kept is an Infrastructure setting (Settings).
An ordinary message waits in the inbox until the recipient finishes its turn. With automatic notices on, the recipient is then told it has mail.
An important message is delivered sooner, but only if the recipient allows important messages and its backend can take a message while it is working. Otherwise it waits like any other. The peer-list tool says which backends deliver early, so a sender can see whether marking a message important will help.
| Backend | Important message while busy |
|---|---|
| GitHub Copilot | Sent into the running turn and read without stopping it |
| Codex | Delivered into the running turn without stopping it |
| OpenAI Compatible | Read while it is running a turn, without stopping it |
| Pi | Read after the current tool calls finish, without interrupting the work |
| Claude | The turn is interrupted as the Stop button does, and any running tool call is cancelled. The plugin then explains that mail, not you, cut it short |
| Grok | The turn is interrupted and any running tool call is cancelled; the plugin then explains that mail cut it short |
| OpenCode | Read mid-turn without stopping it when the agent supports steering; otherwise interrupted like Grok |
A common arrangement is a Coordinator that delegates, CoderPeer sessions that do the work and a ReviewerPeer that reviews it. The plugin ships matching config and instruction templates; Templates lists the settings each one turns on.