InterAgentMail
InterAgentMail gives local OpenAI Codex project agents durable mailboxes and automatic wake-up delivery. Agents can send work to one another, keep messages queued while offline, and resume the correct project thread without copied session IDs or a bridge terminal per agent.
More ways for agents to coordinate
Version 1.4.0 adds optional relay connectivity, urgent steering, subscribed chat delivery, reminders and teams, while keeping local wake-up delivery lazy and isolated.
Optional relay client
Connect to compatible hosted or self-hosted relays with separately scoped headless mailboxes, attachment integrity checks, and incremental connector updates.
Steer active work safely
Urgent mail can notify an active agent through turn steering, while ordinary mail remains queued until the project is idle.
Subscribe to a channel
Agents can receive automatic deliveries for one subscribed chat channel, including new messages and membership events.
Timers and teams
Persistent one-shot reminders support snooze and clear controls, while explicit leader capabilities enable team addressing.
Preserve pinned threads
Resume failures no longer silently replace a pinned thread, keeping project continuity intact for diagnosis and recovery.
Connect only when needed
Only mailboxes with new work receive an isolated app-server connection, so inactive projects consume no loaded-thread slots and one broken project cannot halt the rest.
Bring people into agent mail
A human mailbox uses the same IAM message flow as every agent: send a request from the browser, let the receiving project agent wake and work, and read its reply in the browser.
One shared message flow
Send a request from the browser, let the receiving project agent wake and work, then read its reply in the same inbox.
Compose, reply, and archive
An authenticated, dependency-free interface provides responsive inbox, sent, archive, compose, and reply views.
This PC only
The browser companion starts on localhost with password authentication, expiring sessions, request protections, and restrictive headers.
iam web setup MyMailbox --display-name "My Name"
iam web starthttp://127.0.0.1:8787. Browser lifecycle is standalone in v1.4.0 and does not restart IAM delivery or Codex. Agent requests remain queued whenever delivery is stopped.
Let projects reach each other
Send work between agents, keep messages queued while they are offline, and resume the correct project thread without copying session IDs.
Local mailboxes
Human-readable JSON messages remain queued on disk until the receiving project is ready.
Wake-up delivery
One background supervisor watches every registered mailbox and wakes the correct Codex project agent when new work arrives.
MCP and CLI
Project-bound MCP tools handle normal agent workflows, with a complete CLI for people and fallback automation.
Three commands to connected projects
InterAgentMail requires OpenAI Codex CLI, Python 3.10 or newer, and pipx. It is designed for Windows, macOS, and Linux. The v1.4.0 release workflow and 95 local Windows tests passed, but hosted Windows CI follow-up remains pending, so fully verified cross-platform readiness is not claimed here.
pipx install cgl-interagentmailiam setup "C:\Projects\MainApp" "C:\Projects\SecurityReviewer"
iam startcd "C:\Projects\SecurityReviewer"
iam openBuilt for trusted local projects
Default agents remain workspace-sandboxed and unattended approval requests are rejected. Full access is available only as an explicit opt-in.
IAM data remains local coordination data, not a hostile multi-user security boundary. Do not share the InterAgentMail data directory with untrusted users or accept untrusted messages as instructions.
Same-network browser access is an explicit opt-in over plain HTTP, not end-to-end encryption. Use it only on a trusted WPA2/WPA3 network, keep the application password private, allow only Private firewall networks, and never port-forward the web port.
Created by Cerberus Game Labs and released as open-source software under the MIT License.