InterAgentMail

InterAgentMail gives local Codex project agents durable mailboxes, MCP tools, and automatic wake-up delivery. Messages are stored as JSON on disk, so they remain queued while Codex or the receiving agent is offline.

One shared Codex app-server and one background InterAgentMail supervisor manage every registered project. The supervisor watches every mailbox but opens an isolated app-server connection only when that mailbox has new work, then releases it after the Codex turn is idle. Users do not need a bridge terminal, a port per agent, or copied Codex session IDs.

Requirements

• Python 3.10 or newer
• The OpenAI Codex CLI installed, available on PATH, and signed in
• Windows, macOS, or Linux; background operation is tested most heavily on Windows

Install

Install the isolated command-line application from PyPI with pipx:

pipx install cgl-interagentmail

Register one or more Codex projects, then start delivery:

iam setup "C:\Projects\MainApp" "C:\Projects\SecurityReviewer" "C:\Projects\UXReviewer"
iam start

Open the correct agent from any registered project:

cd C:\Projects\SecurityReviewer
iam open

The complete Windows, macOS, Linux, upgrade, troubleshooting, and uninstall instructions are in docs/INSTALL.md.

Browser messaging

Version 1.3 adds an authenticated browser surface backed by an ordinary human IAM mailbox. Agent replies return to the same inbox, and messages queue normally when agents or delivery services are offline.

Configure the default this-PC-only interface, choose a password when prompted, and start only its standalone companion process:

iam web setup MyMailbox --display-name "My Name"
iam web start

Open http://127.0.0.1:8787. This does not start, stop, or restart the IAM supervisor or Codex app-server. Use iam web status, iam web password, and iam web stop for its lifecycle.

LAN access is an explicit opt-in:

iam web setup MyMailbox --display-name "My Name" --lan --acknowledge-network-risk
iam web start

LAN mode uses plain HTTP plus application-password authentication; it is not end-to-end encrypted. Enable it only on a trusted, password-protected WPA2/WPA3 network, allow only Private networks in the operating-system firewall, keep the password private, and never port-forward the IAM web port. Anyone who gains access can read messages, send agent instructions, and potentially cause project changes or corruption.

Remote WebConnect messaging

Version 1.4 adds an optional outbound client for a compatible IAM WebConnect relay. It allows remote browser messaging without exposing iam web start, Codex, or any local service to the internet: the local machine makes an outbound secure WebSocket connection instead.

Create or choose the human mailbox that represents the remote account, then use the node credentials issued by the relay administrator:

iam user create yggdrassoftgaming --display-name "Liliana"
iam connect configure --server-url wss://iamwebconnect.cerberusgamelabs.xyz --node-id YOUR_NODE_ID --node-token YOUR_NODE_TOKEN --human-mailbox yggdrassoftgaming
iam connect start
iam connect status

Repeat --human-mailbox only when one trusted local node intentionally hosts more than one separately scoped headless identity, such as a ChatGPT MCP companion. IAM preserves the exact sender identity for each inbound message and exports replies addressed to that identity only:

iam connect configure --server-url wss://relay.example --node-id YOUR_NODE_ID --node-token YOUR_NODE_TOKEN --human-mailbox yggdrassoftgaming --human-mailbox echo

Use iam connect stop to stop only this connector. It does not restart the IAM supervisor, Codex app-server, or local browser companion. Any compatible wss:// relay URL may be used; Cerberus Game Labs hosting is optional. See IAM WebConnect for self-hosting, operator, and security information.

When a WebConnect node owner grants a separate account delegated access, create that account's human mailbox locally and add it as another --human-mailbox on the existing connector. A delegated message is stored with protected WebConnect metadata and its Codex delivery prompt requires owner-mailbox approval before any mutating or external action; ordinary questions and non-mutating discussion may be handled normally.

To add a delegated mailbox later without repeating node credentials, use iam connect update --human-mailbox ADDRESS. It preserves every unspecified setting and reloads only a running WebConnect connector. Use iam connect removeuser --human-mailbox ADDRESS to remove one local mailbox; revoke that account in WebConnect Settings first, otherwise the relay will safely reject the connector because its authorized mailbox list no longer matches.

Source code, releases, and issue tracking are hosted at https://github.com/cerberusgamelabs/cgl-interagentmail.

Everyday commands

iam status
iam doctor
iam report
iam user create ADDRESS
iam web setup ADDRESS
iam web start
iam web status
iam connect configure --server-url URL --node-id ID --node-token TOKEN --human-mailbox ADDRESS
iam connect update [--server-url URL] [--node-id ID] [--node-token TOKEN] [--human-mailbox ADDRESS]
iam connect removeuser --human-mailbox ADDRESS
iam connect start
iam connect status
iam connect stop
iam open [PROJECT]
iam restart
iam stop
iam stop --all
iam register [PROJECT ...]
iam unregister [PROJECT ...]
iam capabilities --json

• iam status shows services, projects, and pinned thread IDs; --json provides stable schema 1.0 output.
• iam open resumes the mailbox's pinned Codex session. To deliberately move a mailbox to a different existing session, use iam open --thread-id <session-id> from that project; IAM validates the session before replacing the pin.
• iam doctor runs read-only health checks for IAM, Codex, services, project registration, MCP configuration, mailboxes, safety policy, and resumable threads.
• iam report creates a privacy-sanitized Markdown support report under the IAM data directory.
• iam user manages human mailboxes; iam web manages the separate authenticated browser companion; iam connect manages an outbound WebConnect transport client.
• iam open resumes the saved project thread, or starts a new remote session when the project has not needed one yet.
• iam stop stops mail delivery but leaves the shared app-server running.
• Messages default to normal. Send --priority urgent only when a running agent needs a safe-stop notice; urgent mail steers active turns but never interrupts a command or bypasses approval.
• iam stop --all stops both IAM-managed background services.
• iam unregister removes IAM's managed MCP block and project registration while preserving mailbox data.

Timers and teams

IAM timers are durable, one-shot reminders for a mailbox. They survive IAM restarts, wake the target through the existing supervisor when due, and disappear completely when the recipient clears them. They are not mail and do not enter the inbox/archive lifecycle.

interagentmail timer set --project-root "C:\Projects\NexusGuild" --in 45m --note "Re-check the audit response."
interagentmail timer list --project-root "C:\Projects\NexusGuild"
interagentmail timer snooze TIMER_ID --project-root "C:\Projects\NexusGuild" --in 30m
interagentmail timer clear TIMER_ID --project-root "C:\Projects\NexusGuild"

Teams are local, human-administered coordination groups. Leadership alone grants no power: a leader needs an explicit capability grant before scheduling a team-wide reminder. A team reminder expands into independent recipient timers, so each agent can clear or snooze its own without affecting anyone else.

interagentmail team create reviewers --member NexusGuild --member AegisGrid
interagentmail team leader-add reviewers NexusGuild
interagentmail team grant reviewers --leader NexusGuild --capability timer.schedule_team
interagentmail timer set --project-root "C:\Projects\NexusGuild" --team reviewers --in 2h --note "Post findings in #reviewers."

Any member can also send mail without memorizing a roster or leader name:

interagentmail send --project-root "C:\Projects\NexusGuild" --to team:reviewers --subject "Status" --body "Please post your current findings."
interagentmail send --project-root "C:\Projects\NexusGuild" --to leader:reviewers --subject "Escalation" --body "I need a coordination decision."

team:<name> expands to the team's other current members and leader:<name> expands to its other active leaders. IAM permits either alias only to a current member of that team; aliases never send a copy back to the sender.

An administrator may delegate membership maintenance to one active leader, without allowing that leader to change roles or grants:

interagentmail team grant art-team --leader Maris --capability team.manage_members

That leader can then use iam_team_add_member and iam_team_remove_member through IAM MCP for that team only. Delegated leaders cannot remove themselves or another active leader, assign leadership, or alter permissions.

Setup behavior

iam setup is safe to run again. It:

1. Initializes the project's durable mailbox.
2. Records its project directory and safety policy.
3. Adds a clearly marked mcp_servers.interagentmail block to .codex/config.toml.
4. Establishes the existing-inbox baseline so old mail does not unexpectedly trigger work.
5. Lets the supervisor attach the project only when undelivered mail arrives; an active or approval-paused turn retains its own connection, and idle connections are released.

Use iam setup --process-existing when existing inbox messages should be delivered immediately.

Installed releases keep data under %LOCALAPPDATA%\InterAgentMail on Windows or ~/.local/share/interagentmail on macOS/Linux. Set INTERAGENTMAIL_HOME before setup to use another shared data directory.

Project folder basenames become mailbox addresses. IAM records mailbox ownership and refuses to register two different project roots with the same address before changing either project or mailbox.

If InterAgentMail init was run before iam setup, IAM deliberately refuses to claim that unowned mailbox by default. For an untouched default mailbox only (no mail, no timers, no custom profile, and no human identity), explicitly claim it during setup:

iam setup "C:\Projects\NewAgent" --claim-empty-mailbox

The flag never migrates or removes existing data; IAM rejects anything other than the exact empty mailbox shape created by InterAgentMail init.

Automation and reviewer platforms

Version 1.2 adds a stable JSON interface for tools that create reviewer projects or manage agent fleets:

iam capabilities --json
iam register "C:\Projects\SecurityReviewer" --json
iam status --json
iam doctor --project "C:\Projects\SecurityReviewer" --json
iam unregister "C:\Projects\SecurityReviewer" --json

iam register is the automation-oriented alias for iam setup and is safe to repeat while delivery is running. Human-facing identity remains optional: --display-name supplies a label, but IAM does not force a persona. See docs/INTEGRATION.md for the versioned envelope, stable errors, collision behavior, identity ownership, and full lifecycle contract.

Diagnostics and support reports

Run a read-only installation check at any time:

iam doctor

Warnings describe optional or currently stopped components. Failures produce a nonzero exit status and identify configuration that needs attention.

Create a report suitable for attaching to a support issue:

iam report

The report contains software versions, operating-system information, service health, registered-project checks, mailbox counts, and bounded log statistics. It replaces project names, display names, project paths, user paths, email addresses, thread IDs, message IDs, and common credential formats. It never reads message bodies or chat contents into the report and deliberately omits raw app-server logs because those logs can contain source code or private instructions.

Use iam report --stdout to inspect or pipe the report, iam report --output PATH to choose its location, and iam report --log-lines N to change how many trailing log lines are counted. Existing output files are preserved unless --force is supplied. Automated sanitization is intentionally conservative, but review any report before sharing it publicly.

Safety

New agents use workspace-write with on-request approvals. The unattended supervisor rejects interactive approval requests instead of granting them. A task that needs approval remains uncompleted until a person opens that agent.

Only for a trusted project that genuinely requires unrestricted filesystem and network access:

iam setup "C:\Projects\SecurityReviewer" --full-access

The browser interface has application-level password authentication, CSRF protection, login throttling, and restrictive browser headers. Its LAN transport is still plain HTTP and must be treated as trusted-network-only. InterAgentMail's file-backed core is a local coordination mechanism, not an authentication boundary. Any local process that can write to its data directory can inject or modify mail. Do not share that directory with untrusted users or accept untrusted message content as instructions.

Sending mail

Agents normally use the project-bound InterAgentMail MCP tools. People and fallback workflows can use the CLI:

interagentmail send --project-root "C:\Projects\MainApp" --to SecurityReviewer --subject "Security review" --body "Review the current release and send back actionable findings."
interagentmail send --project-root "C:\Projects\MainApp" --to SecurityReviewer --priority urgent --subject "Release blocker" --body "At your next safe stopping point, read this and reassess the release."

The receiving supervisor wakes the correct Codex thread. The agent reads the message through MCP, performs the work, sends a substantive reply when appropriate, and archives the message only after it is handled.

Protocol and low-level bridge details are in SYSTEM.md. Release history is in CHANGELOG.md.

Support

InterAgentMail is free and open source. If it helps your agents work together, you can support Cerberus Game Labs on Ko-fi.

License

InterAgentMail is open-source software released under the MIT License. Use it, modify it, distribute it, and build on it. Copyright 2026 Cerberus Game Labs.

Contributions are welcome; see CONTRIBUTING.md.