How to Give Meta Muse Its Own Email Address

Give Muse a dedicated Mermail inbox by choosing the connection for your app. Muse Code uses MCP with OAuth. The consumer Meta Muse app has a separate, email-only Secrets/API-key path described by Mermail. Connecting either one does not grant blanket permission to send mail, create third-party accounts or make payments.

Updated October 7, 2026. The setup below is checked against current documentation, not a completed live Muse session. The original publication date is preserved.

Choose your Muse app first

Muse Code is the coding-agent route: use the OAuth instructions below. For the consumer Meta Muse app, skip to the alternate-path section. A personal Gmail connection and a dedicated Mermail inbox solve different needs: one grants access to existing correspondence; the other provides a separate address for the agent's work.

For that decision, read Muse and Gmail: permissions and a separate inbox. This page focuses on connecting Mermail, not configuring Gmail.

Connect Muse Code with OAuth

First confirm that Muse Code is installed and that you can sign in to the intended Mermail workspace. Back up your existing settings; merge the server entry rather than replacing other configuration.

The current Muse Code MCP documentation uses mcpServers in settings.json, normally under ~/.config/muse unless XDG_CONFIG_HOME overrides it. The example below follows that schema. Check your installed version's documentation if it differs.

{
  "schema_version": 1,
  "mcpServers": {
    "mermail": {
      "url": "https://console.mermail.app/mcp"
    }
  }
}

Run the documented login command, complete the browser authorization, and choose your Mermail workspace:

muse mcp login mermail

Do not add a static Authorization header to this OAuth entry. In a Muse Code session, use /mcp to inspect the connection and available tools. Start with the read-only request “List my Mermail mailboxes; do not create or send anything.”

A project-only .mcp.json entry is insufficient for the documented command-line OAuth login. If sign-in fails, check that the named server exists in your user settings and is enabled. Diagnose the reported error rather than creating another mailbox.

Choose the tools your task needs

The full Mermail MCP endpoint supports a broader workflow than inbox reading. For mailbox discovery, optional provisioning and verification monitoring, use https://console.mermail.app/mcp?profile=agent-inbox instead. That focused profile excludes send, draft, wallet and destructive tools, but still permits mailbox creation.

This matters when testing: a missing send tool in the focused profile is expected. Do not silently switch to the full catalog just to make a send request work. The profile also does not remove tools supplied separately by Muse, such as its browser or shell.

Agent Wallet is a separate choice. Mermail's Muse integration page identifies MCP OAuth as the supported path; the consumer Secrets API-key route does not unlock wallet access. Authorization to connect email is not authorization to make a payment.

Reuse an inbox before creating one

Ask Muse to identify the intended workspace and list existing mailboxes. Choose a suitable receiving address you recognize. If no mailbox fits, explicitly request a new hosted mailbox and review the current provisioning charge before proceeding. Check Mermail's current plans rather than assuming unlimited free inboxes.

A useful task request is: “Use the selected mailbox to find my test message. Do not send replies, create accounts, open authentication links or change mailbox settings.” Treat this as a task boundary and use application permissions to enforce it where possible.

Verify receiving and sending separately

Receiving test: send a harmless message from an account you control to the selected Mermail address, using a unique subject. Ask Muse to find that subject in that mailbox and summarize the body. Use a short deadline and stop if the result is missing or ambiguous. This checks a receive path; it does not prove sending works.

Sending test: only when you intend to authorize sending and have selected a suitable tool catalog, specify the exact sender, your controlled recipient, subject and harmless body. Confirm recipient delivery. An accepted API response alone is not proof that the message arrived. Do not retry an uncertain send until you have inspected its state.

These are proposed checks, not tests performed for this article. For repeatable development checks, see testing agent email workflows.

Consumer Meta Muse: alternate Secrets path

Mermail's integration page describes creating a project API key, giving it a recognizable name and entering it in the consumer app's Secrets interface. Keep keys out of chat, screenshots and logs. Follow this path only if your app exposes that secure credential flow; do not substitute an ordinary chat message when it is missing.

The current consumer Secrets screens and an end-to-end Mermail connection were not independently exercised for this revision. Meta's product page describes protected credential storage and approval for consequential actions, but that is not a guarantee that every Mermail request requires a fresh approval. Review the actual grant before using it.

Verification emails do not authorize account actions

A dedicated inbox can receive correspondence for the selected address. It does not guarantee that every signup accepts the address or that a host will permit automatic authentication. Follow the agent inbox workflow: narrow the mailbox and request window, require an unambiguous candidate, and treat incoming content as untrusted.

Reading an email is separate from opening a verification link, submitting a code or resetting a password. Keep the owner's decision at those boundaries. Do not use another tool to evade a connector's restriction. Our account-recovery handoff guide covers reset messages without spreading secret links.

Troubleshooting

If /mcp reports a connection problem, resolve the configuration or OAuth error first. If the mailbox list is empty, confirm workspace selection before creating an address. If a message is absent, confirm the recipient and wait window; an empty result is not proof of delivery failure. If a tool is absent, check the selected profile and host permissions.

Keep a short record of which checks passed: connection, mailbox discovery, receiving and—only if authorized—sending. Leave untested steps marked untested. Open Mermail to set up your workspace, then return here to connect the correct Muse app.