Your inbox, in your agent.

1. Add the BTC.email server address to your client. This grants nothing.
2. Sign in to BTC.email in your browser when the client asks, as you do for any website.
3. Choose the permissions and mailboxes, set an expiry, and approve with your password.
4. Ask your agent to work. Sending, scheduling, and discarding wait for your approval in Settings, and wallet actions finish only in the web app.

You need an approved BTC.email account and a client that supports MCP over HTTP. BTC.email adds no AI model; your client brings its own.

One address is all a client needs to find BTC.email.

https://btc.email/api/mcp

1. Add the server. This only saves the address and the sign-in client; it grants nothing.
2. Start claude, run /mcp, choose btc-email, and authenticate. From a shell, claude mcp login btc-email does the same.
3. Your browser opens BTC.email. Sign in if asked, choose the permissions and mailboxes, and approve with your password.

claude mcp add --transport http --client-id claude-code --callback-port 8765 btc-email https://btc.email/api/mcp

Add --scope user to use it in every project; the default keeps it in the current project. The callback port 8765 must be free on your machine.

claude mcp add-json btc-email '{"type":"http","url":"https://btc.email/api/mcp","oauth":{"clientId":"claude-code","callbackPort":8765,"scopes":"mail.read offline_access"}}'

1. Add this to ~/.codex/config.toml, or to .codex/config.toml in a trusted project. BTC.email never edits your configuration.
2. Run codex mcp login btc-email. Your browser opens BTC.email.
3. Sign in if asked, choose the permissions and mailboxes, and approve with your password.

mcp_oauth_callback_port = 8766

[mcp_servers.btc-email]
url = "https://btc.email/api/mcp"

[mcp_servers.btc-email.oauth]
client_id = "codex"
callback_url = "http://127.0.0.1:8766/callback"

Keep the callback exactly http://127.0.0.1:8766/callback; another port or a suffix is refused.

codex mcp login btc-email --scopes mail.read

Any connection uses the same address, https://btc.email/api/mcp, and browser sign-in with PKCE. BTC.email registers its sign-in clients itself: dynamic registration is off, and only the clients above are accepted today. A custom script or another MCP client cannot sign in until it is added, and no shared key or token can be created by hand.

On a remote or headless machine the sign-in still needs a browser. Claude Code can print the sign-in link instead of opening one: run claude mcp login btc-email --no-browser, open the link on your own computer, then paste the final address back. Codex needs a browser that can reach 127.0.0.1:8766 on the machine it runs on, for example through an SSH port forward.

The approval page lists every permission a client asks for and starts with only the read-only ones selected. Start with mail.read, then add one permission at a time. Reading, drafting, organizing, and sending are separate permissions.

Sending, scheduling, and discarding a draft always wait for your approval under Send approvals, bound to the exact message. A client cannot approve for you. Wallet transfers, purchases, address changes, and security changes finish only in the web app.

You choose the mailboxes, an expiry of one day at most or about one hour, and whether the client may keep access after your browser session ends. Access still follows your account status and each feature’s own limits.

Start read-only. Each prompt names the permission it needs, so the approval you grant matches what you ask.

• Read only

  Grant mail.read

  Using btc-email, list my 5 most recent mail threads (subject and sender only). Do not change anything.

  Copy prompt

  Run this first. It changes nothing.

• Create a draft

  Grant mail.drafts.write

  Using btc-email, create a draft to myself with the subject "Agent test" and the body "hello". Do not send it.

  Copy prompt

  Open BTC.email to see the saved draft.

• Send with approval

  Grant mail.drafts.read, mail.send

  Using btc-email, send the "Agent test" draft.

  Copy prompt

  The send waits for your approval under Settings > Connections > Send approvals. Nothing sends before you approve.

Rotate. A connection cannot be extended in place. To rotate, revoke it, run the login again in the client, and approve a new connection with a fresh label and expiry. Use a label you will recognize, such as the device name.

Revoke. Review a connection below and revoke it, or revoke all of them. Revocation stops future access; the client gets an authentication error on its next request. It cannot undo what a client already read or did, or erase what it stored on its own machine.

Clean up the client. Revoking here is what ends access. Then clear the client’s saved sign-in: claude mcp logout btc-email in Claude Code, which clears local tokens only, or claude mcp remove btc-email to remove the server. In Codex, delete the [mcp_servers.btc-email] block from config.toml.

If you suspect a leak. Revoke all connections first. Then review Devices in Settings for sign-ins you do not recognize and change your password.

• The browser shows a redirect or port error. The callback port must be free and exact: 8765 for Claude Code and 8766 for Codex.
• You cannot approve. New connections need a fresh password check, so an account that signs in only with Lightning cannot approve one yet.
• A tool is missing or refused. The connection lacks that permission. Revoke it and connect again with the permission added.
• The client says it is unauthorized. The connection expired or was revoked. Run the login again.
• A send does nothing. It is waiting for you under Settings > Connections > Send approvals.
• Check what the client saved. claude mcp get btc-email shows the Claude Code entry.

Still stuck? Read the Support questions or write to support@btc.email. Never send a password or sign-in code.