Sickle
Connect an agent
MCP server · remote · any OS

Give your agent your inbox.
All of them.

Sickle connects every mailbox you own — Gmail, Outlook, iCloud, Fastmail, Yahoo, your company’s IMAP server — and hands them to Claude, Codex, Cursor or OpenClaw over MCP.

Works with any MCP client on macOS, Windows or Linux — nothing to install.

Connect in one minuteSee it work
Connect in a minute

Remote. Nothing to install.

Point your agent at a URL, approve the OAuth prompt, done. No binary, no local process, no credentials pasted into a config file.

Server URL
Claude Code
Or paste this into any agent and let it set itself up

Go to Settings → Connectors, open the Add menu and choose Add custom connector, then paste the server URL. The same steps work in Claude on the web.

Claude Desktop settings on the Connectors tab, with the Add menu open showing Add custom connector.

Whichever client you use, it opens a Sickle sign-in page and asks you to approve the access it wants. There are no API keys to copy across, and your assistant never receives your mailbox password — only a token you can revoke at any time.

See it work

You work the inbox. So does your agent.

Same accounts, same folders. When it archives something it is gone from your mail app, because there is only one mailbox.

Inbox triageSickle connected
Scripted demo
    sickleread · change

    Ask anything, or type / for commands

    AutoStandardHigh
    Any mailbox

    Every mailbox you own. Including the awkward one.

    Gmail and Outlook over OAuth. Everything else with a host, a port and a password. No cap on accounts.

    One account.

    Your agent sees a slice of your mail and thinks it’s all of it.

    One provider.

    Fastmail, iCloud, the company server — nothing.

    Read-only.

    It can tell you about the newsletter. It can’t archive it.

    Most email connectors authenticate a single Gmail account. Sickle connects as many mailboxes as you have and hands your agent all of them at once — every provider with an IMAP port, read and change.

    GmailOAuth
    Outlook / 365OAuth
    iCloudapp password
    Fastmailapp password
    Yahooapp password
    Any IMAP hostmanual
    What it does

    Your agent, working your mail.

    One job per card, with the tools it calls. Hover one to watch it happen.

    Search every mailbox at once.

    One question, every account. Results come back with the mailbox they live in.

    search_emails · list_accounts
    invoice from March
    4 results · 2 mailboxes
    • LedgerlyworkInvoice LG-0314 · March2 Apr
    • Hopper & VinepersonalYour March order receipt31 Mar
    • Marta OyelaranworkRe: March invoice — brand refresh28 Mar
    • Quillbury BookspersonalBook club · March invoice3 Mar
    Read the whole thread.

    Not the preview — the conversation, and the line in it that matters.

    read_email_body · read_email
    EH
    Eleanor Hughes
    Here’s v3 with the last redline.
    S
    You
    Legal wants 30 days’ notice.
    EH
    Eleanor Hughes
    Fine by us. Signed copy by Friday?
    Tidy as it goes.

    Mark, move, archive. It works the same folders you do.

    move_email · mark_as_read · list_emails
    Archive3
    • Eleanor HughesRe: SOW v3
    • Deskly14 notifications
    • Hopper & VineWebinar: Omnichannel…
    • Gradient Weekly37 links
    A scoped key, not your password.

    Read, or read and change — granted per client.

    email_read · email_change
    Your agent wants to use your mail
    • Reademail_read
    • Changeemail_change
    • Sendemail_sendnot requested
    move_emailmark_as_readtrash_email
    Nothing is permanent.

    Trash means your Trash folder. No tool deletes for good.

    trash_email
    Inbox
    Empty
    Trash
    Empty
    EHEleanor HughesRe: SOW v3 — last redlinePut back
    Moved back to Inbox
    Revoke any time.

    Disconnect a client and its access ends within the hour.

    Connected assistants2 connected
    • CClaude Desktopread · changeDisconnect
    • CCursoraccess endedDisconnected
    • CCodexread · changeDisconnect
    Before you connect

    Email is untrusted input. Anyone can send you a message, and an assistant reading your mail will also read any instructions hidden inside it. Grant email_change only to clients you trust, and review what your assistant proposes before approving it.

    Ask things like
    No Mac needed

    How your mailboxes get there without the app.

    The connector serves whatever mailboxes your Sickle account holds. You add them on the web, once, and every agent you connect sees all of them.

    1. 01
      Sign in at sickle.app.

      The same account your agent will sign in to when you approve it.

    2. 02
      Open Mailboxes, choose Connect mailbox.

      One dialog, one provider at a time.

    3. 03
      Pick the provider.

      Gmail and Google Workspace, Outlook, Hotmail and Live sign in with OAuth in your browser. iCloud, Yahoo and Mail.ru take an app password. Anything else takes a host, a port and a password.

    4. 04
      Repeat for the second and the third.

      There is no cap. An agent that is already connected sees the new mailbox the next time it calls list_accounts — nothing to reconnect.

    The app

    It comes with a native Mac mail client.

    Every mailbox in one window, a colour per account, an email cleaner and Vim keys. Same mailboxes. Whatever the agent archives is gone from the app, because there is only one inbox.

    See the Mac app
    Pricing

    One subscription. No Mac needed.

    The connector is included in the same subscription as the Mac app — not a separate add-on — and it works from any OS.

    See pricing
    Questions

    Asked before you ask.

    Which agents work?

    Claude Desktop and Claude on the web, Claude Code, Codex, Cursor, OpenClaw — and any other client that can add a remote MCP server over HTTP.

    Do I need the Mac app to use the connector?

    No — the app is optional, and the connector works from any OS. Sign in at sickle.app and add your mailboxes there: Gmail, Outlook, iCloud, Yahoo or any IMAP server. The connector signs in with the same account, so your agent sees every mailbox you add, on the web or in the app.

    Can it send email as me?

    Not today — no tool sends mail, so an assistant cannot email anyone on your behalf. You may see an email_send permission on the approval screen; nothing uses it yet. It is granted separately from reading and changing, so if sending arrives it stays yours to allow or refuse.

    Do you store my email?

    Your agent never receives your mailbox password — only a token you can revoke. The connector reads from your mail server when your agent asks and passes the result on; it does not keep a copy of your mailbox.

    My company runs its own mail server. Does it work?

    Yes. Anything with an IMAP host, a port and a password.

    More than one account?

    As many as you have, in one window and through one agent connection. There is no cap on accounts.

    How do I revoke an agent?

    Sign in to sickle.app, open Connect AI, and disconnect it under Connected assistants. Access it already holds ends within the hour.

    What if an email tries to give my agent instructions?

    It might. Email is untrusted input, and an assistant reading your mail reads whatever is in it. That is why change is a separate scope, why nothing is irreversible, and why you should review what an assistant proposes before approving it.

    Windows, Linux or iOS?

    The connector is not tied to an OS — it runs on our server, so any agent that can add a remote MCP server can use it, wherever that agent runs. Only the mail app is macOS only.

    Is the connector included in the subscription?

    Yes. One subscription covers the Mac app and the agent connector; the connector is not a separate add-on.