Lauther MCP

lauther-mcp

Let your coding agent ask you first, on your phone, before it does something you can't undo.

Agent:  About to drop and recreate `users` on staging. Approving?
Phone:  [ Approve ]  [ Deny ]        ← optionally behind your fingerprint
Agent:  APPROVED after 34s. Confirmed by biometric.

Works with Claude Code, Cursor, Windsurf, or anything else that speaks MCP.

Setup

Get a token in the Lauther app: Apps → ＋ → New token. Then add the server to your MCP config:

{
  "mcpServers": {
    "lauther": {
      "command": "npx",
      "args": ["-y", "lauther-mcp"],
      "env": { "LAUTHER_TOKEN": "lpt_your_token" }
    }
  }
}

Nothing to install — npx fetches it. Node 18+.

The tools

ask_approval

Blocks until you answer, then tells the agent one of three things:

That last row is the one that matters. A timeout is not a yes, and the tool says so in words the model has to read.

Options: details for context, require_biometric to demand a fingerprint, timeout_seconds for how long you're willing to wait (default 120).

On waiting. Lauther's API long-polls for at most 25 seconds. Past that this server keeps asking about the same notification rather than sending another, so a ten-minute wait still puts one question on your phone — not one every half minute.

send_notification

One-way: "the migration finished", "the build broke". Takes title, message, priority and url. Only urgent crosses your quiet hours.

It reports what actually happened, including the case worth knowing about: if no device is registered on your account, you're told that rather than given a cheerful success for a notification nobody received.

get_location

Asks you to share where you are, once. You get a prompt on your phone with Share location and Decline; the agent receives one position, as it was when you tapped.

Options: question (what you see on the prompt), details, require_biometric, timeout_seconds (default 120).

request_photo

Asks you for one picture, taken on the spot or picked from your library. The agent gets the link and the image itself, so it can look at it. The link works for 7 days, after which the photo is deleted. If the image cannot be fetched the agent still gets the text and the link.

Same options and the same four outcomes as get_location.

ask_text

Asks you a short question and waits for you to type the answer on your phone: a verification code, a choice, a name, a fact only you know. The prompt shows the question and a field, with Reply and Decline. Answers run to 500 characters, so it is for short things.

Options: question (default "Answer a question?"), details, placeholder (a hint in the field, such as "6-digit code"), require_biometric, timeout_seconds (default 120).

Telling your agent when to use it

Most models won't reach for an approval tool unless asked. Something like this in your project rules works well:

Before anything irreversible — deploying, deleting data, spending money,
force-pushing, emailing real people, touching production — call
ask_approval and wait. Proceed only on APPROVED.

Suggesting it as a habit

The approval is signed and, when you ask for it, biometric — the answer records that a person confirmed it, not merely that something clicked. That is the difference between an audit trail and a log line.

Related

• lauther-client — the plain Node client, if you want push and approvals in your own code rather than in an agent.
• Docs · Recipes
• Something wrong? hello@lauther.id reaches a human.

Worth knowing

• Hosted only. The relay holds the APNs connection and the identity layer.
• Not end-to-end encrypted. Don't put secrets in the question text.
• The app is free on the App Store and Google Play.

MIT