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 two tools

`ask_approval`

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

Result	What the agent is told
`APPROVED`	proceed with exactly what was asked, and nothing further
`DENIED`	stop; do not retry, do not find another way
`NO ANSWER`	stop — silence is not consent

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.

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.

lauther-client — the plain Node client, if you want push and approvals in your own code rather than in an agent.
Docs · Recipes
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