phonehome

A CLI and MCP that allows an agent to get your realtime location on demand, end to end encrypted.

Requirements

• Node.js 24 or newer
• Installation of the PhoneHome app for Android or iOS
• The paired phone must have location and notification permissions and an active network connection

Install

Install the public package globally:

npm install -g @commit451/phonehome

Configure

Your human has instructions on their PhoneHome app that they can paste to you the agent, which includes the needed API key, encryption phrase, etc. When it is pasted to you, you should keep these values secret and not expose them to anyone else.

Confirm that the phone registration and encryption phrase are synchronized:

phonehome status
phonehome check

No command prints the API key or encryption phrase.

When the account is activated on a new phone, PhoneHome rotates the agent pairing. The old configuration then returns a structured pairing_required error instructing the agent to ask the user for the new pairing code. Copy the new agent setup from PhoneHome > Setup, then run phonehome setup again to replace the local configuration.

Get a location

phonehome location --timeout 60

Successful output is machine-readable JSON:

{
  "requestId": "181cf811-13b2-402c-a863-32a2bd6e636a",
  "latitude": 41.5868,
  "longitude": -93.625,
  "accuracyMeters": 12.5,
  "capturedAtEpochMs": 1700000000000,
  "capturedAt": "2023-11-14T22:13:20.000Z",
  "receivedAtEpochMs": 1700000001000
}

An agent answering “What are some good Mexican restaurants near me right now?” can:

1. run phonehome location;
2. pass latitude and longitude to a local-search or maps tool/MCP;
3. use the current time and opening-hours data from that provider; and
4. present nearby open options without the user having to explain where they are

MCP server

phone-home-mcp exposes PhoneHome directly to MCP clients over local stdio. It uses the same protected config file or PHONE_HOME_* environment variables as the CLI and never sends setup credentials through MCP. Configure the package once with phonehome setup, then add this server to the MCP client's configuration:

{
  "mcpServers": {
    "phonehome": {
      "command": "phone-home-mcp"
    }
  }
}

To use a non-default config file, add "args": ["--config", "/secure/path/config.json"].

The MCP server provides five tools:

Tool	Purpose
phone_home_get_location	Request, wait for, decrypt, and return a current location
phone_home_request_location	Start a request without waiting
phone_home_get_location_result	Poll a split request and decrypt it when complete
phone_home_status	Check whether the paired phone is registered
phone_home_check_pairing	Verify that the agent and active phone share the same key

Use phone_home_get_location for normal requests. MCP clients with short tool-call limits can use phone_home_request_location, save its requestId, and poll phone_home_get_location_result. The server deliberately does not expose setup as a tool, so pairing codes and credentials cannot be submitted through model tool arguments.

Commands

Command	Purpose
phonehome setup [file|-]	Validate and securely save an app setup bundle
phonehome config	Show non-secret active configuration metadata
phonehome status	Check whether the paired phone is registered
phonehome check	Verify the local encryption phrase against the server's one-way check
phonehome location	Request, poll, decrypt, validate, and return a location
phonehome request	Start a request without waiting
phonehome result <id>	Read a request; decrypt it automatically when complete

location, locate, and get-location are aliases. Location options:

• --timeout <seconds>: local wait limit, default 60 seconds;
• --poll-interval <milliseconds>: polling interval, default 1000 ms; and
• --request-id <uuid>: optional client-selected idempotency key.

The standalone request and result commands support agents whose tool calls have short execution limits. Save the request ID from the first command, then call result until its status is terminal.

Environment-only configuration

For ephemeral agent containers, avoid a config file by providing either the full bundle:

export PHONE_HOME_SETUP_BUNDLE='{"apiKey":"...","encryptionPhrase":"..."}'

or both credential fields:

export PHONE_HOME_API_KEY='...'
export PHONE_HOME_ENCRYPTION_PHRASE='...'

An explicit --config path takes precedence over credential environment variables.

Exit codes and errors

All successful non-help commands write one JSON document to stdout. Errors write one JSON document to stderr and never include credentials.

pairing_required includes details.action: "request_new_pairing_code" and a safe message the agent can relay to the user. It means the active phone or encryption phrase no longer matches this configuration; location requests are stopped before an undecryptable response is created.

• 0: success
• 1: invalid command or missing/invalid configuration
• 2: API, protocol, decryption, or runtime failure
• 3: location is still pending, expired, or timed out

Library usage

The npm package also exports the typed client:

import { PhoneHomeClient, parseSetupBundle } from '@commit451/phonehome';

const setup = parseSetupBundle(JSON.parse(process.env.PHONE_HOME_SETUP_BUNDLE!));
const phoneHome = new PhoneHomeClient(setup);
const location = await phoneHome.locate({ timeoutMs: 60_000 });

Code that embeds its own MCP transport can import the server factory from the dedicated subpath:

import { createPhoneHomeMcpServer } from '@commit451/phonehome/mcp';

const server = createPhoneHomeMcpServer({ version: '0.0.5' });

Security model

• Treat the setup bundle and config file as secrets. They contain both the agent API key and the location encryption key.
• The CLI always sends API credentials to PhoneHome's compiled-in HTTPS API origin.
• Encryption synchronization uses SHA-256("phonehome/key-check/v1\\0" || key); the raw encryption phrase is never sent to the server.
• Location payloads use AES-256-GCM with a 12-byte nonce and request-bound AAD: phonehome/location/v1\n{requestId}.
• Decrypted payloads are schema-checked, including coordinate ranges, before being returned.
• The API key, phrase, authorization header, and setup bundle are never logged.

License

MIT