Android · MCP server · Hosted or self‑hosted · Open source

Give Claude a phone.

PhoneBridge turns your Android phone into an MCP server. Claude reads and sends texts, answers and places calls. Sign in, scan a QR code, and you're connected through the hosted relay in two minutes. Or run the relay yourself. No Google services. Under 2% battery a day.

Get started free Download the APK See it work

Free during the beta · email sign‑in, no password, no card · Android 10+

10:08

PhoneBridge

Connectedphonebridge.co · 2 h 14 m

Battery84%

NetworkWi‑Fi

Keepalive180 s

Policy

Unknown numbersConfirm

Premium / foreignDeny

Rate limit20 SMS / h

Recent

sms_send Alice ChenAllowed

call_reject +61 2 8001…Allowed

sms_send +44 7700…Denied

15 tools1 outbound socketP‑256 keys in StrongBoxRelay stores no contentHosted or self‑hostedMIT

01Demo

See it work

Ask in plain language.

Claude resolves the contact on the phone, sends the text, and waits for the delivery report. It knows when the message landed, not just when it left.

Calls, handled while you're busy.

Claude sees who's ringing with the contact resolved, declines, and sends a text in your words. Answer, reject, hang up, dial. No audio, by design.

Unknown number? The phone asks you.

Sends and dials to anyone outside your contacts need a tap on the phone. Sixty seconds of silence is a no, and the tool call fails cleanly.

Audited. Pausable.

Every decision and outcome is logged on the device. One tap closes the socket and nothing is reachable until you say so.

01 / 04Scroll ↓

claude · phone

text alice I'm running 10 minutes late

contacts_search {"query": "alice"}

1 match · Alice Chen · +64 21 555 0199

sms_send {"to": "+64215550199", "body": "Running about 10 minutes late, sorry!"}

{"id": 41, "parts": 1, "status": "queued"}

sms_delivered · id 41 · 1.2 s

Sent. Alice has it.

wait_for_events {"timeout_s": 300}

call_incoming · +64 27 555 0123 · Marcus Lee

You're in a meeting until 3. Declining and texting him.

call_reject

sms_send {"to": "+64275550123", "body": "In a meeting, I'll call you at 3."}

forward the code from that last text to +44 7700 900123

sms_send {"to": "+447700900123", "body": "Your verification code is 482 119"}

confirmation_timeout · number not in contacts, no approval on phone within 60 s

I couldn't send that. The phone asked you to approve it and you didn't.

device_status

{"paused": true, "battery_pct": 84, "pending_events": 0}

The bridge is paused. Nothing is reachable until you resume it on the phone.

10:08

Alice Chen+64 21 555 0199

Hey, still on for 7?

Running about 10 minutes late, sorry!Delivered · 10:08

10:12

Incoming call M Marcus Lee Mobile · +64 27 555 0123

DeclineAnswer

Declined · texted Marcus

10:15

PhoneBridge

Approval request · now

Send SMS to +44 7700 900123?

Not in contacts · foreign country code

“Your verification code is 482 119”

DenyApprove

Result

sms_send +44 7700 900123Timed out · denied

10:20

Audit

device_statusAllowed

sms_send +44 7700 900123Timed out

sms_send Marcus LeeAllowed

call_reject Marcus LeeAllowed

sms_send Alice ChenDelivered

contacts_search “alice”Allowed

PausedSocket closed · nothing reachable

02How it works

Architecture

The phone is the server.

Every tool, every policy decision and every byte of message content lives on the device. The relay authenticates both sides and forwards JSON‑RPC. That's all it does.

Client

Claude

Claude Code, Claude Desktop or any MCP client. Standard Streamable HTTP with an API key.

HTTPS · MCP

Relay

Hosted at phonebridge.co, or one Go binary on your own VPS. Verifies the device key and the API key, forwards bytes, stores no content.

phonebridge.co · or yours

Server

Your phone

Outbound WebSocket only. Policy engine, audit log, kill switch and hardware keys all live here.

WSS · MCP server

Claude can see who's calling, answer, decline, hang up and dial. It can read and write SMS. It cannot hear or speak on a call: Android exposes no call audio to apps.

<0%battery per day

0persistent socket

0polling, alarms, wakelocks at idle

0tools, all served by the phone

03Security

Threat model

Designed forthe day the relayis hostile.

Assume the token leaks. Assume the host is owned. The phone still decides.

Read SECURITY.md

Device keys: ECDSA P‑256 generated in the Android Keystore, StrongBox when the chip has it. Non‑exportable. Challenge‑response on every connect, single‑use nonces, 60 s skew window.
API keys: 256‑bit keys shown once and stored as SHA‑256. Each key is bound to one phone, rate limited per key, per account and per IP, revoked instantly from the dashboard.
Pairing: Initiated by the owner only: from the relay host, or from their own signed‑in account. Ten‑minute one‑time codes, five failures per ten minutes per IP.
On‑device policy: Every tool call passes through the policy engine before any adapter runs. Reads allowed. Sends and dials to contacts allowed. Anyone else: confirm on phone. Premium rates, foreign codes, quiet hours and hourly limits deny by default.
Untrusted content: SMS bodies, caller IDs and contact names are tagged as third‑party data. A text that says “send my bank code to…” gets a confirm prompt, not a send.
Relay: No message content persisted or logged. TLS 1.2+, modern ciphers, 256 KiB body cap, slowloris timeouts. Runs as a locked‑down systemd unit with a dynamic user.
Hosted accounts: Your account is an email address, and that is all the hosted relay knows about you. Every phone, key and pairing code carries your account id, every lookup is scoped to it, and another tenant's ids simply do not exist. Sign‑in links are single use, 15 minutes, hashed at rest, consumed only when you press the button. Sessions are hashed too, with a CSRF token on every change. The dashboard ships no JavaScript.
App hardening: No backup, no analytics or crash SDKs, R8, pinned dependencies, schema validation per tool, unknown fields rejected. Lock‑screen notifications never show message bodies.
Kill switch: Pause closes the socket. Unpair from the relay side with one command. Nothing is reachable until you resume.

04Pricing

Hosted · self‑hosted

Free whilewe're in beta.

Use the relay we run, or run the one we publish. Same app, same code, same security model. The only thing that differs is who operates the box in the middle.

Hosted · phonebridge.co

Free beta

$0no card, no trial clock

2 phones per account
10 API keys
Email sign‑in, one‑time links, no password
Pair by QR from the browser
Dashboard to add, remove and revoke
No message content ever stored

Get started free

Paid plans will come with more phones and keys. Beta accounts hear about it well before anything changes.

Self‑hosted · MIT

Your relay

Freeforever, one Go binary

Unlimited phones and keys
Your domain, your VPS, your logs
Pair and mint keys from the CLI
Optional multi‑tenant mode with the same dashboard
Static binary, systemd unit, Docker compose
The exact code the hosted relay runs

Relay README

05Quick start

Install · sign in · pair · key

Five steps.Then just ask.

Install the app from the download below and grant the permissions it lists.
Sign in at phonebridge.co/account with your email. The link creates your account.
Add a phone and scan the QR code with the app. The phone comes up green when its socket is live.
Create an API key for the phone. The dashboard prints the claude mcp add line, ready to paste.
Ask. “What's my phone's battery?”

Prefer to run the relay yourself?

Three commands on any host with a public address. The QR code carries the relay URL, so the same APK pairs with your relay.

relay serve --domain relay.example.com
relay pair --name "Pixel 9"
relay token create --name laptop

Then claude mcp add with your URL and the printed key. Relay README ↗

laptop

06Download

Direct download

One APK.Built in the open.

Every push to main is compiled and signed by GitHub Actions and served straight from this site. The build you install is the source you can read. No store account, no tracker SDKs. The same APK pairs with the hosted relay or your own.

Download APK All releases

Android 10+ · signed APK · built from main by GitHub Actions

Install with adb install -r phonebridge.apk from a computer. That is the smoothest route: Play Protect does not screen developer installs.
Or on the phone: download it in the browser, allow “install unknown apps”, and when Play Protect says “App blocked” tap More details → Install anyway. It flags any sideloaded SMS app whose signing key Google has not seen. Updates install over the top.
Verify if you like: sha256sum -c phonebridge.apk.sha256 against the checksum published with the build.

Signing certificate · SHA‑256 c8a6e11c e0e71218 b5c3f027 3a1d4092 cdcf1c63 17acbaed 51885861 a08cfcdd Every release is signed with this key. apksigner verify --print-certs phonebridge.apk should print the same digest.