Your texts, forwarded.
Relay is an Android app that automatically forwards incoming SMS messages to another phone number or an email address, based on rules you write. It runs entirely on your device — no account, no servers, no analytics.
What Relay is
Relay is not your device's default SMS app and does not replace your messaging app. It works quietly in the background alongside it, and it forwards nothing at all until you write a rule telling it where to send something.
Relay sees incoming SMS and checks each one against your rules, top-down, in the order you set.
Match on sender, message body, or which SIM received it — with AND/OR groups, regex, and "is in my contacts".
Forwarded by SMS or email, with automatic retries until it lands. It survives being killed, and it survives a reboot.
Who it's for
What it does
equals, contains, starts with, doesn't contain, regex, or "is in my contacts". Fan a single rule out to several destinations. Per-rule schedules and quiet hours. Dual-SIM filtering. A global kill switch.
SMS to any number, with correct multipart handling for long messages. Email through your own SMTP account — Gmail, Outlook, Yahoo or a custom host — plus one-tap Google sign-in for Gmail.
Reusable message templates with {{variable}} chips for sender, body,
time and SIM. Live preview as you type, and a GSM-7 / UCS-2 aware segment counter so
you know what a forward will cost.
Every matched message is written to the database before any send is attempted. Retries back off 30s → 2m → 10m → 30m → 2h, up to 8 attempts, and failures come with a one-tap "Retry now".
Type a pretend message and see exactly which rules match and what would be sent — before anything is sent. Nothing leaves the phone.
A searchable, filterable activity log with a per-attempt timeline for every message, configurable retention, and a metadata-only mode that records which rule matched without storing message bodies.
Privacy
Relay has no backend. We never receive your messages — we couldn't if we wanted to, because there is nothing to receive them.
Said plainly, because it matters: Relay does transmit message content off your device — to the destinations you choose, and only when one of your rules matches. Forwarding to email means your mail provider can see the message. Forwarding by SMS uses your carrier, and standard SMS charges apply.
Signing in with Google
Connecting a Gmail account is optional — you can always use an SMTP App Password instead. If you do use it, this is exactly what Relay asks for and what it does with it.
| Question | Answer |
|---|---|
| What scope is requested? | https://www.googleapis.com/auth/gmail.send — and nothing else. |
| What can it do? | Send an email as you. It grants no read access to your mailbox — Relay cannot open, search or list your mail. |
| What is it used for? | Delivering a forwarded SMS to the email destination you configured, and nothing else. |
| Is the token stored? | No. Relay re-fetches a short-lived token silently at send time. No refresh token is kept on the device. |
| Is Google user data shared? | Never. It is not transmitted to us — there is no backend — and it is not shared with, sold to, or licensed to any third party. |
| How do I revoke it? | Remove the account in Relay, or revoke access at myaccount.google.com/permissions. |
Relay's use of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements.
Permissions, and why
| Permission | Why Relay needs it |
|---|---|
| Receive SMS | Required. Relay cannot check a message against your rules without seeing it. |
| Send SMS | Needed only to forward to a phone number. Email-only forwarding works without it. |
| Contacts | Optional. Shows sender names and powers the "is in my contacts" condition. Never leaves the device, and Relay works fine if you decline. |
| Notifications | To tell you when a forward fails and needs attention. |
Support
Relay is built and maintained by an individual developer. Email is the fastest way to reach me, and I read everything.