Pushstr – Private, Secure, Instant Communication

Pushstr is a lightweight, relay-backed messenger built on Nostr giftwrapped DMs.
No signup, no central server, keys stay local, and messages are end-to-end encrypted.

Generate an address and start communicating within seconds. Everything lives locally until you choose to back it up. Add a contact to begin sending, or share your address to receive messages; the minimal UI surfaces contact activity in real time.

Create as many disposable or long-lived addresses as you like to isolate conversations. Messages are encrypted for the recipient and relayed through multiple nodes to avoid single points of failure.

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Core Use Cases

Simple chatting

• Private conversations with friends or fully anonymous interactions.
• Great for one-off contact: e.g., put a QR code on a poster to create a disposable inbound-only address.

Notes and file sharing

• Install the browser extension and link it with your phone or another computer.
• Send text, images, or arbitrary data privately and securely.

Secure, flexible file transfer

• From text and JPEGs to MP3 or ZIP archives.
• All files are encrypted for the recipient before transport.

Plan-A communications

• Fast, lightweight stack enabling effortless, low-friction messaging.

Plan-B communications

• Multi-relay, multiple-redundancy architecture for extremely high reliability and uptime.

Ephemeral profiles

• Create as many profiles as there are stars in the sky without limitation*.
• Each profile may be used once or forever, depending on your threat model.

* There are approximately 10^53 times more possible Nostr keys than stars in the observable universe.

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Communication Options

Type	Security	Privacy	Reliability	Stability / Redundancy
Legacy apps	Low	Low	High	Low – single-provider failure = total outage
Privacy apps	Medium	Medium	Medium	Low – centralised backend, Cloudflare-level outages
Nostr	High	High	High	High – distributed relays, no single point of failure
Pushstr	High	High	High	Very High – multi-relay redundancy + client-side failover

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Demos

• First time open, show settings, add nickname

• open, show qr, add contact via qr, message

• extension popout, add photo, send to mobile, mobile attaches and sends a photo back

• extension popout, second phone, add mobile contact, message

• rename contact, switch contact, send message to extension

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"Pushbullet on Nostr"

Pushbullet-style messaging over Nostr Giftwrapped DMs. Runs as a Firefox/Chrome extension and as a mobile app (Android/iOS).

Quick, secure, private, anonymous multi-media messaging between devices to help improve productivity.

Android and Firefox are stable - Chrome and iOS function but are a little buggy.

What it does

• Generates or imports a profile (nsec), wraps messages as NIP-17 giftwrap (kind:1059 with inner kind:4), and sends through your relays.
• Listens for messages, decrypts locally and displays messages or download links for larger files.
• Browser extension UI for quick send + options; mobile app mirrors the flow with native share intent and chat view.
• Larger files encrypted for recipient and distributed via Blossom.

Prereqs

• Node 18+, npm
• For browsers: Firefox or Chrome/Chromium
• For mobile: Flutter 3.10+, Android SDK; Xcode for iOS. Rust + cargo-ndk only if you want to rebuild the native library.

Build & run

Browser extension

npm install
# Firefox (MV2)
npm run package
# Chrome (MV3)
MANIFEST_FILE=manifest.chrome.json npm run package

• Output: dist/ plus pushstr.zip. Load dist/ as a temporary add-on (about:debugging in Firefox) or an unpacked extension (chrome://extensions in Chrome).

Mobile app (Android/iOS)

cd mobile
flutter pub get
# Run on attached device/emulator (Android or iOS)
flutter run
# Android release APK
flutter build apk --release
# Load to connected mobile
flutter install --use-application-binary build/app/outputs/flutter-apk/app-release.apk

• Optional Rust rebuild (refresh FFI + native libs):

flutter_rust_bridge_codegen generate
cd pushstr_rust
cargo ndk -t arm64-v8a -t armeabi-v7a -o ../mobile/android/app/src/main/jniLibs build --release

See mobile/QUICKSTART.md for more detail.

Notes

• No cloud backups. Export your nsec and keep it safe.
• Relay outages aren’t retried automatically; reload/refresh to reconnect.
• Vendored vendor/nostr-tools.bundle.js; bump there to update nostr-tools.

Next Steps

1. Publish to Zapstore / mobile app stores
2. Distribute browser extensions