Privacy Policy for SendChat

SendChat ("we", "our", or "the app"), developed by ByteGif, is committed to safeguarding your privacy. This Privacy Policy details our data collection, usage, and permission practices for the SendChat mobile and desktop applications.

Core principle: SendChat is an offline-first, local peer-to-peer (P2P) utility. We do not operate external servers or store your data in the cloud, and we do not collect, track, share, or sell your personal information.

1. Data Collection and Transmission

SendChat is designed so that your data remains under your control:

• No cloud storage: Chat messages, media, and files are transferred directly between devices over your local Wi-Fi or hotspot network via encrypted direct sockets (TCP/IP).
• No user accounts: You do not need an email, phone number, password, or third-party account to use SendChat.
• No tracking SDKs: SendChat does not include advertising SDKs, behavioral tracking tools, or telemetry tools.
• No central servers: We do not operate relay servers that inspect, log, or cache the contents of your communications.

2. Information Accessed on Your Device

SendChat accesses device resources needed for actions you choose to perform:

• Files and media: Accessed when you select files, photos, videos, or documents to share. Received files are saved to your device's designated downloads folder.
• Device identification: Your chosen device display name and platform type (e.g., Android, Windows, macOS, Linux) are broadcast via Multicast DNS (mDNS) and UDP discovery on your local network so nearby devices can identify each other.
• Local message history: Conversations and transfer logs are stored locally on your device in an encrypted SQLite database. This data is not sent to us or any third party.
• Clipboard content: When you enable the optional Clipboard Sync feature, text copied on one paired device can be transferred directly to another paired device over your local network. Clipboard contents are not polled, uploaded, or stored externally.

3. Android Permissions

To provide peer-to-peer sharing and transfer management, SendChat requests the following permissions on Android:

• NEARBY_WIFI_DEVICES / ACCESS_NETWORK_STATE / CHANGE_WIFI_MULTICAST_STATE: Used to discover nearby devices on the local Wi-Fi network using mDNS and UDP.
• FOREGROUND_SERVICE & FOREGROUND_SERVICE_DATA_SYNC: Used to keep active file transfers running in the background while displaying an ongoing notification.
• REQUEST_INSTALL_PACKAGES: Allows you to install application packages (.apk files) received from your paired devices, after you choose to do so and confirm.
• POST_NOTIFICATIONS: Required on Android 13 and later to notify you about incoming transfer requests, transfer progress, and completed downloads.
• CAMERA (optional): Used to scan pairing QR codes on other devices for verification. Camera images and video frames are not recorded or transmitted.

4. Security and Cryptography

Direct local connections between devices use the following security measures:

• Key exchange: Ephemeral key exchange using Elliptic Curve Diffie-Hellman (ECDH).
• Encryption: End-to-end authenticated encryption via AES-256-GCM for packets, messages, and file streams.
• Pairing verification: Mutual authentication using a 6-digit confirmation PIN or QR code to help protect against unauthorized connections and local network snooping.

5. Data Retention and User Control

• Deleting chats and transfers: You can delete individual messages or clear conversation histories in the app.
• Complete data erasure: Because data is stored on your device, uninstalling the app or clearing its storage in your device settings removes locally stored chats, keys, and pairings.

6. Third-Party Sharing

We do not share, disclose, monetize, or sell user personal data or file contents to third parties.

7. Children's Privacy

SendChat is a local network utility and does not collect personal data from users, including children under the age of 13.

8. Changes to This Privacy Policy

We may update this Privacy Policy to reflect app updates or regulatory requirements. Changes will be posted on this page with a revised "Last updated" date.

9. Contact Us

If you have questions or feedback about this Privacy Policy or SendChat, contact us at bytegif@gmail.com or visit the SendChat project on GitHub.