Smart Relay Arrives in SmartKit File Share

Smart Relay is now live in SmartKit File Share as part of the July 31, 2026 update.

This new fallback flow helps file transfers continue when direct P2P is blocked by network restrictions, firewalls, mobile carriers, strict browsers, or device limitations.

A New Fallback for Blocked P2P Transfers

SmartKit File Share now has a server-assisted Smart Relay mode.

When direct P2P cannot connect reliably, Smart Relay gives the sender and receiver another way to complete the transfer without requiring the full file to be uploaded to the server first.

The sender can keep the receiver code and receiver link visible while the transfer is running, so the receiver can join while the upload is still active.

Rolling Chunk Transfer System

Smart Relay uses a rolling chunk system.

Instead of storing the entire file on the server, the sender uploads the file in 1 MB chunks only after the receiver is connected.

The relay keeps a maximum rolling buffer of 8 chunks at a time. That means the server only holds a small temporary window of data during the live transfer, not the full file.

As the receiver downloads chunks, the server clears them immediately to reduce storage usage and keep the relay lightweight.

Dedicated Receiver Flow

The receiver side now has a dedicated Smart Relay join experience.

Receivers can enter the relay code or open the receiver link, view progress, and download the file through the streamed relay flow.

Session handling has also been strengthened so another device cannot hijack the same relay code once a receiver is connected.

Better Transfer Visibility

Smart Relay now reports more useful live transfer status.

The system can show uploaded chunks, delivered chunks, current buffer size, and receiver connection state. This gives the sender and receiver a clearer picture of what is happening during the relay transfer.

Improved Relay Cleanup

Relay cleanup has been improved across expired, cancelled, and manually deleted transfers.

Temporary chunk files and database records are now removed properly, helping keep the relay system clean after a transfer ends or becomes inactive.

iPhone and iPad Compatibility Guidance

SmartKit File Share now shows a clear compatibility warning for iPhone and iPad users.

Because iOS browsers can interrupt live streamed downloads, the interface recommends using Create Share Link on iPhone and iPad instead.

Smart Relay remains best suited for desktop and Android receivers where live streamed downloads are more reliable.

This update gives SmartKit File Share a stronger fallback path when direct P2P is blocked, while keeping relay transfers lightweight, temporary, and easier to monitor.