transfqr CLI

Stream a file as fountain-coded QR codes from your terminal. The receiver is the transfqr phone app.

$ transfqr ./photo.jpg
transfqr · 312 chunks, ~1 min of streaming. ctrl+c stops.

  file        photo.jpg
  size        148.6 KB  (deflate)
  chunks      312  @ blockSize 512
  fileId      a1b2c3d4
  frame       00027

  point a phone running transfqr at this terminal.

  ▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄
  █ ▄▄▄▄▄ █▀ ▄▀ █▀ ▄▀▄▀ ▄█ ▄ ▄▀ ▄ ▀▄ █▀▄▀▄ ▄ █ ▀ █ ▄▀ █ ▄▄▄▄▄ █
  ...

Install

# One-liner (when releases ship):
curl -fsSL https://transfqr.com/install.sh | sh

# Or via npm:
npm i -g transfqr
# or, no install:
npx transfqr ./file.zip

What it does

1. Reads any local file.
2. Compresses (DEFLATE) if the file is large enough to benefit.
3. SHA-256 hashes the (padded) compressed payload.
4. Slices it into K source blocks at blockSize = 512.
5. Builds a Luby Transform encoder.
6. Streams an infinite stream of XOR-combined symbols as ASCII QR codes (~12 frames/sec, base45-encoded so they pack denser).
7. The phone app catches whichever frames it can, decodes once it has K + ε symbols, verifies the hash, decompresses, hands the file to your share sheet.

No internet, no accounts, no servers. The receiver only needs to be running transfqr on a phone (App Store / Play Store).

Limits

• 50 MB hard cap. QR-over-camera tops out around 12 frames/sec; bigger files take impractically long. Use a real network for those.
• Above 5 MB you'll see a friendly warning estimating duration before it starts.
• Both screens must stay still and visible. Background apps will pause the stream.

Privacy

The CLI runs entirely on your machine. It does not phone home, write logs, or read anything outside the file you point it at. The wire protocol is documented at https://transfqr.com/docs/protocol.