Print Daemon (papermintd)

🌿 Print Daemon (papermintd)

papermintd is a lightweight native HTTP microservice daemon built on Tokio and Axum. It runs as a local background service on POS terminals, kiosks, or kitchen display systems, allowing web applications, mobile devices, and browser-based point-of-sale software to print via standard JSON HTTP requests.

---

Why Use a Print Daemon?

Web browsers (Chrome, Safari, Firefox) run in a sandboxed security model that prevents web pages from opening raw TCP sockets to Port 9100 or claiming raw USB devices.

papermintd runs locally (e.g. http://localhost:8080) as a print sidecar:

1. Your web app or Electron POS makes a simple fetch('http://localhost:8080/api/print').
2. papermintd receives the JSON ticket, compiles it into ESC/POS or StarPRNT bytes in ~10μs, and delivers it over USB, TCP, or Serial.
3. Your web app can query real-time sensor telemetry (paper empty, cover open) via GET /api/status.

---

Running the Daemon

# Launch with default port (8080)
cargo run --package papermint-daemon

# Launch with custom host and port
PORT=9100 HOST=0.0.0.0 cargo run --package papermint-daemon

---

Complete API Reference

For the full list of endpoints, request models, and curl examples, see the Daemon REST API Reference.