# Capabilities & limitations

The PN532 is a **hosted NFC controller**, not a low-level RF lab instrument. This project exposes PN532 features honestly:

- **ISO14443-B**: reader support exists with **chip-level caveats** (anticollision / stack-dependent behavior). No promises of full mobile/PICC coverage.
- **Card emulation / TG modes**: PN532 firmware supports target commands; real-world mimicry depends on timing, UID size, and reader expectations — expose experimentally, not as “propable MIFARE magic.”
- **Key recovery**: on-device “brute force” at Proxmark scale is **infeasible**. The UI provides **dictionary / manual** key workflows.
- **Signal / RF metrics**: diagnostics use **PN532 status / timings / retries**, not calibrated dBm.
- **OTA via UI**: `POST /api/ota` is a **stub** (`501`) — ship OTA with `esp_https_ota` + signed images when you need production updates.