Yale ByYou Pro (YDM-B701B) — Full BLE Integration Without the WiFi Bridge
The Problem
The Yale ByYou Pro (YDM-B701B-V2) is a popular smart lock in AU/NZ and parts of Europe. Out of the box, it’s BLE-only — no WiFi, no Thread, no Matter. Yale’s official solution is the Connect Wi-Fi Bridge (~$80–100 AUD), which is overpriced for what amounts to a BLE-to-WiFi relay.
I wanted local control in Home Assistant without buying extra hardware.
The Discovery
After decompiling the Yale Home APK, I discovered the ByYou Pro uses the August BLE protocol (V3, service UUID FE24) — the same protocol as Yale Assure Locks (US), August smart locks, and Yale Doorman. This means HA’s built-in yalexs_ble integration can communicate with it directly.
The only thing missing was the offline BLE key — a 128-bit AES key that’s normally only used by the Yale Home app. It’s not exposed anywhere in the consumer UI.
The Solution
1. Extract the offline key from the Yale cloud API
The Yale Home app talks to api.aaecosystem.com. By running the OAuth flow through HA’s built-in Yale integration (which handles the auth dance), I got a valid access token. Then it’s a single API call to get the lock details including the offline BLE key.
Key gotcha: the AAECosystem API uses x-access-token header, not the standard Authorization: Bearer. That one took a while to figure out.
2. Feed it to yalexs_ble via ESP32 Bluetooth Proxy
With the offline key + MAC address + key slot, HA’s existing yalexs_ble integration just works. I used an ESP32 Bluetooth Proxy positioned near the front door — no USB adapter, no WiFi bridge.
Lock/unlock, battery level, door sensor — all working locally over BLE.
What’s in the repo
I’ve documented the full process including:
- August BLE protocol reverse engineering (GATT services, command format, AES encryption)
- HCI snoop log analysis (packet-by-packet breakdown of a lock/unlock session)
- AAECosystem API discovery (OAuth flow, header format, key extraction)
- BLE sniffing setup guide for Android
GitHub: Requirements
- Yale ByYou Pro (already set up in the Yale Home app)
- Home Assistant
- ESP32 Bluetooth Proxy (or a CSR8510-based USB BT adapter)
- About 30 minutes
Limitations
- BLE range only — you need a proxy/adapter within range of the lock
- Key rotation — if you factory reset or re-pair the lock, the offline key changes and you’ll need to re-extract
- No OTA firmware updates — those still require the Yale Home app
- Apple Home Key works independently of this integration
Huge thanks to bdraco and the HA team for the excellent yalexs_ble integration — this lock works with it out of the box once you have the key. All I did was figure out where the key lives.
Happy to answer questions!