How It Works

bleRPC provides a layered protocol stack on top of BLE GATT:

1. Command Layer — Wraps Protocol Buffers payloads with command metadata (name, type, data length).
2. Encryption Layer (optional) — Encrypts the serialized command with AES-128-GCM after a 4-step key exchange.
3. Container Layer — Fragments payloads into MTU-sized containers for BLE transmission, with reassembly on the receiving side.

All communication uses a single GATT Characteristic: the Central writes requests via Write Without Response and receives responses via Notify.

sequenceDiagram
    participant C as Central<br/>(iOS / Android / Flutter / RN / Python)
    participant P as Peripheral<br/>(Zephyr / Python)
    Note over C: Protobuf encode + Command wrap
    Note over C: Encrypt (if enabled)
    Note over C: Split into MTU containers
    C->>+P: Write Without Response (containers)
    Note over P: Reassemble containers
    Note over P: Decrypt (if enabled)
    Note over P: Decode command + Protobuf
    Note over P: Execute handler
    Note over P: Encode response + Encrypt + Split
    P->>-C: Notify (containers)
    Note over C: Reassemble + Decrypt + Decode
      

Supported Platforms

Central (Client)

Peripheral (Server)

Protocol Libraries