# Bluetooth services and protocols

Canonical page: https://docs.ovok.com/native-sdk/guide/components/bt-management/device-services

Application code normally does not construct a device driver. Use `BTProvider` for the session and choose a declaration from `IntegratedDevices` or `SUPPORTED_DEVICES`. For a protocol that is not in the catalog, use `defineCustomDevice` when its wire format fits the declarative model.

## App-facing boundary [#app-facing-boundary]

- `BTProvider` owns permission checks, manager wiring, scanning, runtime events, and teardown.
- `BTManager` is public for integrations that must own the session lifecycle directly. It does not request permissions or provide the React provider context.
- `BTManagedDevice` instances are received from the manager's discovery callback; apps should not create them directly.
- `AcceptedDevice` is a built-in key or a validated custom declaration.
- `BluetoothError` and `BluetoothErrorCode` describe normalized Bluetooth failures.

The module barrel also exports protocol factories and helpers for specific standard and vendor formats. Treat those as protocol-level APIs; for ordinary app flows, the curated device catalog is the safer pairing of name match, decoder, and measurement types.

## Custom protocol boundary [#custom-protocol-boundary]

The declarative API supports fixed GATT declarations, framed notifications, checksums, measurement fields, repeated history records, and static write commands. The special `lepu` declaration handles the supported Lepu/Viatom framed protocol.

A device that requires protocol steps not expressible by these declarations needs a driver in the SDK. Do not solve that by starting a second native scan loop or by depending on private parser state.

See [Bluetooth device types](/native-sdk/guide/components/bt-management/device-types/), [custom devices](/native-sdk/guide/components/bt-management/custom-devices/), [advanced usage](/native-sdk/guide/components/bt-management/advanced-usage/), and the [Bluetooth guide](/native-sdk/guide/modules/bt-management).