Constants

Every constant is a Swift enum with a raw value carrying the number or string the engine exchanges. Config takes the raw value, so pass DesiredAccuracy.high.rawValue rather than the case itself.

Desired accuracy

Config(desiredAccuracy: DesiredAccuracy.high.rawValue)

Constant	Value	Meaning
`.navigation`	`-2`	Highest precision; only for turn-by-turn. Heaviest battery cost.
`.high`	`-1`	GPS-grade. The default, and what tracking is tuned for.
`.medium`	`10`	~10 m; balanced provider, GPS may not engage.
`.low`	`100`	~100 m; network/cell-grade.
`.veryLow`	`1000`	~1 km.
`.lowest`	`3000`	~3 km. Effectively “which city”.

The accuracy filter rejects fixes worse than locationFilterMaxAccuracy (100 m by default), so setting LOW or coarser while that gate is at its default produces a stream that is mostly rejected. Change both or neither.

Log level

Config(logLevel: LogLevel.info.rawValue)

Constant	Value
`.off`	`0`
`.error`	`1`
`.warning`	`2`
`.info`	`3`
`.debug`	`4`
`.verbose`	`5`

This controls persistence only: the engine always mirrors its lines to os_log. The level decides what is written to the on-device log database that getLog() reads and uploadLog() ships. See Logging & debugging.

Authorization status

Returned by requestPermission() and carried in getState().authorization.

Constant	Value	Meaning
`.notDetermined`	`0`	Nothing asked yet.
`.restricted`	`1`	Blocked by policy (device management).
`.denied`	`2`	Refused; no location.
`.always`	`3`	Background location granted.
`.whenInUse`	`4`	Foreground only.

Accuracy authorization

Constant	Value	Meaning
`.full`	`0`	Precise location.
`.reduced`	`1`	The user granted approximate location only (API 31+).

Reported by getProviderState(). Approximate location (iOS 14+) is a coarse grid: most fixes fail the accuracy gate and tracking is effectively unusable, so it is worth surfacing to the user — or asking for a temporary upgrade with requestTemporaryFullAccuracy(purpose:) — rather than debugging it as a bug.

Activity types

The classification behind the motion state machine, on onMotionChange and location.activity.type.

Constant	Wire value
`.still`	`still`
`.onFoot`	`on_foot`
`.walking`	`walking`
`.running`	`running`
`.onBicycle`	`on_bicycle`
`.inVehicle`	`in_vehicle`
`.unknown`	`unknown`

ActivityType.from(wire) maps a raw string back, falling back to UNKNOWN for anything unrecognised rather than throwing — a new activity class from a future Play Services release degrades instead of crashing.

License codes

BGeoError is a plain Error carrying the engine’s own code and message. It is deliberately not an enum: a code this SDK version has never seen stays diagnosable through code verbatim instead of collapsing into a .unknown case.

Code	When
`LICENSE_MISSING`	Release build, no key in `Info.plist`
`LICENSE_INVALID`	Bad signature or malformed token
`LICENSE_EXPIRED`	Key expired before this SDK build
`LICENSE_APP_MISMATCH`	Key not bound to this bundle id / Team ID
`DISABLED`	Operation needs tracking to be running
`NOT_FOUND`	No such record (e.g. `destroyLocation` with an unknown uuid)
`INVALID_GEOFENCE`	Missing identifier, non-positive radius, bad coordinates
`DECODE_ERROR`	The engine sent something this SDK could not decode

do {
    try await BackgroundGeolocation.start()
} catch let error as BGeoError {
    switch error.code {
    case "LICENSE_EXPIRED": showRenewalPrompt()
    default: print("bgeo:", error.code, error.message ?? "")
    }
}

The same codes arrive through onLocationError as a LocationErrorEvent, so a thrown getCurrentPosition() failure and a streamed watch failure are handled the same way.