Errors

Every failed call, and every stream that ends badly, throws a KitException (in JSON-RPC, an error whose data is a Failure). Act on code. message is for logs: its wording changes between releases.

try {
    visor.camera.takePhoto()
} catch (e: KitException) {
    Log.w(TAG, "photo failed: ${e.code} ${e.reason}: ${e.message}")
}

Code	Meaning	What to do
`scope_denied`	The app does not hold the scope in `scope`.	Ask for it with `RequestScopes`.
`unknown_method`	Visor does not know the method or topic.	Check the name. From the library this cannot happen: it raises `visor_too_old` first.
`invalid_params`	The params do not fit the method.	Fix the call.
`unsupported`	These glasses cannot do it: the prompter without a display, the band without a band.	Check `GlassesStatus.display`, or `BandStatus.paired`, before offering the feature.
`not_connected`	The glasses, or the band, are not connected and did not connect in time.	Tell the person to put the glasses on, or take them out of the case.
`busy`	Something else holds what this needs, for example a video is recording.	Try again later.
`refused`	The glasses or the band turned the request down.	Usually nothing; see the message.
`timeout`	The glasses did not answer in time.	Try again; if it keeps happening, the glasses may need a restart.
`failed`	Anything else. `reason` can say more, for example why an import failed.	See the method's page.
`visor_missing`	Visor is not installed. Raised by the library.	Point the person to Visor.
`visor_too_old`	Visor is older than this call needs. Raised by the library.	Ask the person to update Visor, or check `visor.supports(...)` first.
`visor_gone`	The connection to Visor broke during the call, for example because Visor restarted. Raised by the library.	Call again; the connection comes back on its own.
`closed`	Your app closed the connection while the call ran. Raised by the library.	Nothing.

Some failures carry a reason that says what the person can change:

Reason	With	What to tell the person
`not_set_up`	`unsupported`	Set the band up in Visor's band settings: only the Display holds it now.
`not_shared`	`unsupported`	Turn on Visor > Settings > Neural Band > Share with the phone, for `band.motion`.
`not_allowed`	`refused`	Allow the web app in Visor > Settings > Web apps > the app > Visor access.

Visor adds codes and reasons over time. Treat a code you do not know as failed.