> ## Documentation Index
> Fetch the complete documentation index at: https://rive.app/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Logging

This Rive runtime includes logging capabilities to help with debugging. These logs are *only* for debugging purposes; nothing is sent over the network, and no personally identifiable information (PII) is logged.

The table below showcases the runtimes that support logging.

> [tab] New Runtime
>
> The new runtime supports logging via the `RiveLog` type. To enable logging, set the `RiveLog.logger` property to a `RiveLog.Logger` implementation. The new runtime defaults to no logging, which can be set at any time by setting `RiveLog.logger` to `RiveLog.none`. The new runtime ships with a default implementation that logs to the console, which can be set by using the `RiveLog.system(levels:)` helper function. When using the system logger, any logs that are not emitted at the levels specified will be suppressed.
>
> ```swift theme={null}
> // To enable the default logging implementation, which uses os.Logger
> RiveLog.logger = RiveLog.system(levels: .default)
>
> // To disable logging (the default)
> RiveLog.logger = RiveLog.none
> ```
>
> ### Levels
>
> Logs will be logged at various levels, which are inspired by `OSLogType` . These levels can be used to additionally filter logs to be logged at certain levels only. Available levels are:
>
> * **Notice**: important informational logs
> * **Debug**: commonly used to aid with debugging
> * **Trace**: highly detailed and potentially verbose diagnostic logs, including operations like advancing that may emit at least one log per frame
> * **Info**: logs that provide additional information
> * **Error**: used when an error occurs
> * **Warning**: used when a potential issue is detected
> * **Fault**: used when a severe error occurs
> * **Critical**: used when a fatal error occurs
>
> Convenience presets are also available:
>
> * **.default**: `.debug`, `.warning`, `.error`, `.fault`, `.critical`
> * **.all**: all levels (`.notice`, `.debug`, `.trace`, `.info`, `.error`, `.warning`, `.fault`, `.critical`)
>
> ### Custom Logger
>
> You can also implement your own custom logger by implementing the `RiveLog.Logger` protocol. This allows you to log to any desired sink, such as a file, a network endpoint, or a custom console.
>
> ```swift theme={null}
> nonisolated public protocol Logger: Sendable {
>     nonisolated func notice(tag: Tag, _ message: @escaping () -> String)
>     nonisolated func debug(tag: Tag, _ message: @escaping () -> String)
>     nonisolated func trace(tag: Tag, _ message: @escaping () -> String)
>     nonisolated func info(tag: Tag, _ message: @escaping () -> String)
>     nonisolated func error(tag: Tag, error _: (any Error)?, _ message: @escaping () -> String)
>     nonisolated func warning(tag: Tag, _ message: @escaping () -> String)
>     nonisolated func fault(tag: Tag, _ message: @escaping () -> String)
>     nonisolated func critical(tag: Tag, _ message: @escaping () -> String)
> }
> ```
>
> Once you have implemented your own logger, you can set it to the `RiveLog.logger` property.
>
> ```swift theme={null}
> RiveLog.logger = MyLogger()
> ```

> [tab] Legacy Runtime
>
> ```
> RiveLogger.isEnabled = true // Enable logging; false by default
> RiveLogger.levels = [.debug] // Filter logs; all by default
> RiveLogger.categories = [.viewModel] // Filter categories; all by default
> RiveLogger.isVerbose = true // Include verbose logs; false by default
> ```