Logging

WalletKit logs through tracing. To send those logs to your app’s logging system, implement the Logger interface and pass it to init_logging once, at app startup.

Logger has one method, log(level, message). The level is one of Trace, Debug, Info, Warn, and Error, so your app can map it to os_log, Android Log, Crashlytics, Datadog, or any other sink. Each message starts with the name of the module that logged it, and WalletKit redacts hex secrets from it before your logger receives it.

On iOS and Android, WalletKit calls log from its own background thread, so your logger must be safe to call from any thread.

init_logging behaves as follows:

• Its level argument sets the minimum level. At Trace or Debug, the level applies only to WalletKit and its direct dependencies, and other crates log at Info and above. At Info, Warn, or Error, the level applies to every crate. If you pass no level, the minimum is Info.
• If the RUST_LOG environment variable is set, it takes precedence over level.
• Only the first call takes effect; later calls do nothing.

To check that your logger receives messages, call emit_log(level, message). To redact hex secrets from your own messages in the same way, call sanitize_hex_secrets(text).

Rust

#![allow(unused)]
fn main() {
use std::sync::Arc;
use walletkit::logger::{init_logging, LogLevel, Logger};

struct MyLogger;

impl Logger for MyLogger {
    fn log(&self, level: LogLevel, message: String) {
        println!("[{level:?}] {message}");
    }
}

init_logging(Arc::new(MyLogger), Some(LogLevel::Debug));
}

Swift

In this example, Log stands for your app’s logger.

import WalletKit

final class WalletKitLoggerBridge: WalletKit.Logger {
    static let shared = WalletKitLoggerBridge()

    func log(level: WalletKit.LogLevel, message: String) {
        switch level {
        case .trace, .debug:
            Log.debug(message)
        case .info:
            Log.info(message)
        case .warn:
            Log.warn(message)
        case .error:
            Log.error(message)
        @unknown default:
            Log.error(message)
        }
    }
}

public func setupWalletKitLogging() {
    WalletKit.initLogging(logger: WalletKitLoggerBridge.shared, level: .debug)
}

Kotlin

import android.util.Log
import uniffi.walletkit_core.LogLevel
import uniffi.walletkit_core.Logger
import uniffi.walletkit_core.initLogging

class WalletKitLoggerBridge : Logger {
    override fun log(level: LogLevel, message: String) {
        when (level) {
            LogLevel.TRACE, LogLevel.DEBUG -> Log.d("WalletKit", message)
            LogLevel.INFO -> Log.i("WalletKit", message)
            LogLevel.WARN -> Log.w("WalletKit", message)
            LogLevel.ERROR -> Log.e("WalletKit", message)
        }
    }
}

fun setupWalletKitLogging() {
    initLogging(WalletKitLoggerBridge(), LogLevel.DEBUG)
}

Browser

The browser package has no Logger. WalletKit writes its warnings and errors to the worker’s console, and emitLog writes through the same path. sanitizeHexSecrets redacts hex secrets as on the other platforms.