agents-features-trace/ai.koog.agents.local.features.tracing.writer/TraceFeatureMessageFileWriter

TraceFeatureMessageFileWriter

class TraceFeatureMessageFileWriter<Path>(targetPath: Path, sinkOpener: (Path) -> Sink, format: (FeatureMessage) -> String? = null) : FeatureMessageFileWriter<Path> (source)

A message processor that writes trace events to a file.

This writer captures all trace events and writes them to a specified file using the provided file system. It formats each event type differently to provide clear and readable logs.

Tracing to files is particularly useful for:

Persistent logging that survives application restarts
Detailed analysis of agent behavior after execution
Sharing trace logs with other developers or systems

Example usage:

val agent = AIAgent(...) {
    install(Tracing) {
        // Write trace events to a file
        addMessageProcessor(TraceFeatureMessageFileWriter(
            sinkOpener = fileSystem::sink,
            targetPath = "agent-traces.log"
        ))

        // Optionally provide custom formatting
        addMessageProcessor(TraceFeatureMessageFileWriter(
            sinkOpener = fileSystem::sink,
            targetPath = "custom-traces.log",
            format = { message ->
                "[TRACE] ${message.eventId}: ${message::class.simpleName}"
            }
        ))
    }
}