Configuration

Log Level

setLogLevel(level: LogLevel): void
getLogLevel(): LogLevel

Default: "info". Override with LOG_LEVEL env var.

setLogLevel("debug") // debug, info, warn, error
setLogLevel("error") // error only
setLogLevel("silent") // nothing

Log Format

setLogFormat(format: LogFormat): void
getLogFormat(): LogFormat

Default: "console". Override with LOG_FORMAT env var. Also auto-enabled by NODE_ENV=production.

setLogFormat("json") // {"time":"...","level":"info","name":"myapp","msg":"..."}
setLogFormat("console") // 14:32:15 INFO myapp message

Span Control

enableSpans(): void
disableSpans(): void
spansAreEnabled(): boolean

Trace Filter

setTraceFilter(namespaces: string[] | null): void
getTraceFilter(): string[] | null

Only emit spans matching these namespace prefixes.

setTraceFilter(["myapp:db"]) // Only db spans
setTraceFilter(null) // All spans

Debug Filter

setDebugFilter(namespaces: string[] | null): void
getDebugFilter(): string[] | null

Filter log output by namespace. Supports negative patterns.

setDebugFilter(["myapp"]) // Only myapp and children
setDebugFilter(["myapp", "-myapp:sql"]) // Exclude sql
setDebugFilter(null) // All namespaces

Auto-lowers log level to debug when set.

Output Mode

setOutputMode(mode: OutputMode): void
getOutputMode(): OutputMode
setSuppressConsole(value: boolean): void

Mode	Console	Writers
"console"	Yes	Yes
"stderr"	stderr	Yes
"writers-only"	No	Yes

Environment Variables

Variable	Values	Default
LOG_LEVEL	trace, debug, info, warn, error, silent	info
LOG_FORMAT	console, json	console
DEBUG	*, namespace prefixes, -prefix	(none)
TRACE	1, true, namespace prefixes	(none)
TRACE_FORMAT	json	(none)
NODE_ENV	production	(none)