@lenso/log

Structured Pino logging for Lenso plugins and hosts. createLogger() emits JSON to stderr by default, keeping stdout available for CLI output and MCP protocol messages. Configure your process supervisor to collect stderr. Do not also export these logs through an OpenTelemetry log exporter unless duplicate records are intended; this package only correlates active trace/span IDs and does not register an SDK or exporter.

import { createLogger } from "@lenso/log";

const log = createLogger({ level: "info" });
log.child({ instanceId, pluginId, operation }).info({ jobId }, "started");

Set pretty: true for synchronous readable development output, without a worker transport. An existing Pino logger can be supplied with logger; the returned child is enriched with trace IDs but the supplied logger is not closed. Caller-owned logger configuration and transports remain the caller's responsibility.

Common structured keys such as authorization, cookie, password, token, secret, session, credentials, signature, and connectionString are redacted by default, along with common body and payload fields. For newly created loggers, default err, error, and configured errorKey serializers replace all values (including non-Error objects and primitive throws) with { type: "Error" }. Messages, stacks, causes and arbitrary .code properties are not forwarded. Direct Error writes without a message use "Error details omitted" rather than Pino's inferred error message.

An optional classifyError(error) callback may return explicitly public { code, phase } labels. Only those two string fields are copied; callback failure falls back to omission. Classify by trusted error identity or application policy, not by copying arbitrary .code, .message, or .cause properties. Instance, plugin, operation, request and trace/span correlation fields remain available in ordinary structured bindings.

Explicit custom serializers (including child serializers), hooks and redaction are SDK/logger owner extension points and may opt into raw details. An external logger keeps its owner's serializers and transports: wrapping it adds trace correlation, not error omission. classifyError applies only to newly created loggers, not borrowed loggers. Configure an external logger's safe serializers at its owner boundary before supplying it.

This is not a sandbox or comprehensive secret discovery. Free-form messages, interpolation arguments, deeply nested/custom keys, and external logger configuration require application-level policy. Avoid logging full payloads.