Structured Task Logging

The SDK ships a tiny zero-dependency leveled logger. It writes to stderr by default, so it never pollutes stdout (the CLI's --json output and piped data stay clean). FlexiQ uses it internally; it is exported for your own use too.

import { createLogger } from "@byteveda/flexiq";

const log = createLogger("billing"); // tagged [flexiq:billing]

queue.task("charge", async (amount: number) => {
  log.info("charging", { amount });
  // ...
});

Levels

debug < info < warn < error < silent. The threshold defaults to warn and is read once from FLEXIQ_LOG_LEVEL; override it at runtime:

import { setLogLevel } from "@byteveda/flexiq";

setLogLevel("debug"); // global, immediate

A message can be a string or a thunk that is only evaluated when the level passes the threshold — so expensive log lines cost nothing when filtered out:

log.debug(() => `payload=${JSON.stringify(bigObject)}`);

Extra arguments are appended: Errors render their stack, objects are JSON-stringified.

log.error("delivery failed", err, { webhookId });

Namespaces

createLogger(ns) tags every line [flexiq:ns]; child() nests further:

const log = createLogger("worker"); // [flexiq:worker]
const poolLog = log.child("pool"); // [flexiq:worker:pool]

Custom sink

Replace the output sink to route logs to a file, JSON transport, or a test buffer — globally and immediately:

import { setLogSink } from "@byteveda/flexiq";

setLogSink((level, line) => myTransport.write({ level, line }));