Logger

LoggerOptions

Option	Type	Description
`formatOptions?`	`object`	Output formatting (timestamps, meta, name segment, alignment, colors, stacks).
`level?`	`LogLevel \| undefined`	Minimum severity to emit. Default: `"info"`.
`name?`	`string`	Logger name included in every log line when provided.
`redact?`	`array`	Key names to redact recursively in meta objects (case-insensitive).
`transports?`	`array`	Output transports. Default single console transport.

FormatOptions

Option	Type	Description
`align?`	`number \| false \| undefined`	Min terminal width for right-aligned timestamps; `false` = always compact. Default: `80`.
`colors?`	`boolean \| "auto" \| undefined`	Pretty color override (`true` / `false` / `"auto"`). Default: `"auto"`.
`json?`	`object`	JSON serialization (field order and indentation).
`levels?`	`Partial<Record<ActiveLogLevel, object>>`	Per-level glyph/label/kind overrides for console prefixes.
`meta?`	`boolean \| undefined`	Inline meta JSON on console lines. Default: `true`.
`name?`	`boolean \| undefined`	`[name]` segment on console lines. Default: `true`.
`pretty?`	`boolean \| undefined`	Pretty console mode (glyphs/badges). Applies to console transports. Default: `false`.
`stack?`	`boolean \| undefined`	Stack frames in pretty error/fatal output. Default: `true`.
`time?`	`TimestampOption \| undefined`	Timestamp display. Formats: `"time"` \| `"time12"` \| `"iso"` \| `"utcString"`. Set to `false` or `{ enabled: false }` to omit timestamps. Default: enabled with `"time"` (`HH:MM:SS`) and timezone `"utc"`.

LevelFormatOptions

Option	Type	Description
`fallbackSymbol?`	`string`	ASCII fallback when Unicode glyphs are unsupported.
`kind?`	`LevelPrefixKind \| undefined`	Prefix kind: colored glyph or background badge.
`label?`	`string`	Uppercase label used by plain output and badges.
`symbol?`	`string`	Unicode glyph for symbol prefixes.

JsonFormatOptions

Option	Type	Description
`fieldOrder?`	`array`	Ordered field groups. `meta` expands to alphabetically sorted metadata keys. Missing groups append in the default order. Duplicates are ignored after first use. Default: `["timestamp", "level", "name", "message", "meta"]`.
`pretty?`	`number \| boolean \| undefined`	Pretty-print JSON. `true` uses 2 spaces; a number uses that indentation (clamped to 0–10). Default is compact one-line output. Default: `false`.

Prop	Type	Description
`child`	`function`	Returns a child logger that merges `bindings` into every subsequent log.
`debug`	`function`	Logs diagnostic details at the `debug` level. Hidden by the default threshold.
`error`	`function`	Logs a recoverable failure at the `error` level with structured error details.
`fatal`	`function`	Logs an unrecoverable failure at the highest severity level.
`info`	`function`	Logs general operational information at the default severity level.
`start`	`function`	Logs the beginning or progress of a process at the `info` severity tier.
`success`	`function`	Logs successful completion of a process at the `info` severity tier.
`time`	`function`	Starts a timer for `label`. Returns a stop function that logs at `success` level with `durationMs` in meta.
`trace`	`function`	Logs fine-grained diagnostic details at the lowest severity level.
`warn`	`function`	Logs a potentially harmful or unexpected condition at the `warn` level.
`withRequestId`	`function`	Returns a child logger with `requestId` bound. Generates one when `id` is omitted.

Primary call shape is message, meta? for most levels. error and fatal accept error, message?. Broader (...args: unknown[]) overloads keep the type assignable to cache-style logger contracts; unsupported extra arguments are preserved under details, not printf-interpolated.

ConsoleTransport

Option	Type	Description
`formatOptions?`	`object`	Per-transport formatting overrides (deep-merged over logger `formatOptions`).
`type`	`"console"`	Selects the human-readable console transport.

JsonTransport

Option	Type	Description
`formatOptions?`	`object`	Per-transport formatting overrides (deep-merged over logger `formatOptions`).
`type`	`"json"`	Selects the structured JSON transport, emitting one object per line.

Timestamp and format types

Type / constant	Description
`TimestampFormat`	`"time"` \| `"time12"` \| `"iso"` \| `"utcString"`
`TimestampTimezone`	`"utc"` \| `"local"`
`TimestampOption`	`boolean` or `{ enabled: false }` / `{ enabled: true; format?; timezone? }`
`JsonFieldGroup`	`"timestamp"` \| `"level"` \| `"name"` \| `"message"` \| `"meta"`
`LevelPrefixKind`	`"symbol"` \| `"badge"`

API Reference

createLogger