Console output

A logger prints each line to standard error, pretty on a terminal and as JSON anywhere else, so a developer reads it and a log collector parses it. Every language prints the same bytes for the same line.

16:42:24.094 INFO  api  signed in  user=42
16:42:24.094 WARN  api  slow request  requestId=r-1 route=/notes ms=1200
16:42:24.094 ERROR api  charge failed  order=7
    error: Error: card declined
        at charge (billing.ts:41:9)

{"time":"2026-10-19T16:42:24.094Z","level":"INFO","stream":"api","msg":"signed in","user":42}

#Choosing the format

const log = store.logger('api', { console: 'json', time: 'full', hideStream: true })

log = store.logger("api", console="json", time="full", hide_stream=True)

handler := records.NewHandler(store, "api", console.JSON, console.TimeFull, console.HideStream)

let log = store.logger("api").console(Format::Json).time(Time::Full).hide_stream().layer()?;

console: 'off' prints nothing and keeps every line: a server that ships its console elsewhere, or a test.

#The environment wins

So that a deployment changes how lines look without a build, the environment goes over the code:

• env: { prefix: 'APP' } reads APP_LOG_LEVEL and the rest instead; env: false reads none.
• The environment never turns on a console the code turned off.
• A value none of them can mean is ignored, and said once.

Colours need a terminal, and neither NO_COLOR nor TERM=dumb. FORCE_COLOR makes a pipe pretty and coloured; NO_COLOR still wins.

#A console without a store

A program that wants the logger and no store, a CLI, a script, takes it from the package. The same calls, the same options but buffer and keep, the same lines, kept nowhere:

import { logger, secrets } from '@tinyshed/tinystore'

const log = logger('app', { redact: secrets })

from tinystore import logger, secrets

log = logger("app", redact=secrets)

log := slog.New(console.NewHandler("app", console.Redact(console.Secrets...)))

let log = tinystore::console::logger("app").redact(SECRETS).layer();
tracing_subscriber::registry().with(log).init();

In TypeScript and Python it loads nothing native. Go's package console imports neither the store nor cgo. In Rust the crate's console feature builds it alone, without a store or SQLite. Swapping logger('app') for store.logger('app') later keeps the lines too, with no other change.

#Same bytes everywhere

A line printed is the same bytes in TypeScript, Python, Go and Rust: one file of the repository holds the lines every SDK's tests print byte for byte. A program in two languages behind one log collector parses one format.

#See also

• Records: the engine's overview.
• Logging: levels, fields, with and secrets.