Under the hood

Logging examples

Every line the store logs while handling a request is tagged with that request automatically: no wrapper, no passing the request around. Each example below logs one line on the server and shows you what it carried.

Server Component

Logged while this page rendered, from a helper two awaits deep. Reload to get a new trace id.

2026-11-09T02:06:55.919Z INFO Checked stock

module: logging-examples
sku: MUG-01
inStock: 12

Added by the logger

traceId: 340a82791d149ac16beaf485f5338907— the same on every line of this request
spanId: d639c0bd6ecef0d4— the step that was running when the line was written
method: POST
url: /examples/logging— path and query as received
route: /examples/logging— the matched route pattern, once Next.js has resolved it

In your own code

Name the module where you log; names are typed (see LogModules), and each logger is made once and reused. Production writes one JSON object per line; development pretty-prints and hides the ids.

import { log } from "@turbo-starter/logger"

export async function reserveSample(sku: string) {
  await db.insert(reservations).values({ sku })
  log.info("shop-actions", "Reserved a sample", { sku })
  // → also gets traceId, spanId, method, url, route and action
}

Server Action

An exported action in actions.ts. The logger names it, and the url is the page the form was posted from.

Inline Server Action

Declared inside the page with “use server”. It has no exported name, so the logger falls back to its id.

Route Handler

GET /api/examples/logging, called with fetch from this page. Its own request, so a new trace id.