struxadotcloud/struxa

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feat: global unslop6531421a month ago1042 lines · 34.7 KB

1	---
2	name: review-logging-patterns
3	description: Review code for logging patterns and suggest evlog adoption. Guides setup on Nuxt, Next.js, SvelteKit, Nitro, TanStack Start, React Router, NestJS, Express, Hono, Fastify, Elysia, Cloudflare Workers, and standalone TypeScript. Detects console.log spam, unstructured errors, and missing context. Covers wide events, structured errors, drain adapters (Axiom, OTLP, HyperDX, PostHog, Sentry, Better Stack, Datadog), sampling, enrichers, and AI SDK integration (token usage, tool calls, streaming metrics, telemetry integration, cost estimation, embedding metadata).
4	license: MIT
5	metadata:
6	author: HugoRCD
7	version: "0.5"
8	---
9
10	# Review logging patterns
11
12	Review and improve logging patterns in TypeScript/JavaScript codebases. Transform scattered console.logs into structured wide events and convert generic errors into self-documenting structured errors.
13
14	## When to Use
15
16	- Setting up evlog in a new or existing project (any supported framework)
17	- Reviewing code for logging best practices
18	- Converting console.log statements to structured logging
19	- Improving error handling with better context
20	- Configuring log draining, sampling, or enrichment
21
22	## Quick Reference
23
24	\| Working on... \| Resource \|
25	\| --------------------- \| ------------------------------------------------------------------ \|
26	\| Wide events patterns \| [references/wide-events.md](
27	\| Error handling \| [references/structured-errors.md](
28	\| Code review checklist \| [references/code-review.md](
29	\| Drain pipeline \| [references/drain-pipeline.md](
30
31	## Installation
32
33	```bash
34	npm install evlog
35	```
36
37	---
38
39	## Framework Setup
40
41	### Nuxt
42
43	```typescript
44	// nuxt.config.ts
45	export default defineNuxtConfig({
46	modules: ["evlog/nuxt"],
47	evlog: {
48	env: { service: "
49	include: ["/api/**"],
50	},
51	});
52	```
53
54	All evlog functions (`useLogger`, `createError`, `
55
56	```typescript
57	// server/api/checkout.post.ts - no imports needed
58	export default defineEventHandler(async
59	const log =
60	log.set({
61	return { success:
62	});
63	```
64
65	Drain, enrich, and tail sampling use Nitro hooks in server plugins:
66
67	```typescript
68	// server/plugins/evlog-drain.ts
69	import { createAxiomDrain }
70
71	export default defineNitroPlugin((nitroApp
72	nitroApp.hooks.hook
73	});
74	```
75
76	Client transport (auto-configured Vue plugin):
77
78	```typescript
79	// nuxt.config.ts
80	evlog: {
81	transport: { enabled: true
82	}
83	```
84
85	Client-side: `log`, `setIdentity`, `
86
87	### Next.js
88
89	Step 1: Create central config - all exports come from here:
90
91	```typescript
92	// lib/evlog.ts
93	import type { DrainContext
94	import { createEvlog }
95	import { createUserAgentEnricher, createRequestSizeEnricher
96	import { createDrainPipeline }
97
98	const enrichers = [
99	const pipeline = createDrainPipeline
100	const drain = pipeline
101
102	export const { withEvlog
103	service: "my-app",
104	sampling: {
105	rates: { info: 10
106	keep: [{ status:
107	},
108	routes: {
109	"/api/auth/**": { service:
110	"/api/checkout/**": { service:
111	},
112	keep: (ctx)
113	const user =
114	if (user?.premium
115	},
116	enrich: (ctx)
117	for (const enricher
118	},
119	drain,
120	});
121	```
122
123	Step 2: Wrap route handlers with `withEvlog()
124
125	```typescript
126	// app/api/checkout/route.ts
127	import { withEvlog, useLogger
128
129	export const POST =
130	const log =
131	log.set({
132	log.set({
133	return Response.json
134	});
135	```
136
137	Step 3: Server Actions - same `withEvlog()
138
139	```typescript
140	// app/actions.ts
141	"use server";
142	import { withEvlog, useLogger
143
144	export const checkout =
145	const log =
146	log.set({
147	return { success:
148	});
149	```
150
151	Step 4: Middleware (optional - sets `x-request-id
152
153	```typescript
154	// proxy.ts
155	import { evlogMiddleware }
156	export const proxy =
157	export const config =
158	```
159
160	Step 5: Client Provider - wrap root layout:
161
162	```tsx
163	// app/layout.tsx
164	import { EvlogProvider }
165
166	export default function Layout
167	return (
168	<html lang="
169	<body>
170	<EvlogProvider
171	service="my-app"
172	transport={{ enabled:
173	>
174	{children}
175	</EvlogProvider>
176	</body>
177	</html>
178	);
179	}
180	```
181
182	Step 6: Client logging - in any client component:
183
184	```tsx
185	"use client";
186	import { log, setIdentity
187
188	setIdentity({ userId: "
189	log.info({ action
190	clearIdentity();
191	```
192
193	Step 7 (optional): Instrumentation - startup + global `onRequestError
194
195	Export `createInstrumentation()` from `lib/evlog.ts` alongside `
196
197	Step 8: Client ingest endpoint - receives client logs:
198
199	```typescript
200	// app/api/evlog/ingest/route.ts
201	import { NextRequest }
202
203	const VALID_LEVELS = [
204
205	export async function POST
206	const origin =
207	const host =
208	if (origin &&
209	return Response.json
210	}
211	const body =
212	if (!body?.timestamp
213	return Response.json
214	}
215	const { service:
216	console.log(
217	"[CLIENT LOG]",
218	JSON.stringify({
219	);
220	return new Response
221	}
222	```
223
224	### SvelteKit
225
226	```typescript
227	// src/hooks.server.ts
228	import { initLogger }
229	import { createEvlogHooks }
230
231	initLogger({ env: {
232
233	export const { handle
234	```
235
236	Access the logger via `event.locals.log` in route handlers or `useLogger()` from anywhere in the call stack:
237
238	```typescript
239	// src/routes/api/users/[id]/+server.ts
240	import { json }
241
242	export const GET =
243	locals.log.set
244	return json({
245	};
246	```
247
248	```typescript
249	import { useLogger }
250
251	async function findUsers()
252	const log =
253	log.set({
254	}
255	```
256
257	Full pipeline with drain, enrich, and tail sampling:
258
259	```typescript
260	import { createAxiomDrain }
261
262	export const { handle
263	include: ["/api/**"],
264	drain: createAxiomDrain(),
265	enrich: (ctx)
266	ctx.event.region
267	},
268	keep: (ctx)
269	if (ctx.duration
270	},
271	});
272	```
273
274	### Nitro v3
275
276	```typescript
277	// nitro.config.ts
278	import { defineConfig }
279	import evlog from "evlog/nitro/v3
280
281	export default defineConfig({
282	modules: [evlog({
283	});
284	```
285
286	```typescript
287	// routes/api/checkout.post.ts
288	import { defineHandler }
289	import { useLogger }
290
291	export default defineHandler(async
292	const log =
293	log.set({
294	return { ok:
295	});
296	```
297
298	### TanStack Start
299
300	TanStack Start uses Nitro v3. Install evlog and add a `nitro.config.ts`:
301
302	```typescript
303	// nitro.config.ts
304	import { defineConfig }
305	import evlog from "evlog/nitro/v3
306
307	export default defineConfig({
308	experimental: { asyncContext: true
309	modules: [evlog({
310	});
311	```
312
313	Add the error handling middleware to `__root.tsx`:
314
315	```typescript
316	// src/routes/__root.tsx
317	import { createMiddleware }
318	import { evlogErrorHandler }
319
320	export const Route =
321	server: {
322	middleware: [createMiddleware().
323	},
324	});
325	```
326
327	Use `useRequest()` from `nitro/context` to access the logger:
328
329	```typescript
330	import { useRequest }
331	import type { RequestLogger
332
333	const req = useRequest
334	const log = req
335	log.set({ user
336	```
337
338	### Nitro v2
339
340	```typescript
341	// nitro.config.ts
342	import { defineNitroConfig }
343	import evlog from "evlog/nitro
344
345	export default defineNitroConfig({
346	modules: [evlog({
347	});
348	```
349
350	Import `useLogger` from `evlog/nitro` in routes.
351
352	### NestJS
353
354	```typescript
355	// src/app.module.ts
356	import { Module }
357	import { EvlogModule }
358
359	@Module({
360	imports: [EvlogModule.forRoot
361	})
362	export class AppModule
363	```
364
365	`EvlogModule.forRoot()` registers a global middleware. Use `useLogger()` to access the request-scoped logger from any controller or service:
366
367	```typescript
368	import { useLogger }
369
370	async function findUsers()
371	const log =
372	log.set({
373	}
374	```
375
376	Full pipeline with drain, enrich, and tail sampling:
377
378	```typescript
379	import { createAxiomDrain }
380
381	EvlogModule.forRoot({
382	include: ["/api/**"],
383	drain: createAxiomDrain(),
384	enrich: (ctx)
385	ctx.event.region
386	},
387	keep: (ctx)
388	if (ctx.duration
389	},
390	});
391	```
392
393	For async configuration with NestJS DI, use `forRootAsync()`:
394
395	```typescript
396	EvlogModule.forRootAsync({
397	imports: [ConfigModule],
398	inject: [ConfigService],
399	useFactory: (config)
400	drain: createAxiomDrain({
401	}),
402	});
403	```
404
405	### Express
406
407	```typescript
408	import express from "express
409	import { initLogger }
410	import { evlog, useLogger
411
412	initLogger({ env: {
413
414	const app = express
415	app.use(evlog())
416
417	app.get("/api/users"
418	req.log.set
419	res.json({
420	});
421	```
422
423	Use `useLogger()` to access the logger from anywhere in the call stack without passing `req`:
424
425	```typescript
426	import { useLogger }
427
428	async function findUsers()
429	const log =
430	log.set({
431	}
432	```
433
434	Full pipeline with drain, enrich, and tail sampling:
435
436	```typescript
437	import { createAxiomDrain }
438
439	app.use(
440	evlog({
441	include: ["/api/**"],
442	drain: createAxiomDrain(),
443	enrich: (ctx)
444	ctx.event.region
445	},
446	keep: (ctx)
447	if (ctx.duration
448	},
449	}),
450	);
451	```
452
453	### Hono
454
455	```typescript
456	import { Hono }
457	import { initLogger }
458	import { evlog, type
459
460	initLogger({ env: {
461
462	const app = new
463	app.use(evlog())
464
465	app.get("/api/users"
466	const log =
467	log.set({
468	return c.json
469	});
470	```
471
472	Access the logger via `c.get('log')` in handlers. No `useLogger()` - use `
473
474	Structured errors: throw `createError()`, then in `app.onError` use `
475
476	```typescript
477	import { createError, parseError
478	import type { ContentfulStatusCode
479
480	app.onError((error
481	c.get("log
482	const parsed =
483	return c.json
484	{ message: parsed.
485	parsed.status as
486	);
487	});
488	```
489
490	Full pipeline with drain, enrich, and tail sampling:
491
492	```typescript
493	import { createAxiomDrain }
494
495	app.use(
496	evlog({
497	include: ["/api/**"],
498	drain: createAxiomDrain(),
499	enrich: (ctx)
500	ctx.event.region
501	},
502	keep: (ctx)
503	if (ctx.duration
504	},
505	}),
506	);
507	```
508
509	### Fastify
510
511	```typescript
512	import Fastify from "fastify
513	import { initLogger }
514	import { evlog, useLogger
515
516	initLogger({ env: {
517
518	const app = Fastify
519	await app.register(
520
521	app.get("/api/users"
522	request.log.set
523	return { users:
524	});
525	```
526
527	`request.log` is the evlog wide-event logger (shadows Fastify's built-in pino logger on the request). Fastify's pino logger remains accessible via `fastify.log`.
528
529	Use `useLogger()` to access the logger from anywhere in the call stack without passing `request`:
530
531	```typescript
532	import { useLogger }
533
534	async function findUsers()
535	const log =
536	log.set({
537	}
538	```
539
540	Full pipeline with drain, enrich, and tail sampling:
541
542	```typescript
543	import { createAxiomDrain }
544
545	await app.register(
546	include: ["/api/**"],
547	drain: createAxiomDrain(),
548	enrich: (ctx)
549	ctx.event.region
550	},
551	keep: (ctx)
552	if (ctx.duration
553	},
554	});
555	```
556
557	### Elysia
558
559	```typescript
560	import { Elysia }
561	import { initLogger }
562	import { evlog, useLogger
563
564	initLogger({ env: {
565
566	const app = new
567	.use(evlog())
568	.get("/api/users",
569	log.set({
570	return { users:
571	})
572	.listen(3000);
573	```
574
575	Use `useLogger()` to access the logger from anywhere in the call stack:
576
577	```typescript
578	import { useLogger }
579
580	async function findUsers()
581	const log =
582	log.set({
583	}
584	```
585
586	Full pipeline with drain, enrich, and tail sampling:
587
588	```typescript
589	import { createAxiomDrain }
590
591	app.use(
592	evlog({
593	include: ["/api/**"],
594	drain: createAxiomDrain(),
595	enrich: (ctx)
596	ctx.event.region
597	},
598	keep: (ctx)
599	if (ctx.duration
600	},
601	}),
602	);
603	```
604
605	### React Router
606
607	```typescript
608	// react-router.config.ts
609	import type { Config
610
611	export default {
612	future: {
613	v8_middleware: true,
614	},
615	} satisfies Config;
616	```
617
618	```typescript
619	// app/root.tsx
620	import { initLogger }
621	import { evlog }
622
623	initLogger({ env: {
624
625	export const middleware:
626	```
627
628	Access the logger via `context.get(loggerContext)` in loaders and actions:
629
630	```typescript
631	// app/routes/api.users.$id.tsx
632	import { loggerContext }
633
634	export async function loader
635	const log =
636	log.set({
637	return { users:
638	}
639	```
640
641	Use `useLogger()` to access the logger from anywhere in the call stack without passing context:
642
643	```typescript
644	import { useLogger }
645
646	async function findUsers()
647	const log =
648	log.set({
649	}
650	```
651
652	Full pipeline with drain, enrich, and tail sampling:
653
654	```typescript
655	import { createAxiomDrain }
656
657	export const middleware:
658	evlog({
659	include: ["/api/**"],
660	drain: createAxiomDrain(),
661	enrich: (ctx)
662	ctx.event.region
663	},
664	keep: (ctx)
665	if (ctx.duration
666	},
667	}),
668	];
669	```
670
671	### Cloudflare Workers
672
673	```typescript
674	import { initWorkersLogger, createWorkersLogger
675
676	initWorkersLogger({ env: {
677
678	export default {
679	async fetch(request
680	const log =
681	try {
682	log.set({
683	const response =
684	log.emit({
685	return response;
686	} catch (error)
687	log.error(error
688	log.emit({
689	throw error;
690	}
691	},
692	};
693	```
694
695	### Vite Plugin (any Vite-based framework)
696
697	For any Vite-based project (SvelteKit, Astro, SolidStart, React+Vite, etc.), use the Vite plugin for auto-init, auto-imports, and build-time features:
698
699	```typescript
700	// vite.config.ts
701	import evlog from "evlog/vite
702
703	export default defineConfig({
704	plugins: [
705	evlog({
706	service: "my-app",
707	autoImports: true, //
708	strip: ["debug"],
709	sourceLocation: true, //
710	client: {
711	// client-side logging
712	transport: { endpoint: "
713	},
714	}),
715	],
716	});
717	```
718
719	Server-side middleware (drain, enrich, keep, routes) is still configured in the framework integration (e.g., `evlog()` middleware for Hono/Express/SvelteKit). The Vite plugin handles build-time DX only.
720
721	### Standalone TypeScript
722
723	```typescript
724	import { initLogger, createRequestLogger
725
726	initLogger({ env: {
727
728	const log = createRequestLogger
729	log.set({ source
730	log.emit(); //
731	```
732
733	---
734
735	## Configuration Options
736
737	All options work in Nuxt (`evlog` key), Nitro (passed to `evlog()`), Next.js (`
738
739	\| Option \| Type \| Default \| Description \|
740	\| ------------------------- \| ---------------------------------------- \|
741	\| `env.service` / `service`
742	\| `enabled` \| `boolean
743	\| `pretty` \| `boolean
744	\| `silent` \| `boolean
745	\| `include` \| `string[]
746	\| `exclude` \| `string[]
747	\| `routes` \| `Record<string, { service }>
748	\| `minLevel` \| `'debug' \\| 'info' \\| 'warn' \\| 'error'
749	\| `sampling.rates` \| `object
750	\| `sampling.keep` \| `array
751	\| `drain` \| `(ctx) => void
752	\| `enrich` \| `(ctx) => void
753	\| `keep` \| `(ctx) => void
754	\| `redact` \| `boolean \\| RedactConfig
755
756	### Nitro Hooks (Nuxt, Nitro v2/v3)
757
758	\| Hook \| When \| Use \|
759	\| ----------------- \| ------------------------ \|
760	\| `evlog:drain` \| After enrichment \| Send events to external services
761	\| `evlog:enrich` \| After emit, before drain \| Add derived context
762	\| `evlog:emit:keep` \| During emit \| Custom tail sampling logic
763	\| `close` \| Server shutdown \| Flush drain pipeline buffers
764
765	---
766
767	## Drain Adapters
768
769	\| Adapter \| Import \| Env Vars \|
770	\| --------------------- \| -------------------- \|
771	\| Axiom \| `evlog/axiom` \|
772	\| OTLP \| `evlog/otlp` \|
773	\| HyperDX \| `evlog/hyperdx` \|
774	\| PostHog \| `evlog/posthog` \|
775	\| Sentry \| `evlog/sentry` \|
776	\| Better Stack \| `evlog/better-stack` \|
777	\| Datadog \| `evlog/datadog` \|
778	\| File System \| `evlog/fs` \| None (local file system)
779	\| HTTP (browser ingest) \| `evlog/http` \| None (configure
780
781	In Nuxt/Nitro, use the `NUXT_` prefix (e.g., `NUXT_AXIOM_TOKEN`) so values are available via
782
783	Setup pattern per framework:
784
785	```typescript
786	// Nuxt/Nitro: server/plugins/evlog-drain.ts
787	import { createAxiomDrain }
788	export default defineNitroPlugin((nitroApp
789	nitroApp.hooks.hook
790	});
791
792	// Hono / Express / Elysia: pass drain in middleware options
793	import { createAxiomDrain }
794	app.use(evlog(
795
796	// Fastify: pass drain in plugin options
797	import { createAxiomDrain }
798	await app.register(
799
800	// NestJS: pass drain in module options
801	import { createAxiomDrain }
802	EvlogModule.forRoot({ drain
803
804	// Next.js: pass drain to createEvlog()
805	import { createAxiomDrain }
806	import { createDrainPipeline }
807	const pipeline = createDrainPipeline
808	const drain = pipeline
809	// then: createEvlog({ ..., drain })
810
811	// Standalone: pass drain to initLogger()
812	initLogger({ env: {
813	```
814
815	See [references/drain-pipeline.md](references/drain-pipeline.md
816
817	---
818
819	## Enrichers
820
821	Built-in: `createUserAgentEnricher()`, `createGeoEnricher()`, `
822
823	```typescript
824	// Nuxt/Nitro: server/plugins/evlog-enrich.ts
825	import { createUserAgentEnricher, createGeoEnricher
826	export default defineNitroPlugin((nitroApp
827	const enrichers =
828	nitroApp.hooks.hook
829	for (const enricher
830	});
831	});
832
833	// Next.js: in lib/evlog.ts
834	createEvlog({
835	enrich: (ctx)
836	for (const enricher
837	ctx.event.region
838	},
839	});
840	```
841
842	---
843
844	## Auto-Redaction (PII Protection)
845
846	Built-in redaction scrubs sensitive data from wide events before console output and
847
848	```typescript
849	// Disable in production (opt-out)
850	evlog: { redact: false
851
852	// Add custom paths on top of built-ins
853	evlog: {
854	redact: {
855	paths: ['user.password',
856	}
857	}
858
859	// Only specific built-ins
860	evlog: {
861	redact: {
862	builtins: ['email',
863	}
864	}
865
866	// No built-ins, only custom (uses flat [REDACTED] replacement)
867	evlog: {
868	redact: {
869	builtins: false,
870	paths: ['user.ssn'],
871	patterns: [/SECRET_\w+/
872	}
873	}
874	```
875
876	Built-in patterns with smart masking output:
877
878	\| Pattern \| Example Input \| Masked Output \|
879	\| ------------ \| ----------------------- \|
880	\| `creditCard` \| `4111111111111111
881	\| `email` \| `alice@example.com
882	\| `ipv4` \| `192.168.1.100
883	\| `phone` \| `+33 6 12 34 56 78
884	\| `jwt` \| `eyJhbGciOi...
885	\| `bearer` \| `Bearer sk_live_abc...
886	\| `iban` \| `FR76 3000 6000 ...189
887
888	Works in all frameworks: Nuxt (`evlog` config), Nitro (`evlog()` module options), Next.js (`
889
890	---
891
892	## AI SDK Integration
893
894	Capture token usage, tool calls, model info, streaming metrics, tool execution timing, cost estimation, and embedding metadata from the Vercel AI SDK into wide events. Import from `evlog/ai`. Requires `ai >= 6.0.0` as a peer dependency.
895
896	### Basic setup (middleware)
897
898	```typescript
899	import { createAILogger }
900
901	const log = useLogger
902	const ai = createAILogger
903
904	const result = streamText
905	model: ai.wrap
906	messages,
907	});
908	```
909
910	`ai.wrap()` uses model middleware to transparently capture all LLM calls. Works with `generateText`, `
911
912	### Telemetry integration (deeper observability)
913
914	For tool execution timing, success/failure tracking, and total generation wall time, add `createEvlogIntegration()`:
915
916	```typescript
917	import { createAILogger, createEvlogIntegration
918
919	const ai = createAILogger
920
921	const agent = new
922	model: ai.wrap
923	tools: { searchWeb,
924	stopWhen: stepCountIs(5)
925	experimental_telemetry: {
926	isEnabled: true,
927	integrations: [createEvlogIntegration(ai
928	},
929	});
930	```
931
932	This adds `ai.tools` (per-tool `{ name, durationMs, success, error? }`) and `
933
934	### Embeddings
935
936	```typescript
937	const { embedding,
938	ai.captureEmbed({ usage
939	```
940
941	For `embedMany`, pass the batch count:
942
943	```typescript
944	ai.captureEmbed({ usage
945	```
946
947	### Cost estimation
948
949	Pass a pricing map to get `ai.estimatedCost` in the wide event:
950
951	```typescript
952	const ai = createAILogger
953	cost: {
954	"claude-sonnet-4.6": { input:
955	"gpt-4o": { input:
956	},
957	});
958	```
959
960	### Wide event `
961
962	Includes: `calls`, `model`, `
963
964	Anti-patterns to detect:
965
966	\| Anti-Pattern \| Fix \|
967	\| -------------------------------------- \| ------------------------------------------------------------------------- \|
968	\| Manual token tracking in `onFinish` \| `ai.wrap()
969	\| `console.log('tokens:', result.usage)` \| `ai.wrap()
970	\| No AI observability \| Add `createAILogger(log)` + `ai.wrap()
971	\| No tool execution timing \| Add `createEvlogIntegration(ai)` to `experimental_telemetry.integrations
972	\| Manual cost calculation \| Use `cost` option in `createAILogger()
973
974	---
975
976	## Structured Errors
977
978	```typescript
979	import { createError }
980
981	// Minimal
982	throw createError({ message:
983
984	// Standard
985	throw createError({ message:
986
987	// Complete
988	throw createError({
989	message: "Payment failed",
990	status: 402,
991	why: "Card declined by issuer - insufficient funds",
992	fix: "Please use a different payment method or contact your bank",
993	link: "https://docs.example.com/payments/declined",
994	cause: originalError,
995	});
996
997	// Backend-only context (wide events / drains - never HTTP body or parseError())
998	throw createError({
999	message: "Not allowed",
1000	status: 403,
1001	why: "Insufficient permissions",
1002	internal: { correlationId: "
1003	});
1004	```
1005
1006	Frontend - extract user-facing fields with `parseError()` (`internal` is never returned to clients):
1007
1008	```typescript
1009	import { parseError }
1010
1011	const error = parseError
1012	// error.message, error.status, error.why, error.fix, error.link
1013	```
1014
1015	See [references/structured-errors.md](references/structured-errors.md
1016
1017	---
1018
1019	## Anti-Patterns to Detect
1020
1021	\| Anti-Pattern \| Fix \|
1022	\| ------------------------------------------------ \| ------------------------------------------------------------------------------------- \|
1023	\| Multiple `console.log` in one function \| Single wide event with `log.set()
1024	\| `throw new Error('...')` \| `throw createError({ message, status, why, fix })
1025	\| `console.error(e); throw e` \| `log.error(e); throw createError(...)
1026	\| No logging in request handlers \| Add `useLogger(event)` / `useLogger()
1027	\| Flat log data `{ uid, n, t }` \| Grouped objects: `{ user: {...}, cart: {...} }
1028	\| Logging sensitive data `log.set({ user: body })` \| Explicit fields: `{ user: { id: body.id, plan: body.plan } }
1029	\| Putting support-only IDs in `why` / `message`
1030
1031	See [references/code-review.md](references/code-review.md
1032
1033	---
1034
1035	## Loading Reference Files
1036
1037	Load based on what you're working on - do not load all at once:
1038
1039	- Designing wide events → [references/wide-events.md](references/wide-events.md
1040	- Improving errors → [references/structured-errors.md](references/structured-errors.md
1041	- Full code review → [references/code-review.md](references/code-review.md
1042	- Drain pipeline setup → [references/drain-pipeline.md](references/drain-pipeline.md