review-logging-patterns

What the source does

• FilesystemNone observedNo reads or writes in the source
• NetworkNone observedNo outbound calls in the source
• ShellNone observedNo commands run in the source
• DependenciesPinnedNothing floats
• SecretsNone foundNo keys in source

Five audit layers

Gates applied: no behavioural pass.

README.md

Audit 0.4.1 · source sha d5329db59f8b · 23 Oct 2026Report an issue or request a re-scan

• Publisherhugorcd GitHub organizationOwner of the repository this skill is read from
• Source folderhugorcd/evlog/skills/review-logging-patternsThe exact folder we audited
• LicenceMITAs the repository states it
• Commit pinned for this verdictd5329db59f8bA new audit runs when the source changes
• Repository statusNot archivedLast push 1 day ago
• Sandboxed runNot runSkills are read, not executed; layer L4 is skipped

Its description: Review code for logging patterns and suggest evlog adoption. Optionally use the evlog CLI, shipped with the evlog package (`evlog init` to wire evlog, `evlog agents` to write the conventions into AGENTS.md, `evlog map`…

---
name: review-logging-patterns
description: Review code for logging patterns and suggest evlog adoption. Optionally use the evlog CLI, shipped with the evlog package (`evlog init` to wire evlog, `evlog agents` to write the conventions into AGENTS.md, `evlog map` to score entry-point coverage, `--baseline` to gate regressions in CI) on Nuxt, Nitro, Next.js, TanStack Start, Hono, Express, and Fastify. Guides setup on those plus SvelteKit, React Router, NestJS, Express, Fastify, Elysia, oRPC, Effect, Cloudflare Workers, AWS Lambda, Astro, and standalone TypeScript. Detects console.log spam, unstructured errors, and missing context. Covers wide events, structured errors, drain adapters (Axiom, OTLP, HyperDX, Sazabi, PostHog, Sentry, Better Stack, Datadog, Loki, ClickHouse, NuxtHub, Memory), sampling, enrichers, and AI SDK integration.
license: MIT
metadata:
  author: HugoRCD
  version: "0.9"
---

# Review logging patterns

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.

## When to Use

- Setting up evlog in a new or existing project (any supported framework)
- Reviewing code for logging best practices
- Converting console.log statements to structured logging
- Improving error handling with better context
- Configuring log draining, sampling, or enrichment

## Quick Reference

| Working on...           | Resource                                                           |
| ----------------------- | ------------------------------------------------------------------ |
| Setup (CLI)             | [`evlog init`](https://www.evlog.dev/cli/init): wire evlog into the project |
| Project conventions (CLI) | [`evlog agents`](https://www.evlog.dev/cli/agents): write the evlog block into the project's AGENTS.md |
| Coverage map (CLI)      | [`evlog map`](https://www.evlog.dev/cli/map): score dark entry points |
| CI gating (CLI)         | [`evlog map --min-score / --baseline`](https://www.evlog.dev/cli/ci): gate regressions |
| Wide events patterns    | [references/wide-events.md](references/wide-events.md)             |
| Error handling          | [references/structured-errors.md](references/structured-errors.md) |
| Code review checklist   | [references/code-review.md](references/code-review.md)             |
| Drain pipeline          | [references/drain-pipeline.md](references/drain-pipeline.md)       |
| Audit logs              | [build-audit-logs](../build-audit-logs/SKILL.md) skill + [docs](https://www.evlog.dev/use-cases/audit/overview) |

## Audit logs

For security-sensitive actions (auth, billing, admin, data export), use evlog's audit layer: a typed `audit` field on wide events, not a parallel logger. See the **`build-audit-logs`** skill for end-to-end setup (`log.audit`, `withAudit`, denials, `auditEnricher`, `auditOnly`, `signed`, `mockAudit`).

```typescript
log.audit({
  action: 'invoice.refund',
  actor: { type: 'user', id: user.id },
  target: { type: 'invoice', id: invoice.id },
  outcome: 'success',
})
```

Docs: https://www.evlog.dev/use-cases/audit/overview

## Installation

```bash
npm install evlog
```

## Use the CLI (recommended on Nuxt, Nitro, Next.js, TanStack Start, Hono, Express, Fastify)

The `evlog` executable ships with the `evlog` package: `pnpm evlog`, `npx evlog`, `bunx evlog`. It runs `@evlog/cli` when installed and fetches it on demand otherwise (no dependency added to the project), so it works on a project with nothing yet. Early but worth trying. It reads the project on disk (no traffic, no config needed). On the seven supported frameworks it covers the whole loop: **wire evlog in** (`init`), **score coverage** (`map`), **lock the score in CI** (`--min-score`, `--baseline`). If the CLI is unavailable, the framework has no adapter yet, or the user declines, continue with the manual sections below; the skill does not depend on it. **Ask before installing anything**.

### 1. Setup: `evlog init`

On a project that doesn't use evlog yet, prefer `init` over hand-writing the setup, since it detects the framework, reads what the project already has, and generates config, drains, enrichers, and extras in one pass. It is fully scriptable for agents:

```bash
# preview everything without writing (always start here)
npx evlog init --dry-run --yes

# then apply — flags instead of prompts
npx evlog init --yes \
  --service my-app \
  --drain fs \
  --prodDrain axiom \
  --extras enrichers,pipeline,sampling \
  --sampling medium
```

Useful flags: `--framework` (override detection: `nuxt`, `nitro`, `next`, `tanstack-start`, `hono`, `express`, `fastify`), `--prodDrain` (comma-separated: `axiom`, `otlp`, `posthog`, `sentry`, `better-stack`, `datadog`, `hyperdx`, `sazabi`, `loki`, `clickhouse`), `--extras` (`enrichers`, `pipeline`, `sampling`, `vite`, `error-catalog`, `audit-catalog`, `ai`, `better-auth`), `--enrichers`, `--sampling` (traffic tier: `all`, `low`, `medium`, `high`, `very-high`), `--apps` (monorepo: which workspace packages), `--no-install`. Review the `--dry-run` output with the user before applying. Docs: https://www.evlog.dev/cli/init

### 2. Score: `evlog map`

```bash
npx evlog map --no-write
# agents: npx evlog map --json --no-write
```

What you get:

- A project score and which entry points are still dark
- **FIX FIRST**: the three most valuable places to fix
- **GOING FURTHER**: opportunities (catalogs, audit coverage, AI logging, auth identity) that never cost points
- Per-file inspect: `npx evlog map <file> --no-write` shows the shape the handler could take
- Re-run after fixes and watch the score move

Work FIX FIRST in order, keep changes minimal (`useLogger()`, `log.set()`, `log.audit()`, `createError({ why, fix })`), then re-run with `--no-write`. Omit `--no-write` only when the user wants `evlog.map.json` written.

### 3. Lock it in CI: `--min-score` and `--baseline`

On GitHub Actions, suggest the

Excerpt, first 6,000 characters of SKILL.md, verbatim from the audited commit. It is text from someone else’s repository, quoted so you can judge it before your agent reads it.

npm install evlog

git clone https://github.com/hugorcd/evlog
git -C evlog checkout d5329db59f8b

Works in

1. 2026-10-23
   ✓SAFE B 89 / 100

   first audit · source d5329db59f8b

Questions about review-logging-patterns

• github.com/hugorcd/evlog/tree/main/skills/review-logging-pattern — the audited source at commit d5329db59f8b and every finding aboveObserved · 23 Oct 2026

Spotted something wrong? Report a correction · Methodology