This skill is the official reference for installing, configuring, and correctly using cipher-logger — a lightweight, production-ready HTTP logging library for Node.js (organization: cipherunits, repository: github.com/cipherunits/CipherLogger). Important: do not assume the API based on similarity to winston/pino/morgan — use the exact API documented here.

cipher-logger has three distinct parts that must not be mixed:

1. Logger — the base application logger class (independent of HTTP). Use for logger.info/warn/error/debug.
2. createCipherLogger(config) — factory that creates the main instance, configures optional fields and level, and exposes .express(), .next(), and .logRequest().
3. Framework adapters (cipher.express() and cipher.next()) — ready-made middleware; mount them rather than writing manual request logging.

If the user only asks to "log requests", they usually need steps 2 and 3, not 1.

pnpm add cipher-logger
# Framework packages are peer dependencies:
pnpm add express   # if using Express
pnpm add next      # if using Next.js

Node.js 18+ is required. Install only the peer dependency actually used by the project (e.g., express or next).

1. Create a logger with createCipherLogger({ fields: {...}, level: "info", prefix: "..." }) — enable only the fields the user actually needs; all optional fields default to false.
2. For Express: mount app.use(cipher.express()) before route definitions, otherwise status/duration will be incorrect because the middleware must observe the request.
3. For Next.js: use cipher.next() in middleware.ts (or src/middleware.ts) and always restrict config.matcher to exclude static/image routes to avoid noisy logs.
4. For more detailed guidance, read the related skill files below — only open the section relevant to the user's request:

• skills/fusion-references/SKILL.md — configuration options and optional fields
• skills/fusion-express-integration/SKILL.md — Express integration and sample output
• skills/fusion-nextjs-integration/SKILL.md — Next.js middleware and the important status/duration limitation
• skills/fusion-log-schema/SKILL.md — full log schema (required/optional fields)
• skills/fusion-api-reference/SKILL.md — function/class signatures and TypeScript exports
• skills/fusion-architecture/SKILL.md — internal package structure (for debugging/contrib)

• Check peer dependencies: If the project is Express but express is not installed (or vice versa), a runtime error will occur. Check package.json before suggesting code.
• Default level is "debug", not "info" — in production "info" is usually more appropriate; set it explicitly in config instead of relying on the package default.
• In Next.js middleware, status and duration reflect the middleware's execution, not the final route response (because middleware runs before route handlers). Remind the user of this when they expect the actual response status — route-handler wrappers are planned for future versions but are not available now.
• In Express the opposite is true: status and duration are recorded after res.finish and therefore reflect the real response — explain this difference when comparing adapters.
• Optional fields are off by default; the user must explicitly enable ip, userAgent, query, etc.
• This package is lightweight — don't recommend adding heavy log frameworks like winston/pino unless the user specifically asks; the package is intended to be minimal.
• Exclude static routes in Next.js matcher (example: /((?!_next/static|_next/image|favicon.ico).*)) to avoid excessive noisy logs.

1. Check whether the project is Express or Next.js (via package.json or folder structure).
2. If middleware.ts already exists, merge the new code instead of replacing it (it may contain other middleware like auth or i18n).
3. If the project is a monorepo (e.g. Mananegar), determine which workspace/app the package should be installed into, not necessarily the monorepo root.