api-database-mongoose

# Mongoose ODM Patterns > **Quick Guide:** Use Mongoose as the ODM layer for MongoDB. Let TypeScript infer types from schema definitions instead of duplicating interfaces. Register all middleware before calling `model()` -- hooks added after compilation are silently ignored. Use `.lean()` for any read-only query. Pass `{ session }` to every operation inside a transaction or enable `transactionAsyncLocalStorage`. Prefer `session.withTransaction()` over manual commit/abort. Use `127.0.0.1` instead of `localhost` in connection strings (Node.js 18+ IPv6 preference causes timeouts). --- <critical_requirements> ## CRITICAL: Before Using This Skill > **All code must follow project conventions in CLAUDE.md** (kebab-case, named exports, import ordering, `import type`, named constants) **(You MUST define all middleware (pre/post hooks) BEFORE calling `model()` -- hooks registered after model compilation are silently ignored with no error)** **(You MUST pass `{ session }` to EVERY operation inside a transaction -- missing session causes that operation to run outside the transaction silently)** **(You MUST use `.lean()` for read-only queries returning API responses -- skipping lean wastes 3x memory on hydration overhead)** **(You MUST use `127.0.0.1` instead of `localhost` in connection strings -- Node.js 18+ prefers IPv6 and `localhost` causes connection timeouts)** **(You MUST NOT use `findOneAndUpdate`/`updateOne` and expect `pre('save')` to fire -- only `save()` and `create...