Global

Global Standards

Priority: P0 — Universal Rules

Core Design

• Apply SOLID, especially Single Responsibility: each function, component, class, or service has one clear reason to change.
• Apply KISS: choose the simplest design that solves the current problem correctly.
• Apply DRY: remove repeated logic when the duplication is real and stable, not accidental similarity.
• Apply YAGNI: do not add abstraction, configurability, or extension points without a present need.

Readability

• Use intention-revealing names. A reader should understand purpose without decoding abbreviations.
• Guard clauses and early returns over deep nesting.
• Explicit data flow over hidden side effects.
• Keep units focused enough to reason about quickly. Split when one unit mixes unrelated responsibilities.
• Comments explain why, constraints, or non-obvious tradeoffs — not what the code already says.

Safety

• Validate and sanitize all untrusted input at every boundary.
• Handle errors explicitly. Never swallow exceptions or return failures that hide the cause.
• Add context when propagating errors so failures are diagnosable.
• Never hardcode secrets, tokens, or credentials.
• Never leak sensitive data, PII, or internal stack details to users, clients, or logs.
• Clean up owned resources: subscriptions, listeners, timers, streams, connections.

Security Baseline

Three rules that apply on every code write, regardless of context:

• No raw SQL string concatenation. Parameterized queries or ORMs only.
• No wildcard CORS on authenticated routes. Explicit allowlisted origins only.
• No full ORM entity returned from an API endpoint. Project to DTO always.
• No auth tokens in localStorage/sessionStorage. Use httpOnly cookies; deeper auth rules live in refs/auth.md.

Change Quality

• Remove dead code, debug code, and stale fallbacks before finishing.
• Cover changed logic and important edge cases with appropriate verification.
• Keep behavior, naming, and structure consistent with the existing project unless there is a clear reason to improve.

Anti-Patterns

• Clever code that obscures intent
• Deep nesting instead of guard clauses
• Duplicated business logic across files or layers
• Hardcoded secrets or sensitive data in logs
• Resource lookups without owner or tenant scoping
• Global mutable state
• Premature optimization without measurement
• Debug code or dead code left in production paths
• Component mixing UI, business logic, and data fetching

References

Load only what the current task requires:

• api-design — HTTP semantics, status codes, URL design, versioning, pagination, or OpenAPI
• error-handling — error hierarchies, response envelopes, or error-boundary placement
• security — injection, CORS, SSRF, XSS, OWASP checklist, or running a SAST scan
• auth — OAuth/PKCE flows, token storage, session, CSRF, RBAC, credential hashing, brute-force/rate-limiting, JWT verification, password reset, MFA, service-to-service auth
• architecture — auditing structural debt, detecting logic leakage, or remediating God classes
• performance — profiling bottlenecks, batching queries, or fixing memory leaks
• debug — troubleshooting crashes, tracing failures, or filing a structured bug report
• cicd — vendor-neutral pipeline shape, gating, secrets handling, artifact promotion