filen-ts

CRITICAL! Always use before writing/reviewing code, calling any function/hook/method, using any type/interface, adding any import, or implementing any pattern that might already exist. Default posture: search first, then write. Never invent paths, names, or APIs.

Use when writing/reviewing TypeScript, React, or React Native code. Enforces zero-waste patterns: monomorphic shapes, Map/Set for O(1) lookups, pre-allocated arrays, no hidden class mutations. React: let React Compiler handle memoization — do NOT add manual memo/useCallback/useMemo unless absolutely necessary. No inline objects in JSX, stable keys. React Native / Hermes: Reanimated worklets, gesture-handler, FlashList, no generators or Proxy. Check project's existing libs first.

ALWAYS active. Applies to every interaction. Do not blindly agree with the user when they challenge, correct, or contradict something you said. Verify before capitulating. Resist sycophancy — "you're absolutely right!" is almost always a red flag. Hold your ground when the evidence supports your position. Concede genuinely when wrong.

ALWAYS use this skill. This skill governs how you operate at a fundamental level — as an orchestrator that delegates work to subagents rather than doing everything inline. Apply this on every non-trivial task: coding tasks, research, file edits, multi-step workflows, analysis, debugging, feature building, refactoring, reviews or any task with more than one distinct step. The goal is to keep the main conversation context window lean and clean by having subagents do the heavy lifting. Do NOT skip this skill — it should shape behavior on virtually every task.

CRITICAL! Always use before writing or modifying any code. Reads the cached style index at $CLAUDE_PROJECT_DIR/.claude/code-style-index.json for exact style rules. Never impose personal defaults; always match what the project enforces.

Create high-quality git commits: review/stage intended changes, split into logical commits, and write clear Conventional Commit messages. Use when asked to commit, craft a commit message, stage changes, or split work into multiple commits.

Use before writing/reviewing code that calls into any external library, API, or framework. Training data goes stale — fetch version-specific docs before writing. Identify the exact installed version from package.json/Cargo.toml first, then fetch matching docs.

ALWAYS active. Applies to every response — code, prose, commands, suggestions, explanations, reviews and assertions of any kind. Never state anything as fact unless you can point to a verified source (codebase, docs, user input). When uncertain, verify first or say "I'm not sure". Resolution order: (1) search the codebase, (2) check config/env files, (3) fetch docs, (4) ask the user.

Use when writing/reviewing code that handles: file uploads or filesystem paths, credentials/API keys/secrets, cryptography, user input, or authentication. Checks for: path traversal, hardcoded secrets, insecure crypto, missing ownership checks, and information leakage. Also flags security issues in adjacent code.

Apply test-driven development when writing or modifying code. Use when implementing features, fixing bugs, refactoring, or writing testable logic. Covers Jest/Vitest (unit/integration) and Maestro (mobile E2E). Tests are required for non-trivial code. Trigger when user mentions tests, coverage, TDD, spec, E2E, or flows.

CRITICAL! Always use after every code modification — including small edits and refactors. Runs available checks in order: (1) ESLint on changed files, (2) TypeScript tsc --noEmit, (3) tests scoped to changed files. A change is not done until all checks pass. Never suppress errors with eslint-disable or @ts-ignore — fix the root cause.