The Claude Code Mastery Pack (35 Techniques)

Compact Conversation Skill

/compact compresses 30-45 min of conversation into a focused summary of decisions and current state. Claude stays sharp instead of slowly losing the plot.

Cost Check Skill

/cost displays token usage for the current session. Check hourly during long sessions. Set a mental budget. Surprises are never fun.

Database Seed Builder Skill

Comprehensive dev seed: 5 users across roles, 20 realistic projects, relationships, edge cases (archived project, deleted user, empty project). No "test123" data.

Dependency Check Skill

Before adding a package: "Is it maintained? Security issues? Bundle size? Lighter alternatives for my specific use?" Prevents bloat and risk.

Dependency Conflict Resolver Skill

Paste the conflict error; Claude analyzes which packages require conflicting shared-dep versions, suggests minimum-change resolution with tradeoffs.

Diff Review Skill

After Claude changes files: "Show me a diff of every modified file. Explain each change in one sentence." Catches unintended "helpful" edits you didn't ask for.

Documentation Pass Skill

After finishing a feature: "Read every file you created or modified. Generate comprehensive docs: functions, connections, I/O, non-obvious design decisions." Written immediately is accurate.

Environment Setup Script Skill

setup.sh that onboards a new dev in one command: deps, .env from .env.example, local DB, migrations, seed data, verify by running tests.

Full Error Paste Skill

Paste the COMPLETE error + stack trace, then: "Diagnose the root cause step by step before suggesting a fix." The step-by-step constraint prevents wrong fixes.

Git Blame Investigator Skill

"This function started failing yesterday. Read git log for this file over the past week. Identify which commit likely introduced the issue and explain. Then suggest the fix."

Git Checkpoint Skill

Before every major change: `git add . && git commit -m "checkpoint before [change]"`. When Claude breaks something, you revert in seconds.

Git Hook Writer Skill

Generate a pre-commit hook that runs linter on staged files, type-checks, blocks console.log in production code, blocks commits failing any check. Installs to .husky/pre-commit.

Incremental Build Skill

Never say "build the entire feature." Break into steps: schema → test → endpoint → test → validation → test → frontend → test. 5 steps with tests produces dramatically better code than one mega-prompt.

Init CLAUDE.md Skill

/init scans the codebase and generates a persistent CLAUDE.md (project structure, stack, patterns, architecture decisions) that Claude auto-reads every future session. Run at the start of every new project.

Migration Builder Skill

Schema change prompt that generates migration + repository update + API route updates + TS types, showing every file that needs to change BEFORE modifying anything. Claude shines on multi-layer ripple effects.

Multi-Model Switching Skill

Opus for planning and architecture (deeper thought). Sonnet for implementation (faster + cheaper). Plan with the thinker, build with the builder.

Parallel Session Skill

For large features, run two terminals: one Claude Code for backend, one for frontend. Clean focused context per domain. Connect at the end.

Pattern Enforcer Skill

Add to CLAUDE.md: "API routes follow src/api/example-route.ts. Repositories follow src/repositories/example-repo.ts. Components follow src/components/ExampleComponent.tsx." Patterns auto-match in new files.

Performance Profiler Skill

Claude analyzes for N+1 queries, missing indexes, unnecessary re-renders, large imports that should lazy-load, cacheable endpoints. Prioritizes by estimated impact.

Persistent Memory Skill

/memory adds instructions that apply across all future sessions ("Always use TypeScript strict mode", "Always run tests after /src/core changes"). No repeating rules.

Plan Mode Skill (Shift+Tab)

Switch to plan mode before any implementation. Claude analyzes the codebase and returns an architecture plan with zero code. Review → approve → switch back to build. Prevents more bugs than any other single habit.

Recovery Mode Skill

When Claude is stuck in a broken-implementation loop: "Stop. Read the original working version from git. Restate the goal simply. Start fresh with a different approach." Faster than accumulated-mistake debugging.

Refactoring Planner Skill

800-line file too complex? "Propose a refactoring plan splitting it into focused modules. Show proposed structure, what moves where, verify no imports break. Do NOT start yet." Plan-only output.

Reference File Pattern Skill

Instead of describing code style verbally, point Claude at an existing file: "Follow the same patterns as src/auth/login.ts." Dramatic consistency improvement.

Release Notes Generator Skill

Read git log since last tag; generate release notes organized by features / bug fixes / perf / breaking changes. User-friendly language, not dev jargon.

Screenshot Debug Skill

UI looks wrong? Screenshot + Ctrl+V + "Fix the alignment and card spacing." Visual feedback beats written descriptions every time.

Security Scan Skill

Scan codebase for SQL injection, XSS, exposed secrets, missing input validation, IDOR, rate-limit gaps. Per-finding: severity, location, danger, fix.

Terminal Prefix Skill

! prefix runs the message as a terminal command instead of sending to Claude. Quick tests, git status, navigation — no leaving the Claude Code UI.

Test-First Workflow Skill

"Write tests for X covering normal/zero/100%/negative/string-input cases. Then implement to pass." Behavior defined before code exists; implementation is automatically correct.