coldstart

Domain Presets

Industry-specific guidelines injected into your CLAUDE.md for AI-assisted development

During coldstart init, you pick a domain that matches your project's industry. This injects 15-20 domain-specific guidelines into the generated CLAUDE.md at the root of your monorepo. These guidelines shape how Claude Code writes code for your project — data patterns, security considerations, performance requirements, and anti-patterns to avoid.

How domains work

The domain selection affects only the generated CLAUDE.md. No code is generated differently based on domain — the same auth, billing, and platform code is scaffolded regardless. The domain provides contextual guidelines so that when you use Claude Code (or any AI assistant reading CLAUDE.md), it writes domain-appropriate code from day one.

For example, selecting Finance means Claude Code will:

  • Use integers (cents) for monetary values, never floats
  • Add idempotency keys to transaction operations
  • Consider PCI compliance when handling payment data
  • Follow audit trail patterns for state changes

Available domains

There are 10 domain presets. Choose General if your project doesn't fit a specific category.

How domains affect CLAUDE.md

The generated CLAUDE.md includes a Product Domain section that names the domain and injects all guidelines:

CLAUDE.md (excerpt)
## Product Domain

Category: **Finance** — Banking, budgets, crypto, trading

### Finance Domain Guidelines

- **Money handling**: Always use integers (cents) for monetary values, never floats
- **Currency**: Store ISO 4217 currency codes alongside amounts
- **Transactions**: Every financial operation must be idempotent with unique transaction IDs
- **Precision**: Use Intl.NumberFormat for display, never manual string formatting
- ...

When Claude Code reads this file at the start of every conversation, it applies these guidelines to all code it writes — without you having to repeat them in every prompt.

Choosing the right domain

If your project is about...Choose
Money, payments, trading, budgetsFinance
Health tracking, fitness, medicalHealth
Courses, quizzes, learningEducation
Selling products, marketplaceE-commerce
Social feeds, messaging, profilesSocial
Task management, notes, collaborationProductivity
Video, audio, image contentMedia
Recipes, restaurants, deliveryFood
Games, competitions, gamificationGaming
Everything elseGeneral

You can change the domain after scaffolding by editing the CLAUDE.md directly. Replace the domain section with guidelines from another domain, or write your own.

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