coldstart

Claude Code integration

Scaffold, deploy, and build with AI

Coldstart is designed to work with Claude Code at every stage — scaffolding, infrastructure setup, and development.

The /coldstart skill

Install the skill once:

Terminal
pnpm dlx skills add yabbal/cold-start

Then in Claude Code, type /coldstart or just describe what you want:

Claude Code
> /coldstart

> A fitness tracking app with web and mobile,
  freemium billing via Stripe, Google OAuth

Claude Code cannot run coldstart init (it requires an interactive terminal). Instead, it gathers your options conversationally, writes a .coldstart.json, and runs coldstart replay.

What Claude Code does

Gathers your config

Asks about platforms, billing, domain, OAuth — same options as the interactive CLI, but as a conversation.

Scaffolds the project

Writes the config to a temp file and runs coldstart replay /tmp/config.json. You get the same deterministic output as coldstart init.

Post-scaffold setup

Runs pnpm install, bash scripts/install-skills.sh, and bash scripts/setup-mcps.sh automatically.

Offers infrastructure setup

With the MCP servers now configured, Claude Code can set up your entire stack conversationally:

Claude Code
> Set up my database with Neon
> Configure Stripe billing
> Deploy to Vercel
> Set up Resend for emails

After scaffold workflow

The ideal workflow after scaffolding follows four phases:

Scaffold

Use /coldstart or coldstart init to generate your project. This creates the monorepo structure, all apps, and glue code.

Install skills

Skills are auto-installed during scaffold. If you need to re-run:

Terminal
bash scripts/install-skills.sh

This gives Claude Code deep context about your stack — Better Auth patterns, Drizzle queries, Hono middleware, Expo deployment, etc.

Set up infrastructure via MCP

Use Claude Code conversationally to provision services:

Claude Code
> Create a Neon database, run migrations, configure Resend
  email, set up Stripe products, and deploy to Vercel

Claude Code uses the configured MCP servers to do this without you leaving your terminal.

Build features

With infrastructure in place, start building your app. Claude Code has full context from CLAUDE.md, skills, and your codebase:

Claude Code
> Add a team dashboard page with member list and invite form
> Create an API route for file uploads with S3
> Add push notifications for mobile

Real-world examples

Here are complete conversation examples showing what you can build with Claude Code and Coldstart:

Tips for best results

Be specific about your domain. Instead of "a SaaS app", say "a project management tool for design teams". Coldstart generates 15-20 domain-specific rules in CLAUDE.md — the more specific you are, the better the guidelines.

Mention your billing model explicitly. "Subscription via Stripe" gives you recurring billing with customer portal. "Credits via Polar" gives you pay-as-you-go with credit balance tracking. The billing model affects database schema, middleware, and UI.

Specify OAuth providers you need. Each provider requires environment variables and generates specific UI buttons. Saying "Google and GitHub OAuth" up front avoids re-running the scaffolder later.

MCP servers

Every generated project includes .claude/settings.json with MCP servers configured based on your stack:

MCP serverWhen configuredWhat it doesAuthentication
NeonIf APICreate databases, run SQL, manage branchesAPI key via setup-mcps.sh
VercelIf webManage deployments, domains, logsOAuth (prompted on first use)
PolarIf billing + PolarCreate products, plans, webhooksOAuth (prompted on first use)
RevenueCatIf billing + mobileConfigure products, entitlementsAPI key via setup-mcps.sh
ResendIf APISend emails, manage domainsAPI key via setup-mcps.sh
ExpoIf mobileEAS builds, submissions, OTA updatesOAuth (prompted on first use)

Run bash scripts/setup-mcps.sh after scaffold to set API keys for Neon, Resend, and RevenueCat. OAuth-based servers (Vercel, Polar, Expo) prompt you automatically on first use in Claude Code.

Adding features after scaffold

Claude Code can add modules to an existing project:

Claude Code
> Add mobile to my project
> Add billing with Stripe, subscription model
> Add multi-tenant support
> Enable i18n with English, French, and Spanish

Under the hood, it runs coldstart add <module> with the right flags. The .coldstart.json, CLAUDE.md, skills, and MCP config are regenerated automatically.

What CLAUDE.md contains

Every generated project includes a CLAUDE.md that gives Claude Code full context:

  • Monorepo structure — which apps and packages exist
  • Tech stack — Next.js version, Tailwind config, Hono setup, Drizzle config
  • Domain guidelines — 15-20 industry-specific rules (e.g. "money as integers in cents" for finance, "HIPAA awareness" for health)
  • Billing model — how the billing flow works, which middleware to use
  • Conventions — Biome config, commit format, naming, testing
  • Commands — dev (portless HTTPS URLs), build, test, lint, db commands
  • How-to guides — add a page, add a route, add a table, add a package
  • Anti-patterns — no any, no var, no default exports, no secrets in code

The domain guidelines are very specific. A finance project gets PCI compliance rules, audit trail patterns, and integer money handling. A social project gets cursor pagination, real-time update patterns, and content moderation guidelines.

Installed skills

The skills installer (scripts/install-skills.sh) adds context-aware skills based on your stack:

  • Turborepo best practices
  • Vitest testing patterns
  • Context engineering
  • Spec kit (test planning)
  • PostHog analytics
  • React + Vercel best practices
  • Tailwind v4 + shadcn/ui
  • Design system (Impeccable)
  • Privacy policy generator
  • SEO audit, copywriting, CRO (if landing page)
  • Pricing strategy (if billing)
  • next-intl language addition (if i18n)
  • Expo deployment
  • React Native best practices
  • Reanimated + Skia performance
  • RevenueCat (if billing)
  • Push notification best practices
  • App Store analytics
  • ASC CLI usage
  • Better Auth (3 skills: best practices, email/password, setup)
  • React Email + Resend
  • Hono framework
  • Drizzle ORM
  • Neon PostgreSQL
  • API rate limiting
  • Polar + Better Auth (if Polar billing)

Limitations

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