Stateful, production-fidelity replacements for Stripe, GitHub, Google, AWS, and 7 more services. No API keys. No network. Not mocks.
What this gives you
Stateful
Create a GitHub repo, push commits, open a PR. Send an email through Resend. Charge a card on Stripe. State persists across requests.
Real protocols
OAuth flows with RS256 ID tokens. AWS XML responses. Slack cursor pagination. Your SDK works without changes.
Zero config
Run npx emulate and all 11 services start with sensible defaults. Seed data via YAML when you need it.
Offline and CI-ready
No network, no Docker, no flaky sandbox accounts. Same deterministic behavior in GitHub Actions as on your laptop.
Point your SDK at localhost
Your existing code stays the same. Just change the host.
Use it your way
CLI
Run alongside your dev server. Pick which services you need.
npx emulate --service github,stripe
Programmatic API
Import into Vitest or Jest. Start per-suite, reset between tests.
Next.js adapter
Embed in your app. Same origin, no CORS issues, works on Vercel preview deployments.
npm install @emulators/adapter-next @emulators/github