·4 min read
MVP API Integration Basics for Founders
APIs let your product talk to other services. Understanding them helps you scope your MVP correctly.
What is an API
An API is a way for software to communicate. When your app processes a payment through Stripe, it uses the Stripe API. When it sends emails through Resend, it uses the Resend API.
Common MVP Integrations
| Category | Common APIs |
|---|---|
| Payments | Stripe, PayPal, Paddle |
| Resend, SendGrid, Postmark | |
| Auth | Auth0, Clerk, Firebase Auth |
| Storage | AWS S3, Cloudinary, Uploadthing |
| Analytics | Mixpanel, PostHog, Amplitude |
| AI | OpenAI, Anthropic, Replicate |
Integration Complexity Levels
- •Simple: Drop-in widgets (Stripe Checkout, Calendly embed)
- •Medium: SDK integration (sending emails, processing payments)
- •Complex: Two-way sync, webhooks, custom flows
Questions for Your Developer
- •Which third-party services does the MVP need?
- •Are there costs associated with these APIs?
- •What happens if an API is down?
- •Do we need to store API keys securely?
- •Are there rate limits we might hit?
API Costs to Budget For
- •Most have free tiers covering MVP needs
- •AI APIs can get expensive quickly (budget carefully)
- •Check per-request vs monthly pricing
- •Some charge for overages automatically
Every API integration adds complexity and a potential point of failure. Only integrate what is truly necessary for MVP.