Top 10 APIs
From ~400 public APIs reviewed, these are the critical infrastructure pieces. If we had to start with only 10 external services, these would be it.
The foundation. Repos, issues, Actions, PRs—everything flows through here.
Production-grade authentication. Don't build auth yourself.
File and URL security scanning. Essential for any app accepting uploads.
Public holidays for 90+ countries. Surprisingly essential for scheduling logic.
Decentralized cloud storage. 1TB free, S3-compatible, privacy-first.
Transactional and marketing email. Reliable delivery infrastructure.
URL threat checking. Validate links before users click them.
IP geolocation. Fast, accurate location for localization and analytics.
Crypto market data. Most generous free tier in the space.
Free JSON storage for prototypes. Zero setup, perfect for MVPs.
10 More Worth Your Time
Not critical infrastructure, but genuinely useful for specific needs. These fill gaps the top 10 don't cover.
Email validation API. Catches typos and reduces bounce rates at signup.
Phone number validation with carrier info. Global coverage.
Stock market data API. Real-time and historical pricing.
Deep URL analysis. Screenshots, certificate info, resource loading.
IP reputation checking. Community-driven abuse detection.
IPFS + Filecoin storage. 1TB free for decentralized apps.
380,000+ art images, public domain. Great for backgrounds, textures.
IPFS pinning service. Fast content delivery for decentralized storage.
Developer chat API. Good for open source community integrations.
Book data from the Internet Archive. Covers, subjects, authors.
Gaps We Want to Fill
Notable APIs that should be on public-apis but aren't. These are industry standards we use despite the list's omissions.
| API | Category | Why It Matters | Status |
|---|---|---|---|
| Stripe | Payments | Industry standard for payment processing. Missing is a major gap. | Critical Gap |
| Twilio | Communication | SMS, voice, email. The standard for programmable communications. | Critical Gap |
| AWS SDK | Cloud | S3, Lambda, DynamoDB—the backbone of modern infrastructure. | Critical Gap |
| SendGrid | Enterprise email delivery. More robust than most listed alternatives. | High Priority | |
| Supabase | Database | Open source Firebase alternative. PostgreSQL + realtime. | High Priority |
| Clerk | Auth | Modern auth with React components. Developer experience leader. | High Priority |
| Vercel API | Hosting | Edge deployment, serverless functions. Our default host. | High Priority |
| Firebase | Backend | Realtime database, auth, hosting. Google's BaaS platform. | Medium Priority |
| Cloudflare | Infrastructure | CDN, Workers, D1 database. Edge computing leader. | High Priority |
Contributing Back
We should add these gaps to public-apis via PR. Industry-standard tools belong on the list.