Best APIs & backend
4 products in APIs & backend that have a free tier and are open source, out of 29 in the category. Listed in ranking order and compared on pricing, free tier, API, MCP server, SDK and open source. 4 of 4 have a free tier, 4 of 4 have an API, 3 of 4 offer an MCP server, 4 of 4 are open source.
- Inngest
Durable execution for workflows and AI agents
- Hook0
Open-source webhooks-as-a-service with HMAC signatures, configurable retries, and EU hosting
- FreeIPAPI
Free IP geolocation API for IPv4 and IPv6 addresses, available in JSON and XML formats.
- App AI Gateway
Keep AI provider keys out of your iOS app. Verify each request with App Attest and set limits and budgets per user.
Side by side
| # | Product | Pricing | Free tier | API | MCP server | SDK | Open source |
|---|---|---|---|---|---|---|---|
| 1 | Inngest | Freemium · from $0 | yes | yes | yes | yes | yes |
| 2 | Hook0 | Freemium · from Free tier (100 events/day); paid cloud plans from €59/mo excl. VAT | yes | yes | yes | yes | yes |
| 3 | FreeIPAPI | Freemium | yes | yes | no | no | yes |
| 4 | App AI Gateway | Freemium | yes | yes | yes | yes | yes |
Ranked by verification, completeness, extraction confidence and method (AI model or heuristic fallback), and API/MCP support; ties go to the newest listing. Paid plans aren't an input to the ranking. Facts come from each product's own website, or from its verified owner when they have edited the listing. Each product page shows when it was last verified and how it was extracted.
All 29 products in APIs & backend →
API
curl 'https://toolgrep.com/api/products?category=api-platforms&has_free_tier=1&open_source=1'