Aviationstack ◆
Aviationstack is a scalable REST API for real-time flight tracking, historical flight data, airport info, and global aviation data.

Authorizer (Developer Tools): Self-hosted authentication and fine-grained authorization platform with permission-aware AI for SaaS, dev tools, and e-commerce. Pricing: Open source (free self-host); pay only for cloud infrastructure costs. (data verified July 2026)
Transparency: if you buy through our links we may earn a commission, at no extra cost to you. Rankings cannot be bought. How we rate tools
Authorizer is an open-source, self-hosted authentication and authorization platform that gives you complete control over your identity layer. Unlike hosted identity providers, Authorizer runs on your own infrastructure, keeping every user record in your own database. It combines authentication (OAuth2/OIDC), fine-grained authorization via embedded OpenFGA (Zanzibar model), and permission-aware AI retrieval in a single binary.
Built for product teams running SaaS, developer tools, e-commerce platforms, or AI products who want to avoid per-seat auth taxes and vendor lock-in. Ideal for organizations that need data residency control, custom enterprise SSO, and relationship-based permissions. Less suited for teams wanting a pre-built multi-IdP SSO marketplace or fully managed universal login pages without operational overhead.
Deploy Authorizer on Kubernetes or Docker to replace Auth0 or Firebase Auth in your stack. Use the OpenFGA engine for folder-level access in a document app, or permission-aware AI to pre-filter vector search results based on a user's allow-list. The React SDK lets you add login to any app in three lines of code.
Editorial score from our review methodology — not user ratings.
Authorizer pricing: Open source (free self-host); pay only for cloud infrastructure costs. Billing model: Free.
No per-seat fees. Download the Apache-2.0 licensed binary and deploy on your own infrastructure. You pay only for your cloud hosting costs (e.g., a $5/mo VPS or Kubernetes cluster). Includes all features: OAuth2/OIDC, OpenFGA authorization, permission-aware AI, 13+ database drivers, and SDKs for Go, Python, JS, and React.
Try the live demo at no cost — no credit card required. Watch the 2.0 demo on GitHub.
Don’t take our word for it — ask your AI about Authorizer