Nyxis

Nyxis is a Lean backend framework that generates formally proven authorization safety guarantees for web applications.

Nyxis is a backend framework designed for solo developers building web applications with AI agents. It uses a Cedar schema and policies to define database tables, attributes, and actions, ensuring authorization safety. Developers write schemas and policies, while handlers can be written by AI tools without writing Lean code. The Lean kernel checks authorization safety on every build to prevent unauthorized data access. It integrates with PostgreSQL and Supabase Auth for client requests over HTTP.

Nyxis at a glance

Best for: Software engineer
Runs on: self-hosted, open source
Pricing: Free
Released: October 2026
Category: AI coding tool
Website: github.com/nyxfoundation/nyxis

Key features

Formally proven authorization safety
Cedar schema and policy definition
AI agent handler compatibility
Lake build safety verification
Supabase Auth JWT integration
File storage via signed URLs
Email notifications and external API calls

Use it for

Building secure web backends with AI-written handlers
Managing permissions through Cedar policies
Verifying application authorization via Lean proofs

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