Data Layer

Application state · SQLite · DuckDB · Supabase

The $0 AI Architecture Stack · 2026

What is the Data Layer?

The Data Layer persists application state — users, sessions, logs, and structured records. SQLite is a zero-config embedded database perfect for getting started, DuckDB is a blazing-fast in-process engine for analytics, and Supabase offers a hosted PostgreSQL with auth and storage on a free tier when you need a real backend.

Tools in this Layer

🪶 SQLite

Zero-config embedded SQL database — a single file, no server needed.

🦆 DuckDB

In-process analytical database that runs SQL over millions of rows instantly.

⚡ Supabase

Hosted PostgreSQL with auth, storage, and pgvector on a free tier.

Cost

$0 / free tier

SQLite and DuckDB are free; Supabase has a free tier.

Explore the Full $0 AI Stack

1 Frontend Layer 2 Agent Orchestrator 3 RAG Pipeline 4 LLM Layer 5 Tool Use via MCP 6 Code Agent 7 Data Layer 8 Deployment Layer