Foil Engine Documentation

Build AI-powered NPCs with dynamic conversations, state machines, and scoring.

Learn

Personas, scenarios, states, transitions, and scoring.

Real-world NPC templates and patterns.

Step-by-step guide to creating an NPC conversation flow.

Validate your NPC with chat preview and testing strategies.

Share your NPC via publish links.

JWT auth, rate limits, and error handling.

Send messages and manage conversation sessions.

Create, list, and manage NPC personas.

Install with pip for Python projects.

Install with npm for Node.js, web, or Bun.

Add via UPM for Unity 2021.3+.