FastUI - panacea or pipe dream? — Samuel Colvin

FastUI offers a unified declarative protocol for defining UI components between frontend and backend with a JSON contract

Key benefits include:

• Type safety through Pydantic models that generate TypeScript interfaces
• Pre-built common UI components like forms, tables, pagination
• Reduced duplication of schema definitions between frontend/backend
• Easy unit testing due to JSON contract between components
• Can be used independently of frontend framework (not React-specific)

Current limitations:

• Best suited for internal admin applications currently
• Custom client-side logic requires additional implementation
• Project is still early and needs more development
• Not yet ideal for complex end-user applications

Core architecture:

• Uses FastAPI for backend
• Components defined through Pydantic models
• Contract between frontend/backend is JSON with predefined types
• Can leverage existing React components while maintaining separation

Differentiators from alternatives:

• Doesn’t require full buy-in to a specific framework
• Can be integrated into existing applications
• Provides good defaults while allowing customization
• Focus on avoiding duplicate work across projects

Goals and philosophy:

• Simplify and unify web application development
• Reduce duplication of common UI patterns
• Maintain separation between UI and application logic
• Enable reuse of existing frontend technologies