How to Build Agent-native: Lessons From Four Apps

Katie Parrott distills lessons from Every’s four AI products (Cora, Spiral, Sparkle, Monologue) into a practical framework for agent-native architecture. The core advice: start with three simple tools and let the AI figure out the rest, rather than over-engineering the tool surface upfront.

The piece covers patterns for when to give agents autonomy versus when to constrain them, how to design tool interfaces that compound over time, and what agent-native architecture looks like compared to traditional API-first design.

RDCO mapping: Directly relevant to our agent architecture decisions. The “start with three tools” heuristic is worth testing against our current MCP server setup. The lessons from four production apps carry more weight than theoretical frameworks.