Flo Runtime Book

This book is the public guide for writing Flo skill manifests and script tools.

It covers the supported authoring surface exposed through:

• skill and tool manifests
• flo.d.ts
• import * as flo from "flo:runtime"
• the local Node preload shim in flo_hooks.mts

Use this book when you are building or maintaining skills. Use the internal docs/ directory only when you are working on Flo itself.

What This Book Covers

• how to structure *.tool.yaml and *.skill.yaml
• how to write TypeScript or JavaScript tools
• how to call tools, store state, read vault secrets, emit debug events, and use browser automation
• how to orchestrate child tasks with flo.task.spawnChildren(...)

What This Book Does Not Cover

• backend-service deployment
• message bus internals
• database schema
• transport topology
• internal control-plane behavior

Those topics are intentionally kept out of this book so the content stays focused on skill authors.