Documentation

Xo (pronounced ex-oh) is a small, statically typed language for backends and web services, designed so AI agents can write, check, cross compile, and debug programs with fast, structured feedback.

• Why Xo? (FAQ): what Xo is for, how it relates to Go, and what experimental means.
• Getting started: build the toolchain and run a first program.
• A tour of Xo: twelve short steps through the language.
• Diagnostic codes: every error code, with an example and a fix.
• Core language specification: the source of truth for syntax and semantics.
• Standard library: prelude methods and the std packages.

Every page is also available as Markdown for agents: add index.md to its URL, or start from /llms.txt.