unified is a syntax tree processor that lets you parse, inspect, transform, and serialize content with plugins.
The tool solves the problem of working with structured representations of content by providing a unified interface for processing abstract syntax trees. It works by accepting content, parsing it into a tree structure, running transformations through a plugin system, and serializing the result back to a string. The core processor accepts plugins that can inspect or modify the tree at any stage, and supports both synchronous and asynchronous workflows.
You should use unified when building tools that need to inspect or transform content programmatically. It suits projects like site generators, linters, code formatters, or any system that needs to work with multiple content types. If you are working with a single content type like markdown, the specialized ecosystem packages built on unified (such as remark for markdown, rehype for HTML, or retext for natural language) may be more convenient. However, unified itself is the right choice when you need to handle different kinds of content together or want to compose utilities across multiple ecosystems.
The project maintains a large ecosystem of packages built around it and receives ongoing maintenance with active plugin development. The tool is widely adopted in established projects and continues to be used as a foundation for content processing workflows across different domains.
