The core innovation of Streamdown lies in its real-time syntax repair system, which consists of a three-layer processing mechanism: the lexical analysis layer uses a sliding window to detect incomplete markup, the syntax analysis layer builds an elastic AST tree to accommodate temporary nodes, and the rendering layer realizes a smooth transition through virtual DOM difference updates. Specific cases show that when processing a block of code being generated by AI (which usually takes 10 seconds to complete), the component is able to build a code highlighting framework within 1 second of the markup's appearance, and gradually fill in the content afterwards.
The mechanism supports 12 Markdown elements including nested lists and multi-level headings, with an error recovery accuracy of 92.3%. In Vercel's internal tests, compared to the standard react-markdown component, its partial rendering success rate increased from 58% to nearly 100%.
This answer comes from the articleStreamdown: A Markdown Renderer Designed for AI Streaming ResponsivenessThe
