Remend is a new standalone package that brings intelligent incomplete Markdown handling to any application.

Previously part of Streamdown's Markdown termination logic, Remend is now a standalone library (npm i remend) you can use in any application.

Link to headingWhy it matters

AI models stream Markdown token-by-token, which often produces incomplete syntax that breaks rendering. For example:

• Unclosed fences

• Half-finished bold/italic markers

• Unterminated links or lists

Without correction, these patterns fail to render, leak raw Markdown, or disrupt layout:

**This is bold text
[Click here](https://exampl
`const foo = "bar

Remend automatically detects and completes unterminated Markdown blocks, ensuring clean, stable output during streaming.

import remend from "remend";
const partialMarkdown = "This is **bold text";
const completed = remend(partialMarkdown);
// Result: "This is **bold text**"

As the stream continues and the actual closing markers arrive, the content seamlessly updates, giving users a polished experience even mid-stream.

It works with any Markdown renderer as a pre-processor. For example:

import remend from "remend";
import { unified } from "unified";
import remarkParse from "remark-parse";
import remarkRehype from "remark-rehype";
import rehypeStringify from "rehype-stringify";
const streamedMarkdown = "This is **incomplete bold";
// Run Remend first to complete incomplete syntax
const completedMarkdown = remend(streamedMarkdown);
// Then process with unified
const file = await unified()
  .use(remarkParse)
  .use(remarkRehype)
  .use(rehypeStringify)
  .process(completedMarkdown);
console.log(String(file));

Remend powers the markdown rendering in Streamdown and has been battle-tested in production AI applications. It includes intelligent rules to avoid false positives and handles complex edge cases like:

• Mathematical expressions with underscores in LaTeX blocks

• Product codes and variable names with asterisks/underscores

• List items with formatting markers

• Nested brackets in links

To get started, either use it through Streamdown or install it standalone with: