New npm package for automatic recovery of broken streaming markdown

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:

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

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

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

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

npm i remend