n8n-nodes-markdown-chunker

An n8n community node that splits Markdown into retrieval-ready chunks with heading-aware metadata — the missing link between document conversion and your vector store.

convert → chunk → embed. Pair it with n8n-nodes-docx-to-md or n8n-nodes-url-to-md to turn any document or web page into clean Markdown, then slice it into chunks an embeddings model can actually use.

Why this node

Generic text splitters cut on character counts. They happily slice a code block in half, tear a table apart, and strip the heading context a retriever needs to rank a passage. Markdown Chunker understands document structure:

• Heading-hierarchy splitting — start a fresh chunk at #/##/### headings, down to a configurable depth.
• Parent-heading path on every chunk — metadata.headingPath carries the ancestor headings (e.g. ["Guide", "Setup"]), so a retrieved chunk keeps its context.
• Atomic code blocks & tables — fenced code (```/~~~) and GFM tables are never broken across a chunk boundary.
• Size target + overlap — a soft character target with optional overlap for size-driven splits.
• Zero runtime dependencies, no fs/env access — eligible for the n8n Cloud verified-node panel.
• usableAsTool: true — callable directly by AI agents.

Installation

In n8n: Settings → Community Nodes → Install, then enter n8n-nodes-markdown-chunker.

Or with npm in a self-hosted instance:

npm install n8n-nodes-markdown-chunker

Use as an AI Agent tool

The node ships with usableAsTool: true, so an AI Agent can call it directly — e.g. to chunk a document it just fetched before embedding it.

On n8n Cloud and recent self-hosted versions this works out of the box. On older self-hosted instances, enable community-node tool usage:

N8N_COMMUNITY_PACKAGES_ALLOW_TOOL_USAGE=true

Then attach Markdown Chunker to an AI Agent's Tool input.

Parameters

Field	Default	Description
Source Field	markdown	Input field holding the Markdown text to chunk.
Destination Output Field	text	Output field that receives each chunk's text.
Max Heading Depth	3	Start a new chunk at ATX headings of this level or shallower (1 = only #).
Target Chunk Size (Chars)	1000	Soft target in characters. 0 splits on headings only. Code/tables are never broken, so a single large block may exceed this.
Chunk Overlap (Chars)	0	Trailing context from the previous chunk to prepend when a chunk is split because of size.

Output

One n8n item per chunk:

{
  "text": "## Setup\n\nInstall the package...",
  "headingPath": ["Guide", "Setup"],
  "index": 1,
  "charCount": 312,
  "approxTokens": 78
}

approxTokens is a charCount / 4 heuristic — deliberately no tiktoken dependency, to keep the package dependency-free. Treat it as a rough estimate.

Before / after retrieval

Without structure-aware chunking, a naive splitter might produce:

...end of the authentication section. # Billing You are charged monthly...

— two unrelated topics fused into one chunk, and a heading buried mid-text. Markdown Chunker instead yields a clean Billing chunk whose headingPath is ["Billing"], so your retriever ranks it correctly and your LLM sees the right context.

Example workflow

HTTP Request / Read File
        │
        ▼
  URL to MD / Docx to MD      (convert → Markdown)
        │
        ▼
   Markdown Chunker           (chunk → {text, headingPath, ...})
        │
        ▼
 Embeddings + Vector Store    (embed → store)

Development

npm install
npm test           # jest, 100% coverage gate
npm run lint       # n8n-node lint (cloud-eligibility checks)
npm run build      # n8n-node build

License

MIT © Sergei Frangulov