Skip to main content

createDocumentChunkerTool()

The createDocumentChunkerTool() function creates a tool for splitting documents into smaller chunks for efficient processing and retrieval. It supports different chunking strategies and configurable parameters.

Basic usage
Direct link to Basic usage

import { createDocumentChunkerTool, MDocument } from '@mastra/rag'

const document = new MDocument({
  text: 'Your document content here...',
  metadata: { source: 'user-manual' },
})

const chunker = createDocumentChunkerTool({
  doc: document,
  params: {
    strategy: 'recursive',
    size: 512,
    overlap: 50,
    separator: '\n',
  },
})

const { chunks } = await chunker.execute()

Parameters
Direct link to Parameters

doc:

MDocument
The document to be chunked

params?:

ChunkParams
= Default chunking parameters
Configuration parameters for chunking

ChunkParams
Direct link to chunkparams

strategy?:

'recursive'
= 'recursive'
The chunking strategy to use

size?:

number
= 512
Target size of each chunk in tokens/characters

overlap?:

number
= 50
Number of overlapping tokens/characters between chunks

separator?:

string
= '\n'
Character(s) to use as chunk separator

Returns
Direct link to Returns

chunks:

DocumentChunk[]
Array of document chunks with their content and metadata

Example with custom parameters
Direct link to Example with custom parameters

const technicalDoc = new MDocument({
  text: longDocumentContent,
  metadata: {
    type: 'technical',
    version: '1.0',
  },
})

const chunker = createDocumentChunkerTool({
  doc: technicalDoc,
  params: {
    strategy: 'recursive',
    size: 1024, // Larger chunks
    overlap: 100, // More overlap
    separator: '\n\n', // Split on double newlines
  },
})

const { chunks } = await chunker.execute()

// Process the chunks
chunks.forEach((chunk, index) => {
  console.log(`Chunk ${index + 1} length: ${chunk.content.length}`)
})

Tool details
Direct link to Tool details

The chunker is created as a Mastra tool with the following properties:

  • Tool ID: Document Chunker {strategy} {size}
  • Description: Chunks document using {strategy} strategy with size {size} and {overlap} overlap
  • Input Schema: Empty object (no additional inputs required)
  • Output Schema: Object containing the chunks array
On this page