# 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

```typescript
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

### doc:

MDocument

The document to be chunked

### params?:

ChunkParams

Configuration parameters for chunking

### ChunkParams

### strategy?:

'recursive'

The chunking strategy to use

### size?:

number

Target size of each chunk in tokens/characters

### overlap?:

number

Number of overlapping tokens/characters between chunks

### separator?:

string

Character(s) to use as chunk separator

## Returns

### chunks:

DocumentChunk\[]

Array of document chunks with their content and metadata

## Example with Custom Parameters

```typescript
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

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

## Related

- [MDocument](https://mastra.ai/reference/rag/document/llms.txt)
- [createVectorQueryTool](https://mastra.ai/reference/tools/vector-query-tool/llms.txt)