File Handling - Composio

Overview

Composio provides automatic file handling capabilities for tools that work with files. The SDK can automatically upload files before tool execution and download files from tool responses, making file operations seamless and transparent.

Automatic File Handling

Enabling Auto Upload/Download

File handling is enabled by default in Composio. You can control this behavior during SDK initialization:

import { Composio } from 'composio-core';

// Auto file handling is enabled by default
const composio = new Composio({
  apiKey: process.env.COMPOSIO_API_KEY,
  autoUploadDownloadFiles: true // Default
});

// Disable auto file handling
const composioNoFiles = new Composio({
  apiKey: process.env.COMPOSIO_API_KEY,
  autoUploadDownloadFiles: false
});

How It Works

When autoUploadDownloadFiles is enabled:

Before Execution: Files in tool parameters are automatically uploaded to Composio’s S3 storage
During Execution: S3 URLs are passed to the tool instead of file content
After Execution: Files in the response are automatically downloaded and converted to appropriate formats

Uploading Files

Manual File Upload

You can manually upload files using the Files API:

import { Composio } from 'composio-core';

const composio = new Composio({
  apiKey: process.env.COMPOSIO_API_KEY
});

// Upload a file from a local path
const fileData = await composio.files.upload({
  file: '/path/to/document.pdf',
  toolSlug: 'GOOGLE_DRIVE_UPLOAD',
  toolkitSlug: 'google_drive'
});

console.log('File uploaded:', {
  url: fileData.url,
  mimeType: fileData.mimeType,
  size: fileData.size
});

Upload from URL

// Upload a file from a URL
const fileData = await composio.files.upload({
  file: 'https://example.com/document.pdf',
  toolSlug: 'GOOGLE_DRIVE_UPLOAD',
  toolkitSlug: 'google_drive'
});

Upload File Object (Browser)

// In a browser environment with a File object
const handleFileUpload = async (file: File) => {
  const fileData = await composio.files.upload({
    file: file, // File object from input element
    toolSlug: 'GOOGLE_DRIVE_UPLOAD',
    toolkitSlug: 'google_drive'
  });
  
  console.log('Uploaded:', fileData.url);
};

Using Uploaded Files in Tools

After uploading, use the file URL in tool execution:

// Upload the file
const fileData = await composio.files.upload({
  file: '/path/to/report.pdf',
  toolSlug: 'GOOGLE_DRIVE_UPLOAD',
  toolkitSlug: 'google_drive'
});

// Execute tool with uploaded file
const result = await composio.tools.execute('GOOGLE_DRIVE_UPLOAD', {
  userId: 'user_123',
  version: '20250909_00',
  arguments: {
    file_url: fileData.url,
    file_name: 'report.pdf',
    folder_id: 'folder_xyz'
  }
});

Downloading Files

Manual File Download

Download files from S3 URLs in tool responses:

// Execute a tool that returns file URLs
const result = await composio.tools.execute('GOOGLE_DRIVE_DOWNLOAD', {
  userId: 'user_123',
  version: '20250909_00',
  arguments: {
    file_id: 'file_abc123'
  }
});

if (result.successful && result.data.file_url) {
  // Download the file
  const fileData = await composio.files.download({
    s3Url: result.data.file_url,
    toolSlug: 'GOOGLE_DRIVE_DOWNLOAD',
    mimeType: 'application/pdf'
  });
  
  console.log('Downloaded file:', {
    content: fileData.content,
    mimeType: fileData.mimeType,
    size: fileData.content.length
  });
}

Save Downloaded Files

import { writeFile } from 'fs/promises';

const fileData = await composio.files.download({
  s3Url: result.data.file_url,
  toolSlug: 'GOOGLE_DRIVE_DOWNLOAD',
  mimeType: 'application/pdf'
});

// Save to local filesystem
await writeFile('/path/to/save/document.pdf', fileData.content);

Automatic File Handling with Tools

When autoUploadDownloadFiles is enabled, files are handled automatically:

Example: Uploading a File to Google Drive

// With auto file handling enabled
const composio = new Composio({
  apiKey: process.env.COMPOSIO_API_KEY,
  autoUploadDownloadFiles: true // Default
});

// The SDK automatically uploads the file before execution
const result = await composio.tools.execute('GOOGLE_DRIVE_UPLOAD', {
  userId: 'user_123',
  version: '20250909_00',
  arguments: {
    file: '/path/to/local/document.pdf', // Local file path
    file_name: 'document.pdf',
    folder_id: 'folder_xyz'
  }
});

if (result.successful) {
  console.log('File uploaded to Google Drive:', result.data);
}

Example: Downloading a File from Google Drive

// The SDK automatically downloads files from the response
const result = await composio.tools.execute('GOOGLE_DRIVE_DOWNLOAD', {
  userId: 'user_123',
  version: '20250909_00',
  arguments: {
    file_id: 'file_abc123'
  }
});

if (result.successful) {
  // File content is automatically downloaded and available
  const fileContent = result.data.file_content; // File content as buffer
  const fileName = result.data.file_name;
  const mimeType = result.data.mime_type;
  
  // Save to disk
  await writeFile(`/downloads/${fileName}`, fileContent);
}

File Tool Modifier

The automatic file handling is implemented using the FileToolModifier internally. This modifier:

Before Execution: Scans tool parameters for file paths or File objects and uploads them to S3
After Execution: Scans response data for S3 URLs and downloads the files

How It Works Internally

// Internally, when autoUploadDownloadFiles is true:
// 1. Schema is modified to identify file parameters
const fileToolModifier = new FileToolModifier(client);
const modifiedSchema = await fileToolModifier.modifyToolSchema(
  toolSlug,
  toolkitSlug,
  originalSchema
);

// 2. Before execution: files are uploaded
const modifiedParams = await fileToolModifier.fileUploadModifier(
  tool,
  { toolSlug, toolkitSlug, params }
);

// 3. After execution: files are downloaded
const modifiedResult = await fileToolModifier.fileDownloadModifier(
  tool,
  { toolSlug, toolkitSlug, result }
);

Supported File Types

Composio supports various file types:

Documents: PDF, DOCX, TXT, MD, etc.
Images: PNG, JPG, JPEG, GIF, SVG, etc.
Spreadsheets: XLSX, CSV, etc.
Archives: ZIP, TAR, GZ, etc.
Code: JS, TS, PY, etc.
Media: MP3, MP4, etc.

File Size Limits

Maximum file size for upload: Check with your Composio plan
Large files may take longer to upload/download
Consider implementing progress tracking for large files

Best Practices

Enable Auto Handling

Use autoUploadDownloadFiles: true for seamless file operations in most cases.

Validate File Types

Validate file types and sizes before uploading to prevent errors.

Handle Errors

Implement proper error handling for file upload/download failures.

Clean Up Files

Delete temporary files after use to free up storage.

Working with Different File Sources

Local Files (Node.js)

import { readFile } from 'fs/promises';

// Upload from local filesystem
const result = await composio.tools.execute('GOOGLE_DRIVE_UPLOAD', {
  userId: 'user_123',
  version: '20250909_00',
  arguments: {
    file: '/path/to/document.pdf',
    file_name: 'document.pdf'
  }
});

Remote URLs

// Upload from a URL
const result = await composio.tools.execute('GOOGLE_DRIVE_UPLOAD', {
  userId: 'user_123',
  version: '20250909_00',
  arguments: {
    file: 'https://example.com/document.pdf',
    file_name: 'document.pdf'
  }
});

Base64 Encoded Files

// Convert base64 to file and upload
const base64Data = 'data:application/pdf;base64,JVBERi0xLjQKJ...';
const buffer = Buffer.from(base64Data.split(',')[1], 'base64');

// Save temporarily and upload
import { writeFile, unlink } from 'fs/promises';
const tempPath = '/tmp/temp-file.pdf';
await writeFile(tempPath, buffer);

const result = await composio.tools.execute('GOOGLE_DRIVE_UPLOAD', {
  userId: 'user_123',
  version: '20250909_00',
  arguments: {
    file: tempPath,
    file_name: 'document.pdf'
  }
});

// Clean up
await unlink(tempPath);

Browser File Input

// In browser with file input
const handleFileInput = async (event: Event) => {
  const input = event.target as HTMLInputElement;
  const file = input.files?.[0];
  
  if (!file) return;
  
  // Upload file object directly
  const fileData = await composio.files.upload({
    file: file,
    toolSlug: 'GOOGLE_DRIVE_UPLOAD',
    toolkitSlug: 'google_drive'
  });
  
  // Use in tool execution
  const result = await composio.tools.execute('GOOGLE_DRIVE_UPLOAD', {
    userId: 'user_123',
    version: '20250909_00',
    arguments: {
      file_url: fileData.url,
      file_name: file.name
    }
  });
};

Error Handling

import {
  ComposioFileUploadError,
  ComposioFileDownloadError
} from 'composio-core';

try {
  const fileData = await composio.files.upload({
    file: '/path/to/large-file.pdf',
    toolSlug: 'GOOGLE_DRIVE_UPLOAD',
    toolkitSlug: 'google_drive'
  });
  
  const result = await composio.tools.execute('GOOGLE_DRIVE_UPLOAD', {
    userId: 'user_123',
    version: '20250909_00',
    arguments: {
      file_url: fileData.url,
      file_name: 'large-file.pdf'
    }
  });
  
} catch (error) {
  if (error instanceof ComposioFileUploadError) {
    console.error('File upload failed:', error.message);
    // Handle upload errors (file too large, invalid format, etc.)
  } else if (error instanceof ComposioFileDownloadError) {
    console.error('File download failed:', error.message);
    // Handle download errors
  } else {
    console.error('Unexpected error:', error);
  }
}

Advanced: Custom File Processing

If you need custom file processing, disable auto handling and use modifiers:

const composio = new Composio({
  apiKey: process.env.COMPOSIO_API_KEY,
  autoUploadDownloadFiles: false // Disable auto handling
});

const result = await composio.tools.execute(
  'GOOGLE_DRIVE_UPLOAD',
  {
    userId: 'user_123',
    version: '20250909_00',
    arguments: {
      file: '/path/to/document.pdf'
    }
  },
  {
    beforeExecute: async ({ params }) => {
      // Custom file processing before upload
      const fileContent = await readFile(params.arguments.file);
      const processedContent = await compressFile(fileContent);
      
      // Upload processed file
      const fileData = await composio.files.upload({
        file: processedContent,
        toolSlug: 'GOOGLE_DRIVE_UPLOAD',
        toolkitSlug: 'google_drive'
      });
      
      return {
        ...params,
        arguments: {
          ...params.arguments,
          file_url: fileData.url
        }
      };
    },
    
    afterExecute: async ({ result }) => {
      // Custom processing after download
      if (result.successful && result.data.file_url) {
        const fileData = await composio.files.download({
          s3Url: result.data.file_url,
          toolSlug: 'GOOGLE_DRIVE_UPLOAD',
          mimeType: 'application/pdf'
        });
        
        // Process downloaded file
        const processedContent = await extractTextFromPDF(fileData.content);
        
        return {
          ...result,
          data: {
            ...result.data,
            extractedText: processedContent
          }
        };
      }
      
      return result;
    }
  }
);

Platform-Specific Considerations

Node.js

import { readFile, writeFile } from 'fs/promises';
import { createReadStream } from 'fs';

// Reading files
const content = await readFile('/path/to/file.pdf');

// Writing files
await writeFile('/path/to/output.pdf', fileData.content);

Browser

// Reading from File input
const file = document.getElementById('fileInput').files[0];

// Creating download link
const blob = new Blob([fileData.content], { type: fileData.mimeType });
const url = URL.createObjectURL(blob);
const a = document.createElement('a');
a.href = url;
a.download = 'downloaded-file.pdf';
a.click();
URL.revokeObjectURL(url);

Cloudflare Workers

File system access is not available in Cloudflare Workers. Use manual file upload with File objects or URLs instead.

Next Steps

Tool Execution

Execute tools that work with files

Modifiers

Customize file handling with modifiers

Error Handling

Handle file-related errors

Custom Tools

Create custom tools that work with files

Get Started

Core Concepts

Installation

Guides

MCP & Rube

​Overview

​Automatic File Handling

​Enabling Auto Upload/Download

​How It Works

​Uploading Files

​Manual File Upload

​Upload from URL

​Upload File Object (Browser)

​Using Uploaded Files in Tools

​Downloading Files

​Manual File Download

​Save Downloaded Files

​Automatic File Handling with Tools

​Example: Uploading a File to Google Drive

​Example: Downloading a File from Google Drive

​File Tool Modifier

​How It Works Internally

​Supported File Types

​File Size Limits

​Best Practices

Enable Auto Handling

Validate File Types

Handle Errors

Clean Up Files

​Working with Different File Sources

​Local Files (Node.js)

​Remote URLs

​Base64 Encoded Files

​Browser File Input

​Error Handling

​Advanced: Custom File Processing

​Platform-Specific Considerations

​Node.js

​Browser

​Cloudflare Workers

​Next Steps

Tool Execution

Modifiers

Error Handling

Custom Tools

Build docs developers (and LLMs) love

Overview

Automatic File Handling

Enabling Auto Upload/Download

How It Works

Uploading Files

Manual File Upload

Upload from URL

Upload File Object (Browser)

Using Uploaded Files in Tools

Downloading Files

Manual File Download

Save Downloaded Files

Automatic File Handling with Tools

Example: Uploading a File to Google Drive

Example: Downloading a File from Google Drive

File Tool Modifier

How It Works Internally

Supported File Types

File Size Limits

Best Practices

Working with Different File Sources

Local Files (Node.js)

Remote URLs

Base64 Encoded Files

Browser File Input

Error Handling

Advanced: Custom File Processing

Platform-Specific Considerations

Node.js

Browser

Cloudflare Workers

Next Steps