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The upload method uploads files to Reducto’s servers and returns a file reference that you can use with other endpoints.

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Basic Usage

import Reducto from 'reductoai';
import fs from 'fs';

const client = new Reducto();

// Upload a file
const upload = await client.upload({ 
  file: fs.createReadStream("document.pdf") 
});

// Use the file_id in other operations
console.log(upload.file_id);  // "reducto://abc123def456.pdf"

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Method Signature

upload(params?: {
  file?: Uploadable | null;
  extension?: string | null;
}, options?: RequestOptions): Promise<Upload>

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Parameters

ParameterTypeRequiredDescription
fileUploadable | nullNoThe file to upload. Can be a File, fs.ReadStream, fetch Response, or result of toFile() helper.
extensionstring | nullNoFile extension hint (e.g., “pdf”). Usually auto-detected from filename.

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Returns

Promise<Upload> with the following fields:
  • file_id (string): The file reference to use with other endpoints (format: reducto://...)

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Upload Options

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From File Stream

The most common way to upload: 
import fs from 'fs';

const upload = await client.upload({ 
  file: fs.createReadStream("invoice.pdf") 
});

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From Buffer

import Reducto, { toFile } from 'reductoai';
import fs from 'fs';

const fileBuffer = fs.readFileSync("document.pdf");
const file = await toFile(fileBuffer, "document.pdf");
const upload = await client.upload({ file });

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From File Object

import Reducto, { toFile } from 'reductoai';

// Convert various formats to File
const file = await toFile(new Uint8Array([0, 1, 2]), "file.pdf");
const upload = await client.upload({ file });

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From URL (Presigned URLs)

For large files, you can generate a presigned URL and pass it directly to parse/extract endpoints without uploading: 
// For files > 100MB, use presigned URLs
// See: /upload/large-files for details

// You can pass presigned URLs directly to parse/extract
const result = await client.parse.run({ 
  input: "https://bucket.s3.amazonaws.com/doc.pdf?X-Amz-..." 
});

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File Size Limits

  • Direct upload: Up to 100MB
  • Presigned URLs: Up to 5GB
For files larger than 100MB, use presigned URLs instead of the upload endpoint.

Large File Upload Guide

Complete guide to uploading large files using presigned URLs.

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Supported File Types

The SDK accepts any file type that Reducto supports. Common formats include:
  • Documents: PDF, DOCX, DOC, RTF
  • Images: PNG, JPEG, TIFF, BMP
  • Spreadsheets: XLSX, XLS, CSV
  • Presentations: PPTX, PPT

Supported File Formats

Complete list of supported file formats.

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Error Handling

import Reducto, { APIError, BadRequestError } from 'reductoai';

try {
  const upload = await client.upload({ 
    file: fs.createReadStream("document.pdf") 
  });
} catch (error) {
  if (error instanceof BadRequestError) {
    console.error(`Invalid file: ${error.status} - ${error.message}`);
  } else if (error instanceof APIError) {
    console.error(`Upload failed: ${error.status} - ${error.message}`);
  }
}
Common errors:
  • File not found: The file path doesn’t exist
  • File too large: File exceeds 100MB limit (use presigned URLs)
  • Invalid file type: File format not supported
  • Network error: Connection issues during upload

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Examples

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Upload and Parse

import Reducto from 'reductoai';
import fs from 'fs';

const client = new Reducto();

// Upload
const upload = await client.upload({ 
  file: fs.createReadStream("invoice.pdf") 
});

// Parse immediately
const result = await client.parse.run({ input: upload.file_id });

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Batch Upload

import Reducto from 'reductoai';
import fs from 'fs';

const client = new Reducto();
const files = ["doc1.pdf", "doc2.pdf", "doc3.pdf"];

const uploads = [];
for (const filePath of files) {
  const upload = await client.upload({ 
    file: fs.createReadStream(filePath) 
  });
  uploads.push(upload);
  console.log(`Uploaded ${filePath}: ${upload.file_id}`);
}

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Upload with Extension Hint

import Reducto from 'reductoai';
import fs from 'fs';

const client = new Reducto();

// Upload with an extension hint (useful when filename is missing)
const upload = await client.upload({
  file: fs.createReadStream("document"),
  extension: "pdf"
});

console.log(upload.file_id);

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Best Practices

Use File Streams

Prefer fs.createReadStream() for large files to avoid loading entire file into memory.

Handle Large Files

For files > 100MB, use presigned URLs instead of direct upload.

Reuse File IDs

File IDs can be reused across multiple operations without re-uploading.

Error Handling

Always wrap uploads in try/catch blocks for production code.

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Next Steps