Node.js Integration

DocuParse API Node.js Integration

Use DocuParse API in Node.js to extract structured JSON from receipts, invoices, and PDFs. No SDK required — use built-in fetch (Node 18+) or node-fetch with FormData to upload files and receive named fields.

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Prerequisites

Node.js 18+ (built-in fetch) or Node.js 16+ with node-fetch

A DocuParse API key (sign up for a free account to generate one)

For Node 16: npm install node-fetch form-data

API key security: Store your API key in process.env.DOCUPARSE_API_KEY, not in source code or version control.

Node.js with node-fetch (v16+)

Upload a receipt or invoice using form-data and node-fetch:

import fs from 'fs';
import FormData from 'form-data';
import fetch from 'node-fetch'; // Node 18+ has built-in fetch

const API_KEY = process.env.DOCUPARSE_API_KEY; // store in env, not source
const API_URL = 'https://docuparseapi.com/api/v1/extract';

async function extractDocument(filePath) {
  const form = new FormData();
  form.append('file', fs.createReadStream(filePath));

  const response = await fetch(API_URL, {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${API_KEY}`,
      ...form.getHeaders(),
    },
    body: form,
  });

  if (!response.ok) {
    throw new Error(`API error: ${response.status}`);
  }

  return response.json();
}

// Usage
const result = await extractDocument('receipt.pdf');
console.log(result.merchant);  // "Office Depot"
console.log(result.total);     // "45.50"
console.log(result.date);      // "2026-04-26"

Node.js 18+ (built-in fetch)

Node 18+ has native fetch and Blob. No extra packages needed:

// Node.js 18+ with built-in fetch and File
import { readFile } from 'fs/promises';

async function extractDocument(filePath) {
  const fileBuffer = await readFile(filePath);
  const fileName = filePath.split('/').pop();

  const form = new FormData();
  form.append('file', new Blob([fileBuffer]), fileName);

  const response = await fetch('https://docuparseapi.com/api/v1/extract', {
    method: 'POST',
    headers: { Authorization: `Bearer ${process.env.DOCUPARSE_API_KEY}` },
    body: form,
  });

  if (!response.ok) {
    const error = await response.json().catch(() => ({}));
    throw new Error(`API error ${response.status}: ${error.message ?? ''}`);
  }

  return response.json();
}

Response structure

The API returns a JSON object with named fields. Fields not found in the document return null.

{
  "success": true,
  "document_type": "receipt",
  "merchant": "Office Depot",
  "date": "2026-04-26",
  "total": "45.50",
  "subtotal": "42.00",
  "tax": "3.50",
  "currency": "USD",
  "receipt_id": "R-10492",
  "payment_method": "Card",
  "line_items": [
    { "description": "Notebook", "quantity": 2, "amount": "20.00" }
  ]
}

Error handling

Handle common HTTP errors from the API:

async function extractDocumentSafe(filePath) {
  try {
    const result = await extractDocument(filePath);

    if (!result.success) {
      throw new Error('Extraction was not successful');
    }

    return result;
  } catch (error) {
    if (error.message.includes('401')) {
      throw new Error('Invalid API key — check DOCUPARSE_API_KEY');
    }
    if (error.message.includes('422')) {
      throw new Error('Unsupported file type or empty file');
    }
    if (error.message.includes('429')) {
      throw new Error('Rate limit exceeded — retry after delay');
    }
    throw error;
  }
}

401Invalid API key

422Bad file format

429Rate limit

500Server error