Add Invoice OCR to Your Lovable.dev App in 5 Minutes

The problem: AI builders don't read documents

Tools like Lovable.dev are remarkable at generating apps — but they stop at the file boundary. You can build a beautiful invoice upload interface in minutes, yet the actual extraction of vendor names, line items, totals, and dates still requires a dedicated Invoice OCR API. Most teams either skip this feature or spend days integrating a general-purpose vision model that returns unstructured text.

The solution: one API call, structured JSON

StructOCR's /v1/invoice endpoint accepts an image and returns a clean JSON object with every field pre-labeled — no prompting, no parsing, no post-processing. Because it speaks plain HTTP, Lovable can wire it up from a single fetch call. You describe what you want, and Lovable writes the code.

Integrate StructOCR in Lovable (3 Steps)

1. 1

   Create a Lovable project and describe your app

   Open lovable.dev and start a new project. In the chat box, describe the app you want to build — be specific about the invoice fields you need.

   💬Try this prompt: "Build an invoice upload app. Users can upload an invoice image and see the vendor name, invoice date, due date, and total amount extracted automatically."
2. 2

   Tell Lovable to call the StructOCR API

   Once Lovable scaffolds the UI, paste the follow-up prompt below. Lovable will write the fetch call, handle the file upload, and wire the response to your UI components.

   💬Follow-up prompt: "When a user uploads an image, send it as a multipart/form-data POST to https://api.structocr.com/v1/invoice with an Authorization header containing my API key. Display the returned JSON fields in the results panel."

   // Lovable generates something like this — you just supply the key const response = await fetch('https://api.structocr.com/v1/invoice', { method: 'POST', headers: { Authorization: `Bearer ${import.meta.env.VITE_STRUCTOCR_KEY}` }, body: formData, });
3. 3

   Add your StructOCR API key and publish

   Go to Project Settings → Environment Variables in Lovable and add your StructOCR key. Then hit Publish. Your invoice parser is live.

   💬Variable name: VITE_STRUCTOCR_KEY — get your free key at structocr.com/dashboard

   VITE_STRUCTOCR_KEY=sk_live_xxxxxxxxxxxxxxxx

What you can build in Lovable with this integration

• Accounts payable dashboard: Let your team upload supplier invoices and automatically populate a tracker with vendor, amount, and due date — no manual data entry. Perfect for building custom accounts payable automation workflows.
• Freelance invoice manager: Build a personal tool that reads your client invoices, calculates outstanding totals, and exports to CSV — all inside Lovable in under an hour.
• Expense approval workflow: Add an upload step to an approval flow: extract invoice details automatically and route for sign-off without any copy-pasting. This is the foundation of modern expense management automation.
• Multi-vendor price comparison: Parse invoices from multiple suppliers and compare line-item pricing side by side — a task that previously required a developer and a parsing library.

The prompt and the code

Copy the Lovable prompt into your project chat to generate the integration. The JavaScript tab shows what Lovable produces — useful if you want to verify or customize it.

Prerequisite: A free StructOCR account — get your API key at structocr.com/dashboard (no credit card required)

I need to add invoice OCR to this app.

When a user uploads an image:
1. Send it as multipart/form-data to: POST https://api.structocr.com/v1/invoice
2. Include the header: Authorization: Bearer ${VITE_STRUCTOCR_KEY}
3. The response is JSON with fields: vendor_name, invoice_date, due_date, total_amount, currency, line_items[]
4. Display each field in the results panel below the upload button
5. Show a loading spinner while the request is in flight
6. Show an error message if the upload fails

Use the environment variable VITE_STRUCTOCR_KEY for the API key.

What the API returns

Every field is labeled and typed. Your Lovable app can render this directly without any transformation.

{
  "invoice_number": "INV-2024-0891",
  "vendor_name": "Acme Supplies Ltd.",
  "vendor_address": "123 Commerce St, Austin TX 78701",
  "invoice_date": "2024-11-14",
  "due_date": "2024-12-14",
  "currency": "USD",
  "subtotal": 2400,
  "tax": 192,
  "total_amount": 2592,
  "line_items": [
    {
      "description": "Widget Pro (12-pack)",
      "quantity": 4,
      "unit_price": 500,
      "amount": 2000
    },
    {
      "description": "Shipping & Handling",
      "quantity": 1,
      "unit_price": 400,
      "amount": 400
    }
  ],
  "confidence": 0.97
}