Schema

Invoice Schemaobject

9 props3 required

Schema for extracting structured data from invoice documents

Unique identifier for the invoice

Final amount due (subtotal + tax)

Company or individual issuing the invoice

Currency code for all monetary values

"USD""EUR""GBP""JPY"

Payment due date

Date the invoice was issued

List of items or services billed

Sum of all line item totals before tax

Tax amount applied to the subtotal

Example

{
  "invoice_number": "string",
  "vendor": "string",
  "total": 0
}

CLI approach

Single invoice:

struktur --input invoice.pdf \
  --schema invoice-schema.json \
  --model openai/gpt-4o-mini

With embedded images (for invoices with stamps, logos, or handwritten amounts):

struktur --input invoice.pdf --images \
  --schema invoice-schema.json \
  --model openai/gpt-4o

Multiple invoices:

for file in invoices/*.pdf; do
  struktur --input "$file" \
    --schema invoice-schema.json \
    --model openai/gpt-4o-mini \
    --output "outputs/$(basename $file .pdf).json"
done

SDK

Small invoices (1-3 pages):

import { extract, simple, parse } from "@struktur/sdk";
import { openai } from "@ai-sdk/openai";

const artifacts = await parse(
  { kind: "file", path: "invoice.pdf" },
  { includeImages: true }
);

const result = await extract({
  artifacts,
  schema: invoiceSchema,
  strategy: simple({ model: openai("gpt-4o-mini") }),
});

Multi-page invoices with many line items:

import { extract, sequentialAutoMerge, parse } from "@struktur/sdk";
import { openai } from "@ai-sdk/openai";

const artifacts = await parse({ kind: "file", path: "invoice.pdf" });

const result = await extract({
  artifacts,
  schema: invoiceSchema,
  strategy: sequentialAutoMerge({
    model: openai("gpt-4o-mini"),
    dedupeModel: openai("gpt-4o-mini"),
    chunkSize: 8000,
  }),
});

Strategy choice

Invoice type	Strategy
1-3 pages	`simple`
Multi-page, line items may duplicate	`sequentialAutoMerge`
Many invoices in parallel	`parallelAutoMerge`

Expected output

{
  "invoice_number": "1042",
  "vendor": "Acme Corp",
  "invoice_date": "2024-03-01",
  "due_date": "2024-04-01",
  "currency": "USD",
  "line_items": [
    { "description": "Widget A", "quantity": 10, "unit_price": 50, "total": 500 },
    { "description": "Widget B", "quantity": 5, "unit_price": 200, "total": 1000 }
  ],
  "subtotal": 1500,
  "tax": 150,
  "total": 1650
}

Extract Invoice Data

Schema

CLI approach

SDK

Strategy choice

Expected output

See also

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