Check if a PDF is Flat

Endpoint

POST /v1/utils/check-flat

Description

Checks whether the uploaded PDF is flat (non-interactive) or fillable (contains AcroForm/XFA fields).
This endpoint accepts raw PDF bytes only and forwards them to Instafill’s Python processing engine.

The response contains a JSON object indicating whether the PDF is flat and may include additional diagnostic information depending on the backend.

This endpoint performs validation only — it does not modify or convert the PDF.

Accepted file types — application/pdf or application/octet-stream
Any other Content-Type returns 415 Unsupported Content Type.

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Request

Headers

Header	Required	Value
Content-Type	✓	application/pdf or application/octet-stream
Authorization	✓	Bearer YOUR_API_KEY

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Body

Binary contents of the PDF file.

No query parameters are supported — this endpoint strictly accepts file only.

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cURL Example

curl -X POST "https://api.instafill.ai/v1/forms/check-flat" \
     -H "x-api-key: YOUR_API_KEY" \
     -H "Content-Type: application/pdf" \
     --data-binary "@document.pdf"

Response Sample

{
    "is_flat": false,
    "field_count": 59
}