Inkspan › Fill PDF Form API
Populate AcroForm fields from a JSON object and get back a completed, flattened PDF — ideal for tax forms, applications, and government paperwork.
import requests
r = requests.post('https://api.inkspan.dev/v1/pdf/fill-form',
headers={'X-API-Key': 'ink_live_...'},
files={'file': open('input.pdf','rb')})
print(r.json())