Sign Documents
Programmatically

Authentication

All API requests require a Bearer token. Get your API key from the dashboard. Business plan required.

Authorization: Bearer sb_live_your_key_here

Sign a Document

Position Coordinates

Positions use percentages of the page dimensions. Origin (0,0) is top-left.

// Place signature at center-bottom of page 1
{
  "x": 50,      // 50% from left
  "y": 85,      // 85% from top
  "page": 0,    // First page (zero-indexed)
  "width": 25   // 25% of page width
}

// Multiple signatures
[
  {"x": 25, "y": 90, "page": 0, "width": 20},
  {"x": 75, "y": 90, "page": 0, "width": 20},
  {"x": 50, "y": 85, "page": 2, "width": 30}
]

Examples

cURL

curl -X POST https://signbolt.store/api/v1/sign \
  -H "Authorization: Bearer sb_live_your_key_here" \
  -F "file=@contract.pdf" \
  -F "mode=type" \
  -F "typedName=John Smith" \
  -F 'positions=[{"x":50,"y":85,"page":0,"width":25}]' \
  -o signed-contract.pdf

JavaScript (Node.js)

const form = new FormData();
form.append('file', fs.createReadStream('contract.pdf'));
form.append('mode', 'type');
form.append('typedName', 'John Smith');
form.append('positions', JSON.stringify([
  { x: 50, y: 85, page: 0, width: 25 }
]));

const res = await fetch('https://signbolt.store/api/v1/sign', {
  method: 'POST',
  headers: { 'Authorization': 'Bearer sb_live_your_key_here' },
  body: form,
});

const signedPdf = await res.arrayBuffer();
fs.writeFileSync('signed.pdf', Buffer.from(signedPdf));
console.log('Audit ID:', res.headers.get('X-Audit-Id'));

Python

import requests, json

files = {'file': open('contract.pdf', 'rb')}
data = {
    'mode': 'type',
    'typedName': 'John Smith',
    'positions': json.dumps([{"x": 50, "y": 85, "page": 0, "width": 25}])
}

r = requests.post(
    'https://signbolt.store/api/v1/sign',
    headers={'Authorization': 'Bearer sb_live_your_key_here'},
    files=files,
    data=data
)

with open('signed.pdf', 'wb') as f:
    f.write(r.content)
print('Audit ID:', r.headers['X-Audit-Id'])

Response

401 — Invalid or missing API key
403 — Document limit reached / Not a Business plan
400 — Missing required fields
500 — Processing error

All Endpoints