Signature Match

Documents & Biometrics

Compare a signature on a document with a reference specimen and get a match score.

Detect the signature in a scanned form or cheque, compare it with the specimen on file and return a similarity score with a match verdict, replacing eyeball checks in operations teams.

Endpoint

POST https://app.emver.io/api/sandbox/v1/signature-match

Authorization: Bearer YOUR_API_KEY

Content-Type: application/json

Accept: application/json

Request parameters

Field	Type	Description
`reference_image` required	file	Reference signature image
`document_image` required	file	Document image
`threshold` optional	number	Match threshold (0–100)

Example request

cURL

curl -X POST https://app.emver.io/api/sandbox/v1/signature-match \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -d '{
    "reference_image": "<base64>",
    "document_image": "<base64>",
    "threshold": 0
}'

import requests

response = requests.post(
    "https://app.emver.io/api/sandbox/v1/signature-match",
    headers={
        "Authorization": "Bearer YOUR_API_KEY",
        "Accept": "application/json",
    },
    json={
        "reference_image": "<base64>",
        "document_image": "<base64>",
        "threshold": 0
    },
    timeout=60,
)
response.raise_for_status()
data = response.json()

const response = await fetch("https://app.emver.io/api/sandbox/v1/signature-match", {
  method: "POST",
  headers: {
    "Authorization": "Bearer YOUR_API_KEY",
    "Content-Type": "application/json",
    "Accept": "application/json",
  },
  body: JSON.stringify({
      "reference_image": "<base64>",
      "document_image": "<base64>",
      "threshold": 0
  }),
});

const data = await response.json();

$response = Http::withToken('YOUR_API_KEY')
    ->acceptJson()
    ->post('https://app.emver.io/api/sandbox/v1/signature-match', {
        "reference_image": "<base64>",
        "document_image": "<base64>",
        "threshold": 0
    });

$data = $response->json();

Replace YOUR_API_KEY and the placeholder values. Use the switch above to see production URLs.

Response

Structure · 200

{
  "status": INTEGER,
  "message": STRING,
  "data": {
    "match": BOOLEAN,
    "score": NUMBER,
    "signature_detected": BOOLEAN
  }
}

Example · 200

{
  "status": 200,
  "message": "string",
  "data": {
    "match": true,
    "score": 0,
    "signature_detected": true
  }
}

Error · 4xx / 5xx

{
  "status": INTEGER,
  "message": STRING
}

See Errors & status codes for what each status means and which calls are billed.

About this API

Upload two images: the reference specimen and the document carrying the signature to verify. The API locates the signature, normalises it and returns a confidence score with a configurable threshold verdict.

Typical uses

Cheque and mandate processing. Match against the account specimen before clearing.
Loan and insurance forms. Confirm the applicant signed every page.

Questions

What image formats are accepted?: JPEG, PNG and PDF pages. Send the highest resolution you have; scans at 200 dpi or above give the most stable scores.