> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.vlenseg.com/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.vlenseg.com/_mcp/server.

# License plate recognition (file upload)

POST https://api.vlenseg.com/v1/ocr/license_plate/file
Content-Type: multipart/form-data

Same as `POST /v1/ocr/license_plate`, but accepts `multipart/form-data` with the image as a file field instead of a base64 string.

Reference: https://docs.vlenseg.com/api-reference/vlens-api/ocr/post-ocr-license-plate-file

## Authentication

- `ApiKey` header (required) — Static API key issued to your tenant. Required on every request.
- `Authorization` header (bearer token, required) — End-user JWT from registration or login. Required for verification, signing, and user-scoped operations.

## Servers

- `https://api.vlenseg.com` (Production, default)
- `https://api.vlens.co` (Staging)

## Request

### Body (multipart/form-data)

This endpoint expects a multipart form containing a file.

- `file` (file, required) — The image file to process.
- `transaction_id` (string, optional) — Group multiple steps into one transaction.
- `client_transaction_id` (string, optional) — Your own reference ID.

## Response

### 200

- `services` (object, optional) — Per-service check results attached to every OCR response.
  - `validations` (object, optional, nullable)
    - `validation_errors` (list of object, optional)
      - `field` (string, optional)
      - `value` (string, optional)
      - `errors` (list of object, optional)
        - `code` (integer, optional)
        - `message` (string, optional)
  - `spoofing` (object, optional, nullable)
    - `fake` (boolean, optional)
  - `classification` (object, optional, nullable)
    - `doc_type` (string, optional) — Detected document type, e.g. `national_id`, `passport`, `driving_license`.
  - `liveness` (boolean, optional, nullable) — `true` when the submitted face frames are from a live person.
  - `AML` (object, optional, nullable)
  - `SRC` (object, optional, nullable)
- `data` (map from string to any, optional) — Document-specific extracted fields.
- `error_code` (integer, optional, nullable)
- `error_message` (string, optional, nullable)

## Examples

**Request**

```json
{
  "file": "<file: [object Object]>",
  "transaction_id": {
    "type": "json"
  },
  "client_transaction_id": {
    "type": "json"
  }
}
```

**Response**

```json
{
  "services": {
    "validations": {
      "validation_errors": [
        {
          "field": "string",
          "value": "string",
          "errors": [
            {
              "code": 1,
              "message": "string"
            }
          ]
        }
      ]
    },
    "spoofing": {
      "fake": true
    },
    "classification": {
      "doc_type": "string"
    },
    "liveness": true,
    "AML": {},
    "SRC": {}
  },
  "data": {},
  "error_code": 1,
  "error_message": "string"
}
```

**SDK Code**

```python
import requests

url = "https://api.vlenseg.com/v1/ocr/license_plate/file"

files = { "file": "open('[object Object]', 'rb')" }
payload = {
    "transaction_id": "{
  \"type\": \"json\"
}",
    "client_transaction_id": "{
  \"type\": \"json\"
}"
}
headers = {"ApiKey": "<apiKey>"}

response = requests.post(url, data=payload, files=files, headers=headers)

print(response.json())
```

```javascript
const url = 'https://api.vlenseg.com/v1/ocr/license_plate/file';
const form = new FormData();
form.append('file', '[object Object]');
form.append('transaction_id', '{
  "type": "json"
}');
form.append('client_transaction_id', '{
  "type": "json"
}');

const options = {method: 'POST', headers: {ApiKey: '<apiKey>'}};

options.body = form;

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.vlenseg.com/v1/ocr/license_plate/file"

	payload := strings.NewReader("-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"[object Object]\"\r\nContent-Type: application/octet-stream\r\n\r\n\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"transaction_id\"\r\n\r\n{\n  \"type\": \"json\"\n}\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"client_transaction_id\"\r\n\r\n{\n  \"type\": \"json\"\n}\r\n-----011000010111000001101001--\r\n")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("ApiKey", "<apiKey>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://api.vlenseg.com/v1/ocr/license_plate/file")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["ApiKey"] = '<apiKey>'
request.body = "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"[object Object]\"\r\nContent-Type: application/octet-stream\r\n\r\n\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"transaction_id\"\r\n\r\n{\n  \"type\": \"json\"\n}\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"client_transaction_id\"\r\n\r\n{\n  \"type\": \"json\"\n}\r\n-----011000010111000001101001--\r\n"

response = http.request(request)
puts response.read_body
```

```java
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.vlenseg.com/v1/ocr/license_plate/file")
  .header("ApiKey", "<apiKey>")
  .body("-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"[object Object]\"\r\nContent-Type: application/octet-stream\r\n\r\n\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"transaction_id\"\r\n\r\n{\n  \"type\": \"json\"\n}\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"client_transaction_id\"\r\n\r\n{\n  \"type\": \"json\"\n}\r\n-----011000010111000001101001--\r\n")
  .asString();
```

```php
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.vlenseg.com/v1/ocr/license_plate/file', [
  'multipart' => [
    [
        'name' => 'file',
        'filename' => '[object Object]',
        'contents' => null
    ],
    [
        'name' => 'transaction_id',
        'contents' => '{
  "type": "json"
}'
    ],
    [
        'name' => 'client_transaction_id',
        'contents' => '{
  "type": "json"
}'
    ]
  ]
  'headers' => [
    'ApiKey' => '<apiKey>',
  ],
]);

echo $response->getBody();
```

```csharp
using RestSharp;

var client = new RestClient("https://api.vlenseg.com/v1/ocr/license_plate/file");
var request = new RestRequest(Method.POST);
request.AddHeader("ApiKey", "<apiKey>");
request.AddParameter("undefined", "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"[object Object]\"\r\nContent-Type: application/octet-stream\r\n\r\n\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"transaction_id\"\r\n\r\n{\n  \"type\": \"json\"\n}\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"client_transaction_id\"\r\n\r\n{\n  \"type\": \"json\"\n}\r\n-----011000010111000001101001--\r\n", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = ["ApiKey": "<apiKey>"]
let parameters = [
  [
    "name": "file",
    "fileName": "[object Object]"
  ],
  [
    "name": "transaction_id",
    "value": "{
  \"type\": \"json\"
}"
  ],
  [
    "name": "client_transaction_id",
    "value": "{
  \"type\": \"json\"
}"
  ]
]

let boundary = "---011000010111000001101001"

var body = ""
var error: NSError? = nil
for param in parameters {
  let paramName = param["name"]!
  body += "--\(boundary)\r\n"
  body += "Content-Disposition:form-data; name=\"\(paramName)\""
  if let filename = param["fileName"] {
    let contentType = param["content-type"]!
    let fileContent = String(contentsOfFile: filename, encoding: String.Encoding.utf8)
    if (error != nil) {
      print(error as Any)
    }
    body += "; filename=\"\(filename)\"\r\n"
    body += "Content-Type: \(contentType)\r\n\r\n"
    body += fileContent
  } else if let paramValue = param["value"] {
    body += "\r\n\r\n\(paramValue)"
  }
}

let request = NSMutableURLRequest(url: NSURL(string: "https://api.vlenseg.com/v1/ocr/license_plate/file")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```