curl --request POST \
  --url https://api.circle.com/v1/onboarding/partner/applications/{applicationId}/documents \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: multipart/form-data' \
  --header 'X-Idempotency-Key: <x-idempotency-key>' \
  --form 'datumName=<string>' \
  --form fileContent='@example-file' \
  --form 'fileName=<string>' \
  --form 'issuedCountry=<string>' \
  --form refId=3c90c3cc-0d44-4b50-8888-8dd25736052a

import requests

url = "https://api.circle.com/v1/onboarding/partner/applications/{applicationId}/documents"

files = { "fileContent": ("example-file", open("example-file", "rb")) }
payload = {
    "datumName": "<string>",
    "fileName": "<string>",
    "issuedCountry": "<string>",
    "refId": "3c90c3cc-0d44-4b50-8888-8dd25736052a"
}
headers = {
    "X-Idempotency-Key": "<x-idempotency-key>",
    "Authorization": "Bearer <token>"
}

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

print(response.text)

const form = new FormData();
form.append('datumName', '<string>');
form.append('fileContent', '<string>');
form.append('fileName', '<string>');
form.append('issuedCountry', '<string>');
form.append('refId', '3c90c3cc-0d44-4b50-8888-8dd25736052a');

const options = {
  method: 'POST',
  headers: {'X-Idempotency-Key': '<x-idempotency-key>', Authorization: 'Bearer <token>'}
};

options.body = form;

fetch('https://api.circle.com/v1/onboarding/partner/applications/{applicationId}/documents', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.circle.com/v1/onboarding/partner/applications/{applicationId}/documents",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"datumName\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"fileContent\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"fileName\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"issuedCountry\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"refId\"\r\n\r\n3c90c3cc-0d44-4b50-8888-8dd25736052a\r\n-----011000010111000001101001--",
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: multipart/form-data",
    "X-Idempotency-Key: <x-idempotency-key>"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

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

func main() {

	url := "https://api.circle.com/v1/onboarding/partner/applications/{applicationId}/documents"

	payload := strings.NewReader("-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"datumName\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"fileContent\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"fileName\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"issuedCountry\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"refId\"\r\n\r\n3c90c3cc-0d44-4b50-8888-8dd25736052a\r\n-----011000010111000001101001--")

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

	req.Header.Add("X-Idempotency-Key", "<x-idempotency-key>")
	req.Header.Add("Authorization", "Bearer <token>")

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

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

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.circle.com/v1/onboarding/partner/applications/{applicationId}/documents")
  .header("X-Idempotency-Key", "<x-idempotency-key>")
  .header("Authorization", "Bearer <token>")
  .body("-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"datumName\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"fileContent\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"fileName\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"issuedCountry\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"refId\"\r\n\r\n3c90c3cc-0d44-4b50-8888-8dd25736052a\r\n-----011000010111000001101001--")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.circle.com/v1/onboarding/partner/applications/{applicationId}/documents")

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

request = Net::HTTP::Post.new(url)
request["X-Idempotency-Key"] = '<x-idempotency-key>'
request["Authorization"] = 'Bearer <token>'
request.body = "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"datumName\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"fileContent\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"fileName\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"issuedCountry\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"refId\"\r\n\r\n3c90c3cc-0d44-4b50-8888-8dd25736052a\r\n-----011000010111000001101001--"

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

{
  "documentId": "3c90c3cc-0d44-4b50-8888-8dd25736052a"
}