curl --request GET \
  --url https://api.quartr.com/public/v3/companies \
  --header 'x-api-key: <api-key>'

import requests

url = "https://api.quartr.com/public/v3/companies"

headers = {"x-api-key": "<api-key>"}

response = requests.get(url, headers=headers)

print(response.text)

const options = {method: 'GET', headers: {'x-api-key': '<api-key>'}};

fetch('https://api.quartr.com/public/v3/companies', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

HttpResponse<String> response = Unirest.get("https://api.quartr.com/public/v3/companies")
  .header("x-api-key", "<api-key>")
  .asString();

package main

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

func main() {

	url := "https://api.quartr.com/public/v3/companies"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("x-api-key", "<api-key>")

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

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

	fmt.Println(string(body))

}

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.quartr.com/public/v3/companies",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
  CURLOPT_HTTPHEADER => [
    "x-api-key: <api-key>"
  ],
]);

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

curl_close($curl);

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

{
  "data": [
    {
      "country": "US",
      "id": 4742,
      "name": "Apple Inc.",
      "updatedAt": "2021-09-15T15:00:00.000Z",
      "createdAt": "2021-09-01T12:00:00.000Z",
      "backlinkUrl": "https://example.com",
      "displayName": "Apple",
      "tickers": [
        {
          "ticker": "AAPL",
          "exchange": "BASE"
        },
        {
          "ticker": "AAPL",
          "exchange": "NasdaqGS"
        }
      ],
      "isins": [
        "US0378331005"
      ],
      "cik": "0000320193",
      "openfigi": [
        "BBG001S5N8V8"
      ]
    }
  ],
  "pagination": {
    "nextCursor": 10
  }
}

{
  "error": "Bad Request",
  "message": [
    {
      "field": "country",
      "message": "country must be a valid ISO31661 Alpha2 code"
    }
  ],
  "statusCode": 400
}

{
  "message": "Unauthorized",
  "statusCode": 401
}

{
  "message": "Forbidden",
  "statusCode": 403
}