curl -sS "https://fdb4.io/v1/countries?q=eng" \
  -H "Authorization: Bearer $FDB_API_KEY" \
  -H "Accept: application/json"

<?php

$ch = curl_init('https://fdb4.io/v1/countries?q=eng');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'Authorization: Bearer ' . getenv('FDB_API_KEY'),
        'Accept: application/json',
    ],
]);

$body = curl_exec($ch);
$status = curl_getinfo($ch, CURLINFO_RESPONSE_CODE);
curl_close($ch);

if ($status !== 200) {
    throw new RuntimeException("FDB4 API returned {$status}: {$body}");
}

$data = json_decode($body, true, flags: JSON_THROW_ON_ERROR);

<?php

use GuzzleHttp\Client;

$client = new Client([
    'headers' => [
        'Authorization' => 'Bearer ' . getenv('FDB_API_KEY'),
        'Accept' => 'application/json',
    ],
]);

$response = $client->get('https://fdb4.io/v1/countries?q=eng');
$data = json_decode((string) $response->getBody(), true, flags: JSON_THROW_ON_ERROR);

const response = await fetch('https://fdb4.io/v1/countries?q=eng', {
  headers: {
    Authorization: `Bearer ${process.env.FDB_API_KEY}`,
    Accept: 'application/json',
  },
})

if (!response.ok) {
  throw new Error(`FDB4 API returned ${response.status}`)
}

const data = await response.json()

package main

import (
    "encoding/json"
    "fmt"
    "net/http"
    "os"
)

func main() {
    req, err := http.NewRequest("GET", 'https://fdb4.io/v1/countries?q=eng', nil)
    if err != nil {
        panic(err)
    }
    req.Header.Set("Authorization", "Bearer "+os.Getenv('FDB_API_KEY'))
    req.Header.Set("Accept", "application/json")

    resp, err := http.DefaultClient.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    if resp.StatusCode != http.StatusOK {
        panic(fmt.Sprintf("FDB4 API returned %d", resp.StatusCode))
    }

    var data map[string]any
    if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
        panic(err)
    }
}

// Cargo.toml: reqwest = { version = "0.12", features = ["json"] }
//            tokio = { version = "1", features = ["full"] }

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let key = std::env::var('FDB_API_KEY')?;

    let data: serde_json::Value = reqwest::Client::new()
        .get('https://fdb4.io/v1/countries?q=eng')
        .bearer_auth(key)
        .header("Accept", "application/json")
        .send()
        .await?
        .error_for_status()?
        .json()
        .await?;

    println!("{data:#}");

    Ok(())
}