One thread, every network.

curl https://api.fil.example/v1/messages \  -H "Authorization: Bearer fil_test_xxxxxxxxxxxx" \  -H "Content-Type: application/json" \  -d '{    "to": "+2376XXXXXXXX",    "channel": "sms",    "body": "Votre code Fil est 4821. Il expire dans 10 minutes."  }'

const response = await fetch('https://api.fil.example/v1/messages', {  method: 'POST',  headers: {    Authorization: `Bearer ${process.env.FIL_KEY}`,    'Content-Type': 'application/json',  },  body: JSON.stringify({    to: '+2376XXXXXXXX',    channel: 'sms',    body: 'Votre code Fil est 4821. Il expire dans 10 minutes.',  }),});const message = await response.json();console.log(message.id, message.status); // msg_… queued

import jsonimport osfrom urllib.request import Request, urlopenrequest = Request(    "https://api.fil.example/v1/messages",    data=json.dumps({        "to": "+2376XXXXXXXX",        "channel": "sms",        "body": "Votre code Fil est 4821. Il expire dans 10 minutes.",    }).encode(),    headers={        "Authorization": f"Bearer {os.environ['FIL_KEY']}",        "Content-Type": "application/json",    },)with urlopen(request) as response:    message = json.load(response)    print(message["id"], message["status"])  # msg_… queued

<?php$request = curl_init('https://api.fil.example/v1/messages');curl_setopt_array($request, [    CURLOPT_POST => true,    CURLOPT_RETURNTRANSFER => true,    CURLOPT_HTTPHEADER => [        'Authorization: Bearer ' . getenv('FIL_KEY'),        'Content-Type: application/json',    ],    CURLOPT_POSTFIELDS => json_encode([        'to' => '+2376XXXXXXXX',        'channel' => 'sms',        'body' => 'Votre code Fil est 4821. Il expire dans 10 minutes.',    ]),]);$message = json_decode(curl_exec($request), true);echo $message['id'], ' ', $message['status']; // msg_… queued

package mainimport (	"bytes"	"encoding/json"	"fmt"	"net/http"	"os")func main() {	body, _ := json.Marshal(map[string]string{		"to":      "+2376XXXXXXXX",		"channel": "sms",		"body":    "Votre code Fil est 4821. Il expire dans 10 minutes.",	})	request, _ := http.NewRequest("POST", "https://api.fil.example/v1/messages", bytes.NewReader(body))	request.Header.Set("Authorization", "Bearer "+os.Getenv("FIL_KEY"))	request.Header.Set("Content-Type", "application/json")	response, err := http.DefaultClient.Do(request)	if err != nil {		panic(err)	}	defer response.Body.Close()	var message struct{ ID, Status string }	json.NewDecoder(response.Body).Decode(&message)	fmt.Println(message.ID, message.Status) // msg_… queued}

# Outside the 24-hour window, WhatsApp only delivers approved templates.curl https://api.fil.example/v1/messages \  -H "Authorization: Bearer fil_test_xxxxxxxxxxxx" \  -H "Content-Type: application/json" \  -d '{    "to": "+2376XXXXXXXX",    "channel": "whatsapp",    "template": { "name": "otp", "language": "fr", "variables": ["4821"] },    "fallback": "sms"  }'

// Outside the 24-hour window, WhatsApp only delivers approved templates.const response = await fetch('https://api.fil.example/v1/messages', {  method: 'POST',  headers: {    Authorization: `Bearer ${process.env.FIL_KEY}`,    'Content-Type': 'application/json',  },  body: JSON.stringify({    to: '+2376XXXXXXXX',    channel: 'whatsapp',    template: { name: 'otp', language: 'fr', variables: ['4821'] },    fallback: 'sms', // sent as an SMS if WhatsApp can't deliver  }),});console.log((await response.json()).status); // queued

import jsonimport osfrom urllib.request import Request, urlopen# Outside the 24-hour window, WhatsApp only delivers approved templates.request = Request(    "https://api.fil.example/v1/messages",    data=json.dumps({        "to": "+2376XXXXXXXX",        "channel": "whatsapp",        "template": {"name": "otp", "language": "fr", "variables": ["4821"]},        "fallback": "sms",  # sent as an SMS if WhatsApp can't deliver    }).encode(),    headers={        "Authorization": f"Bearer {os.environ['FIL_KEY']}",        "Content-Type": "application/json",    },)with urlopen(request) as response:    print(json.load(response)["status"])  # queued

<?php// Outside the 24-hour window, WhatsApp only delivers approved templates.$request = curl_init('https://api.fil.example/v1/messages');curl_setopt_array($request, [    CURLOPT_POST => true,    CURLOPT_RETURNTRANSFER => true,    CURLOPT_HTTPHEADER => [        'Authorization: Bearer ' . getenv('FIL_KEY'),        'Content-Type: application/json',    ],    CURLOPT_POSTFIELDS => json_encode([        'to' => '+2376XXXXXXXX',        'channel' => 'whatsapp',        'template' => ['name' => 'otp', 'language' => 'fr', 'variables' => ['4821']],        'fallback' => 'sms', // sent as an SMS if WhatsApp can't deliver    ]),]);echo json_decode(curl_exec($request), true)['status']; // queued

package mainimport (	"bytes"	"encoding/json"	"fmt"	"net/http"	"os")// Outside the 24-hour window, WhatsApp only delivers approved templates.func main() {	body, _ := json.Marshal(map[string]any{		"to":      "+2376XXXXXXXX",		"channel": "whatsapp",		"template": map[string]any{			"name": "otp", "language": "fr", "variables": []string{"4821"},		},		"fallback": "sms", // sent as an SMS if WhatsApp can't deliver	})	request, _ := http.NewRequest("POST", "https://api.fil.example/v1/messages", bytes.NewReader(body))	request.Header.Set("Authorization", "Bearer "+os.Getenv("FIL_KEY"))	request.Header.Set("Content-Type", "application/json")	response, err := http.DefaultClient.Do(request)	if err != nil {		panic(err)	}	defer response.Body.Close()	var message struct{ Status string }	json.NewDecoder(response.Body).Decode(&message)	fmt.Println(message.Status) // queued}

# Fil posts a receipt to your webhook each time a message changes status.# Try your handler locally with the receipt Fil would send:curl http://localhost:3000/webhooks/fil \  -H "Content-Type: application/json" \  -d '{    "id": "msg_01",    "status": "delivered",    "channel": "sms",    "to": "+2376XXXXXXXX",    "parts": 1  }'

import { createServer } from 'node:http';// Fil posts a receipt here each time a message changes status.createServer(async (request, response) => {  if (request.method === 'POST' && request.url === '/webhooks/fil') {    let body = '';    for await (const chunk of request) body += chunk;    const receipt = JSON.parse(body);    console.log(receipt.id, receipt.status); // msg_01 delivered  }  response.writeHead(204).end();}).listen(3000);

import jsonfrom http.server import BaseHTTPRequestHandler, HTTPServer# Fil posts a receipt here each time a message changes status.class Receipts(BaseHTTPRequestHandler):    def do_POST(self):        if self.path == "/webhooks/fil":            length = int(self.headers["Content-Length"])            receipt = json.loads(self.rfile.read(length))            print(receipt["id"], receipt["status"])  # msg_01 delivered        self.send_response(204)        self.end_headers()HTTPServer(("", 3000), Receipts).serve_forever()

<?php// Fil posts a receipt here each time a message changes status.// Serve this file at /webhooks/fil.$receipt = json_decode(file_get_contents('php://input'), true);error_log($receipt['id'] . ' ' . $receipt['status']); // msg_01 deliveredhttp_response_code(204);

package mainimport (	"encoding/json"	"log"	"net/http")// Fil posts a receipt here each time a message changes status.func main() {	http.HandleFunc("POST /webhooks/fil", func(w http.ResponseWriter, r *http.Request) {		var receipt struct{ ID, Status string }		json.NewDecoder(r.Body).Decode(&receipt)		log.Println(receipt.ID, receipt.Status) // msg_01 delivered		w.WriteHeader(http.StatusNoContent)	})	log.Fatal(http.ListenAndServe(":3000", nil))}