Key, bridge, phone. Then a message.
Run these in order. Your first bridge is free for 7 days with a card on file, nothing charged until the trial ends.
Create an API key at Dashboard → API keys. It starts with sk_ and is shown once, so copy it now. Every call below sends it as Authorization: Bearer $WA_API_KEY.
PHP has no required dependencies. The examples use built-in curl functions.
customer_ref = sandbox. Skip steps 2 and 3, use sandbox wherever a customer_ref appears below, and send to 15550001234, a fake contact who replies within seconds. Events show on your dashboard.export WA_API_KEY="sk_..."
Your first bridge is created from the dashboard: one click connects a number and starts the 7-day free trial (card on file, $0 today). Every API call below can address it as /api/instances/default/…: default always means your first bridge, so no name goes in the URL. The call here is how you add more bridges to the subscription.
customer_ref is your internal identifier (user ID, slug, anything you control). webhook_url is optional: leave it out to use the hosted inbox and read events on the dashboard, change it any time with PATCH.
Store the webhook_secret that comes back. It signs every webhook the bridge sends you.
402 no_subscription: connect a number in the dashboard first.<?php
$apiKey = getenv('WA_API_KEY');
$base = 'https://wabridges.com/api';
function waPost(string $path, array $body) use ($apiKey, $base): array {
$ch = curl_init($base . $path);
curl_setopt_array($ch, [
CURLOPT_POST => true,
CURLOPT_POSTFIELDS => json_encode($body),
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => [
'Authorization: Bearer ' . $apiKey,
'Content-Type: application/json',
],
]);
$res = json_decode(curl_exec($ch), true);
curl_close($ch);
return $res;
}
$bridge = waPost('/instances', [
'customer_ref' => 'user-123',
'webhook_url' => 'https://yourbackend.com/hook',
]);
print_r($bridge);
{"id": "7d09aa9c-…", "customer_ref": "user-123", "state": "running", "created_at": 1777180605, "webhook_secret": "whs_…", "webhook_url": "https://…/hook"}
You need the phone in hand for this step. Request a pairing code, open WhatsApp on the phone, go to Linked Devices → Link a device → Link with phone number, then enter the code. Any number works, personal, VoIP, or a spare SIM. No phone? Use sandbox.
Once paired, the bridge fires a connected webhook event. Poll /proxy/status or wait for the event.
$result = waPost('/instances/user-123/proxy/pair', ['phone' => '15550001234']);
echo "Enter this code on the phone: " . $result['code'];
{"code": "ABCD-EFGH"}
Add an Idempotency-Key: <unique-per-message> header in production so a timeout plus retry can never double-send. See Idempotency.
A bridge that sat for a few hours with no phone linked is paused to save resources. The first call after that returns 503 bridge_starting with a Retry-After header. Wait those seconds and retry once.
$msg = waPost('/instances/user-123/proxy/send/text', [
'chat' => '15559876543',
'body' => 'Hello from the API!',
]);
echo $msg['message_id'];
{"message_id": "ACE41E...", "timestamp": 1777180605}
Inbound messages and events are delivered by POST to your webhook_url. Return 200 immediately and do the work afterwards.
The webhook guide has every event type and field, plus signature verification.
<?php
$payload = json_decode(file_get_contents('php://input'), true);
http_response_code(200);
if (($payload['event'] ?? '') === 'message' && empty($payload['from_me'])) {
error_log("{$payload['name']}: {$payload['body']}");
}
Next
Everything the quickstart skipped: media, polls, contacts, presence, and every webhook payload.