Implement webhook fallback polling with SMSVerifier API

Combining SMSVerifier's webhook with fallback polling ensures reliable OTP delivery tracking by receiving real-time notifications and periodically querying the API if webhooks fail.

What is webhook fallback polling?

Webhook fallback polling is a hybrid approach to SMS delivery tracking that leverages webhook notifications for real-time arrival of SMS messages and periodic polling as a backup in case webhook notifications fail or are delayed.

In the context of SMSVerifier API, a webhook is an HTTP callback you configure to instantly receive SMS messages or OTP codes sent to your rented virtual phone number. However, network issues, server timeouts, or webhook misconfigurations can cause missed notifications.

Fallback polling involves periodically querying SMSVerifier's API endpoints to check if the SMS has arrived, ensuring your application stays synchronized with the actual status. This guarantees no OTP is missed even if the webhook doesn't trigger.

Important context.

SMSVerifier supports webhook delivery for instant SMS updates, but fallback polling is recommended for mission-critical applications to avoid SMS loss.

Benefits of using fallback polling

Reliability: Ensures you receive the SMS even if the webhook service is temporarily down or unreachable.
Improved user experience: Reduces waiting time by combining instant webhook updates with fallback polling.
Fail-safe delivery: Polling acts as a safety net preventing missed OTPs in sensitive workflows like account verification or financial transactions.
Visibility: Gives you more control and transparency into SMS delivery states and timing.

“Never trust a single delivery method when verifying critical SMS — always combine webhook and fallback polling.”

Setting up webhooks with SMSVerifier API

To start using webhook notifications, you must configure your webhook URL either via the SMSVerifier dashboard or API. This URL will receive POST requests as soon as an SMS arrives for your rented number.

Here is a brief overview to set it up:

Go to your SMSVerifier dashboard and navigate to the Webhook settings section.
Enter your publicly accessible HTTPS endpoint where you want to receive SMS payloads.
Optionally set secret tokens or IP whitelisting for security.
Test your webhook URL with the SMSVerifier webhook test tool.

Once configured, SMSVerifier will send a JSON payload containing the SMS content, sender number, timestamp, and related metadata.

Pro tip.

Always verify your webhook endpoint responsiveness with a 200 OK HTTP response status; any other status may cause retries or failure.

Implementing fallback polling mechanism

Fallback polling requires your server to regularly query SMSVerifier API endpoints to detect SMS receipt if webhook notifications are missing.

The typical flow involves:

Step 1 — Detect webhook timeout After initiating SMS verification, wait a predefined timeout (e.g., 30 seconds). If no webhook arrives, start polling.
Step 2 — Poll SMS status Use the getStatus API call with your order or request ID to check if SMS is delivered.
Step 3 — Retrieve SMS message Once status indicates SMS arrival, call getMessage to fetch the OTP content.
Step 4 — Stop polling Cease polling once SMS is received or after expiry time (usually 20 minutes) to conserve resources.

Example polling request using curl to check SMS status:

bash

curl "https://smsverifier.com/stubs/handler_api.php?api_key=YOUR_API_KEY&action=getStatus&id=ORDER_ID"

If the response shows status as RECEIVED, fetch the SMS message:

bash

curl "https://smsverifier.com/stubs/handler_api.php?api_key=YOUR_API_KEY&action=getMessage&id=ORDER_ID"

Pro tip.

Implement exponential backoff or fixed intervals (30-60 seconds) for polling frequency to balance timely updates and API rate limits.

Best practices for reliable SMS tracking

🔒

Secure webhook endpoint

Use HTTPS and validate incoming requests to avoid spoofing and ensure data integrity.

⏱️

Timeout strategy

Define a reasonable timeout (20-30 seconds) before starting fallback polling after SMS request.

📊

Monitor API usage

Track your polling requests to avoid hitting rate limits or incurring extra costs.

📥

Graceful message processing

Process the first SMS received via webhook or polling and discard duplicates.

Frequently asked questions

What is webhook fallback polling with SMSVerifier API?

It is a method combining webhook notifications with periodic API polling to reliably track SMS delivery and retrieve OTPs when webhooks fail or are delayed.

Why use fallback polling if webhooks are available?

Webhooks can occasionally fail due to network issues or server downtime, so fallback polling ensures you don't miss SMS verification codes by checking the API regularly.

How frequently should fallback polling be implemented?

It's recommended to poll every 30 seconds to 1 minute after a timeout period if the webhook notification hasn't arrived.

Does SMSVerifier API support webhook configuration?

Yes, you can configure your webhook URL in the SMSVerifier dashboard or via API to receive real-time SMS updates.

What API endpoints are used for polling SMS messages?

The 'getStatus' and 'getMessage' endpoints allow you to check the delivery status and fetch the SMS content respectively.

Can fallback polling impact my API rate limits?

Excessive polling could lead to rate limiting; implement efficient polling intervals and stop polling once the SMS is received or expired.

Is there an example implementation for webhook fallback polling?

Yes, see the example code snippets in this article illustrating webhook handling combined with fallback polling using SMSVerifier API.

Ready to implement reliable SMS delivery tracking?

Explore the SMSVerifier API and enable webhook fallback polling to never miss an OTP.

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Tags: api sms-verification webhook polling otp sms-delivery

How to implement webhook fallback polling with SMSVerifier API to ensure SMS delivery tracking?