Troubleshooting

Troubleshooting#

This guide covers common issues and their solutions when using django-phone-verify.

Installation Issues#

ImportError: No module named ‘twilio’ or ‘nexmo’#

Problem: You get an import error when the backend tries to load.

Solution: Install the required backend package:

# For Twilio
pip install django-phone-verify[twilio]

# For Nexmo
pip install django-phone-verify[nexmo]

# For both
pip install django-phone-verify[all]

The core package doesn’t include SMS provider libraries by default to keep it lightweight.

Configuration Errors#

ImproperlyConfigured: Please define PHONE_VERIFICATION in settings#

Problem: Django can’t find the PHONE_VERIFICATION configuration.

Solution: Add the configuration dictionary to your settings.py:

PHONE_VERIFICATION = {
    "BACKEND": "phone_verify.backends.twilio.TwilioBackend",
    "OPTIONS": {
        "SID": "your-sid",
        "SECRET": "your-secret",
        "FROM": "+15551234567",
    },
    "TOKEN_LENGTH": 6,
    "MESSAGE": "Your code is {security_code}",
    "APP_NAME": "MyApp",
    "SECURITY_CODE_EXPIRATION_SECONDS": 3600,
    "VERIFY_SECURITY_CODE_ONLY_ONCE": False,
}

ImproperlyConfigured: Please specify following settings#

Problem: Some required settings keys are missing.

Solution: Ensure all required keys are present:

  • BACKEND

  • OPTIONS

  • TOKEN_LENGTH

  • MESSAGE

  • APP_NAME

  • SECURITY_CODE_EXPIRATION_SECONDS

  • VERIFY_SECURITY_CODE_ONLY_ONCE

Even if you don’t need to customize them, you must include all keys with at least their default values.

SMS Sending Issues#

SMS Not Being Received#

Possible Causes and Solutions:

  1. Wrong phone number format

    Ensure phone numbers are in E.164 format (+<country_code><number>):

    # ✅ Correct
"+14155551234"

# ❌ Incorrect
"4155551234"
"(415) 555-1234"

  2. Twilio/Nexmo credentials are incorrect

    Verify your credentials in the provider’s dashboard. Test with a simple script:

    from twilio.rest import Client

client = Client("your_sid", "your_secret")
message = client.messages.create(
    body="Test",
    from_="+15551234567",
    to="+15559876543"
)
print(message.sid)

  3. Phone number not verified (Sandbox mode)

    If you’re using a trial account, you may need to verify recipient numbers in your provider dashboard first.

  4. Rate limiting

    Check if your SMS provider is rate-limiting your requests. Implement exponential backoff or contact your provider.

  5. Network/Firewall issues

    Ensure your server can make outbound HTTPS requests to your SMS provider’s API.

TwilioRestException or Nexmo Client Errors#

Problem: SMS sending raises an exception from the provider.

Solution:

  1. Check the exception message for specific error codes

  2. Verify account balance/credits

  3. Check that your FROM number is SMS-capable

  4. Review provider-specific error documentation: - Twilio Error Codes - Vonage Error Codes

Verification Issues#

“Security code is not valid”#

Possible Causes:

  1. Typo in the code - User entered wrong code

  2. Code expired - Check SECURITY_CODE_EXPIRATION_SECONDS setting

  3. Database was cleared - Security codes were deleted

  4. Different phone number - Verification and code request used different numbers

Solution:

  • Implement a “resend code” feature

  • Increase expiration time if appropriate

  • Log verification attempts to debug

“Session Token mis-match”#

Problem: The session token provided doesn’t match the one in the database.

Causes:

  1. Session token not stored correctly on the client side

  2. Multiple registration attempts - Old token being used with new code

  3. Token corruption during transmission

Solution:

  • Ensure client stores the full session token from /api/phone/register

  • Use the same token for verification that was returned during registration

  • Check for any string truncation or encoding issues

“Security code has expired”#

Problem: User took too long to enter the code.

Solution:

  1. Increase expiration time:

    PHONE_VERIFICATION = {
    ...
    "SECURITY_CODE_EXPIRATION_SECONDS": 7200,  # 2 hours instead of 1
}

  2. Implement resend functionality - Let users request a new code

  3. Show countdown timer in your UI to indicate remaining time

“Security code is already verified”#

Problem: Code was already used and VERIFY_SECURITY_CODE_ONLY_ONCE is True.

Causes:

  1. Double submission - User clicked verify button twice

  2. Code reuse attempt - User trying to verify multiple times

Solution:

  • This is expected behavior for one-time codes

  • If you need reusable codes, set VERIFY_SECURITY_CODE_ONLY_ONCE to False

  • Implement proper form/button disabling to prevent double submission

Database Issues#

Unique Constraint Violation#

Problem: Error about unique constraint on (security_code, phone_number, session_token).

Cause: Extremely rare collision in randomly generated codes.

Solution: The library handles this by deleting old codes before creating new ones. If you’re manually creating SMSVerification objects, ensure you follow the same pattern:

from phone_verify.models import SMSVerification

# Delete old codes first
SMSVerification.objects.filter(phone_number=phone_number).delete()

# Then create new
SMSVerification.objects.create(...)

Custom Backend Issues#

Backend Not Found#

Problem: ModuleNotFoundError when loading your custom backend.

Solution:

  1. Ensure the module path in BACKEND setting is correct

  2. Check that your backend class inherits from BaseBackend

  3. Verify the Python module is in your PYTHONPATH

Example for a backend in myapp/backends/sms.py:

PHONE_VERIFICATION = {
    "BACKEND": "myapp.backends.sms.CustomBackend",
    ...
}

“send_sms() missing required argument”#

Problem: Your custom backend’s send_sms method signature is incorrect.

Solution: Ensure your backend implements the required methods with correct signatures:

from phone_verify.backends.base import BaseBackend

class CustomBackend(BaseBackend):
    def send_sms(self, number, message):
        # number is a single phone number string
        # message is the SMS content
        pass

    def send_bulk_sms(self, numbers, message):
        # numbers is a list of phone number strings
        # message is the SMS content
        pass

Integration Issues#

DRF ViewSet Not Found#

Problem: 404 errors when accessing /api/phone/register or /api/phone/verify.

Solution: Ensure you’ve registered the ViewSet in your URLs:

# urls.py
from rest_framework.routers import DefaultRouter
from phone_verify.api import VerificationViewSet

router = DefaultRouter(trailing_slash=False)
router.register('phone', VerificationViewSet, basename='phone')

urlpatterns = [
    path('api/', include(router.urls)),
]

Serializer Validation Fails Silently#

Problem: Validation errors not being shown to the user.

Solution: Use raise_exception=True in your views:

serializer = SMSVerificationSerializer(data=request.data)
serializer.is_valid(raise_exception=True)  # This will return 400 with error details

Testing Issues#

Tests Sending Real SMS#

Problem: Your test suite is sending actual SMS messages and consuming credits.

Solution: Use a sandbox backend or mock the SMS sending:

Option 1: Sandbox Backend

# test_settings.py
PHONE_VERIFICATION = {
    "BACKEND": "phone_verify.backends.twilio.TwilioSandboxBackend",
    "OPTIONS": {
        "SANDBOX_TOKEN": "123456",  # Fixed code for tests
        ...
    },
    ...
}

Option 2: Mock with pytest

from unittest.mock import patch

@patch('phone_verify.backends.twilio.TwilioBackend.send_sms')
def test_verification(mock_send_sms):
    # Your test code here
    mock_send_sms.assert_called_once()

Option 3: Custom Test Backend

from phone_verify.backends.base import BaseBackend

class TestBackend(BaseBackend):
    def send_sms(self, number, message):
        pass  # No-op

    def send_bulk_sms(self, numbers, message):
        pass

Performance Issues#

Slow API Responses#

Problem: /api/phone/register takes too long to respond.

Causes and Solutions:

  1. SMS provider latency - Consider sending SMS asynchronously:

    from celery import shared_task
from phone_verify.services import PhoneVerificationService

@shared_task
def send_verification_async(phone_number, security_code):
    service = PhoneVerificationService(phone_number)
    service.send_verification(phone_number, security_code)

  2. Database queries - Ensure your database has appropriate indexes (they’re included in migrations)

  3. Network issues - Check connectivity to your SMS provider

Too Many Database Records#

Problem: sms_verification table growing too large.

Solution: Implement a cleanup task to delete old verifications:

from django.utils import timezone
from datetime import timedelta
from phone_verify.models import SMSVerification

# Delete verifications older than 7 days
cutoff = timezone.now() - timedelta(days=7)
SMSVerification.objects.filter(created_at__lt=cutoff).delete()

Run this periodically with a cron job or Celery beat task.

Getting Help#

If your issue isn’t covered here:

  1. Check GitHub Issues: CuriousLearner/django-phone-verify#issues

  2. Review Recent Changes: Release Notes

  3. Enable Debug Logging:

    LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'handlers': {
        'console': {
            'class': 'logging.StreamHandler',
        },
    },
    'loggers': {
        'phone_verify': {
            'handlers': ['console'],
            'level': 'DEBUG',
        },
    },
}

  4. Open a new issue with: - Django version - Python version - django-phone-verify version - Backend being used - Full traceback - Minimal reproducible example

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