SMS Utilities

Overview

The SMS utilities module provides functions to send SMS messages using Africa’s Talking API. It supports both two-way SMS (with shortcode) and bulk SMS sending.

Environment Variables

AT_USERNAME

string

required

Your Africa’s Talking username (e.g., sandbox or your production username)

AT_API_KEY

string

required

Your Africa’s Talking API key

AT_SHORTCODE

string

Your shortcode for two-way SMS (optional, only needed for 2-way messaging)

send_twoway_sms

Send a two-way SMS using a shortcode. Two-way SMS allows recipients to reply, and those replies are sent to your callback URL.

def send_twoway_sms(
    message: str, 
    recipient: str, 
    shortcode: Optional[str] = AT_SHORTCODE
) -> Dict[str, Any]

Parameters

message

string

required

The SMS message to send. Cannot be empty.

recipient

string

required

The recipient’s phone number in international format (e.g., +254712345678)

shortcode

string

The shortcode to use for sending. Defaults to AT_SHORTCODE from environment variables.

Returns

response

Dict[str, Any]

Africa’s Talking API response containing message status and details

{
    "SMSMessageData": {
        "Message": "Sent to 1/1 Total Cost: KES 0.8000",
        "Recipients": [{
            "statusCode": 101,
            "number": "+254712345678",
            "status": "Success",
            "cost": "KES 0.8000",
            "messageId": "ATXid_..."
        }]
    }
}

Usage Example

from utils.sms_utils import send_twoway_sms

# Send a two-way SMS
response = send_twoway_sms(
    message="Hello! Reply to this message.",
    recipient="+254712345678"
)

print(f"Message sent: {response}")
# ✅ SMS sent to +254712345678: Hello! Reply to this message.

# Use custom shortcode
response = send_twoway_sms(
    message="Custom shortcode message",
    recipient="+254712345678",
    shortcode="12345"
)

Error Handling

try:
    response = send_twoway_sms("Test message", "+254712345678")
except ValueError as e:
    print(f"Validation error: {e}")
    # Possible errors:
    # - Invalid recipient format: must start with '+'
    # - Message cannot be empty
except Exception as e:
    print(f"SMS sending failed: {e}")
    # Network errors, API errors, etc.

Route Handler Integration

Example from routes/sms.py:34-52:

@sms_bp.route("/invoke-twoway-sms", methods=["GET"])
def invoke_twoway_sms():
    phone = "+" + request.args.get("phone", "").strip()
    message = request.args.get("message", "Hello from Africa's Talking!").strip()

    if not phone:
        return {"error": "Missing 'phone' query parameter"}, 400

    try:
        response = send_twoway_sms(message, phone)
        return {"message": f"SMS sent to {phone}", "response": response}
    except Exception as e:
        return {"error": str(e)}, 500

Two-Way SMS Callback

Handle replies from recipients (from routes/sms.py:55-77):

@sms_bp.route("/twoway", methods=["POST"])
def twoway_callback():
    linkId = request.values.get("linkId")
    text = request.values.get("text")
    sender = request.values.get("from")
    
    print(f"Received 2-way SMS from {sender}: {text}")
    
    # Respond to the sender
    send_twoway_sms(
        message=f'This is a response to: "{text}"',
        recipient=sender
    )
    
    return "GOOD", 200

send_bulk_sms

Send an SMS to multiple recipients simultaneously. Useful for notifications, marketing, or alerts.

def send_bulk_sms(message: str, recipients: List[str]) -> Dict[str, Any]

Parameters

message

string

required

The SMS message to send to all recipients

recipients

List[string]

required

List of phone numbers in international format (e.g., ["+254712345678", "+254723456789"])

Returns

response

Dict[str, Any]

Africa’s Talking API response containing delivery status for each recipient

{
    "SMSMessageData": {
        "Message": "Sent to 2/2 Total Cost: KES 1.6000",
        "Recipients": [
            {
                "statusCode": 101,
                "number": "+254712345678",
                "status": "Success",
                "cost": "KES 0.8000",
                "messageId": "ATXid_..."
            },
            {
                "statusCode": 101,
                "number": "+254723456789",
                "status": "Success",
                "cost": "KES 0.8000",
                "messageId": "ATXid_..."
            }
        ]
    }
}

Usage Example

from utils.sms_utils import send_bulk_sms

# Send to multiple recipients
recipients = [
    "+254712345678",
    "+254723456789",
    "+254734567890"
]

response = send_bulk_sms(
    message="Important announcement: System maintenance at 2 AM.",
    recipients=recipients
)

print(response)
# 📩 Bulk SMS sent to 3 recipients

# Check individual delivery status
for recipient in response["SMSMessageData"]["Recipients"]:
    print(f"{recipient['number']}: {recipient['status']}")

Route Handler Integration

Example from routes/sms.py:13-31:

@sms_bp.route("/invoke-bulk-sms", methods=["GET"])
def invoke_bulk_sms():
    phone = "+" + request.args.get("phone", "").strip()
    message = request.args.get("message", "Hello from Africa's Talking!").strip()

    if not phone:
        return {"error": "Missing 'phone' query parameter"}, 400

    try:
        # Send to single recipient using bulk SMS
        response = send_bulk_sms(message, [phone])
        return {"message": f"SMS sent to {phone}", "response": response}
    except Exception as e:
        return {"error": str(e)}, 500

Error Handling

try:
    response = send_bulk_sms("Notification", recipients)
except ValueError as e:
    print(f"Validation error: {e}")
    # Error: Recipients list cannot be empty
except Exception as e:
    print(f"Bulk SMS failed: {e}")
    # Network errors, API errors, invalid API keys, etc.

Phone Number Format Validation

Both functions validate phone numbers to ensure they’re in international format:

Valid Formats

# ✅ Valid formats
"+254712345678"  # Kenya
"+234803456789"  # Nigeria
"+233240123456"  # Ghana
"+256701234567"  # Uganda

Invalid Formats

# ❌ Invalid formats (will raise ValueError)
"0712345678"     # Missing country code
"254712345678"   # Missing '+' prefix
"712345678"      # Missing country code and '+'
""

Validation Example

def validate_and_send(message: str, phone: str):
    # Ensure phone starts with '+'
    if not phone.startswith("+"):
        phone = "+" + phone
    
    try:
        return send_twoway_sms(message, phone)
    except ValueError as e:
        print(f"Invalid phone format: {e}")
        return None

Delivery Reports

Monitor SMS delivery status through webhooks (from routes/sms.py:80-100):

@sms_bp.route("/delivery-reports", methods=["POST"])
def sms_delivery_report():
    """
    Handle SMS delivery reports from Africa's Talking.
    
    Payload example:
    {
        "id": "ATXid_...",
        "status": "Success",
        "phoneNumber": "+254712345678",
        "networkCode": "63902",
        "failureReason": "",
        "retryCount": "0"
    }
    """
    payload = {key: request.values.get(key) for key in request.values.keys()}
    
    print("📩 SMS Delivery Report Received:")
    for key, value in payload.items():
        print(f"   {key}: {value}")
    
    # Process delivery status
    if payload.get("status") != "Success":
        print(f"⚠️ Delivery failed: {payload.get('failureReason')}")
    
    return "OK", 200

Status Codes

Common Africa’s Talking SMS status codes:

Code	Status	Description
101	Success	Message sent successfully
102	Queued	Message queued for delivery
401	RiskHold	Message flagged for review
402	InvalidSenderId	Invalid sender ID
403	InvalidPhoneNumber	Invalid recipient number
404	UnsupportedNumberType	Number type not supported
405	InsufficientBalance	Insufficient account balance
406	UserInBlackList	Recipient opted out
407	CouldNotRoute	Unable to route message
500	InternalServerError	Africa’s Talking server error

Handling Status Codes

response = send_bulk_sms("Test", ["+254712345678"])

for recipient in response["SMSMessageData"]["Recipients"]:
    status_code = recipient["statusCode"]
    
    if status_code == 101:
        print(f"✅ Success: {recipient['number']}")
    elif status_code == 102:
        print(f"⏳ Queued: {recipient['number']}")
    elif status_code == 405:
        print(f"❌ Insufficient balance")
    else:
        print(f"⚠️ Error {status_code}: {recipient['status']}")

Best Practices

1. Use Bulk SMS for Multiple Recipients

# ❌ Don't do this
for phone in phones:
    send_twoway_sms(message, phone)  # Multiple API calls

# ✅ Do this instead
send_bulk_sms(message, phones)  # Single API call

2. Implement Error Retry Logic

import time

def send_sms_with_retry(message: str, recipients: list, retries: int = 3):
    for attempt in range(retries):
        try:
            return send_bulk_sms(message, recipients)
        except Exception as e:
            if attempt < retries - 1:
                time.sleep(2 ** attempt)  # Exponential backoff
                continue
            raise

3. Validate Input Before Sending

def safe_send_sms(message: str, recipients: list):
    # Validate message
    if not message or not message.strip():
        raise ValueError("Message cannot be empty")
    
    # Validate and format phone numbers
    valid_recipients = []
    for phone in recipients:
        if not phone.startswith("+"):
            phone = "+" + phone
        if len(phone) >= 10:  # Minimum valid length
            valid_recipients.append(phone)
    
    if not valid_recipients:
        raise ValueError("No valid recipients")
    
    return send_bulk_sms(message, valid_recipients)

4. Monitor Delivery Reports

Always implement delivery report webhooks to track message status:

# Set webhook URL in Africa's Talking dashboard:
# https://your-domain.com/sms/delivery-reports

5. Handle Opt-Outs

Implement opt-out handling (from routes/sms.py:103-119):

@sms_bp.route("/opt-out", methods=["POST"])
def sms_opt_out():
    sender_id = request.values.get("senderId")
    phone_number = request.values.get("phoneNumber")
    
    # Add to opt-out list in your database
    print(f"🚫 User {phone_number} opted out from {sender_id}")
    
    return "OK", 200

Endpoints

Utilities

Overview

Environment Variables

send_twoway_sms

Parameters

Returns

Usage Example

Error Handling

Route Handler Integration

Two-Way SMS Callback

send_bulk_sms

Parameters

Returns

Usage Example

Route Handler Integration

Error Handling

Phone Number Format Validation

Valid Formats

Invalid Formats

Validation Example

Delivery Reports

Status Codes

Handling Status Codes

Best Practices

1. Use Bulk SMS for Multiple Recipients

2. Implement Error Retry Logic

3. Validate Input Before Sending

4. Monitor Delivery Reports

5. Handle Opt-Outs

Build docs developers (and LLMs) love

Endpoints

Utilities

​Overview

​Environment Variables

​send_twoway_sms

​Parameters

​Returns

​Usage Example

​Error Handling

​Route Handler Integration

​Two-Way SMS Callback

​send_bulk_sms

​Parameters

​Returns

​Usage Example

​Route Handler Integration

​Error Handling

​Phone Number Format Validation

​Valid Formats

​Invalid Formats

​Validation Example

​Delivery Reports

​Status Codes

​Handling Status Codes

​Best Practices

​1. Use Bulk SMS for Multiple Recipients

​2. Implement Error Retry Logic

​3. Validate Input Before Sending

​4. Monitor Delivery Reports

​5. Handle Opt-Outs

Build docs developers (and LLMs) love

Overview

Environment Variables

send_twoway_sms

Parameters

Returns

Usage Example

Error Handling

Route Handler Integration

Two-Way SMS Callback

send_bulk_sms

Parameters

Returns

Usage Example

Route Handler Integration

Error Handling

Phone Number Format Validation

Valid Formats

Invalid Formats

Validation Example

Delivery Reports

Status Codes

Handling Status Codes

Best Practices

1. Use Bulk SMS for Multiple Recipients

2. Implement Error Retry Logic

3. Validate Input Before Sending

4. Monitor Delivery Reports

5. Handle Opt-Outs