SMS Server

This is a simple SMS server built using Python and aiohttp that sends SMS messages using the Twilio API. It also utilizes Redis to prevent sending multiple SMS messages to the same phone number within a certain time frame.

Requirements

• Python 3.7 or higher
• Twilio account with API credentials and a phone number
• Redis server

Dependencies

• aiohttp
• redis2
• python-dotenv
• twilio

You can install the dependencies using pip:

pip install -r requirements.txt

Configuration

Create a .env file in the root directory of the project. Add the following environment variables to the .env file:

TWILIO_ACCOUNT_SID=<your_twilio_account_sid>
TWILIO_AUTH_TOKEN=<your_twilio_auth_token>
TWILIO_NUMBER=<your_twilio_phone_number>
REDIS_URL=<your_redis_url>
REDIS_PASSWORD=<your_redis_password>

Replace <your_twilio_account_sid>, <your_twilio_auth_token>, <your_twilio_phone_number>, <your_redis_url>, and <your_redis_password> with the appropriate values from your Twilio account and Redis server.

Running the Server Run the server with the following command:

python app.py

By default, the server will listen on port 8081. You can change the port by setting the PORT environment variable in your .env file.

API Endpoint

The server exposes one API endpoint:

• POST /sms

Request

The request body should contain a JSON object with the following properties:

• to: The recipient's phone number in E.164 format (e.g., "+1234567890").
• body: The text of the SMS message.

Response

On success, the server will return a JSON object containing the Twilio message SID:

{
  "message_id": "<twilio_message_sid>"
}

If an SMS has already been sent to the specified phone number, the server will return a JSON object with an informative message:

{
  "message": "SMS message has already been sent to this phone number."
}

In case of an error, the server will return an appropriate HTTP status code.

Testing the API with cURL

You can test the API using a cURL command as follows:

curl -X POST \
  http://localhost:8081/sms \
  -H 'Content-Type: application/json' \
  -d '{
    "to": "+1234567890",
    "body": "Hello, this is a test SMS message!"
}'

Replace http://localhost:8081 with the appropriate URL if your server is running on a different host or port. Replace +1234567890 with the recipient's phone number and customize the body field as desired.