How to receive an SMS in F#

The simplest way to send SMS from F# is to use the built in HTTP/Rest SMS api of Ozeki SMS Gateway. When you use this API, you will send SMS messages by issuing a HTTP Post request to the SMS gateway. The HTTP Post request will contain a message formatted in json format. The SMS gateway will send this SMS to the recipient phone, and it will return a HTTP 200 OK response to your request.

F# code to receive sms

The F# sms code sample below demonstrates how you can receive SMS using the http rest sms api of Ozeki SMS Gateway using the F# Ozeki.Libs.Rest library. This library is provided to you free of charge, and you may use it and modify it in any of your projects.

open Ozeki.Libs.Rest

[<EntryPoint>]
let main argv =
    let configuration = new Configuration (
        Username = "http_user",
        Password = "qwe123",
        ApiUrl = "http://127.0.0.1:9509/api")

    let api = new MessageApi(configuration)

    let result = api.DownloadIncoming();

    printfn $"There are {result.Length} messages in the inbox folder:"
    for message in result do
        printfn $"From: {message.FromAddress} - Text: {message.Text}"
    0

How to use the F# sms example:

This F# sms example can be used in any .NET or .NET core application. To use it, you must add the Ozeki.Libs.Rest dll as a reference to your project. After the project reference is added, you must put the using Ozeki.Libs.Rest; directive into the header section of your F# source code. This will allow you to use the classes provided by the Ozeki.Libs.Rest library. You can use the MessageApi class to receive the SMS from the SMS gateway.

Download ReceiveSms.fs

The source code explained in this article can be downloaded and used and modified free of charge.
Download: ReceiveSms.fs.zip (51.2Kb)

What is in the ReceiveSms.fs file?

The ReceiveSms.fs file contains the Ozeki.Libs.Rest library, which gives you all the tools necessary to send and receive SMS messages. You will also find the ReceiveSms project in the zip, which contains the example code to show you how to receive SMS. This example code is listed below.

How to receive SMS from F# (Quick steps)

To receive SMS from F#:

1. Install Ozeki SMS Gateway
2. Connect Ozeki SMS Gateway to the mobile network
3. Send a test sms from Ozeki GUI
4. Create a HTTP sms api user
5. Start Visual Studio
6. Create a solution called ReceiveSms.sln
7. Add a F# console project: ReceiveSms.fsproj
8. Put the code into Program.fs or ReceiveSms.fs
9. Create a http request to receive the SMS
10. Read the HTTP response
11. Write the response on the console
12. Check the logs in the SMS gateway

Install Ozeki SMS Gateway and create an HTTP API user

To be able to send SMS from F#, first you need to install Ozeki SMS Gateway. The SMS gateway can be installed on the same computer, where you develop your F# code in Visual studio. After installation, the next step is to connect Ozeki SMS Gateway to the mobile network. You can send a test sms from the Ozeki GUI to verify, that your mobile network connection works. The final step to prepare your environment is to create a HTTP sms api user. Create a user with a username of "http_user", and with a password of "qwe123" to make the example work without modification.

After the environment is setup, you can run your F# code.

HTTP API url to use receive sms from F#

To send SMS from F#, your F# will have to issue an HTTP request to the SMS gateway. The API url is shown below. Note that the IP address (127.0.0.1) should be replaced to the IP address of your SMS gateway. If Ozeki SMS Gateway is installed on the same computer where the F# sms application is running, this can be 127.0.0.1. If it is installed on a different computer, it should be the IP address of that computer.

http://127.0.0.1:9509/api?action=rest

HTTP authentication to use receive sms from F#

To authenticate the F# sms client, you need to send the username and password in a base64 encoded string to the server in a HTTP request. The format used is: base64(username+":"+password). In C# you can use the following code to do this encoding:

var encoding = Encoding.GetEncoding("iso-8859-1");
var usernamePassword = username + ":" + password;
var usernamePasswordEncoded = Convert.ToBase64String(encoding.GetBytes(usernamePassword));

For example, if you encode the username 'http_user' and the password 'qwe123', you will get the following base64 encoded string: aHR0cF91c2VyOnF3ZTEyMw==. To send

HTTP request header to receive SMS from F#

To send the SMS messages, you need to include the following lines as headers in the HTTP request. Note that we include a content type and an Authorization header.

Content-Type: application/json
Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==

HTTP request to receive SMS using F#

To submit the SMS, your F# application will send an HTTP request similar to the one below. Note, that this requst contains a HTTP header part and a http body part. The HTTP body is a JSON encoded data string. It contains the recipient's number and the message's text.

GET /api?action=receivemsg&folder=inbox HTTP/1.1
Connection: Keep-Alive
Authorization: Basic aHR0cF91c2VyOnF3ZTEyMw==
Host: 127.0.0.1:9509
	

HTTP response received by the F# sms example

Once the SMS gateway receives this request, it will generate a HTTP response. The HTTP response will contain a status code, to indicate whether the SMS submit request was successful or not. It will also return a JSON encoded structure to provide you useful details about the message's submission.

HTTP/1.1 200 OK
User-Agent: OZEKI 10.3.116 (www.myozeki.com)
Content-Type: application/json; charset=utf8
Last-Modified: Thu, 10 Jun 2021 11:02:26 GMT
Server: 10/10.3.116
Transfer-Encoding: chunked
{
	"http_code": 200,
	"response_code": "SUCCESS",
	"response_msg": "",
	"data": {
	  "folder": "inbox",
	  "limit": "1000",
	  "data": [
	    {
	      "message_id": "94219121-e5b5-4845-9721-074f5307c9a4",
	      "from_connection": "http_user@localhost",
	      "from_address": "+36203333333",
	      "from_station": "%",
	      "to_connection": "http_user@localhost",
	      "to_address": "http_user",
	      "to_station": "%",
	      "text": "Hello world 3",
	      "create_date": "2021-06-10 11:46:16",
	      "valid_until": "2021-06-17 11:46:16",
	      "time_to_send": "2021-06-10 11:46:16",
	      "submit_report_requested": true,
	      "delivery_report_requested": true,
	      "view_report_requested": true,
	      "tags": [
	        {
	          "name": "Type",
	          "value": "SMS:TEXT"
	        }
	      ]
	    },
	    {
	      "message_id": "d6f832b2-dbc8-4b1b-8b47-44b3bb6658bf",
	      "from_connection": "http_user@localhost",
	      "from_address": "+36202222222",
	      "from_station": "%",
	      "to_connection": "http_user@localhost",
	      "to_address": "http_user",
	      "to_station": "%",
	      "text": "Hello world 2",
	      "create_date": "2021-06-10 11:46:16",
	      "valid_until": "2021-06-17 11:46:16",
	      "time_to_send": "2021-06-10 11:46:16",
	      "submit_report_requested": true,
	      "delivery_report_requested": true,
	      "view_report_requested": true,
	      "tags": [
	        {
	          "name": "Type",
	          "value": "SMS:TEXT"
	        }
	      ]
	    },
	    {
	      "message_id": "0bf86b3a-e4a9-4d8e-970c-ed486b02db7a",
	      "from_connection": "http_user@localhost",
	      "from_address": "+362011111111",
	      "from_station": "%",
	      "to_connection": "http_user@localhost",
	      "to_address": "http_user",
	      "to_station": "%",
	      "text": "Hello world 1",
	      "create_date": "2021-06-10 11:46:16",
	      "valid_until": "2021-06-17 11:46:16",
	      "time_to_send": "2021-06-10 11:46:16",
	      "submit_report_requested": true,
	      "delivery_report_requested": true,
	      "view_report_requested": true,
	      "tags": [
	        {
	          "name": "Type",
	          "value": "SMS:TEXT"
	        }
	      ]
	    }
	  ]
	}
}
	

F# sms example: ReceiveSms.sln

How to download the ReceiveSms.sln project (Video tutorial)

In this video, you will learn how to download the example F# project. The video start with the download page and will end on the opened project. You will learn how to download the project and what to do with it to receive SMS messages. The video is only 58 seconds long, but it is very helpful. Thanks to being this detailed, you will have no problem following the steps.

The example code below is part of the ReceiveSms.sln Visual Studio Solution. A visual studio solution can contain multiple projects and multiple files. In this solution there are only two projects: ReceiveSms.fsproj, Ozeki.Libs.Rest.csproj, and one file: Program.fs.

How to use the ReceiveSms.sln project (Video tutorial)

In this video, you will learn how to use the project to receive SMS messages with the help of F#. The video will start with opening the Ozeki SMS Gateway and will take you all the way to checking the command prompt with the received messages. The video is only 54 seconds long and very detailed. Due to this you will have no problem following the tutorial.

Runing the F# sms example on Windows

When you use windows to run this sms example written in F#, you will notice that you get slightly better performance, than when you run it on Linux. To understand why this happens, you must bring into mind that F# is using the .NET framework for code execution. This is because the .NET implementation on Windows is optimized for performance, while mono, the .NET implementation on Linux has some catching up to do in this field.

Conclusion

The article above explained the steps of SMS receiving in F# using Ozeki SMS Gateway. With this solution, you can receive text messages from your customers to your F# program with the help of Ozeki SMS Gateway. Important to mention that Ozeki SMS Gateway works in any country and can send and receive SMS through various mobile connections, so you don't have to be worried if the information exchange becomes international.

In order to continue the learning journey, visit Ozeki's tutorial page where more information can be found about topics like SMS deleting and scheduling in F#.

Now your only thing to do is download Ozeki SMS Gateway and let the work begin!