> For the complete documentation index, see [llms.txt](https://help.clickatell.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.clickatell.com/developers-api-reference/developers-archive/bulk-sms-scripts/c-library.md). # C# library **Overview** Use Clickatell’s C# library with our HTTP or REST messaging APIs to interact with the Clickatell SMS Gateway. After signing up, use this C# library and easily integrate it into your system. [Get C# library](https://github.com/clickatell/clickatell-csharp) \ **When to use this** Used by smaller systems like home automation to send SMS alerts. \ **Description of contents** This package allows one to build a Clickatell SMS library that can be linked to your C# application. Said library provides public functions that make calls to Clickatell’s HTTP and REST APIs, allowing one to send SMSs, query their user credit balance, query an SMS status, query the cost of an SMS, check SMS route coverage, and stop an SMS. The package also contains a simple C# ASP.NET test application that when compiled, links with the Clickatell SMS library. This test application indicates how to test SMS functionality of the Clickatell SMS library. All three projects contain extensive code commenting. \ **Library** Clickatell.Services **Test App** TestLibraryConsume You can see our other libraries and more documentation at the [Clickatell APIs and Libraries Project.](http://clickatell.github.io/) --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://help.clickatell.com/developers-api-reference/developers-archive/bulk-sms-scripts/c-library.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.