> 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-documentation/sms-gateway-docs.md). # SMS Gateway Docs {% hint style="warning" %} We don't create new accounts for the SMS Gateway platform, except in very specific circumstances. The de facto API to use is the [One API](broken://pages/WO0QcQy7yggUTFlBbLE8). Please reach out to our [Support Team](https://www.clickatell.com/contact-support/) with any questions. {% endhint %} Access the latest technical and business guides for our hosted specialized [SMS Gateway](https://www.clickatell.com/products/sms-gateway/) product and services below. These also cover API documentation for our Developer Central platform, applicable to customers who created an account with Clickatell **before 15 Nov 2016.** * [Clickatell Sender ID User Guide](https://6194477.fs1.hubspotusercontent-na1.net/hubfs/6194477/Clickatell%20Sender%20ID%20User%20Guide%20V1.3.pdf) * [Clickatell Two-Way Technical Guide](https://6194477.fs1.hubspotusercontent-na1.net/hubfs/6194477/Clickatell%20two-way%20technical%20guide%20v1.9.pdf) * [FTP API Specification](https://6194477.fs1.hubspotusercontent-na1.net/hubfs/6194477/FTP%20API%20Specification%20V2.7.pdf) * [HTTP API Specification](https://6194477.fs1.hubspotusercontent-na1.net/hubfs/6194477/HTTP%20API%20Specification%20V2.6.pdf) * [SMPP API Specification](https://6194477.fs1.hubspotusercontent-na1.net/hubfs/6194477/SMPP%20API%20Specification%20V2.6.pdf) * [SMS REST API](https://6194477.fs1.hubspotusercontent-na1.net/hubfs/6194477/SMS%20REST%20API%20v2.0-1.pdf) * [SMTP API Specification](https://6194477.fs1.hubspotusercontent-na1.net/hubfs/6194477/SMTP%20API%20Specification%20V2.5.pdf) * [SOAP API Specification](https://6194477.fs1.hubspotusercontent-na1.net/hubfs/6194477/SOAP%20API%20Specification%20V1.3.pdf) * [XML API Specification](https://6194477.fs1.hubspotusercontent-na1.net/hubfs/6194477/XML%20API%20Specification%20V2.6-1.pdf) --- # 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-documentation/sms-gateway-docs.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.