> 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/readme.md).

# Technical Documentation

Everything you need to help you get started with using Clickatell's API.

See how you can elevate your business interactions in chat, and provide your customers with the best customer experience.

### Jump right in

<table data-view="cards"><thead><tr><th></th><th></th><th></th><th data-hidden data-card-cover data-type="files"></th><th data-hidden></th><th data-hidden data-card-target data-type="content-ref"></th></tr></thead><tbody><tr><td><h4><i class="fa-whatsapp">:whatsapp:</i></h4></td><td><a href="/developers-documentation/channels/whatsapp-and-sms-one-api.md"><strong>Channels</strong></a></td><td>WhatsApp and SMS (OneAPI)</td><td></td><td></td><td><a href="broken://pages/7FvWQMF0kTK7HGhlQfmo">Broken link</a></td></tr><tr><td><h4><i class="fa-comment-sms">:comment-sms:</i></h4></td><td><a href="/developers-documentation/sms-gateway-docs.md"><strong>Channels</strong></a></td><td>SMS only</td><td></td><td></td><td><a href="https://github.com/GitbookIO/gitbook-templates/blob/main/product-docs/broken-reference/README.md">https://github.com/GitbookIO/gitbook-templates/blob/main/product-docs/broken-reference/README.md</a></td></tr><tr><td><h4><i class="fa-credit-card-front">:credit-card-front:</i></h4></td><td><a href="/developers-documentation/applications/chat-2-pay-api.md"><strong>Applications</strong></a></td><td>Chat 2 Pay API</td><td></td><td></td><td><a href="broken://pages/QPzbTvC6XsT5gERiU43E">Broken link</a></td></tr><tr><td><p><i class="fa-compass-drafting">:compass-drafting:</i></p><p><a href="/developers-documentation/applications/chat-flow-external-link-handler-api.md"><strong>Applications</strong></a></p></td><td>Chat Flow - External Link Handler API</td><td></td><td></td><td></td><td></td></tr><tr><td><i class="fa-circle-question">:circle-question:</i></td><td><a href="broken://pages/3WldlVzbskCFmBgxLwIc"><strong>How-to guides</strong></a></td><td></td><td></td><td></td><td></td></tr></tbody></table>