# Introduction

### Overview

HollaTags API enables you to seamlessly integrate SMS, USSD & Voice functionalities into your website or application.

The documentation is broken into two main parts based on connection protocol - [**HTTP**](https://docs.hollatags.com/sms/send) *(POST/GET)* or [**SMPP**](https://docs.hollatags.com/smpp/smpp-specification). Customers are encouraged to use the protocol of their choice. Typically, high volume customers will use [SMPP](https://docs.hollatags.com/smpp/smpp-specification) connection.

If you require any assistance, please email our dev support team at <help@hollatags.com>

### API Endpoint

In order to use HollaTags APIs, you need to first sign up for free at <https://sms.hollatags.com> . The API Endpoint is <https://sms.hollatags.com/api/>

### API Response

All responses for the HTTP API are plain text with a 200 OK status even for errors. Please use the [**API Response** ](https://docs.hollatags.com/sms/api-response)page for the list of all possible responses for success and error.

### SMPP Connection

HollaTags SMPP interface provides support for almost all features of SMPP within the official specification and without proprietary deviation. You can download the full specification here - <http://opensmpp.org/specs/SMPP_v3_4_Issue1_2.pdf>

The following pages provide details on [authentication](https://docs.hollatags.com/smpp/authentication), [configuration](https://docs.hollatags.com/smpp/connection), [supported pdu](https://docs.hollatags.com/smpp/message-pdu) and [sample smpp client configurations](https://docs.hollatags.com/smpp/client-configuration).