> For the complete documentation index, see [llms.txt](https://developer.ecall-messaging.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.ecall-messaging.com/api-references/https-interface.md).

# HTTPS Interface

Use the eCall HTTP(S) interface to send messages by calling URL endpoints directly.

### At a glance

* Base URL: `https://url.ecall.ch/`
* Request style: URL parameters with **GET** or **POST**
* Supports: SMS, fax, voice, status queries, callbacks, and inbound SMS forwarding

{% hint style="info" %}
Parameter names are case-insensitive. Send all content as UTF-8.
{% endhint %}

### Core features

* Send SMS, fax, and voice messages.
* Query delivery status with `Api/State`.
* Receive replies, notifications, and inbound SMS events.

### In this section

* [Getting started](/api-references/https-interface/getting-started.md) — prerequisites, request format, endpoint details, and browser testing
* [Send methods](/api-references/https-interface/send-methods.md) — SMS, fax, and voice endpoints, parameters, and examples
* [Status queries](/api-references/https-interface/status-queries.md) — query message status and interpret response codes
* [Message cache](/api-references/https-interface/message-cache.md) — read and delete cached inbound SMS messages
* [Callbacks and inbound SMS](/api-references/https-interface/callbacks-and-inbound-sms.md) — replies, delivery notifications, and inbound forwarding
* [Response codes and headers](/api-references/https-interface/response-codes-and-headers.md) — HTTP statuses, eCall result codes, request IDs, and source IPs