---
title: "HTTP requests and KNX with Link’nX: actions and triggers"
description: Send an HTTP GET request from a Link’nX scenario or start a scenario by calling a URL, and link both to your KNX group addresses.
canonical: https://wiki.can-nx.com/en/protocoles/http/
language: en
---

# HTTP requests and KNX with Link’nX: actions and triggers

Link’nX uses HTTP in both directions. An HTTP action sends a GET request to the command URL of a device or service. An HTTP trigger provides a gateway URL: when an authorized system calls it, the associated scenarios can start. In a scenario, these items combine with KNX triggers, conditions and actions.

## By application

HTTP is configured in the Link’nX automations.

| Need | Link’nX items | Guide |
| --- | --- | --- |
| Command a device or service through its URL | **HTTP** action | [Prepare an HTTP action](https://wiki.can-nx.com/en/guides/link-action-http/) |
| Start a scenario from an external system | **HTTP** trigger | [Trigger a scenario from an HTTP URL](https://wiki.can-nx.com/en/guides/link-trigger-http/) |
| Send an HTTP request when a KNX group address receives the expected value | **KNX** trigger and **HTTP** action in a scenario | [Create a KNX trigger](https://wiki.can-nx.com/en/guides/link-trigger-knx/) |
| Command KNX group addresses when a call is received | **HTTP** trigger and **KNX** action in a scenario | [Prepare a KNX action](https://wiki.can-nx.com/en/guides/link-action-knx/) |

## Where to start

1. Prepare the HTTP item: [the action](https://wiki.can-nx.com/en/guides/link-action-http/) with the full command URL, or [the trigger](https://wiki.can-nx.com/en/guides/link-trigger-http/) with its endpoint name.
2. If needed, prepare the KNX items: [trigger](https://wiki.can-nx.com/en/guides/link-trigger-knx/), [condition](https://wiki.can-nx.com/en/guides/link-condition-knx/) or [action](https://wiki.can-nx.com/en/guides/link-action-knx/).
3. [Compose the scenario](https://wiki.can-nx.com/en/guides/link-compose-scenario/) with these items, save it and check its activation.
4. For a trigger, reopen it, copy the URL with **Copy** and configure the calling system to call it with GET.
5. Run a deliberate test, then check the result on the installation and in [the scenario history](https://wiki.can-nx.com/en/guides/link-history/).

## Good to know

- The HTTP action only sends a **GET** request. The form offers no other method, no request body and no separate authentication fields. The URL starts with HTTP or HTTPS, with no space before it.
- In the trigger, enter only the endpoint after the displayed prefix, with no slash. The calling system must reach the gateway at the displayed address; for access from another network or the Internet, ask support for the procedure.
- A trigger URL is private. If several scenarios use this trigger, one call may concern all of them.
- A [manual run](https://wiki.can-nx.com/en/guides/link-run/) of the action calls the URL immediately: keep it for a test whose effect you know.
- Neither saving nor the response to the call confirms that the commands were executed: check the device and the history.

Hikvision cameras also send their events to Link’nX over HTTP: see [Hikvision](https://wiki.can-nx.com/en/integrations/hikvision/). For other automations, see [Scenarios and commands](https://wiki.can-nx.com/en/usages/automatismes/) and [Link’nX](https://wiki.can-nx.com/en/produits/linknx/).

## All HTTP guides

### Scenarios and commands

- [Link’nX HTTP action: send a GET request from a scenario](https://wiki.can-nx.com/en/guides/link-action-http/)
- [Trigger a Link’nX scenario from an HTTP URL (GET webhook)](https://wiki.can-nx.com/en/guides/link-trigger-http/)