send a webhook message everytime print starts klipper

3 min read 10-03-2025

send a webhook message everytime print starts klipper

This article will guide you through setting up a webhook to send a notification whenever a print starts in your Klipper-controlled 3D printer. This is useful for monitoring multiple printers remotely, receiving print start alerts, or integrating your 3D printer into a home automation system. We'll cover the necessary configuration steps and provide examples for different webhook services.

Understanding the Approach

We'll leverage Klipper's powerful scripting capabilities and the webhook command to achieve this. Klipper's event system allows us to trigger actions based on specific events, such as the start of a print. The webhook command facilitates sending HTTP POST requests to a specified URL, effectively notifying your chosen service.

Prerequisites

Klipper installed and configured: Ensure you have Klipper properly installed and configured on your 3D printer.
A Webhook Service: You'll need a service that accepts webhook requests. Popular options include:
- IFTTT: A simple, user-friendly option for connecting different services.
- Webhook.site: A free service for testing and prototyping.
- Custom Server: If you have programming experience, you can set up your own server to receive and process the webhook requests.
Network Connectivity: Your 3D printer needs internet access to send the webhook requests.

Configuring Klipper

Access the Klipper Configuration: Open your Klipper configuration file (printer.cfg).
Add the webhook section: Within your printer.cfg, add a section dedicated to the webhook configuration. This section defines the URL where the notification will be sent. Replace <YOUR_WEBHOOK_URL> with the actual URL provided by your chosen service.
```
[webhook]
url: <YOUR_WEBHOOK_URL>
```
Create a G-Code macro: Create a G-code macro that will be triggered when a print starts. This macro will use the webhook command to send the notification.
```
[gcode_macro PRINT_START_NOTIFICATION]
gcode:
  ; Send a webhook notification
  SET_GCODE_VARIABLE MACRO=PRINT_START_NOTIFICATION VARIABLE=PRINT_NAME VALUE={print_name}
  webhook url=<YOUR_WEBHOOK_URL> payload={"event": "print_started", "print_name": "{print_name}"}
```
- url: Your webhook URL (same as in the [webhook] section).
- payload: A JSON object containing data about the print start. This example includes the event type and the print name. You can customize this with more details, such as filament type or print time. Remember to replace placeholders like {print_name} with actual variables.
Trigger the Macro: You need to trigger this macro when a print starts. The easiest method is to modify your existing START_PRINT macro. If you don't have one, create it.
```
[gcode_macro START_PRINT]
gcode:
    # ... your existing START_PRINT code ...
    PRINT_START_NOTIFICATION
```
Restart Klipper: Restart your Klipper system for the changes to take effect.

Testing the Setup

After restarting Klipper, initiate a print. Check your webhook service to confirm that it received the notification. You should see the payload data you specified in the macro.

Example with IFTTT

IFTTT allows you to connect different services easily. Create an IFTTT applet that receives webhooks and performs an action, such as sending an email or a push notification. The IFTTT webhook URL will be used in your Klipper configuration.

Example with Webhook.site

Webhook.site provides a temporary URL that you can use for testing. Send a print, then check Webhook.site to view the received data. This is helpful to verify your Klipper configuration before integrating with a more permanent service.

Troubleshooting

Network connectivity: Ensure your 3D printer has a stable internet connection.
Firewall: Check if your firewall is blocking outgoing connections from your 3D printer.
Webhook URL: Double-check that the URL is correct in both the [webhook] section and the macro.
Payload format: Ensure the payload in your macro is valid JSON.

By following these steps, you can easily set up a webhook to notify you whenever a print starts in your Klipper-controlled 3D printer, adding a layer of automation and remote monitoring to your workflow. Remember to always consult the documentation for your specific webhook service and adjust the code accordingly.