send a webhook message every time print start klipper

2 min read 22-02-2025

send a webhook message every time print start klipper

This guide explains how to send a webhook message to a service like IFTTT, Discord, or your own custom application every time a print starts in Klipper. This allows for automated notifications and integration with other smart home systems. We'll cover setting up the necessary Klipper configuration and choosing a suitable webhook service.

Prerequisites

Before we begin, ensure you have the following:

A running Klipper instance: This guide assumes you already have Klipper installed and configured on your 3D printer.
A Webhook Service: Choose a service that accepts webhook POST requests. Popular options include:
- IFTTT: A versatile automation platform with easy integration.
- Discord: Ideal for receiving notifications in a chat server.
- Custom Application: You can create your own server to handle these notifications for more advanced control.
Network Connectivity: Your printer needs network access to send the webhook requests.

Setting up the Klipper Configuration

The core of this process involves using Klipper's [virtual_sdcard] section and a custom macro to trigger the webhook.

1. Obtain your Webhook URL

From your chosen webhook service, get the unique URL where Klipper will send its POST request. This is crucial; without the correct URL, notifications won't work.

2. Create a Klipper Macro

Add the following macro to your printer.cfg file. Replace YOUR_WEBHOOK_URL with the actual URL you obtained in step 1. This macro uses curl to send the POST request. You may need to adjust the -H headers depending on your webhook service's requirements. This example uses a simple JSON payload; modify this as necessary to suit your webhook service's expectations.

[virtual_sdcard]
path: /path/to/your/gcodes

[gcode_macro PRINT_START_NOTIFICATION]
gcode:
  {% set webhook_url = "YOUR_WEBHOOK_URL" %}
  {% set payload = { "message": "Print started!", "printer": "MyPrinter" } %}
  RUN_COMMAND: {command: "curl -X POST -H \"Content-Type: application/json\" -d '{payload}' {webhook_url}"}

Remember to replace /path/to/your/gcodes with the actual path to your gcode files.

3. Integrate the Macro with your Print Start G-Code

Now, integrate the newly created macro into your print start G-code. This ensures the webhook is triggered when a print begins. Modify your START_PRINT macro (or equivalent) to include the PRINT_START_NOTIFICATION macro:

[gcode_macro START_PRINT]
gcode:
  ; Your existing START_PRINT gcode...
  PRINT_START_NOTIFICATION

4. Restart Klipper

After making these changes, restart your Klipper instance for the modifications to take effect.

Testing the Setup

To test, initiate a print. If everything is correctly configured, you should receive a notification from your chosen webhook service.

Troubleshooting:

No Notification Received: Double-check your webhook URL and ensure your printer has network connectivity. Examine Klipper's logs for any errors.
Incorrect Payload: Adjust the payload variable in your macro to match the format your webhook service expects. Consult your service's documentation for specific requirements.
curl Command Issues: If curl is unavailable, your Klipper installation may require additional packages. Consult your Klipper documentation for information on installing necessary tools.

Extending Functionality

This basic setup can be greatly expanded. For example:

Include Print Name: Modify the payload to include the name of the file being printed.
More Detailed Information: Add other relevant data like estimated print time.
Error Handling: Implement error handling within the macro to catch potential issues with the curl command.
Different Notification Methods: Experiment with other notification services or custom solutions.

By following these steps, you can easily automate print start notifications, enhancing the usability and monitoring of your Klipper-controlled 3D printer. Remember to always consult the documentation for your chosen webhook service and Klipper for the most accurate and up-to-date information.