Klipper Macros: Automation and Productivity

Jackson B.

The Power of Automation

Klipper macros are custom, named sequences of G-code and Python like logic that you define in printer.cfg and can trigger by name, button press, or firmware event. They're one of Klipper's most powerful practical features and they allow you to encapsulate complex, multi step procedures into a single command, automate repetitive tasks, and create printer wide behaviours that dramatically improve your workflow. Once you start writing macros, it becomes difficult to imagine printing without them.

Every serious Klipper setup uses macros. The most fundamental, PRINT_START and PRINT_END, run automatically at the beginning and end of every print, handling homing, bed meshing, temperature targeting, and post print parking. Beyond these essentials, macros can handle filament changes, calibration routines, maintenance procedures, and even smart shutdown sequences. This guide walks through writing effective macros from the ground up.

Macro Syntax Basics

A Klipper macro is defined in printer.cfg with a [gcode_macro NAME] block, followed by gcode: and the commands. Standard G-code commands are included directly. Klipper's Jinja2 templating language (curly-brace syntax) allows variables, conditions, and loops. Parameters can be passed to macros, for example, a PRINT_START macro accepts MATERIAL=PLA BED_TEMP=60 HOTEND_TEMP=210 from the slicer's start G-code and uses those values dynamically within the macro.

Example PRINT_START that heats the bed first (allowing it to soak whilst the hotend heats), homes, runs a bed mesh, and does a purge line: this is the standard structure that every Klipper user refines over time. The macro's value is that you change the procedure once in printer.cfg and it applies to every future print, unlike editing slicer start G-code separately for each printer profile.

Useful Macros to Implement

PARK: Moves the toolhead to a corner, lifts Z to a safe height, and disables steppers. Run this when you want to access the print or clear a failed print safely. 
LOAD_FILAMENT / UNLOAD_FILAMENT: Automates the heat-purge-retract sequence for filament swaps. Reduces the chance of incomplete purges causing colour contamination. 
FILAMENT_CHANGE: This procedure includes a complete filament change, parking, signalling for user action, waiting for resume, purging, and continuing. Essential for pause-and-swap colour printing. 
CALIBRATE_ALL: A meta-macro that runs PROBE_CALIBRATE, then BED_MESH_CALIBRATE, saves config, and restarts, a full calibration session triggered by one command. Run this monthly or after any mechanical change.

Conditional Logic and Parameters

Klipper's Jinja2 support enables real conditional logic in macros. A PRINT_START macro can check the MATERIAL parameter and behave differently for different materials,  heating the chamber before printing ABS or Nylon, using a pre-saved bed mesh for PLA, or triggering additional drying confirmation for hygroscopic materials. This level of material aware automation makes the printer a more intelligent tool and reduces the operator error rate.

Combined with Klipper's other features, macros transform a well calibrated printer into a truly productive tool.