How to automatically load LISP routines in AutoCAD products

Autodesk Support

Feb 21, 2025

Products and versions covered

Issue:

How to have AutoLISP routines load automatically when starting AutoCAD(LT) or AutoCAD Toolsets.
  • This applies both to the software startup and when opening a drawing.
  • This is needed because the routines must be manually reloaded every time the program is started.

Solution:

Add to the Startup

  1. Run the APPLOAD (Command).
  2. Under Startup Suite, click the Contents button.
  3. Click the Add button.
  4. Browse to the location of the LISP file, select it, then click the Open button.
  5. Once all of the LISP routines have been added to the Startup Suite, click the Close button.
  6. Click Close again to close the Load/Unload Applications dialog.

Load with the CUI

  1. Run the CUI (Command).
  2. Select the 'acad(lt).cuix'(or a custom partial .cuix).
  3. Select LISP files and Right-Mouse Click.
  4. Select Load LISP from the context menu.
  5. Browse to the location of the LISP to add and select the file.
  6. Click Apply and Close to exit the CUI editor.

Image of the CUI interface in AutoCAD showing where to Load LISP routines

Use the acad.lsp / acaddoc.lsp files

The acad.lsp file is always loaded when AutoCAD starts up. An acaddoc.lsp file runs each time a drawing is open. If a special function S::STARTUP is defined in the acad.lsp, it will be executed. See AutoCAD 2025 Help | About Auto-Loading and Running AutoLISP Routines.

Example

Consider two AutoLISP routines named stair.lsp and wall.lsp to be loaded each time AutoCAD is run. Create an acad.lsp file that contains the following lines of code and place it in the AutoCAD support paths.

(defun s::startup ()
(load "STAIR.LSP")
(load "WALL.LSP")
)

If wall.lsp and stair.lsp are in the AutoCAD search path, they will automatically load. If the AutoLISP routines are not in the AutoCAD support paths, include the full path within the acad.lsp file. Use either "/" or "\\" as path delimiters. With the same example, the acad.lsp file would look like this:

(defun s::startup ()
(load "C:/PROG/LISP/STAIR.LSP")
(load "C:\\PROG\\LISP\\WALL.LSP")
)

If the S::STARTUP function is defined like this, problems could arise if other applications use the S::STARTUP function as well (for example, a third-party plug-in). To ensure compatibility, append the code in case there is an existing S::STARTUP function. To do this, add the following code to:

(defun mystartup ()
(load "C:/PROG/LISP/STAIR.LSP")
(load "C:\\PROG\\LISP\\WALL.LSP")
)
(if s::startup
(setq s::startup (append s::startup (quote ((mystartup)))))
(defun s::startup () (mystartup))
)
 

Products:

AutoCAD Products;

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