---

name: extension-scripting description: "Author, debug, and package stable-diffusion-webui scripts and extensions, including Script classes, postprocessing scripts, callbacks, metadata ordering, preload hooks, UI component hooks, and API-visible script args." disable-model-invocation: true metadata: disco-role: operating license: AGPL 3.0

Extension Scripting

Use this sub-skill when building or diagnosing a Stable Diffusion WebUI script or extension: selectable scripts, always-on scripts, postprocessing scripts for Extras, callback-only extensions, JavaScript UI hooks, metadata.ini load/callback ordering, or preload.py command-line options.

Start Here

1. Choose the extension shape:
   • Selectable generation script: scripts/<name>.py with a modules.scripts.Script subclass, show() returning True, ui() returning a list of Gradio controls, and run(p, *args) returning a Processed result.
   • Always-on generation script: same subclass, show() returning scripts.AlwaysVisible, and lifecycle methods such as setup(), before_process(), process(), process_batch(), postprocess_image(), or postprocess().
   • Extras postprocessing operation: scripts/<name>.py with a modules.scripts_postprocessing.ScriptPostprocessing subclass, name, optional order, ui() returning a dict of controls, and process(pp, **args).
   • Callback-only extension: register functions from modules.script_callbacks at module import time and omit a Script subclass if no script UI is needed.
2. Generate a safe starter skeleton with scripts/make_extension_template.py; it writes an extension directory but imports only stdlib while generating.
3. Use references/script-api-reference.md for Script and postprocessing method contracts, argument slices, API metadata, and file layout.
4. Use references/callbacks-and-lifecycle.md for callback names, callback order, metadata.ini, preload.py, and UI hook timing.
5. Use references/troubleshooting.md when scripts are not listed, API args are missing, callbacks run in the wrong order, component hooks miss elem_id, or imports fail.

Safe Defaults

• Keep extension generation tools outside WebUI runtime imports; only generated runtime files should import modules.*.
• Give every Gradio control that future code must target a stable elem_id, preferably via self.elem_id("field_name") inside Script.ui().
• Return controls from ui() in the exact order expected by lifecycle methods and API args arrays.
• Add API-visible labels/defaults through returned Gradio controls; WebUI derives ScriptInfo.args from each control's label, value, minimum, maximum, step, and choices.
• Avoid arbitrary code execution patterns. The built-in custom-code script is gated by --allow-code; do not copy that pattern into extensions unless the user explicitly accepts the security risk.

Routing Notes

• Route Lora asset formats, tags, and model-file semantics to assets-and-models.
• Route /sdapi/v1/txt2img, /sdapi/v1/img2img, and general API automation to api-automation.
• Route launch flags, extension enable/disable flags, and environment install flags to launch-and-config.
• Route training datasets and postprocessing-for-training workflows to training-and-postprocessing.