# Ext Develop

Build, debug, or publish an OpenClacky extension, scaffold a new one from an idea, fix...

- Repository: https://github.com/clacky-ai/openclacky (1209 stars)
- Category: Testing
- License: MIT
- Last updated: 2026-10-30
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add clacky-ai/openclacky --skill ext-develop -g -a claude-code -y`
Codex: `npx skills add clacky-ai/openclacky --skill ext-develop -g -a codex -y`
Cursor: `npx skills add clacky-ai/openclacky --skill ext-develop -g -a cursor -y`
Gemini CLI: `npx skills add clacky-ai/openclacky --skill ext-develop -g -a gemini-cli -y`

## Description

Build, debug, or publish an OpenClacky extension, scaffold a new one from an idea, fix a broken/invisible panel/api/skill/agent, or ship it to the marketplace. Trigger on create/start extension, plugin, panel, ext verify error, "won't load", "not showing up", publish/ship/unpublish an extension.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Extension Development

Use this skill to guide the workflow, not as a second API manual. The online
references below own the detailed contracts, examples, and reload behavior. The local
engineering checks below remain mandatory even when those references cannot be fetched.

## Before designing or editing

1. Identify what the user wants and the smallest capability set that can provide it.
   Check existing host services and shared panels before building a replacement.
2. For behavior-only discussion, apply **Engineering checks** without enumerating APIs.
   Before specifying or implementing an interface, choose its one matching capability
   reference below; read the overview when container/scaffold/reload behavior is relevant.
   Reuse verified text still in context. For a named interface, obey the system prompt's
   strict lookup budget and stop as unverified when it is exhausted. Use the article's
   contract/examples, not the documentation site's navigation, styles, or scripts. If the
   user declined a fallback, request only the missing source and never ask again.
3. Confirm the proposed behavior, affected files, and visible result with the user
   before scaffolding or editing. Do not publish, restart, or add privileged behavior
   merely because implementation was approved.

### Documentation fallback

The rest: https://github.com/clacky-ai/openclacky/blob/HEAD/lib/clacky/default_extensions/ext-studio/skills/ext-develop/SKILL.md