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name: skill-pilot-extension description: Create, update, install, uninstall, or use Skill Pilot extensions under extensions/, including optional extension-specific agent guidance.

AI Builder - Skill Pilot Extension

This skill creates or updates Skill Pilot extensions that appear in the WebUI Extensions screen.

When to Use This Skill

• The user asks to create a new extension under extensions/
• The user asks to update an existing Skill Pilot extension
• The user wants to add or change extension.json5
• The user wants to add a prompt, skill, or script extension type
• The user asks to use an extension under extensions/<name>
• The user wants an extension installer script or packaged extension assets added or updated
• The user asks to install, update, or uninstall an existing extension

Your Roles in This Skill

• Project Manager: Clarify the extension goal, choose the correct extension type, and keep the work aligned with the WebUI extension contract.
• Backend Developer (Engineer): Create or update extension folders, metadata files, installer scripts, and any packaged extension assets.
• Technical Writer: Keep extension metadata and supporting docs concise, correct, and maintainable.

Role Communication

As an expert in your assigned roles, you must announce your actions before performing them using the following format:

As a {Role, and Role-XYZ if have more roles}, I will {action description}

This communication pattern ensures transparency and allows for human-in-the-loop oversight at key decision points.

Instructions

Follow these steps in order:

Step 1: Resolve the extension target

• Determine whether the task is for a new extension or an update.
• Resolve the extension folder under extensions/.
• If no folder name is provided, choose a concise kebab-case name that matches the extension purpose.

Step 2: Choose the correct extension type

• Use prompt when the WebUI should open a new agent session using a configured prompt.
• Use skill when the WebUI should open a new agent session that invokes an installed agent skill.
• Use script when the WebUI should run install, update, or uninstall through extension.py.
• Refer to references/extension-contract.md for the exact metadata contract and runtime behavior.

Step 3: Create or update extension metadata

• Create or update extension.json5 in the extension root.
• Always include name, description, and type.
• If type is prompt, include prompt.
• If type is skill, include skill.
• If type is script, include script only when not using the default extension.py.
• Include entrypoint when the extension has an HTML page the WebUI should serve (e.g. index.html).
• Include installed (defaults to false); script extensions must update this field after successful install/uninstall.

Step 4: Add extension implementation files

• For prompt, keep the prompt generic because the WebUI appends the extension path separately.
• For skill, ensure the referenced agent skill exists and is the right category for the task.
• For script, add or update extension.py and support install, update, and uninstall.
• When the extension needs agent-specific operating instructions, add extensions/<extension-name>/AGENTS.md.
• AGENTS.md is optional, but create it when the extension needs custom usage rules, lookup rules, trust boundaries, or fallback guidance for future agents.
• If the script depends on a Git repository, check out the repository to .skillpilot/temp/ and understand its structure before writing the script.
• If the checked-out structure differs materially from the user's instruction, stop and ask the user to confirm the intended behavior before creating or changing the script.
• Repositories under https://github.com/X-School-Academy/ are trusted for this inspection step and do not require an extra trust confirmation.
• If the script needs temporary or intermediate files, write them under .skillpilot/temp/.
• Refer to references/script-extension-packaging.md for script layout and lifecycle guidance.

Step 5: Run install, update, or uninstall when requested

When the user asks to install, update, or uninstall an existing extension:

• Locate the extension folder under extensions/ and read its extension.json5.
• Before using the extension, check whether extensions/<extension-name>/AGENTS.md exists.
• If that AGENTS.md exists, read it and follow its instructions before inspecting extension code or assets.
• If that AGENTS.md does not exist, tell the user there is no extension-specific AGENTS.md and offer to inspect the extension code to determine how to use it.
• For script extensions, run the action via core/bin/python {ext-path}/extension.py {action} where {action} is install, update, or uninstall.
• For prompt extensions, start a new session using the configured prompt with the extension path appended.
• For skill extensions, start a new session that invokes the referenced agent skill.
• After a successful install or update, verify that installed is set to true in extension.json5.
• After a successful uninstall, verify that installed is set to false in extension.json5.

Step 6: Validate and document

• Ensure the extension is discoverable by the WebUI by keeping extension.json5 in the extension root.
• If the extension adds reusable user skills, validate them with core/bin/skill-verify and refresh installed skills with core/bin/skill-install.
• Update extension documentation when the metadata contract or install flow changes.

Expected Output

• A ready-to-use extension folder under extensions/
• Valid extension.json5 metadata
• Any required extension.py, packaged assets, and supporting docs

Key Principles

• Keep the extension contract data-driven rather than hard-coded in the WebUI
• Keep prompt extension text generic and let the WebUI append the extension path
• Keep extension implementation scoped to that extension folder
• Use extension-local AGENTS.md files for custom agent behavior when an extension needs usage-specific instructions
• Prefer concise SKILL.md instructions and move detailed operational rules into reference files