canvas-extension-api

94 / 100 · Low risk

Fine to try. Some of what it can do is expected: a coding skill usually runs build and test commands.

By OpenHands/extensions (GitHub) · coding · 182 stars · scanned at commit b98ac06

This skill should be used when the user asks to "create an OpenHands App", "scaffold a Canvas App", "build an app with the Canvas Extensions API", "build an Agent Canvas App", "bundle a single-file Canvas App", "build a Sidecar-backed Canvas App", "add onboarding for an App service", "add a custom interface to Agent Canvas", "validate an OpenHands App", "make a Canvas App look native", "match Agent Canvas styles", "style a canvas extension", "reuse OpenHands design tokens", "add native Tailwind…

Works with any agent that supports SKILL.md skills.

What this skill can do

Runs commands on your computer

This is disclosed by the author in the skill's SKILL.md or README. Expected for a coding skill.

Found in 6 places.

skills/canvas-extension-api/SKILL.md, line 34node /path/to/canvas-extension-api/scripts/validate-extension.mjs /path/to/app
skills/canvas-extension-api/SKILL.md, line 232node /path/to/canvas-extension-api/scripts/validate-extension.mjs /path/to/app-package
skills/canvas-extension-api/scripts/validate-extension.test.mjs, line 2import { spawnSync } from "node:child_process";

Show 3 more

skills/canvas-extension-api/scripts/validate-extension.test.mjs, line 34return spawnSync(process.execPath, [validator.pathname, root, ...options], {
skills/canvas-extension-api/scripts/validate-extension.test.mjs, line 59const result = spawnSync(
skills/canvas-extension-api/scripts/validate-extension.test.mjs, line 74const result = spawnSync(

Connects to the internet

This is disclosed by the author in the skill's SKILL.md or README.

Found in 2 places.

skills/canvas-extension-api/references/connections.md, line 103const events = new WebSocketCallbackClient({
skills/canvas-extension-api/references/connections.md, line 120const socket = new WebSocket(eventsUrl);

Install

Paste this into your terminal. It downloads exactly the version we scanned, not whatever is newest.

if [ -e ~/.agents/skills/'canvas-extension-api' ] || [ -L ~/.agents/skills/'canvas-extension-api' ]; then echo 'A skill folder named canvas-extension-api already exists — not replacing it' >&2; false; else d=$(mktemp -d) && git clone --quiet --filter=blob:none --no-checkout 'https://github.com/OpenHands/extensions' "$d" && git -C "$d" checkout --quiet 'b98ac0671a51cc91bab3609bf4d334c7c832dd98' -- 'skills/canvas-extension-api' && mkdir -p ~/.agents/skills && cp -R "$d"/'skills/canvas-extension-api' ~/.agents/skills/'canvas-extension-api' && rm -rf "$d"; fi

Codex reads ~/.agents/skills directly. For Claude Code, Cursor, Copilot, Gemini CLI, Antigravity or OpenCode, also link it. For Claude Code: ln -s ~/.agents/skills/'canvas-extension-api' ~/.claude/skills/'canvas-extension-api' (other agents: ~/.cursor/skills, ~/.copilot/skills, ~/.gemini/skills, ~/.gemini/config/skills, ~/.config/opencode/skills). Or install through the finder skill, which does both.

Badge for your README

The badge for OpenHands/extensions shows the score of its lowest-scoring skill.

SkillTrust badge for OpenHands/extensions

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Score history

Date	Version	Score
2026-11-12	`b98ac06`	94