comfyui-frontend-extensions

comfyui-frontend-extensions is a skill for Claude Code from artokun/comfyui-mcp. It costs 76 tokens per session (5,364 once invoked), scanned A, original, MIT.

A programming guide for building ComfyUI v2 web-interface extensions with its published extension package. ComfyUI is a tool for creating image workflows with connected nodes.

In plain words
What is it for?
Use it when writing or editing ComfyUI custom-node JavaScript, sidebar panels, widgets, commands, hotkeys, events, or extensions being moved from version 1 to version 2.
Why use it?
It replaces older global-variable and code-patching methods with separate, typed functions and cleanup handles. This makes extension code easier to structure and update.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the comfy plugin — 42 skills, 11 commands, 4 agents, 2 hooks shipped together

Good fit Use it when writing or editing ComfyUI custom-node JavaScript, sidebar panels, widgets, commands, hotkeys, events, or extensions being moved from version 1 to version 2.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/artokun/comfyui-mcp/comfyui-frontend-extensions
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add artokun/comfyui-mcp --skill comfyui-frontend-extensions
Clone the repo
git clone --depth 1 https://github.com/artokun/comfyui-mcp

Made for: Claude Code.

Or install comfy, the plugin that ships this one along with the rest of its 42 skills, 11 commands, 4 agents, 2 hooks.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for comfyui-frontend-extensions

README.md
[![agentmods](https://agentmods.dev/badge/skills/artokun/comfyui-mcp/comfyui-frontend-extensions/github.svg)](https://agentmods.dev/skills/artokun/comfyui-mcp/comfyui-frontend-extensions)
Your own site
<a href="https://agentmods.dev/skills/artokun/comfyui-mcp/comfyui-frontend-extensions"><img src="https://agentmods.dev/badge/skills/artokun/comfyui-mcp/comfyui-frontend-extensions/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for comfyui-frontend-extensions

Your own site · 80×15
<a href="https://agentmods.dev/skills/artokun/comfyui-mcp/comfyui-frontend-extensions"><img src="https://agentmods.dev/badge/skills/artokun/comfyui-mcp/comfyui-frontend-extensions.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 76 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,364 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00076 $0.05364
Opus 5.5 $0.00030 $0.02146
Sonnet 5.5 $0.00015 $0.01073
Haiku 4.5 $0.00008 $0.00536

Measured 1mo ago against content hash 547062066d04, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

comfyui-frontend-extensions scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

plugin/skills/comfyui-frontend-extensions/SKILL.md · 504 lines

How it starts

The opening of the file, as written. The whole thing — 504 lines — stays where its author put it; the contents beside it link to each section on GitHub.

ComfyUI v2 Frontend Extension API

The v2 extension API is the published npm package @comfyorg/extension-api. It replaces the legacy app.registerExtension() / nodeType.prototype monkey-patching model with a typed, tree-shakeable, import-based API.

If you are converting an existing v1 extension, read references/migrate-v1-to-v2.md for a pattern-by-pattern mapping.

Mental model

v1 (legacy) v2 (@comfyorg/extension-api)
One giant app.registerExtension({...}) call One defineX per concern, each independently disposable
window.app / app.* globals Direct import from the package; no window.app at module-eval time
nodeType.prototype.onExecuted = ... patching node.on('executed', fn) on a NodeHandle
Mutate widget.value, assign widget.callback widget.setValue(v) / widget.on('valueChange', fn)
api.addEventListener('execution_start', fn) execution.on('start', fn) (typed namespaces)
Manual removeEventListener bookkeeping Every subscription returns Unsubscribe; every defineX returns DisposableHandle

Core principles baked into the API:

  • Import, don't reach for globals. import { defineNode } from '@comfyorg/extension-api'. No window.app dependency at module evaluation time.
  • Read via getters, write via command-dispatch setters. getValue() reads; setValue() dispatches an undo-able, serializable command. Read-only invariants (set at construction) are readonly accessors (node.type, widget.name).
  • Observe via typed on(...) subscriptions. Each returns an Unsubscribe cleanup function. No Vue refs/signals are ever exposed; Vue reactivity is the internal engine only.
  • Everything is disposable. Every defineX returns a DisposableHandle with an idempotent, synchronous dispose().

Registration entry points

All imported from @comfyorg/extension-api:

Function Purpose Returns
defineNode(opts) Primary entry — react to node lifecycle (replaces prototype patching) NodeExtensionOptions
defineExtension(opts) App-scoped lifecycle (init/setup) + shell UI host ExtensionOptions
defineWidget(opts) Register a custom widget type (DOM via mount) WidgetExtensionOptions
defineSidebarTab(opts) Add a left-sidebar tab (Vue or custom) DisposableHandle
defineBottomPanelTab(opts) Add a bottom-panel tab DisposableHandle
defineToolbarButton(opts) Add an action-bar button DisposableHandle
defineCommand(opts) Register an invokable command DisposableHandle
defineHotkey(opts) Bind a key combo to a command id DisposableHandle
defineSetting(opts) Add a settings-menu entry DisposableHandle
defineAboutBadge(opts) Add a badge to the About page DisposableHandle

Read the full file on GitHub · 504 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 1mo ago First seen · 504 lines · 76 tokens per session scan A 547062066d04

Subscribe to this mod's changes

comfyui-frontend-extensions is a skill published in the GitHub repository artokun/comfyui-mcp (871 stars, last pushed yesterday), licensed MIT. It adds 76 tokens to every session and 5,364 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories

chief-strategy-officer

Owns where the business plays and how it wins over a multi-year horizon — portfolio choices, corporate development, strategic partnerships, and planning under uncertainty. Use this for a decision about which markets or businesses to be in, whether to build, buy, or partner, how to allocate capital across business…

cbrock84/headcount · 93 tokens

chief-revenue-officer

Owns the revenue engine end to end: sales, monetization, pricing, customer success, retention, and partnerships. Use this for pricing and packaging decisions, sales strategy and coverage, forecast and pipeline health, churn and expansion, partner and channel strategy, or when marketing-sourced demand is not…

cbrock84/headcount · 0 tokens

dev

One-command dev loop boot. Spins up portless (named HTTPS subdomain), emulate (stateful API mocks), the project's dev server, and an agent-browser session, all keyed to the current git branch. Use when starting a feature branch, switching worktrees, or returning to a project after a break. Skips silently with install…

yonatangross/orchestkit · 76 tokens

storybook-mcp-integration

Reference for the Storybook MCP server itself (@storybook/addon-mcp): 6 tools across 3 toolsets (dev, docs, testing), availability detection, and per-agent toolset filtering. Use when setting up the server or calling these tools directly against components that already exist. For the end-to-end pipeline that turns a…

yonatangross/orchestkit · 91 tokens

voice

A brand-voice analysis skill that studies a user's past posts and replies to describe how they think and write. Brand voice means the recurring tone, wording, rhythm, humor, and boundaries in someone's writing.

akseolabs-seo/AK-Threads-booster · 57 tokens

personal-guide-render

Instructions for understanding the status of a personal guide that the platform builds automatically from stored user data. The platform creates daily lessons and rebuilds the full guide weekly on its servers.

TserenTserenov/FMT-exocortex-template · 49 tokens