What is mcp-app-create?

A guide for building MCP Apps: interactive web interfaces connected to tools in an MCP-enabled host. Each app links a tool, which provides data, with an HTML resource, which displays it.

Adding a user interface to an existing MCP tool or creating a new interactive MCP server app. It covers registering the tool and HTML resource, connecting their lifecycle, and selecting a frontend framework.

It explains the connection between the tool, the web interface, and the host so the app can show results interactively. It also helps choose an approach based on whether the project uses React or plain JavaScript.

How Bazilio-san/mcp-vkusvill configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to Bazilio-san/mcp-vkusvill. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/Bazilio-san/mcp-vkusvill/master/.claude/skills/mcp-app-create/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/Bazilio-san/mcp-vkusvill

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/bazilio-san/mcp-vkusvill/mcp-app-create/github.svg)](https://agentmods.dev/skills/bazilio-san/mcp-vkusvill/mcp-app-create)

Your own site

<a href="https://agentmods.dev/skills/bazilio-san/mcp-vkusvill/mcp-app-create"><img src="https://agentmods.dev/badge/skills/bazilio-san/mcp-vkusvill/mcp-app-create/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/bazilio-san/mcp-vkusvill/mcp-app-create"><img src="https://agentmods.dev/badge/skills/bazilio-san/mcp-vkusvill/mcp-app-create.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 77 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,606 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.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00077	$0.02606
Opus 5.5	$0.00031	$0.01042
Sonnet 5.5	$0.00015	$0.00521
Haiku 4.5	$0.00008	$0.00261

Measured 2mo ago against content hash d52c36a77506, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

mcp-app-create 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 2mo 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:

mcp-app-create — 92% identical, 10 lines differ

.claude/skills/mcp-app-create/SKILL.md · 229 lines

How it starts

The opening of the file, as written. The whole thing — 229 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Create MCP App

Build interactive UIs that run inside MCP-enabled hosts like Claude Desktop. An MCP App combines an MCP tool with an HTML resource to display rich, interactive content.

Core Concept: Tool + Resource

Every MCP App requires two parts linked together:

Tool - Called by the LLM/host, returns data
Resource - Serves the bundled HTML UI that displays the data

The tool's _meta.ui.resourceUri references the resource's URI.

Host calls tool → Host renders resource UI → Server returns result → UI receives result.

Quick Start Decision Tree

Framework Selection

Framework	`@modelcontextprotocol/ext-apps` Support	Best For
React	`useApp` hook provided	Teams familiar with React
Vanilla JS	Manual lifecycle	Simple apps, no build complexity
Vue/Svelte/Preact/Solid	Manual lifecycle	Framework preference

Project Context

Adding to existing MCP server:

Import registerAppTool, registerAppResource from @modelcontextprotocol/ext-apps
Add tool registration with _meta.ui.resourceUri
Add resource registration serving bundled HTML

Creating new MCP server:

Set up server with transport (stdio or HTTP)
Register tools and resources
Configure build system with vite-plugin-singlefile

Getting Reference Code

Clone or update the MCP Apps SDK repository (@modelcontextprotocol/ext-apps) using the bundled helper. The folder ./mcp-ext-apps/ is already in .gitignore and is intentionally persistent — it serves as the long-lived reference checkout that this skill (and the mcp-app-add-to-server skill) read from. Do not delete it after use.

node scripts/clone-mcp-ext-apps.js --tag latest

The script clones into ./mcp-ext-apps/ on first run, pulls the default branch on subsequent runs, and (with --tag latest) checks out the latest released npm tag so the cloned tree matches the published @modelcontextprotocol/ext-apps version. Add --json to capture machine- readable metadata (path, ref, commit) for downstream automation.

Read the full file on GitHub · 229 lines

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.

2mo ago First seen · 229 lines · 77 tokens per session scan A d52c36a77506

Subscribe to this mod's changes

mcp-app-create is a skill published in the GitHub repository Bazilio-san/mcp-vkusvill (1 stars, last pushed 4mo ago), licensed MIT. It adds 77 tokens to every session and 2,606 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 2026-08-31.

Building agents Frontend

mcp-app-create next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
mcp-app-createBazilio-san/mcp-vkusvill	Skill	1	4mo ago	MIT	A	77	Claude Code
imagegenopenai/codex	Skill	133k	yesterday	Apache-2.0	A	113	Codex
playwright-climicrosoft/playwright	Skill	99k	yesterday	Apache-2.0	A	19	Claude Code
local-ai-agentsmicrosoft/ai-agents-for-beginners	Skill	79k	4d ago	MIT	A	200	Claude Code, Codex
systematic-debuggingobra/superpowers	Skill	313k	3d ago	MIT	A	21	Claude Code
next-cache-components-adoptionvercel/next.js	Skill	143k	yesterday	MIT	A	95	Claude Code
next-partial-prefetching-adoptionvercel/next.js	Skill	143k	yesterday	MIT	A	103	Claude Code

mcp-vkusvill: Skill for Claude Code