What is mcp-app-add-to-server?

Instructions for adding interactive HTML views to an existing MCP server. MCP is a standard for connecting AI agents to tools, while these views let a host show a tool’s results in an embedded interface as well as text.

Use them when pairing MCP tools with sandboxed HTML resources, linking each tool to its view, or consulting the MCP Apps SDK for implementation details.

They explain how to add a user interface without removing the server’s support for clients that only handle text.

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-add-to-server/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-add-to-server/github.svg)](https://agentmods.dev/skills/bazilio-san/mcp-vkusvill/mcp-app-add-to-server)

Your own site

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

Per session 97 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 4,080 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	$0.00097	$0.04080
Opus 5.5	$0.00039	$0.01632
Sonnet 5.5	$0.00019	$0.00816
Haiku 4.5	$0.00010	$0.00408

Measured 2mo ago against content hash 94b7c701e991, 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-add-to-server 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-add-to-server — 92% identical, 12 lines differ

.claude/skills/mcp-app-add-to-server/SKILL.md · 434 lines

How it starts

The opening of the file, as written. The whole thing — 434 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Add UI to MCP Server

Enrich an existing MCP server's tools with interactive UIs using the MCP Apps SDK (@modelcontextprotocol/ext-apps).

How It Works

Existing tools get paired with HTML resources that render inline in the host's conversation. The tool continues to work for text-only clients — UI is an enhancement, not a replacement. Each tool that benefits from UI gets linked to a resource via _meta.ui.resourceUri, and the host renders that resource in a sandboxed iframe when the tool is called.

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-create 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.

Protocol Specification

The formal MCP Apps spec lives in the same repository — read it for authoritative protocol semantics that source files and examples only illustrate:

File	Contents
`./mcp-ext-apps/specification/2026-01-26/apps.mdx`	SEP-1865 (Stable, 2026-01-26) — `ui://` URI scheme, `_meta.ui` contract, iframe sandboxing, host↔UI JSON-RPC messages, security model

Where to look first:

For protocol questions (wire format, required _meta keys, mandatory host/server behaviors, message semantics) — consult ./mcp-ext-apps/specification/2026-01-26/apps.mdx. The spec is the source of truth for what MUST happen.
For TypeScript API questions (which helper to call, handler signatures, idiomatic usage) — consult @modelcontextprotocol/ext-apps sources under ./mcp-ext-apps/src/ and its examples. The package is the source of truth for how to invoke the protocol from code.

Read the full file on GitHub · 434 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 · 434 lines · 97 tokens per session scan A 94b7c701e991

Subscribe to this mod's changes

mcp-app-add-to-server is a skill published in the GitHub repository Bazilio-san/mcp-vkusvill (1 stars, last pushed 4mo ago), licensed MIT. It adds 97 tokens to every session and 4,080 once invoked, about $0.0004 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-add-to-server next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
mcp-app-add-to-serverBazilio-san/mcp-vkusvill	Skill	1	4mo ago	MIT	A	97	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