Ready to supercharge your AI agents?

Install any skill in seconds. Free to start, no credit card required.

Create MCP App · tldraw | DecimalAI

agent toolingby tldraw

Create MCP App

tldraw/create-mcp-app

Source tldraw/tldraw ↗License NOASSERTION

This skill should be used when the user asks to "create an MCP App", "add a UI to an MCP tool", "build an interactive MCP View", "scaffold an MCP App", or needs guidance on MCP Apps SDK patterns, UI-resource registration, MCP App lifecycle, or host integration. Provides comprehensive guidance for building MCP Apps with interactive UIs.

SkillScore100Maintained

Automatic

AI Engineer pack

Last verified 8/7/2026

What it changes

Passed 22 of 22 test cases with the skill, and 9 of 22 without it.

Without skill41%

With skill100%

Checks it passed that the model alone missed

Calls app.sendLog with level info
Calls app.sendLog with level error
Calls useHostStyles passing the app instance

and 22 more in the full report

13 fixed9 passed either way0 still failing0 broke

Pass-rate lift: +59 pp
Tokens: +104%
Agent turns: 0%
Response time: -38%

Model gemini-3.6-flashMeasured 8/7/2026v122 of 22 cases passed with skill

Tokens, turns and time describe resource use, not a dollar price.

Use this skill

Save it into your project's skills folder. Claude Code picks it up in its next session.

curl -fsSL --create-dirs -o .claude/skills/tldraw-create-mcp-app/SKILL.md https://app.decimal.ai/s/tldraw-create-mcp-app/SKILL.md

Want it pinned and updatable? pip install "decimalai>=0.15", then decimalai skills add tldraw-create-mcp-app, and start Claude Code with claude --plugin-dir "$(git rev-parse --show-toplevel)/.agents"

1 · One-time — install the CLI (docs ↗)

pip install "decimalai>=0.15"

2 · Get the skill — writes .agents/skills/tldraw-create-mcp-app/ and pins it in .decimal/skills.lock

decimalai skills add tldraw-create-mcp-app

No CLI? Get the same file — curl · raw file

curl -fsSL --create-dirs -o .claude/skills/tldraw-create-mcp-app/SKILL.md https://app.decimal.ai/s/tldraw-create-mcp-app/SKILL.md

Raw file: /s/tldraw-create-mcp-app/SKILL.md ↗ · machine-readable summary at /s/tldraw-create-mcp-app.json ↗

Safety checks: 3 of 3 passed

Code scan CleanIntent PassedContent Clean

See it in action

One of 13 test cases the skill fixed. Same model, same prompt, with and without the skill.

1 of 13

Prompt

When registering an MCP tool that should open an interactive UI in the host, what property must be included in the tool's metadata to link it to its corresponding HTML resource URI?

What was checked, without and with the skill
Checked	Without skill	With skill
Specifies the URI string inside _meta.ui.resourceUri	Missed	Passed

case-16 · gemini-3.6-flash · 8/7/2026 · answers are capped and redacted

What's inside

The instructions your model reads when the skill loads.

SKILL.md362 linessingle file

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
Link - The tool's _meta.ui.resourceUri references the resource

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

Quick Start Decision Tree

Framework Selection

Framework	SDK 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 SDK
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

Track record

Benchmark

22 / 22

test cases passed, vs 9 / 22 without

Adoption

Users: 0
Times used: 0

Safety and source details

SkillSafety

✓ 3 of 3 passed

Code scan15 of 15 checks clean

0 critical · 0 warning · 0 info — scanner v4 — 8/3/2026

View 15 scanner checks

live_secretremote_code_executionreverse_shelldata_exfiltrationssrf_metadataagent_snoopinganti_refusaldestructive_commandsobfuscated_unicodeunicode_homoglyphopaque_blobsuspicious_urltool_overreachtrigger_abuseprompt_injection_phrasing

IntentSafe

LLM judge · does the skill do what it claims

ContentClean

LLM judge · policy & harmful-content review

Source

Imported

tldraw / tldraw

apps/mcp-app/.claude/skills/create-mcp-app/SKILL.md

View on GitHub ↗

License NOASSERTIONImported 8/3/2026Version v1

Other skills for the same job

Published skills whose descriptions closely match this one, with their headline benchmark lift.

More skills from the same source and nearby in the registry, with their headline benchmark lift.

Ready to supercharge your AI agents?

See it in action

What's inside

Create MCP App

Core Concept: Tool + Resource

Quick Start Decision Tree

Framework Selection

Project Context

Track record

Benchmark

Adoption

SkillSafety

Source

Other skills for the same job

Related skills