Agent skill

MCP App Builder

by alpic-ai in alpic-ai/skybridge

Guide developers through creating and updating MCP Apps. An agent skill from alpic-ai/skybridge.

MITAuto-check passedAgent Workflows

Install MCP App Builder

skills CLI
$ npx skills add alpic-ai/skybridge --skill mcp-app-builder -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install alpic-ai/skybridge mcp-app-builder --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/alpic-ai/skybridge.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/mcp-app-builder .claude/skills/mcp-app-builder && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
mcp-app-builder
GitHub stars
2.2k
Token cost
~906 tokens
SKILL.md length
337 words
Files
2
Skills in repo
3
Repo updated
First seen
Licence
MIT

At a glance

Guide developers through creating and updating MCP Apps. An agent skill from alpic-ai/skybridge.

  • Works in 3 steps: Copy template → copy-template.md: when… → Run locally → run-locally.md: when ready… → Evals → evals.md: when checking that a…
  • A user wants to create
  • SKILL.md covers Setup, Architecture, Implementation and Deploy
  • Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

MCP App Builder is an agent skill from alpic-ai/skybridge. Guide developers through creating and updating MCP Apps. Covers the full lifecycle: brainstorming ideas against UX guidelines, bootstrapping projects, implementing tools/views, debugging, running dev servers, deploying and connecting apps to ChatGPT. Use when a user wants to create or update a MCP App, MCP server or use the Skybridge framework.

Its SKILL.md is about 910 tokens, which your agent loads only when the skill is triggered. The skill folder holds 1 other file.

It sits in Agent Workflows, covering MCP servers and Brainstorming. It works with Model Context Protocol, OpenAI, React and TypeScript. The repository describes itself as: Skybridge is a full-stack TypeScript framework for MCP Apps and ChatGPT Apps. Type-safe. React-powered. Platform-agnostic. The licence is MIT.

When your agent uses it

  • A user wants to create
  • Update a MCP App
  • Use the Skybridge framework

Example prompts

  • “/mcp-app-builder”

Workflow steps

3 steps, taken from the first numbered list in SKILL.md.

  1. Copy template → copy-template.md: when starting a new project with ready SPEC.md
  2. Run locally → run-locally.md: when ready to test, need dev server or ChatGPT/Claude connection
  3. Evals → evals.md: when checking that a real model reaches the right tools from natural prompts, in a test

What it can do on your machine

Read from SKILL.md and the folder at commit 6dd4439. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    No scripts in the folder and no shell commands in SKILL.md.

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    Links to these hosts (documentation or services it may open):

    • docs.skybridge.tech
    • skybridge.tech

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

MCP App Builder loads about 906 tokens when it runs. Until then it costs about 91 tokens; SKILL.md has 337 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~91
When it runs · the whole SKILL.md, loaded when a task matches
~906

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from alpic-ai/skybridge at commit 6dd4439, republished under its MIT licence (© alpic-ai). 337 words, ~906 tokens.

Download SKILL.mdSave it as .claude/skills/mcp-app-builder/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.
name
mcp-app-builder
description
Guide developers through creating and updating MCP Apps. Covers the full lifecycle: brainstorming ideas against UX guidelines, bootstrapping projects, implementing tools/views, debugging, running dev servers, deploying and connecting apps to ChatGPT. Use when a user wants to create or update a MCP App, MCP server or use the Skybridge framework.

Creating MCP Apps

Those are conversational experiences that extend AI assistants through tools and custom UI views. They're built as MCP servers invoked during conversations.

⚠️ The app is consumed by two users at once: the human and the AI Assistant LLM. They collaborate through the view—the human interacts with it, the LLM sees its state. Internalize this before writing code: the view is your shared surface.

SPEC.md keeps track of the app's requirements and design decisions. Keep it up to date as you work on the app.

No SPEC.md? → Read discover.md first. Nothing else until SPEC.md exists.

SPEC.md exists? → Read SPEC.md, then follow architecture.md to design the change. Update SPEC.md, then read the relevant Implementation references below before writing code.

Migrating from Skybridge < 0.36.x? → Read migrate-to-v1.md first. Users may reference skybridge >= 0.36.x as v1.

Migrating from Skybridge 1.x to 2.x? → Fetch the v2.0.0 release notes first and follow them.

Building an ecommerce app? → Read ecommerce.md first.

Setup

  1. Copy template → copy-template.md: when starting a new project with ready SPEC.md
  2. Run locally → run-locally.md: when ready to test, need dev server or ChatGPT/Claude connection
  3. Evals → evals.md: when checking that a real model reaches the right tools from natural prompts, in a test

Architecture

Design or evolve UX flows and API shape → architecture.md

Implementation

  • Fetch and render data → fetch-and-render-data.md: when implementing server handlers and view data fetching
  • State and context → state-and-context.md: when persisting view UI state and updating LLM context
  • Prompt LLM → prompt-llm.md: when view needs to trigger LLM response
  • UI guidelines → ui-guidelines.md: display modes, layout constraints, theme, device, and locale
  • External links → open-external-links.md: when redirecting to external URLs or setting "open in app" target
  • Download file → download-file.md: when saving content to the user's filesystem
  • OAuth → oauth.md: when tools need user authentication to access user-specific data
  • CSP → csp.md: when declaring allowed domains for fetch, assets, redirects, or iframes

Deploy

  • Ship to production → deploy.md: when ready to deploy via Alpic
  • Publish to ChatGPT/Claude Directories → publish.md: when ready to submit for review

Full API docs: https://docs.skybridge.tech/api-reference.md

Release notes & changelog: https://skybridge.tech/changelog.md

© alpic-ai, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 1 other file in skills/mcp-app-builder of alpic-ai/skybridge.

  • SKILL.md
  • references

Open the folder on GitHubat commit 6dd4439

Compare with similar skills

MCP App Builder next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

MCP App Builder compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
MCP App Builder this skillalpic-ai/skybridge2.2k—~906Automated safety check: PassMIT
Nextcrmpdovhomilja/nextcrm-app717—~3.3kAutomated safety check: PassMIT
MCP Server Builder with mcp-usemcp-use/mcp-use11k—~923Automated safety check: PassApache-2.0
Agent RecallGoldentrii/AgentRecall-X371—~5.2kAutomated safety check: NotesMIT
Plugin AuthoringXiaoPuOuO/openchatx-mcp257—~709Automated safety check: PassMIT
Magic ResumeMagic-Resume/Magic-Resume101—~663Automated safety check: PassMIT

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Categories

Questions about MCP App Builder

What does MCP App Builder do?

Guide developers through creating and updating MCP Apps. An agent skill from alpic-ai/skybridge. MCP App Builder is an agent skill from alpic-ai/skybridge. Guide developers through creating and updating MCP Apps.

When should I use MCP App Builder?

MCP App Builder fits situations like: A user wants to create; update a MCP App; use the Skybridge framework.

How do I install MCP App Builder in Claude Code?

Run `npx skills add alpic-ai/skybridge --skill mcp-app-builder -a claude-code`. Or copy the skill folder (skills/mcp-app-builder in alpic-ai/skybridge) into .claude/skills/mcp-app-builder in your project. Claude Code loads it when a task matches its description.

How do I install MCP App Builder in Codex?

Run `npx skills add alpic-ai/skybridge --skill mcp-app-builder -a codex`. Or copy the skill folder (skills/mcp-app-builder in alpic-ai/skybridge) into .agents/skills/mcp-app-builder in your project. Codex loads it when a task matches its description.

Can I use MCP App Builder in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add alpic-ai/skybridge --skill mcp-app-builder -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/mcp-app-builder, .gemini/skills/mcp-app-builder, .github/skills/mcp-app-builder and .opencode/skills/mcp-app-builder in your project.

What does MCP App Builder need to run?

SKILL.md names no scripts, command-line tools or credentials: MCP App Builder is instructions for the agent only.

Does MCP App Builder access the network?

SKILL.md names 2 domains. As links in the text: docs.skybridge.tech and skybridge.tech. This is read from the text; nothing was executed.

Is MCP App Builder safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does MCP App Builder use?

MCP App Builder is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does MCP App Builder use?

About 906 tokens (SKILL.md is roughly 3.6k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to MCP App Builder?

Skills that share tags, products or a category with MCP App Builder: Nextcrm (pdovhomilja/nextcrm-app, 717 stars), MCP Server Builder with mcp-use (mcp-use/mcp-use, 11k stars), Agent Recall (Goldentrii/AgentRecall-X, 371 stars) and Plugin Authoring (XiaoPuOuO/openchatx-mcp, 257 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains MCP App Builder?

alpic-ai (a GitHub organization) maintains it in alpic-ai/skybridge, which has 2,152 GitHub stars. The repository holds 3 skills in this directory. The repository was last updated on October 8, 2026.

Source: alpic-ai/skybridge on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.