mcp-app-builder

v2026.09.24

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.

GitHub
Install command
npx skhub add alpic-ai/mcp-app-builder
Markdown
SKILL.md

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

Discovery
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Version
Latest version metadata

Version

v2026.09.24

Published

Sep 24, 2026

Category

Uncategorized

License

MIT

Source path

skills/mcp-app-builder

Default branch

main

Latest commit

8bc3175

Tree SHA

b2cf07a