alpic-ai/skybridge is a full-stack TypeScript and React framework for building MCP apps, which are interactive user interfaces connected to MCP servers and usable in clients such as Claude and ChatGPT. It helps developers create type-safe apps with development tooling, client compatibility, React hooks, and agent-oriented APIs. The catalogue skills, instructions, setting, and hook support workflows for building MCP apps with Skybridge.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add alpic-ai/skybridge --skill mcp-app-buildergit clone --depth 1 https://github.com/alpic-ai/skybridgeWrote 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.
[](https://agentmods.dev/skills/alpic-ai/skybridge/mcp-app-builder)<a href="https://agentmods.dev/skills/alpic-ai/skybridge/mcp-app-builder"><img src="https://agentmods.dev/badge/skills/alpic-ai/skybridge/mcp-app-builder/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.
<a href="https://agentmods.dev/skills/alpic-ai/skybridge/mcp-app-builder"><img src="https://agentmods.dev/badge/skills/alpic-ai/skybridge/mcp-app-builder.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00071 | $0.00858 |
| Opus 5.5 | $0.00028 | $0.00343 |
| Sonnet 5.5 | $0.00014 | $0.00172 |
| Haiku 4.5 | $0.00007 | $0.00086 |
Grade A, and why
mcp-app-builder 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 22d 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.
This is a copy
88% identical to chatgpt-app-builder — 28 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 56 lines — stays where its author put it; the contents beside it link to each section on GitHub.
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
- Copy template → copy-template.md: when starting a new project with ready SPEC.md
- Run locally → run-locally.md: when ready to test, need dev server or ChatGPT/Claude connection
- 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
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 22d ago Changed f952efae5acf
- 1mo ago Changed · +3 lines 0606763c6dbd
- 1mo ago First seen · 53 lines · 71 tokens per session scan A d954cbb76c48
mcp-app-builder is a skill published in the GitHub repository alpic-ai/skybridge (2,177 stars, last pushed 2d ago), licensed MIT. It adds 71 tokens to every session and 858 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 88% identical to chatgpt-app-builder, differing in 28 lines, and is treated as a copy.
Other skills, from other repositories
fullstack-ai-app-builder
A method for building and launching complete AI-powered web applications, from requirements and technical planning through the front end, back end, AI integration, and deployment. It is aimed at people who want to create an application without a back-end engineer.
stripe-projects
Provision SaaS services + sync creds via Stripe Projects.
status
Show whether Mem0 memory is working in this repository, covering configuration, capture state, pending flushes, and whether the Mem0 API key is valid. Use when the user asks whether memory is on, why a memory is missing, or anything looks broken.
mem0-test-integration
Verify a Mem0 integration produced by /mem0-integrate. Runs in the same workspace on the same branch (loose coupling) — installs dependencies, runs the repo's native test suite, then exercises a real end-to-end smoke flow against the user's API key. Produces a scorecard. TRIGGER when: user has just run /mem0-integrate…
mem0-oss-to-platform
Plan, then execute, a migration of a project from the mem0 open-source / self-hosted SDK (local Memory class) to the mem0 Platform / hosted SDK (MemoryClient). TRIGGER when: the developer wants to move, switch, or migrate mem0 off OSS/self-hosted to the hosted API, e.g. "migrate my mem0 setup to the platform", "switch…
blind-sqli
Blind SQL injection under hostile WAF — manual bypass playbook for when sqlmap fails because common tokens (SUBSTRING, IF, AND, WHERE, single quotes) are filtered. Covers token-fingerprinting probe loops, arithmetic-multiplication boolean evaluation, hex-encoded literals, and exponential-probe binary search. Loaded on…