Agent skill

Chatgpt App Builder

by alpic-ai in alpic-ai/skybridge

Guide developers through creating and updating ChatGPT plugins.

MITAuto-check passedAgent Workflows

Install Chatgpt App Builder

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

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

GitHub CLI
$ gh skill install alpic-ai/skybridge chatgpt-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/chatgpt-app-builder .claude/skills/chatgpt-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
chatgpt-app-builder
GitHub stars
2.2k
Token cost
~1k tokens
SKILL.md length
391 words
Files
31 (incl. references)
Skills in repo
3
Repo updated
First seen
Licence
MIT

At a glance

Guide developers through creating and updating ChatGPT plugins.

  • 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

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

Its SKILL.md is about 1k tokens, which your agent loads only when the skill is triggered. The skill folder holds 32 other files, including reference files (for example `evals/README.md`, `evals/architecture.json` and `evals/communicate-with-host.json`).

It sits in Agent Workflows, covering MCP servers and Brainstorming. It works with OpenAI, Model Context Protocol, 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 ChatGPT plugin (formerly called a ChatGPT app) / MCP server for ChatGPT
  • Use the Skybridge framework

Example prompts

  • “/chatgpt-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 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

Chatgpt App Builder loads about 1k tokens when it runs, and up to ~27k if it reads all its reference files. Until then it costs about 107 tokens; SKILL.md has 391 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~107
When it runs · the whole SKILL.md, loaded when a task matches
~1k
With references · SKILL.md plus every file in references/, read only if the agent opens them
~27k

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). 391 words, ~1,026 tokens.

Download SKILL.mdSave it as .claude/skills/chatgpt-app-builder/SKILL.md (or your agent's skills folder). This skill also uses 30 other files; get the full folder from GitHub.
name
chatgpt-app-builder
description
Guide developers through creating and updating ChatGPT plugins. Covers the full lifecycle: brainstorming ideas against UX guidelines, bootstrapping projects, implementing tools/views, debugging, running dev servers, deploying and connecting plugins to ChatGPT. Use when a user wants to create or update a ChatGPT plugin (formerly called a ChatGPT app) / MCP server for ChatGPT, or use the Skybridge framework.

Creating Plugins For LLMs

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

⚠️ The plugin is consumed by two users at once: the human and the ChatGPT 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 plugin's requirements and design decisions. Keep it up to date as you work on the plugin.

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

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.

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 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

Show full SKILL.md (179 more words)Show less

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
  • OAuth → oauth.md: when tools need user authentication to access user-specific data
  • Assets and styling → assets-and-styling.md: when adding images, fonts or CSS to views
  • CSP → csp.md: when declaring allowed domains for fetch, assets, redirects, or iframes
  • Events → events.md: when ChatGPT should react to activity in the app without the user, such as new comments or incidents
  • OpenAI MCP extensions → openai-extensions.md: when the view should open from the ChatGPT sidebar, a conversation side panel, a file, or a deep link, or use ChatGPT at-mentions, titled messages or local files

Deploy

  • Ship to production → deploy.md: when ready to deploy via Alpic
  • Publish to ChatGPT Directory → 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 30 other files (references) in skills/chatgpt-app-builder of alpic-ai/skybridge.

  • SKILL.md
  • evals/README.md
  • evals/architecture.json
  • evals/communicate-with-host.json
  • evals/discover.json
  • evals/fetch-and-render-data.json
  • evals/open-external-links.json
  • evals/skill.json
  • evals/state-and-context.json
  • evals/ui-guidelines.json
  • evals/update-existing.json
  • references/architecture.md
  • references/assets-and-styling.md
  • references/copy-template.md
  • references/csp.md
  • references/deploy.md
  • references/discover.md
  • references/download-file.md
  • references/ecommerce.md
  • … and 12 more

Open the folder on GitHubat commit 6dd4439

Used in 1 other repository

We found 2 copies of this SKILL.md (exact, near-identical or edited) in other folders. This page covers the copy in alpic-ai/skybridge, which our catalogue first saw on October 7, 2026.

Compare with similar skills

Chatgpt 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.

Chatgpt App Builder compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Chatgpt App Builder this skillalpic-ai/skybridge2.2k—~1kAutomated safety check: PassMIT
Nextcrmpdovhomilja/nextcrm-app715—~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
GitHub Commentingjuspay/neurolink145—~698Automated safety check: PassMIT

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Questions about Chatgpt App Builder

What does Chatgpt App Builder do?

Guide developers through creating and updating ChatGPT plugins. Chatgpt App Builder is an agent skill from alpic-ai/skybridge. Guide developers through creating and updating ChatGPT plugins.

When should I use Chatgpt App Builder?

Chatgpt App Builder fits situations like: A user wants to create; update a ChatGPT plugin (formerly called a ChatGPT app) / MCP server for ChatGPT; use the Skybridge framework.

How do I install Chatgpt App Builder in Claude Code?

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

How do I install Chatgpt App Builder in Codex?

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

Can I use Chatgpt 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 chatgpt-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/chatgpt-app-builder, .gemini/skills/chatgpt-app-builder, .github/skills/chatgpt-app-builder and .opencode/skills/chatgpt-app-builder in your project.

What does Chatgpt App Builder need to run?

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

Does Chatgpt 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 Chatgpt 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 Chatgpt App Builder use?

Chatgpt 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 Chatgpt App Builder use?

About 1k tokens (SKILL.md is roughly 4.1k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 26k tokens, read only when the agent opens those files.

What are the alternatives to Chatgpt App Builder?

Skills that share tags, products or a category with Chatgpt App Builder: Nextcrm (pdovhomilja/nextcrm-app, 715 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 Chatgpt 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.