custom-gpt-builderlisted

## When to use this skill Trigger phrases: - "build a custom GPT" / "make a GPT" / "GPT for [client]" - "ChatGPT GPT" / "custom gpt creator" - "publish to the GPT Store" / "GPT Store listing" Do NOT trigger on: - **Google Gemini Gems** — use a Gemini-specific builder; out of scope for this skill - **M365 Copilot declarative agents** (agent builder inside M365 Copilot) — `m365-copilot-builder` - **Copilot Studio agents** (Power Platform low-code, topics, autonomous triggers) — `copilot-studio-builder` - **OpenAI API work** (Assistants/Responses API, fine-tuning) — GPTs are a ChatGPT product surface, not an API. Bespoke integration territory. - **ChatGPT Projects** — a Project is a private workspace (chats + files + continuity for ONE person), not a distributable assistant. If the client wants "a GPT just for my own ongoing work", recommend a Project and stop (comparison table: `references/platform-limits.md`). ## What you're building A **Custom GPT** = ChatGPT + fixed instructions (≤8,000 chars) + up to 20 knowledge files + capability toggles + optional Actions (OpenAPI-described API calls). Built in the GPT editor's **Configure** tab by a business user on a Plus-or-better plan; distributed by link, workspace, or GPT Store. Free-plan users can use the result, not build it. The deliverable is a **paste-ready bundle** the client's business user enters into the GPT editor themselves, plus a setup guide. No client account access needed. References (read befor