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2 min read#agents#chatgpt#developers

A custom GPT that makes link pages

The schema is the easy half. The instructions — what to ask, what never to invent — are what separates a useful assistant from a page generator.

The action

A custom GPT takes an OpenAPI document and turns its operations into actions the model may call. Ours is published at /openapi.json, generated from the validators the server runs, so the operations you import are exactly the ones that exist. Authentication can be left out entirely: creating a page needs no key, and the create call returns one for whatever it made.

Import it, keep the four operations you need — check a name, validate, create, read a page — and hide the rest. A model offered fourteen tools it never uses spends attention deciding between them, and a smaller surface produces a steadier assistant.

  1. Ask before building: the address, the display name, one sentence of bio, the links with labels, the social profiles, a photo URL, anything 18+.
  2. Never invent a link, a phone number or a biography. An empty field is honest; a plausible one is a lie the owner has to find.
  3. Validate first, then create with an idempotency key, then read the page back as text and compare.
  4. Finish by giving the person two links and one sentence about what the claim link does.

Instructions worth copying

  • «Do not proceed until the person has answered every question. Ask again rather than guessing.»
  • «If the address is taken, show the suggestions and ask. Do not pick one on their behalf.»
  • «Mark any link to adult content as 18+, whether or not you were asked to.»
  • «One page unless more were requested. Ten per account is a ceiling, not a target.»

What the GPT cannot do for them

It cannot decide which five of eleven links belong on a phone screen, and it should say so rather than quietly choosing. It cannot write a bio in someone’s voice from three words. And it cannot judge whether a photograph works as a round avatar, which is why the crop anchor exists and why the finished page is worth a look on an actual phone.

It also cannot mint or revoke keys or delete an account: those need a browser session, on purpose. An assistant that loses its key asks the owner for a new one from the dashboard, which is the correct direction for that request to travel.

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