Build a GPT and a project in ChatGPT

When each fits

OpenAI's own rule of thumb: use a project to organize related chats, files and instructions around ongoing work, and use a custom GPT for a reusable assistant with saved instructions and approved reference files (OpenAI, Creating a GPT). A project holds one job's files, instructions and chats. A GPT is a saved set of instructions you reopen for the same task.

The example: Instruction to Checklist

The job: paste any instruction and get a numbered checklist of what to do, with the paragraph reference beside each item. People ask for this every week and the prompt is always the same, which is when a GPT pays off.

The GPTs page in ChatGPT: Discover custom versions of ChatGPT that combine instructions, extra knowledge, and any combination of skills; a Search GPTs box; category tabs from Top Picks to Education; and three Featured GPTs from outside companies. — The GPTs page, which is also the GPT store. A GPT can be kept private to you, shared with anyone who has the link, or published to the store, depending on the sharing setting you pick when you save it.

The GPT editor filled in for a GPT named Instruction to Checklist: a description, four short paragraphs of instructions, and a conversation starter. In the Preview pane on the right a sample instruction has been pasted and the GPT replies with a six-item numbered checklist, each item ending in its paragraph reference, then a Deadlines found line and an Assumptions line. — The editor filled in, and a test run in the Preview pane on the right.

What went into each box:

Box	What we wrote
Name	Instruction to Checklist
Description	Paste any instruction, NAVADMIN or SOP and get a numbered checklist of what to do, with the paragraph reference beside each item.
Instructions, line 1	You turn Navy and DoD instructions into action checklists for the people who must carry them out.
Instructions, line 2	When the user pastes or attaches an instruction: produce a numbered checklist, one action per line, in the order the actions must happen. After each item put the paragraph or section reference in brackets.
Instructions, line 3	Rules: use only the text provided. Never add a step, deadline, name or number that is not in the source. If something is unclear or missing, write [CONFIRM] and say what is missing. Keep each item under 20 words.
Instructions, line 4	End with two lines: Deadlines found (list them) and Assumptions (list them, or None).
Conversation starter	Turn this instruction into a checklist
Knowledge, model, capabilities	None, no recommended model, Web Search off

Read the four instruction lines again: a role, the job and its output shape, the rules and the failure behavior, and a closing summary the reader can check. That pattern fits almost any GPT.

Test before Create

The preview pane is a live chat with the draft GPT. We pasted a four-paragraph sample instruction and got six checklist items, each ending in its paragraph reference, then "Deadlines found: 30 September; 5 October; within 10 working days of return; first training meeting in October" and "Assumptions: Department heads report for their departments." That last line is the GPT admitting an inference, which is what the rules asked for. Only after the preview behaves do you press Create.

The finished GPT, Instruction to Checklist, opened like a chat: its name and description at the centre, a conversation-starter button reading Turn this instruction into a checklist, and the usual chat box with the model selector GPT 5.6 Terra. — The finished GPT, opened like a chat: name, description, the starter button, the usual chat box.

Two warnings on the editor itself

The editor says it twice: conversations with your GPT can reveal its instructions, and can reveal the files you uploaded. Put nothing in a GPT that the people who will use it may not read.

A project, for the job that lasts

ChatGPT's Create project dialog: a project name, a Web Search tool checkbox, and the note that projects keep chats, files and custom instructions in one place. — Projects, then Create: a name and the Web Search switch.

The Edit project dialog in ChatGPT: Project title, an Instructions box described as set context and customize how ChatGPT responds in this project, and a Tools section with a single Web Search checkbox. — Edit project, under the menu at top right: the project's standing instructions and its tools.

A project holds files (Sources tab, up to 40), standing instructions, and every chat about the job. Build one for quarter-end awards, for an inspection, for a change of command. A personal ChatGPT project is private to you; a Team or Enterprise workspace can add sharing with named teammates. Where a project cannot be shared, the instructions are the thing to hand off: four lines anyone can paste into their own GPT.

Vendor facts checked 25 Sep 2026; re-verify before relying on them.