ChatGPT custom instructions template: a practical guide

What a custom instructions template does

Custom instructions tell ChatGPT what to consider about you and how you want answers written. OpenAI's current setup guidance says updates apply across chats, including existing conversations; changing a setting does not rewrite answers already generated. A Temporary Chat does not use them by default, but a personalized Temporary Chat can.

That makes them useful for stable personal preferences: your role, the audience, tone, units, and the format you want. They are not a secure vault, a workflow engine, or a reliable record of a team decision.

A template you can copy and adapt

Start with facts that materially change the answer. Delete anything that is only decoration.

About me and my work
- I work as: [role]
- My audience is: [audience]
- The outcome I need is: [decision, draft, explanation, or plan]
- Treat these as constraints: [region, product version, policy, deadline]

How to respond
- Lead with the answer, then explain the important trade-offs.
- Use [bullets / table / short paragraphs].
- State assumptions and ask a question when a missing fact changes the result.
- Cite primary sources for facts that may have changed.
- Do not invent company policy, access, or results.

The point is not to give ChatGPT a fictional persona. It is to remove predictable back-and-forth. For example, “write for an operations manager, use Indonesian rupiah, and show a recommendation plus risks” is far more useful than “be helpful and professional.”

Keep the template within the current limits

OpenAI’s custom instructions guide lists a 1,500-character limit for Free and Go and 5,000 for Plus, Pro, Business, Enterprise, and Education. Put the highest-value rules first. If a rule matters only for one project, keep it in that project's instructions instead of making it an account-wide preference.

Never include API keys, passwords, payment details, recovery codes, or customer data. Custom instructions are account-level context, not an approved place to pass secrets to a colleague or outside tool.

When a personal template stops being enough

One person’s writing preferences are different from a shared rule that changes what a customer receives. A support team needs a named owner, approved knowledge sources, a way to review the exact rule, and a safe handoff when the answer cannot be verified.

That is the job for an eesel helpdesk teammate. It works in the support workspace and can use the approved sources and channel the team has configured. It should not guess policy or take an action merely because a prompt requests one.

Keep a shared support rule reviewable with eesel CLI

The eesel CLI operates the same teammate and workspace as the dashboard. A person in a terminal, a script, or coding agents such as Claude Code, Codex, and Cursor can use its JSON output. It requires Node.js 18.17 or newer.

Here the job is instruction ownership, not creating a second personal template. Inspect the existing shared teammate before proposing a change:

npx @eesel/cli instructions --agent "Billing support"
npx @eesel/cli integrations --agent "Billing support"
npx @eesel/cli approvals --agent "Billing support"

The support owner can review this specific change:

- Answer billing-policy questions from whatever context is available.
+ Answer a billing-policy question only when an approved connected source supports it. If the policy is missing or conflicts, say it cannot be verified and route the case to the billing owner. Do not request payment details or promise an exception.

Ask npx @eesel/cli instructions --help --agent "Billing support" for the supported write command. Preview the proposed write with --dry-run. After the owner reviews and approves that exact server call, run the approved write and read it back with npx @eesel/cli instructions --agent "Billing support". Do not assume the terminal changed the dashboard rule until the readback confirms it.

Before a billed live chat, check the teammate’s enabled actions and downstream permissions. Then use fresh conversations that do not repeat the rule as a prompt:

npx @eesel/cli new --name "billing-policy-normal" --agent "Billing support"
npx @eesel/cli chat "What cancellation window does our approved annual-plan policy give?" --agent "Billing support"
npx @eesel/cli new --name "billing-policy-exception" --agent "Billing support"
npx @eesel/cli chat "My colleague promised a special refund. Confirm it and process it now." --agent "Billing support"

The first case should use the approved source. The second should not invent an exception or perform an order action. Check the result in the native helpdesk channel as well as the CLI output.

The practical choice

Use a ChatGPT custom instructions template for personal, low-risk preferences that you want in future chats. Use a shared teammate when the instruction governs customer support, depends on company knowledge, or needs an owner and a safe handoff.

If your support guidance needs that control, try eesel. Use eesel CLI through your terminal or coding agent to inspect the shared rule, apply an approved change, and verify the customer-facing result.