Write instructions for your Chirp

When you're done, your Chirp knows its job, its tone and its limits.

Who can do this: anyone who can edit the Chirp, on any plan.

What you'll need: a few sentences about what the Chirp should do. Moving a Custom GPT? Open it in ChatGPT, click Configure, and copy everything in its Instructions box.

Add the instructions

1. Open the Chirp and find 2. Instructions.

2. Write or paste the instructions into the box. A Custom GPT's instructions work here as they are.

   

3. Click Save, then try the Chirp in the preview. If it's already published, click Publish changes so visitors get the new instructions too.

The box takes up to 100,000 characters; the count under it shows how much you've used. If both the instructions and the description are empty, a reminder says Add instructions so your Chirp knows what to do. You can still save.

What to include

Good instructions answer four questions, in plain sentences:

• What is it for? "You help people plan meals for the week."
• Who is it talking to? "Busy parents who cook on weeknights."
• How should it sound? "Warm, short answers, no jargon."
• What should it never do? "Never give medical advice; suggest a doctor instead."

If the Chirp has knowledge files, say when to use them: "Answer from the attached guides first, and say which guide you used."

Keep them private

Under 6. Capabilities, Keep instructions confidential is on for every new Chirp: the Chirp is told to politely decline when a visitor asks to see its instructions. Leave it on unless you're happy for anyone to read them. It's an instruction to the AI, not a lock, so a determined visitor may still coax parts out: never put passwords or private details in instructions.

If it doesn't work

• The Chirp ignores part of the instructions. Put the most important rule first and say it once, clearly. Very long instructions with many rules are harder for any model to follow.
• Visitors still get the old behaviour. You saved but didn't publish: click Publish changes.