# What is a Chirp?

> A Chirp is an AI chat helper with its own instructions, files, AI model and web address.

Source: https://www.chirpbuilder.com/help/start-here/what-is-a-chirp  
Plans: Everyone  
Last checked: 2026-10-26

A Chirp is an AI chat helper you build for a job: a course tutor, a coaching helper, a product guide,
a writing partner. It's Chirp Builder's version of a Custom GPT. You decide what it knows, how it
talks and which AI model writes its answers.

![The editor for Garden Helper: the Identity section on the left and a preview of the chat on the right.](https://mjmtbasmrtksluvlnema.supabase.co/storage/v1/object/public/help-media/web-optimized/start-here/what-is-a-chirp/SS-START-002-01__editor-parts__essentials__desktop__v01.webp?v=4a5160afd0)

## The parts of a Chirp

You set up each Chirp in its editor (1), and try it in the preview beside it (2). The editor has
numbered sections:

1. **Identity:** the name, picture and description visitors see, and its **Web address**
   (chirpbuilder.com/c/your-chirp).
2. **Instructions:** what the Chirp does and how it talks. A Custom GPT's instructions work here as
   they are.
3. **Conversation starters:** up to 12 questions visitors can tap to begin.
4. **Knowledge:** files the Chirp answers from, such as PDFs, Word documents and spreadsheets.
5. **Model:** the AI model that writes the answers. See [Choose your Chirp's AI model](https://www.chirpbuilder.com/help/openrouter/choose-a-model).
6. **Capabilities:** web search, image creation, files from visitors, and keeping your instructions
   private.
7. **Actions:** let the Chirp read or change data in other apps, like a Custom GPT's Actions.
8. **Sharing:** who can open it.
9. **Branding and button:** its colors, greeting and an optional button under the chat.
10. **Visitor limits:** daily message limits and a pause switch that protect your AI credit.

## Who can see a Chirp

Under **Sharing**, every Chirp is one of these:

- **Draft:** only you. New Chirps start here.
- **Unlisted:** anyone with the link.
- **Public:** anyone, and it's listed on your public profile.

## How a Chirp differs from a Custom GPT

- Visitors don't need a ChatGPT account, or any account, to chat.
- You pick the AI model for each Chirp, from many companies.
- The AI cost goes to your own OpenRouter account, with no markup.
  See [What OpenRouter is, and who pays for what](https://www.chirpbuilder.com/help/openrouter/what-is-openrouter).
- Some Custom GPT features don't exist here, such as running code. The words for everything else are in
  [The words we use](https://www.chirpbuilder.com/help/start-here/glossary).