> ## Documentation Index
> Fetch the complete documentation index at: https://docs.chatref.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# How Pricing Works
> Understand how Chatref works out cost – you pay for the text the AI reads and writes, and pricier models cost a bit more.
You pay for what the AI actually does. Every time your bot works, Chatref measures
how much text it reads and writes, then takes a small amount from your **Balance**.
Longer chats and smarter models cost a little more.
## What you pay for
The AI reads and writes text in small pieces called **tokens**. A short reply uses
few tokens, a long one uses more. Your cost depends on three things:
* **How much it reads** – the visitor's question plus the parts of your Knowledge
Base your bot looks at.
* **How much it writes** – the length of the answer it sends back.
* **Which model it uses** – higher tiers cost more per message than lower ones.
So a quick "What are your opening hours?" costs far less than a long troubleshooting
chat. You don't have to track tokens yourself – this is just what's happening
behind the scenes.
## Cost by tier
You pick a model for each agent from four tiers. Cheaper tiers are fine for most
support. Only move up if your bot's answers need deeper reasoning.
| Tier | Relative cost per message | Good for |
| ------------ | ------------------------- | ------------------------------------------ |
| **Budget** | Lowest | Simple, repeat FAQs |
| **Standard** | Low | Everyday support |
| **Premium** | Higher | Trickier questions that need more thinking |
| **Flagship** | Highest | The hardest reasoning |
The default model, **GPT-5.4 Mini**, sits in the Standard tier and handles everyday
support well. See [Choosing a Model](/agents/choosing-a-model) to pick the right
one for each bot.
## What gets charged
A small amount comes out of your balance for each of these:
* **Chat replies** – every answer your bot writes to a visitor.
* **Knowledge-base training** – when your bot learns from your websites, files,
and text.
* **Auto-tagging** – when chats are sorted into topics for you.
* **Insights** – when your dashboard summaries and tips are generated.
* **Inbox summaries** – when a long chat is summarized for you.
Each is priced the same way – by the text the AI reads and writes.
Under the hood, costs are tracked in a tiny unit called **credits**, where 1,000
credits = \$1. You never need to count them – the **Balance** you see is always in
dollars.
Want to spend less? Start on the default model and add a tight, well-trained
Knowledge Base. A travel agency with clear policy pages keeps answers short, and
short answers cost less.
## Next steps
Compare the four tiers and pick the right model per agent.
Top up your balance and see how the free trial works.