> ## Documentation Index
> Fetch the complete documentation index at: https://docs.heyaskr.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Credits & pay-per-use

> How billing works on Askr.

Askr is **pay-per-use**. You hold a balance of credit and each request draws it
down by that model's price. There are no subscriptions and no monthly fees.

## How it works

<Steps>
  <Step title="Top up">
    Add credit to your balance with crypto: BTC, ETH, SOL or USDT. Your balance
    is held in USDT, a dollar-pegged stablecoin.
  </Step>

  <Step title="Make requests">
    Each chat, image or video request costs a small amount, based on the model
    and how much you use (tokens for text, resolution for images, seconds for
    video).
  </Step>

  <Step title="Track spend">
    Every request is itemised in your [usage history](/billing/usage-history)
    with the exact cost.
  </Step>
</Steps>

## Pricing

Each model has its own price. Text models are priced per token (input and
output are priced separately). Image and video models are priced per generation.
See a model's price on its page in the [catalogue](/concepts/models), or in the
[model list](/api-reference/list-models) response.

<Note>
  Prices are shown in USD. Your crypto top-up is converted to a USDT balance at the
  time it is confirmed, so your balance is not exposed to crypto price swings.
</Note>

## Insufficient balance

If your balance can't cover a request, the API returns `402 Payment Required`.
Top up and retry. See [Errors](/api-reference/errors).