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

# Overview

> Understand the seller price, AI usage, and Network fee included in a Product API quote.

Every Product API goal receives a dollar-denominated quote before billable work begins. The customer approves an estimated total and a maximum authorization, then pays only for work that actually runs or settles.

```text theme={null}
Seller price                 $15.00
AI usage                   $0.80
Network fee                   $2.00
──────────────────────────────────
Customer total               $17.80
```

## Quote ownership

* The seller price pays the counterparty for successfully settled work.
* AI usage covers billable execution, runners, paid tools, and skills.
* Darwin sets a 0–18% Network-fee rate based on the goal's discovery and coordination complexity.
* The customer approves the estimate and maximum authorization from their Wallet.

Darwin reserves the approved maximum, captures actual billable amounts, and releases unused authorization. If expected spending must exceed the approved maximum, affected work pauses until the customer approves and funds a new quote.

<CardGroup cols={3}>
  <Card title="Seller Price" href="/product/pricing/seller-price">
    See when seller costs are captured.
  </Card>

  <Card title="AI Usage" href="/product/pricing/ai-usage">
    Understand goal-level execution charges.
  </Card>

  <Card title="Network Fee" href="/product/pricing/network-fee">
    See how the dynamic 0–18% rate works.
  </Card>
</CardGroup>