# How paying works (/docs/paying)

Searching quarry is always free. What costs money is asking a dataset a question
and getting its passages back. Each dataset shows its price on its public page and
in search results, and there are three ways to get its passages.

## Free datasets [#free-datasets]

Some sellers price their dataset at 0. Your agent gets the passages without paying,
signing in, or holding a wallet. quarry only limits how fast one agent can ask.

## A monthly subscription [#a-monthly-subscription]

A subscription gives your quarry account a set number of questions per month on
one dataset, for a fixed monthly price paid by card through Stripe. Every agent you
connect to your account shares those questions.

To use one:

* Connect your agents to your account: add the sign-in address,
  `https://quarry.market/api/agent/mcp`, to your assistant and sign in when it asks,
  or give your code an [API key](/docs/subscriptions#api-keys).
* Click **Subscribe** on the dataset's public page and pay in Stripe Checkout, or
  let a connected assistant prepare the Checkout link for you.

See [Subscriptions and API keys](/docs/subscriptions).

## Pay per question from a wallet [#pay-per-question-from-a-wallet]

An agent that holds its own USDC wallet can pay for each question as it goes, with
no quarry account. This uses x402, an open standard for paying for a web request in
USDC. Chat assistants like Claude or ChatGPT don't have a wallet, so they use free
datasets or a subscription. See [Paying with x402](/docs/x402).

> **Public beta on a test network**
>
> quarry runs on Base Sepolia, a test network, during the beta. Per-question payments use test USDC, which has no cash value.

## What you pay for [#what-you-pay-for]

A question is one request your agent sends to a dataset, not one message you type.
To answer you, an assistant may ask a dataset more than once, or ask several
datasets, and each of those is a question.

* Each question uses one of your subscription's monthly questions or, when paying
  per question, costs the dataset's price. It's the same whether your agent takes
  five passages or twenty.
* A question counts only when the search succeeds. A request that fails, or that
  quarry turns down before searching, costs nothing.
* A successful search counts even when the passages don't answer the question well:
  quarry always returns the closest passages it has. The free preview in search
  results and the dataset's description help your agent pick the right dataset
  first.
* Per-question payments are final: an answered question can't be refunded. A
  monthly subscription stops renewing when you cancel, and keeps working until the
  end of the month you paid for.

## What you can do with passages [#what-you-can-do-with-passages]

You may use the passages you get, paid or free, for your own purposes, and quote
them with a citation: the file name, the page when there is one, and the dataset's
listing. You may not resell them, republish them in bulk, or use repeated questions
to rebuild a dataset. A subscription can add usage terms of its own, shown on the
dataset's page. The [terms](/terms) have the full rules.