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

# Nanopayment

> Pay-per-call API access in USDC. No subscription, no API key, no signup.

## What it is

Nanopayment is one of two ways to pay for Arrays data — the other is a [subscription](/pricing). Instead of a plan and an API key, your code or AI agent calls our API and **pays per request in USDC** using the [x402 HTTP standard](https://x402.org) and [Circle Gateway](https://www.circle.com/gateway).

It works across both integration methods: call it directly from the [REST API](/api-reference/introduction), or let an agent using [Skills](/skills/overview) pay as it goes.

No subscription. No API key. No procurement.

<Info>
  Read the launch blog: [Arrays Financial Data launches on Nanopayments, powered by Circle Gateway](https://arrays.org/blog/arrays-financial-data-launches-on-nanopayments-powered-by-circle-gateway).
</Info>

## How it works

<Steps>
  <Step title="Your client calls an Arrays endpoint">
    No auth header needed.
  </Step>

  <Step title="The server returns HTTP 402 Payment Required">
    The response includes payment terms: amount in USDC, recipient address, supported chains.
  </Step>

  <Step title="Your wallet signs an EIP-3009 authorization">
    Off-chain signature — no gas, no transaction broadcast.
  </Step>

  <Step title="Client retries with the signature">
    Arrays validates with Circle Gateway, settles the USDC, and returns the data — all in \~500ms.
  </Step>
</Steps>

## Pricing (today)

<Note>
  Nanopayment currently covers **15 crypto endpoints**. Stocks, ETF, macro, and options are planned for the next two quarters.
</Note>

<Tabs>
  <Tab title="Basic tier · $0.008 / call">
    * Token info
    * Spot OHLCV
    * Futures OHLCV
    * Funding rate
    * Open interest
    * Long-short ratio
    * Volume
    * Token unlock events
    * Circulating supply
    * Market cap
    * Fear & Greed index
    * Company crypto holdings
  </Tab>

  <Tab title="Advanced tier · $0.03 / call">
    * Market metrics
    * Crypto screener (snapshot)
    * Crypto screener (time range)
  </Tab>
</Tabs>

## When to use it

<CardGroup cols={2}>
  <Card title="✅ Perfect for">
    * Autonomous AI agents that pay for their own data
    * Burst / low-volume usage where a subscription is overkill
    * On-chain native projects already holding USDC
    * Prototyping without account creation
  </Card>

  <Card title="❌ Not ideal for">
    * Stock / ETF / macro queries (not yet supported)
    * High-volume usage where Pro subscription is cheaper
    * Teams that need a dashboard, usage analytics, or SLAs
  </Card>
</CardGroup>

## Next step

<Card title="Build your first paid call" icon="rocket" href="/nanopayment/quickstart">
  TypeScript end-to-end example in under 30 lines.
</Card>