# Pricing & limits

> f1ow pricing for the crypto MCP server and API — free trial, monthly subscription, per-call units, x402 pay-per-call, and which calls are not charged.

Source: https://www.f1ow.com/docs/pricing-limits

## Free trial

Every new account starts with **7 days and 500 tool calls**, whichever ends first. No card is required. Trials are limited to one per person.

## Subscription

**$49 buys 30 days and 12,500 tool calls.** Pay by USDC or USDT on Base, Arbitrum, Polygon or Ethereum.

- **Stacking, no minimum term.** Pay again whenever you like. The new period and calls stack onto what is left.
- **Paying ends a trial.** Your first payment replaces the trial with a fresh paid period and allowance.
- **One balance everywhere.** MCP, REST and WebSocket calls, by API key or OAuth, all draw on the same account.

See the [refund policy](https://www.f1ow.com/refunds) for details.

## What a call costs

**Every tool call uses one unit**, whichever tool it is and however much it assembles. These calls are not charged:

- calls refused before running: an unknown key, an ended period, no balance, or a burst limit,
- calls that fail on our side (a `5xx`): the unit is refunded.

On WebSocket, a `tools/call` costs one unit, and a subscription costs one unit **each time it pushes a changed result**. Unchanged checks are free.

## When you run out

Calls are refused with a message and a link to the dashboard. Over MCP this appears as a tool error your client shows; over REST it is a `402` problem. Entitlement is re-checked on every call, so after you pay the next call succeeds on the same connection. There is nothing to reconnect.

Track usage per key and per tool in the dashboard.

## Pay per call

Agents without an account can use [x402](https://www.f1ow.com/docs/auth#x402), paying per call in USDC on Base. Prices vary by tool, from fractions of a cent for simple lookups to more for the research composites.