Why a subscription price belongs in USDC, not SOL.

How much did a fixed SOL price move in one year?

A subscription priced at a fixed amount of SOL would have lost about half its dollar value between October 2025 and October 2026. We pulled SOL-USD daily candles from Coinbase's public exchange API on 15 October 2026 and read the closing price on the 14th of a few months. Each close is the price at the end of that UTC day.

The months in between were no calmer. The lowest close of the year was $62.15 on 6 June 2026. The steepest 30-day fall ran from 13 January to 12 February 2026, from $145.43 to $78.33, down 46.1%. The steepest 30-day rise ran from 28 July to 27 August 2026, from $73.73 to $109.18, up 48.1%. Of the 336 thirty-day windows in the year, 177 moved more than 10% in one direction or the other.

These are past prices and say nothing about where SOL goes next. The point for billing is the spread. A customer on a 0.1 SOL monthly plan would have paid $20.26 at the 14 October 2025 close and $7.12 at the 14 June 2026 close for the same service, and the merchant would have received each of those.

Why can a fixed on-chain cap not follow a dollar price paid in SOL?

A fixed on-chain cap cannot follow a dollar price paid in SOL because the cap is a number of token units, set once, while the number of SOL in 20 dollars changes every day. Fianto's recurring charges run on the Solana Foundation's Subscriptions program. A plan in that program records an amount per period, a token mint (the token's on-chain identity, such as USDC), the period and the destination wallets. The amount is an integer in the token's smallest unit. Fianto's Subscriptions program docs state the rule plainly: "The amount, the mint, the period and the destinations can never change once the plan exists."

Now try to bill 20 dollars a month in SOL with a fixed cap. Set the cap at what 20 dollars bought on 14 October 2025, 0.0987 SOL, and the program would have refused the November charge, which needed 0.1441 SOL. Set it with room, say 0.3 SOL, and the customer approves up to roughly three times the bill so that the merchant can still collect in a bad month, and even that would have fallen short on 6 June 2026, when 20 dollars took 0.3218 SOL. Either the charge fails or the customer signs a wide cap. Neither is a good subscription.

A price in a dollar stablecoin removes the conflict: the bill and the cap are written in the same unit, so the cap can sit exactly at the bill. How the program limits a collector, compared with a plain token delegation, is in Solana token delegation explained.

What does a USDC price look like on chain with Fianto?

A 19.00 USDC monthly price on Fianto becomes a plan whose cap is 19.01 USDC per period, stored on chain as 19,010,000 units, because USDC has 6 decimals. The cap is the price plus Fianto's service fee, which is zero during the beta, plus the flat 0.01 USDC network fee the customer pays with every subscription charge today. Fianto creates the plan when the first subscription checkout session for that price is created, before anyone pays.

The customer approves once and pays the first period in the same transaction. Every 30 days after that, Fianto collects 19.00 USDC to the merchant and, today, 0.01 USDC to its treasury, and the program checks the total against the cap. After the beta, the service fee of about 0.1 to 0.5% is added on top of the price and paid by the customer; plans keep the terms they were created with. The merchant pays nothing, not even a network fee.

Because the cap is a ceiling, a charge below it is allowed. That is how a discount code works on a subscription: the subscriber stays on the same plan, whose cap is the full price, and Fianto pulls less while the discount lasts. A charge above the cap is refused by the program.

Who carries the price risk in each pricing unit?

The pricing unit decides who absorbs a move in SOL's price: the merchant, the customer, or nobody in the bill itself.

The first row suits a merchant and customers who both want to hold SOL and accept the swings. Fianto does not offer it, nor the second: the only currency in Fianto is USDC on Solana. If your customers hold only SOL, they need to swap some for USDC before they subscribe. A multi-coin gateway such as NOWPayments takes other coins; see NOWPayments vs Fianto.

What risks does pricing in USDC keep?

Pricing in USDC removes SOL's price swings from the bill but keeps the risks of the stablecoin and of Solana itself. USDC is issued by Circle, whose USDC page says, as of 15 October 2026: "USDC is a digital dollar backed 100% by highly liquid cash and cash-equivalent assets and is redeemable 1:1 for US dollars." Its value depends on that backing and on redemption working. Once the US GENIUS Act takes effect, section 4(a)(5)(A)(iv) requires every permitted issuer to have "technical capabilities, policies, and procedures to block, freeze, and reject specific or impermissible transactions that violate Federal or State laws, rules, or regulations." The law's dates and rules are in the GENIUS Act explained for merchants.

The customer also still needs SOL. They sign the subscribe transaction, so their wallet pays its Solana fee, under $0.01, and the account rent. As of 15 October 2026 the subscription account holds about 0.00144 SOL, returned when the customer reclaims it after the subscription ends, and a wallet's first subscription also sets up an account of about 0.00119 SOL that is not returned. Solana is cutting rent in phases, so the checkout shows the exact live amount before the customer signs. Why a USDC payer needs SOL at all is in why you need SOL to send USDC.

A USDC price also does not protect a merchant whose costs are in another currency, such as euros. And it does not follow inflation: 19.00 USDC stays 19.00 until you change it.

How do you set or change a USDC price on Fianto?

1. In the dashboard, add a recurring price to a product: monthly (every 30 days) or yearly (every 365 days). Any amount from 0.01 to 1,000,000 USDC, with up to 6 decimals.
2. Sell it through a shop, a payment link or a checkout session from your server. The first subscription checkout session for the price creates its plan on chain.
3. To change the price later, add a new price to the same product. New subscribers who check out on it pay the new price.
4. When you end the old price, its subscribers are cancelled at the end of the period they have paid for, because a plan's amount can never change. They can subscribe again at the new price.

The full sequence for a price change, and what each subscriber sees, is in how to change the price of a stablecoin subscription. What a USDC subscription costs each side is on the USDC subscriptions page.