The Fianto blog, page 10.
Notes on USDC subscriptions on Solana: how renewals are collected, what Fianto ships, and the numbers behind it.
Older posts.
What is a blockchain transaction? A merchant mental model, with one real USDC payment
A blockchain transaction is a signed request that asks the network to change some accounts, such as moving 25 USDC from a customer to a shop, and that the network either runs in full or not at all. On Solana it holds a list of instructions, the accounts they touch, a recent blockhash that makes it expire, and the signatures of whoever authorises it. A one-off Fianto payment today is three instructions and one signature, the customer's, and costs the customer 5,060 lamports of network fee as Fianto builds it.
SolanaWhat is a Solana address? Public keys, PDAs and token accounts in one payment
A Solana address is a 32-byte account identifier written as a base58 string, and it is one of two kinds: the public key of a keypair, which someone can sign for, or a program derived address, which nobody holds a key for. Your wallet address is a public key; your USDC sits in a token account at a program derived address calculated from that wallet. To get paid you give the wallet address, never the token account, and a Fianto merchant proves that wallet by signing with it.
WalletsSeed phrase vs private key vs wallet address, explained for merchants
Think of them as three generations of one secret. The seed phrase is a list of 12 to 24 words from which a wallet derives every private key it holds; each private key controls exactly one address and signs for it; the address is the public half of that key, the part you hand out to get paid. Only the address is ever meant to be shared. Fianto asks for nothing more than the address and a signature made in your wallet, never the phrase and never a key.
SolanaPrograms, not smart contracts: how Solana runs a subscription payment
A Solana program is what other chains call a smart contract, with one structural difference: the program account holds only executable code, and every piece of state it works on lives in separate accounts that the program owns. A payment program on Solana is therefore a program plus a set of accounts, usually at program derived addresses. The Subscriptions program behind Fianto shows the pattern: a plan account for each price and its terms, one subscription account per subscriber and plan, and one authority account per wallet and token.
PaymentsAI agents paying with stablecoins: the rails that exist on 15 October 2026
As of 15 October 2026, an AI agent can pay in stablecoins through two working mechanisms: x402, which puts a stablecoin payment inside an HTTP request, and Solana's Allowances, which let a person give an agent a capped, expiring budget it spends on its own. Both are live and documented by the teams behind them; Coinbase's developer platform says it has processed more than 100 million x402 payments across Base and Solana. Fianto implements neither: its checkout is built for a person with a wallet, and the Fianto agent skill helps coding agents write integrations, it does not let an agent pay.
StablecoinsStablecoins vs CBDCs vs tokenized deposits: three kinds of digital money compared
The three differ in who owes you the money. A stablecoin such as USDC is a token issued by a private company and backed by its reserves; a central bank digital currency (CBDC) is a direct liability of a central bank; a tokenized deposit is a bank deposit recorded on a programmable ledger, a claim on that bank. As of 15 October 2026 the digital euro is still in preparation, a US executive order bars federal agencies from acting to establish, issue or promote a CBDC, and the BIS's Project Agorá is testing tokenized deposits between banks, while USDC already circulates on public blockchains.
StablecoinsPYUSD, USDG, EURC: other stablecoins on Solana, compared with USDC
Besides USDC, three regulated stablecoins with their own Solana mints are PayPal USD (PYUSD) and Global Dollar (USDG), both from Paxos entities, and Circle's euro coin EURC. They differ in issuer, currency and token program: PYUSD and USDG run on Token-2022 with a permanent delegate, a key that can move or burn tokens in any holder's account, while USDC and EURC run on the original Token program without one. Fianto, which publishes this post, accepts native USDC only.
DataStablecoinsUSDC on Solana in numbers: supply, share and costs, read on 15 October 2026
On 15 October 2026 the USDC mint on Solana reported a supply of about 7.76 billion USDC, while Circle's own figure for USDC on Solana was about 6.77 billion, 9.3% of the 72.71 billion USDC Circle counted across all chains, second only to Ethereum. The two Solana numbers differ because Circle counts circulation, and its reserve report leaves out tokens that exist on Solana but are not issued to any holder. Moving USDC on Solana costs a base fee of 5,000 lamports per signature.
WalletsCan a merchant take more than I approved? Crypto subscription approval limits
No. A USDC subscription paid through Fianto runs on the Solana Foundation's Subscriptions program, which lets a collection through only if it stays within the cap for the period, the price plus the fees, and goes to a wallet the plan names. Your wallet may still list the approval as unlimited, because one approval is shared by every subscription your wallet pays through the program; the limits sit in each subscription's on-chain terms, not in that approval.
PaymentsCrypto payment terms for merchants: a glossary of wallets, tokens, transactions and billing
Most of the jargon in a crypto payment names one of five things: the wallet and accounts that hold the money, the token and its units, the transaction that moves it, the approval behind a subscription, and the merchant tools around the sale, plus two scams that target wallets. This glossary defines fifty of those terms in a sentence or two each, as they apply to USDC on Solana, and links every one to the post that explains it in full. Where Fianto has a specific number, such as 6 decimals for USDC or four attempts at a failed renewal, the definition gives it.
CompareStripe stablecoin subscriptions vs Fianto: countries, chains, fees
As of 14 October 2026, Stripe's stablecoin subscriptions are a private preview that US businesses request access to, they charge 1.5% per payment, and the money settles in the merchant's Stripe balance in fiat. Fianto bills USDC on Solana only, pays each charge straight into the merchant's own wallet, and charges the merchant nothing. Stripe fits better when customers have no wallet or the business wants dollars in a bank; Fianto fits when customers already hold USDC on Solana or Stripe is not an option.
CompareCoinbase Commerce alternatives: what changed and where to move
Coinbase told merchants to leave Coinbase Commerce by 31 March 2026. Merchants with a legal entity in the US or Singapore could move to Coinbase Business, which is custodial and accepts USDC; everyone else had to find another provider. This guide compares five options on the points that decide a move: who holds the money, what customers can pay with, recurring billing, fees and who can sign up.