Smart Balance

Smart Balance is the unified spendable number a Decal customer sees across the platform. It rolls up every supported stablecoin in every connected wallet and presents a single dollar figure — the customer's true spending power, not a per-wallet or per-token slice.

The customer never has to decide which wallet to open or which token to spend. Smart Balance shows what they can spend; Smart Payments handles how that spend actually happens when they pay.

What's included

Smart Balance aggregates across two dimensions: wallets and tokens.

Connected wallets

Every wallet a customer has connected to Decal contributes to Smart Balance. This includes:

• Self-custody wallets (Phantom, Solflare, Backpack, etc.)
• Embedded wallets created by Decal during sign-up

When a customer connects a new wallet, its balances are picked up automatically. Disconnecting a wallet removes its balances from the rollup.

Supported stablecoins

Decal supports these Solana-native USD stablecoins:

• USDC — USD Coin (Circle)
• USDT — Tether USD (Tether)
• USDS — USDS (Sky)
• PYUSD — PayPal USD (PayPal)
• USDG — Global Dollar (Paxos)
• CASH — Phantom's Cash

Every supported stablecoin is treated as a 1:1 digital dollar. There is no per-token discount or peg adjustment. Tokens not in this list are ignored — they remain in the wallet but don't contribute to Smart Balance.

Wallet A (Phantom):    USDC: $40    USDG: $10
Wallet B (Solflare):   USDC: $25    PYUSD: $30

Smart Balance:         $105  (all supported stablecoins, all connected wallets)

How it updates

Smart Balance is a live view of on-chain state. When a customer's wallet receives a stablecoin transfer, the balance reflects it within seconds. When they spend, it goes down accordingly.

There is no holding account on Decal's side. The customer's funds remain in their wallets at all times — Smart Balance is purely a presentational rollup of balances the customer already controls.

How it powers Smart Payments

When a customer initiates a payment, Smart Balance defines the universe of available funds and Smart Payments decides which of those funds to actually use. The two are paired:

• Smart Balance answers "how much can I spend?"
• Smart Payments answers "which tokens, from which wallets, will this payment use?"

A payment can never exceed Smart Balance, and Smart Payments will always assemble the cheapest path within the balance pool. If the customer's wallets collectively hold enough digital dollars, the payment goes through — regardless of which token or which wallet the funds come from.

What customers see

In Decal's customer-facing surfaces (the wallet, the checkout page, peer-to-peer flows), Smart Balance is the headline number. Per-wallet and per-token breakdowns are available a level deeper for customers who want to see the composition, but the default view is the single spendable figure.

This applies whether the customer is:

• Paying a merchant via hosted checkout
• Sending money to another Decal user
• Topping up a stored value account
• Tapping to pay at a point-of-sale terminal

The same balance, the same logic, everywhere.

What this means for your integration

Smart Balance is a customer-side concept — it shapes what a customer sees and what they can spend, not what a merchant integrates against. As a merchant, you don't query or interact with Smart Balance directly.

Related

• Smart Payments — the engine that decides which tokens fund each payment
• Checkout Sessions — where Smart Balance and Smart Payments come together at pay time