Chains & Tokens

Web3Card is multichain. Each user picks the chain where their vault lives, and each program defines which tokens it accepts for top-ups.

API v1 · Legacy

This page is part of the reference of the first version of the Web3Card API, kept here for reference. API v1 does not take new integrations: API v2 replaces it, and the platform today works as described in the rest of this manual.

Supported chains

Chain	Identifier	Vaults	Notes
Ethereum	ethereum	✓	Mainnet
Polygon	polygon	✓	PoS
Arbitrum	arbitrum	✓	Arbitrum One
BNB Chain	bnb	✓	BSC

Additional chains are added program by program. Talk to your integration manager about chains not listed here.

Settlement currencies

Card authorizations settle in stablecoins:

Token	Identifier	Chains
USDC	USDC	All supported chains
USDT	USDT	All supported chains

The program's settlement currency is configured per vault at deployment (currency field).

Project tokens

Programs can enable top-ups in their own token. When a user tops up with the project token, the platform converts it to the vault's settlement currency at market rate at the moment of top-up, and credits the vault with the resulting stablecoin balance.

This gives your token a concrete, daily utility: it becomes a way to load a card that works anywhere.

{
  "topUp": {
    "token": "YOURTOKEN",
    "amountIn": "1500.00",
    "converted": { "currency": "USDC", "amountOut": "487.35" },
    "rate": "0.32490",
    "chain": "polygon"
  }
}

Token top-up availability, pairs, and conversion venues are configured during program onboarding.