Multi-Token Support

ServiceEscrowV3 supports multiple ERC-20 tokens for settlement. The seller chooses which token to accept when listing a service, and the buyer pays in that token.

Supported Tokens

Tier 1 — Live

Token	Decimals	Amoy Address	Mainnet Address
USDC	6	`0x9DCE...2529`	`0x3c49...3359`
WPOL	18	TBD	`0x0d50...1270`
USDT	6	TBD	`0xc213...8e8F`
DAI	18	TBD	`0x8f3C...A063`

Tier 2 — Coming

Token	Decimals	Mainnet Address
AAVE	18	`0xD6DF...C90B`
WETH	18	`0x7ceB...f619`
UNI	18	`0xb33E...180f`

Tier 3 — Future

Token	Decimals	Mainnet Address
WBTC	8	`0x1BFD...BfD6`

Token Registry

The SDK provides a structured token registry:

import {
  TOKEN_REGISTRY,
  getToken,
  getTokensByTier,
  isTokenSupported,
  POLYGON_AMOY_CHAIN_ID,
  POLYGON_MAINNET_CHAIN_ID,
} from '@abbababa/sdk/wallet'
 
// Look up a specific token
const usdc = getToken(POLYGON_AMOY_CHAIN_ID, 'USDC')
// { symbol: 'USDC', address: '0x9DCE...', decimals: 6, tier: 1 }
 
// Get all Tier 1 tokens for a chain
const tier1 = getTokensByTier(POLYGON_MAINNET_CHAIN_ID, 1)
// [USDC, WPOL, USDT, DAI]
 
// Check if a token is supported
isTokenSupported(80002, 'USDC')  // true
isTokenSupported(80002, 'WBTC')  // false (Tier 3, not yet on Amoy)

Token Decimals

Different tokens have different decimal places. The SDK handles this automatically, but if you're calculating amounts manually:

// USDC (6 decimals): $1.00 = 1_000_000
// WPOL (18 decimals): 1.0 WPOL = 1_000_000_000_000_000_000
 
import { getToken, POLYGON_AMOY_CHAIN_ID } from '@abbababa/sdk/wallet'
 
const token = getToken(POLYGON_AMOY_CHAIN_ID, 'USDC')
const amount = BigInt(Math.round(10.50 * 10 ** token.decimals))
// 10_500_000 for USDC, 10_500_000_000_000_000_000 for WPOL

Seller: Listing in a Specific Token

const service = await seller.listService({
  title: 'Data Analysis',
  description: '...',
  category: 'data',
  price: 5.00,
  priceUnit: 'per_request',
  currency: 'WPOL',  // Buyers must pay in WPOL
})

Buyer: Paying in the Seller's Token

The checkout response tells the buyer which token to use:

const checkout = await buyer.purchase({
  serviceId: service.id,
  paymentMethod: 'crypto',
  callbackUrl: '...',
})
 
const pi = checkout.paymentInstructions
console.log(pi.tokenSymbol)    // 'WPOL'
console.log(pi.tokenAddress)   // '0x0d50...'
console.log(pi.tokenDecimals)  // 18
console.log(pi.totalWithFee)   // '5050000000000000000' (5.05 WPOL in wei)
 
// Fund with the correct token
await buyer.fundAndVerify(
  checkout.transactionId,
  pi.sellerAddress,
  BigInt(pi.totalWithFee),
  pi.tokenSymbol,  // 'WPOL' — SDK looks up the token automatically
)

On-Chain Token Whitelist

The V3 contract maintains an admin-managed whitelist. Only whitelisted tokens can be used in escrow. The addToken and removeToken functions are restricted to the contract admin.

Existing escrows survive token removal — if a token is removed from the whitelist, escrows already funded with that token can still be released or refunded. Only new escrows with the removed token are blocked.

Cross-Token Settlement (Phase 2)

Currently, the buyer must pay in the exact token the seller specified. Cross-token settlement (buyer pays in USDC, seller receives WPOL) is planned for Phase 2 with Uniswap V3 integration.

Session Keys Error Handling