Token Support

sBTC Escrow v5 supports two token types natively: STX (Stacks native token) and sBTC (Bitcoin-backed SIP-010 token).

Token Types

The token-type parameter is passed when creating an escrow and determines how funds are transferred:

clarity
;; STX escrow
(contract-call? .escrow-v6 create-escrow seller u1000000 u"Payment" u960 u0)

;; sBTC escrow
(contract-call? .escrow-v6 create-escrow seller u100000 u"Payment" u960 u1)

Amount Limits

Each token has independent min/max constraints:

Conversion Helpers

SDK

typescript
import { TokenType } from 'sbtc-escrow-sdk';

// The SDK handles amounts in smallest units
const stxAmount = 1_000_000;   // 1 STX
const sbtcAmount = 100_000;    // 0.001 BTC

Frontend Utilities

typescript
import { microToSTX, satsToBTC, toSmallestUnit } from '@/lib/utils';

microToSTX(1_000_000);                    // 1
satsToBTC(100_000_000);                   // 1
toSmallestUnit(1, TokenType.STX);         // 1_000_000
toSmallestUnit(0.001, TokenType.SBTC);    // 100_000

How Transfers Work

STX Transfers

STX uses native stx-transfer? built into Clarity:

clarity
;; Buyer → Contract (on create)
(try! (stx-transfer? total-deposit tx-sender (as-contract tx-sender)))

;; Contract → Seller (on release)
(as-contract (try! (stx-transfer? amount (as-contract tx-sender) seller)))

sBTC Transfers

sBTC uses the SIP-010 fungible token standard via contract-call?:

clarity
;; Buyer → Contract (on create)
(try! (contract-call? .sbtc-token transfer
  total-deposit tx-sender (as-contract tx-sender) none))

;; Contract → Seller (on release)
(as-contract (try! (contract-call? .sbtc-token transfer
  amount (as-contract tx-sender) seller none)))

sBTC Contract Addresses

Post-Conditions

Both frontend and SDK use Stacks post-conditions to guarantee transaction safety:

• STX escrows: Pc.principal(sender).willSendEq(totalDeposit).ustx()
• sBTC escrows: Pc.principal(sender).willSendEq(totalDeposit).ft(sbtcContract, 'sbtc-token')

Post-conditions are enforced at the protocol level — if the actual transfer doesn't match the post-condition, the entire transaction is reverted.