# 2.1 Direct Interaction with On-chain Contracts #### 2.1.1 EVM Compatible Chains There are two contract interfaces available: `userLock` and `userBurn`. * For tokens whose names include `@` (e.g., `wanUSDT@wanchain`，`WAN@ethereum`), which are WanBridge Wrapped Tokens, the `userBurn` interface needs to be called. * For all other tokens, the `userLock` interface should be used. * For all ERC-20 tokens, an `approve` transaction must be executed first. ```json function userLock(bytes32 smgID, uint tokenPairID, uint value, bytes userAccount) external payable function userBurn(bytes32 smgID, uint tokenPairID, uint value, uint fee, address tokenAccount, bytes userAccount) external payable ``` #### 2.1.2 Tron The process for Tron follows the same structure as described in **2.1.1 EVM-Compatible Chains**. #### 2.1.3 Solana There are two transaction types: `userLock` and `userBurn`. For tokens on Solana, users must determine whether they are Solana-native tokens or Wanchain-mapped tokens. **Determining Token Type and Transaction Type** * If the token is a Wanchain-mapped token, use the `userBurn` transaction type. * If the token is a Solana-native token, use the `userLock` transaction type. **General Transaction Requirements** For cross-chain transactions, you can build transactions using your preferred wallet and Solana libraries such as `solana-web3.js` and `anchor`. #### 2.1.3.1 userLock Transaction Type **Program requirements** * **programId**: `E3iKvJgGNycXrmsh2aryY25z29PpU4dvo4CBuXCKQiGB` **Instruction Definition** ``` pub fn user_lock(ctx: Context, smg_id: [u8; 32], token_pair_id: u32, amount: u64, user_account: Vec) ``` **Accounts Requirements** * **user:** User wallet account * **sol\_vault**: `AKXdNCG4GcTQ1knC7kno9bggHuq8MG9CCb8yQd8Nx2vL` * **programId:** `E3iKvJgGNycXrmsh2aryY25z29PpU4dvo4CBuXCKQiGB` * **seeds**: `[Buffer.from("vault", "utf8")]` * **user\_ata:** Token ATA account for the user wallet; null if the cross-chain token is SOL * **token\_vault:** Token ATA account for `sol_vault`; null if the cross-chain token is SOL * **mapping\_token\_mint**: Cross-chain token account; null if the cross-chain token is SOL * **fee\_receiver:** `CXxYYAtiUhdUagJNQ6UAB9gmHdxeujUPdn4iRg9HeuSz` * **admin\_board\_program:** `7jYCM8k5Nvwg5vyPpLk2yjivQhexPDMXuK8CSbUKqL6B` * **config\_account:** `9o7zWu1n3q1MCAQp5y8RYmhhVjNpkfhpbSDMeYvjwhZP` * **token\_pair\_account:** Token pair account for the token pair ID * **programId:** **7jYCM8k5Nvwg5vyPpLk2yjivQhexPDMXuK8CSbUKqL6B** * **seeds:** `[Buffer.from("TokenPairInfo", "utf8"), new BN(tokenPairId).toArrayLike(Buffer, "le", 4)]` * **cctp\_admin\_board\_fee\_account:** Chain fee account for the target chain ID from token pair info * **programId:** `dFYBRAFvZKq9F4mYGkLQu8DbfZRFrmi5dNSTDfwC3a8` * **seeds:** `[Buffer.from("FeeData", "utf8"), new BN(toChainId).toArrayLike(Buffer, "le", 4)]` * **token\_program:** `TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA` * **associated\_token\_program:** `ATokenGPvbdGVxr1b2hvZbsiqW5xWH25efTNsLJA8knL` * **system\_program:** `11111111111111111111111111111111` #### 2.1.3.2 userBurn Transaction Type **Program Requirements** * **programId:** `E3iKvJgGNycXrmsh2aryY25z29PpU4dvo4CBuXCKQiGB` **Instruction Definition** ``` pub fn user_burn(ctx: Context, smg_id: [u8; 32], token_pair_id: u32, amount: u64, fee: u64, token_account: Pubkey, user_account: Vec) ``` **Accounts Requirements** * **user:** User wallet account * **user\_ata:** Token ATA account for the user wallet * **mapping\_token\_mint:** Cross-chain token account * **config\_account:** `9o7zWu1n3q1MCAQp5y8RYmhhVjNpkfhpbSDMeYvjwhZP` * **token\_manager\_program:** `6PcqfvWkBv3m9F5XBU2kMAedycs6BPzDGfi8zcWam3kH` * **fee\_receiver:** `CXxYYAtiUhdUagJNQ6UAB9gmHdxeujUPdn4iRg9HeuSz` * **admin\_board\_program:** `7jYCM8k5Nvwg5vyPpLk2yjivQhexPDMXuK8CSbUKqL6B` * **token\_pair\_account:** Token pair account for the token pair ID * **programId:** `7jYCM8k5Nvwg5vyPpLk2yjivQhexPDMXuK8CSbUKqL6B` * **seeds:** `[Buffer.from("TokenPairInfo", "utf8"), new BN(tokenPairId).toArrayLike(Buffer, "le", 4)]` * **cctp\_admin\_board\_fee\_account:** Chain fee account for the target chain ID from token pair info * **programId:** `dFYBRAFvZKq9F4mYGkLQu8DbfZRFrmi5dNSTDfwC3a8` * **seeds:** `[Buffer.from("FeeData", "utf8"), new BN(toChainId).toArrayLike(Buffer, "le", 4)]` * **token\_program:** `TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA` * **associated\_token\_program:** `ATokenGPvbdGVxr1b2hvZbsiqW5xWH25efTNsLJA8knL` * **system\_program:** `11111111111111111111111111111111` #### 2.1.3.3 References **PublicKey.findProgramAddressSync** * **Solana Documentation** * #### 2.1.4 ADA There are two types of transactions: `userLock` and `userBurn`. For tokens on the Cardano network, the user must determine whether they are Cardano native tokens or Wanchain-mapped tokens. **Determine Cardano Token Types and Transaction Types** * If the token policy ID is `25c5de5f5b286073c593edfd77b48abc7a48e5a4f3d4cd9d428ff935`, the token is a Wanchain-mapped token, and the `userBurn` transaction type should be used. * If the token policy ID is any other value, the token is a Cardano native token, and the `userLock` transaction type should be used. **General Transaction Requirements** For cross-chain transactions, users can build transactions using their preferred wallet along with the Lucid library or other libraries. * If a network fee is required, the transaction must include an additional output UTXO in ADA with the actual `networkFee`, sent to the fee receiver address: `addr1qyxqtjnck8f0gyzys6kwpydd5lrcjue6tg8f2elqhs65ffy7trczz375trxwfgc7zvkvxrxcr4plz8tnqv6qre7u722qhe650r` #### **2.1.4.1 userLock Transaction Type** **Metadata Requirements for Cross-Chain Information** ```haskell let data = { 1: { type: TX_TYPE.userLock, tokenPairID: Number(tokenPairID), fromAccount: this.tool.splitMetadata(fromAccount), toAccount, smgID } }; data = this.wasm.encode_json_str_to_metadatum(JSON.stringify(data), this.wasm.MetadataJsonSchema.BasicConversions); return this.wasm.GeneralTransactionMetadata.from_bytes(data.to_bytes()); ``` **Metadata Example from Cardano Explorer** ```json 1 { "type": 1, "smgID": "0x000000000000000000000000000000000000000000000041726965735f303333", "toAccount": "0x8b157b3ffead48c8a4cdc6bddbe1c1d170049da4", "fromAccount": [ "addr1q8nd57644dctpmh5z49u9kxdsr6t2px0jg0es4gjpy7kvzk2decd8n4d28t", "9helaqh6eq8tqpqxjn5km60dxreegmzuqesanym" ], "tokenPairID": 553 } ``` **Output Requirements to Locked Account of Cardano Contract** * Only one output UTXO to the locked address is allowed. * Inline Datum: ``` let ls = wasm.PlutusList.new(); ls.add(wasm.PlutusData.new_integer(wasm.BigInt.from_str('1'))); return wasm.PlutusData.new_constr_plutus_data( wasm.ConstrPlutusData.new( wasm.BigNum.from_str('0'), ls ) ) ``` **Inline Datum Example from Cardano Explorer** ```json { "fields": [ { "int": 1 } ], "constructor": 0 } ``` #### **2.1.4.2 userBurn Transaction Type** **Metadata Requirements for Cross-Chain Information** ```haskell let data = { 1: { type: TX_TYPE.userBurn, tokenPairID: Number(tokenPairID), fromAccount: this.tool.splitMetadata(fromAccount), toAccount, smgID } }; data = this.wasm.encode_json_str_to_metadatum(JSON.stringify(data), this.wasm.MetadataJsonSchema.BasicConversions); return this.wasm.GeneralTransactionMetadata.from_bytes(data.to_bytes()); ``` **Metadata Example from Cardano Explorer** ```json 1 { "type": 8, "smgID": "0x000000000000000000000000000000000000000000000041726965735f303335", "toAccount": "0xca077dff2499ca3338d039abdc1939c287ca8690", "fromAccount": [ "addr1qyrpkudmpvwyy79senufvfzc6dfq5qszkp6h099wrjcngp3zvct9scn6xme", "ks504tjgkmdd4wjjk9j6y3k6g9cthjlusuy3lpm" ], "tokenPairID": 510 } ``` **Minting Requirements** * The transaction must include only one token mint for the cross-chain token and amount. #### 2.1.4.3 References Referene codes for Cardano transaction handling in cross-chain SDK: * * * Reference cross-chain transaction examples: * * *