# On Chain Verification

{% hint style="info" %}
This on chain verification will verify the validity of the ZKP (Zero Knowledge Proof) curcuit and the underlying inputs that were used
{% endhint %}

#### JavaScript

1. Define ABI for both verifier and 0xKYC soulbound contracts:

```javascript
       
const verifierAbi = [{"inputs":[{"components":[{"components":[{"internalType":"uint256","name":"X","type":"uint256"},{"internalType":"uint256","name":"Y","type":"uint256"}],"internalType":"struct Pairing.G1Point","name":"a","type":"tuple"},{"components":[{"internalType":"uint256[2]","name":"X","type":"uint256[2]"},{"internalType":"uint256[2]","name":"Y","type":"uint256[2]"}],"internalType":"struct Pairing.G2Point","name":"b","type":"tuple"},{"components":[{"internalType":"uint256","name":"X","type":"uint256"},{"internalType":"uint256","name":"Y","type":"uint256"}],"internalType":"struct Pairing.G1Point","name":"c","type":"tuple"}],"internalType":"struct ZkVerifier.Proof","name":"proof","type":"tuple"},{"internalType":"uint256[3]","name":"input","type":"uint256[3]"}],"name":"verifyTx","outputs":[{"internalType":"bool","name":"r","type":"bool"}],"stateMutability":"view","type":"function"}]
       
       
const soulboundAbi = [ { "inputs": [ { "internaltype": "string", "name": "name_", "type": "string" }, { "internaltype": "string", "name": "symbol_", "type": "string" } ], "statemutability": "nonpayable", "type": "constructor" }, { "anonymous": false, "inputs": [ { "indexed": false, "internaltype": "address", "name": "_soul", "type": "address" } ], "name": "burn", "type": "event" }, { "anonymous": false, "inputs": [ { "indexed": false, "internaltype": "address", "name": "_soul", "type": "address" } ], "name": "mint", "type": "event" }, { "anonymous": false, "inputs": [ { "indexed": true, "internaltype": "address", "name": "previousowner", "type": "address" }, { "indexed": true, "internaltype": "address", "name": "newowner", "type": "address" } ], "name": "ownershiptransferred", "type": "event" }, { "anonymous": false, "inputs": [ { "indexed": false, "internaltype": "address", "name": "_soul", "type": "address" } ], "name": "update", "type": "event" }, { "inputs": [], "name": "_name", "outputs": [ { "internaltype": "string", "name": "", "type": "string" } ], "statemutability": "view", "type": "function" }, { "inputs": [], "name": "_symbol", "outputs": [ { "internaltype": "string", "name": "", "type": "string" } ], "statemutability": "view", "type": "function" }, { "inputs": [], "name": "_totalsbt", "outputs": [ { "internaltype": "uint256", "name": "", "type": "uint256" } ], "statemutability": "view", "type": "function" }, { "inputs": [ { "internaltype": "address", "name": "_soul", "type": "address" } ], "name": "burn", "outputs": [], "statemutability": "nonpayable", "type": "function" }, { "inputs": [ { "internaltype": "address", "name": "_soul", "type": "address" } ], "name": "getsbtdata", "outputs": [ { "internaltype": "uint256[2]", "name": "", "type": "uint256[2]" }, { "internaltype": "uint256[2][2]", "name": "", "type": "uint256[2][2]" }, { "internaltype": "uint256[2]", "name": "", "type": "uint256[2]" }, { "internaltype": "uint256[3]", "name": "", "type": "uint256[3]" } ], "statemutability": "view", "type": "function" }, { "inputs": [ { "internaltype": "address", "name": "_soul", "type": "address" } ], "name": "hassoul", "outputs": [ { "internaltype": "bool", "name": "", "type": "bool" } ], "statemutability": "view", "type": "function" }, { "inputs": [ { "internaltype": "uint256[2]", "name": "a", "type": "uint256[2]" }, { "internaltype": "uint256[2][2]", "name": "b", "type": "uint256[2][2]" }, { "internaltype": "uint256[2]", "name": "c", "type": "uint256[2]" }, { "internaltype": "uint256[3]", "name": "input", "type": "uint256[3]" }, { "internaltype": "address", "name": "to", "type": "address" } ], "name": "mint", "outputs": [], "statemutability": "nonpayable", "type": "function" }, { "inputs": [], "name": "name", "outputs": [ { "internaltype": "string", "name": "", "type": "string" } ], "statemutability": "view", "type": "function" }, { "inputs": [], "name": "owner", "outputs": [ { "internaltype": "address", "name": "", "type": "address" } ], "statemutability": "view", "type": "function" }, { "inputs": [], "name": "renounceownership", "outputs": [], "statemutability": "nonpayable", "type": "function" }, { "inputs": [], "name": "symbol", "outputs": [ { "internaltype": "string", "name": "", "type": "string" } ], "statemutability": "view", "type": "function" }, { "inputs": [], "name": "totalsbt", "outputs": [ { "internaltype": "uint256", "name": "", "type": "uint256" } ], "statemutability": "view", "type": "function" }, { "inputs": [ { "internaltype": "address", "name": "newowner", "type": "address" } ], "name": "transferownership", "outputs": [], "statemutability": "nonpayable", "type": "function" }, { "inputs": [ { "internaltype": "address", "name": "_soul", "type": "address" }, { "components": [ { "internaltype": "uint256[2]", "name": "a", "type": "uint256[2]" }, { "internaltype": "uint256[2][2]", "name": "b", "type": "uint256[2][2]" }, { "internaltype": "uint256[2]", "name": "c", "type": "uint256[2]" }, { "internaltype": "uint256[3]", "name": "input", "type": "uint256[3]" } ], "internaltype": "struct zksbt. Proof", "name": "_souldata", "type": "tuple" } ], "name": "updatesbt", "outputs": [ { "internaltype": "bool", "name": "", "type": "bool" } ], "statemutability": "nonpayable", "type": "function" }, { "inputs": [ { "internaltype": "address", "name": "_soul", "type": "address" }, { "internaltype": "address", "name": "verifieraddress", "type": "address" } ], "name": "validateattribute", "outputs": [ { "internaltype": "bool", "name": "", "type": "bool" } ], "statemutability": "view", "type": "function" } ]
   
```

2. Get proof of the wallet address you want to verifiy by calling the method `.getSBTData()` within the soulbound contract and store the output into `proof` and `inputs` variables:

```javascript
 const soulbound = new web3.eth.Contract(soulboundAbi, soulboundContractAddress);
 const verifier = new web3.eth.Contract(verifierAbi, verifierContractAddress);
 const sbtData = await soulbound.methods.getSBTData(walletAddress).call();
 const proof = [sbtData[0], sbtData[1], sbtData[2]];
 const inputs = sbtData[3];
```

3. Finally call `.verifyTx()` from the verifier contract with this proof data to get the verification of the ZK:

```javascript
const isVerified = await verifier.methods.verifyTx(proof, inputs).call();
```


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