diff --git a/src/constants/HubV3ABI.js b/src/constants/HubV3ABI.js
new file mode 100644
index 0000000..4b36b4e
--- /dev/null
+++ b/src/constants/HubV3ABI.js
@@ -0,0 +1,33 @@
+export default [
+  "constructor(address)",
+  "event Approval(address indexed,address indexed,uint256 indexed)",
+  "event ApprovalForAll(address indexed,address indexed,bool)",
+  "event OwnershipTransferred(address indexed,address indexed)",
+  "event Transfer(address indexed,address indexed,uint256 indexed)",
+  "function approve(address,uint256)",
+  "function balanceOf(address) view returns (uint256)",
+  "function changeVerifier(address)",
+  "function collectFees()",
+  "function fees(bytes32) view returns (uint256)",
+  "function getApproved(uint256) view returns (address)",
+  "function getIdentifier(address,bytes32) pure returns (bytes32)",
+  "function getSBT(address,bytes32) view returns (tuple(uint256,uint256[],bool))",
+  "function isApprovedForAll(address,address) view returns (bool)",
+  "function name() view returns (string)",
+  "function owner() view returns (address)",
+  "function ownerOf(uint256) view returns (address)",
+  "function renounceOwnership()",
+  "function revokeSBT(address,bytes32)",
+  "function safeTransferFrom(address,address,uint256)",
+  "function safeTransferFrom(address,address,uint256,bytes)",
+  "function sbtOwners(bytes32) view returns (uint256, bool)",
+  "function sendSBT(bytes32,uint256,uint256,uint256,uint256,uint256[],bytes) payable",
+  "function setApprovalForAll(address,bool)",
+  "function setFee(bytes32,uint256)",
+  "function supportsInterface(bytes4) view returns (bool)",
+  "function symbol() view returns (string)",
+  "function tokenURI(uint256) view returns (string)",
+  "function transferFrom(address,address,uint256)",
+  "function transferOwnership(address)",
+  "function usedNullifiers(uint256) view returns (bool)",
+];
diff --git a/src/constants/misc.js b/src/constants/misc.js
index c551864..eb6c886 100644
--- a/src/constants/misc.js
+++ b/src/constants/misc.js
@@ -1 +1,12 @@
 export const defaultActionId = 123456789;
+
+export const hubV3Address = "0x06E370E885C994F13111F0329e0A85afA57b4074";
+export const hubV3Chain = 10;
+
+export const govIdIssuerAddress =
+  "0x03fae82f38bf01d9799d57fdda64fad4ac44e4c2c2f16c5bf8e1873d0a3e1993";
+export const phoneIssuerAddress =
+  "0x2998cab3d07a64315f1e8399ecef60a19f478231663f8740703bd30a42a91ed4";
+
+export const v3KYCSybilResistanceCircuitId =
+  "0x729d660e1c02e4e419745e617d643f897a538673ccf1051e093bbfa58b0a120b";
diff --git a/src/services/sybil-resistance.js b/src/services/sybil-resistance.js
index d2ce2d1..73f35c7 100644
--- a/src/services/sybil-resistance.js
+++ b/src/services/sybil-resistance.js
@@ -7,7 +7,13 @@ import {
   sybilResistanceAddrsByNetwork,
   sybilResistancePhoneAddrsByNetwork,
 } from "../constants/contractAddresses.js";
+import {
+  hubV3Address,
+  govIdIssuerAddress,
+  v3KYCSybilResistanceCircuitId,
+} from "../constants/misc.js";
 import AntiSybilStoreABI from "../constants/AntiSybilStoreABI.js";
+import HubV3ABI from "../constants/HubV3ABI.js";
 
 async function sybilResistanceGovId(req, res) {
   try {
@@ -31,8 +37,8 @@ async function sybilResistanceGovId(req, res) {
     }
 
     // Check blocklist first
-    const result = await blocklistGetAddress(address);
-    if (result.Item) {
+    const blockListResult = await blocklistGetAddress(address);
+    if (blockListResult.Item) {
       return res.status(200).json({ result: false });
     }
 
@@ -40,6 +46,7 @@ async function sybilResistanceGovId(req, res) {
 
     const provider = providers[network];
 
+    // Check v1/v2 contract
     const v1ContractAddr = sybilResistanceAddrsByNetwork[network];
     const v1Contract = new ethers.Contract(
       v1ContractAddr,
@@ -48,7 +55,29 @@ async function sybilResistanceGovId(req, res) {
     );
     const isUnique = await v1Contract.isUniqueForAction(address, actionId);
 
-    return res.status(200).json({ result: isUnique });
+    if (isUnique || network !== "optimism") {
+      return res.status(200).json({ result: isUnique });
+    }
+
+    // Check v3 contract
+    try {
+      const hubV3Contract = new ethers.Contract(hubV3Address, HubV3ABI, provider);
+
+      const sbt = await hubV3Contract.getSBT(address, v3KYCSybilResistanceCircuitId);
+
+      const publicValues = sbt[1];
+      const issuerAddress = publicValues[4];
+
+      return res
+        .status(200)
+        .json({ result: govIdIssuerAddress === issuerAddress.toHexString() });
+    } catch (err) {
+      if ((err.errorArgs?.[0] ?? "").includes("SBT is expired")) {
+        return res.status(200).json({ result: false });
+      }
+
+      throw err;
+    }
   } catch (err) {
     console.log(err);
     logWithTimestamp(