diff --git a/src/main/tjava/com/r35157/libs/jupiter/perps/impl/anchoridl/AnchorIdlJupiterPerpsCustodyDecoder.tjava b/src/main/tjava/com/r35157/libs/jupiter/perps/impl/anchoridl/AnchorIdlJupiterPerpsCustodyDecoder.tjava
index 7829bf3..78b86c4 100644
--- a/src/main/tjava/com/r35157/libs/jupiter/perps/impl/anchoridl/AnchorIdlJupiterPerpsCustodyDecoder.tjava
+++ b/src/main/tjava/com/r35157/libs/jupiter/perps/impl/anchoridl/AnchorIdlJupiterPerpsCustodyDecoder.tjava
@@ -7,9 +7,9 @@ import com.r35157.libs.solana.SolanaAccountInfo;
 import java.math.BigInteger;
 import java.util.Base64;
 
-class AnchorIdlJupiterPerpsCustodyDecoder {
+public class AnchorIdlJupiterPerpsCustodyDecoder {
 
-    ΩSPLMintAddressΩ decodeMint(
+    public ΩSPLMintAddressΩ decodeMint(
             SolanaAccountInfo custodyAccountInfo
     ) {
         byte[] data = Base64.getDecoder().decode(custodyAccountInfo.dataBase64());
@@ -23,7 +23,7 @@ class AnchorIdlJupiterPerpsCustodyDecoder {
         return readPublicKey(data, MINT_OFFSET);
     }
 
-    BigInteger decodeCurrentCumulativeInterestRate(
+    public BigInteger decodeCurrentCumulativeInterestRate(
             SolanaAccountInfo custodyAccountInfo
     ) {
         byte[] data = Base64.getDecoder().decode(custodyAccountInfo.dataBase64());
diff --git a/src/main/tjava/com/r35157/libs/jupiter/perps/impl/anchoridl/AnchorIdlJupiterPerpsPositionDecoder.tjava b/src/main/tjava/com/r35157/libs/jupiter/perps/impl/anchoridl/AnchorIdlJupiterPerpsPositionDecoder.tjava
index a6bdba7..288e5e2 100644
--- a/src/main/tjava/com/r35157/libs/jupiter/perps/impl/anchoridl/AnchorIdlJupiterPerpsPositionDecoder.tjava
+++ b/src/main/tjava/com/r35157/libs/jupiter/perps/impl/anchoridl/AnchorIdlJupiterPerpsPositionDecoder.tjava
@@ -12,7 +12,7 @@ import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.util.Base64;
 
-class AnchorIdlJupiterPerpsPositionDecoder {
+public class AnchorIdlJupiterPerpsPositionDecoder {
 
     JupiterPerpsPosition decode(
             ΩJupiterPerpsPositionAccountΩ positionAccount,
@@ -57,10 +57,7 @@ class AnchorIdlJupiterPerpsPositionDecoder {
                 .valueOf(rawSizeUsd)
                 .movePointLeft(6);
 
-        BigInteger cumulativeInterestSnapshot = readU128(
-                data,
-                CUMULATIVE_INTEREST_SNAPSHOT_OFFSET
-        );
+        BigInteger cumulativeInterestSnapshot = decodeCumulativeInterestSnapshot(accountInfo);
 
         JupiterPerpsPosition pos = new JupiterPerpsPosition(
                 positionAccount,
@@ -74,7 +71,7 @@ class AnchorIdlJupiterPerpsPositionDecoder {
         return pos;
     }
 
-    BigInteger decodeCumulativeInterestSnapshot(SolanaAccountInfo accountInfo) {
+    public BigInteger decodeCumulativeInterestSnapshot(SolanaAccountInfo accountInfo) {
         byte[] data = Base64.getDecoder().decode(accountInfo.dataBase64());
 
         if (data.length < CUMULATIVE_INTEREST_SNAPSHOT_OFFSET + U128_LENGTH) {
@@ -90,13 +87,7 @@ class AnchorIdlJupiterPerpsPositionDecoder {
         return value;
     }
 
-    BigInteger decodeCurrentCumulativeInterestRate(
-            SolanaAccountInfo collateralCustodyAccountInfo
-    ) {
-        return null;
-    }
-
-    ΩSolanaAddressΩ decodeCustodyAccount(SolanaAccountInfo accountInfo) {
+    public ΩSolanaAddressΩ decodeCustodyAccount(SolanaAccountInfo accountInfo) {
         byte[] data = Base64.getDecoder().decode(accountInfo.dataBase64());
 
         if (data.length < CUSTODY_OFFSET + PUBLIC_KEY_LENGTH) {
@@ -111,6 +102,23 @@ class AnchorIdlJupiterPerpsPositionDecoder {
         );
     }
 
+    public ΩSolanaAddressΩ decodeCollateralCustodyAccount(
+            SolanaAccountInfo accountInfo
+    ) {
+        byte[] data = Base64.getDecoder().decode(accountInfo.dataBase64());
+
+        if (data.length < COLLATERAL_CUSTODY_OFFSET + PUBLIC_KEY_LENGTH) {
+            throw new IllegalArgumentException(
+                    "Jupiter Perps position account data is too short: " + data.length
+            );
+        }
+
+        return readPublicKey(
+                data,
+                COLLATERAL_CUSTODY_OFFSET
+        );
+    }
+
     private JupiterPerpsPositionDirection decodeDirection(
             byte rawSide
     ) {
diff --git a/src/main/tjava/com/r35157/nenjim/hubd/impl/ref/Main.tjava b/src/main/tjava/com/r35157/nenjim/hubd/impl/ref/Main.tjava
index ed7957e..61be688 100644
--- a/src/main/tjava/com/r35157/nenjim/hubd/impl/ref/Main.tjava
+++ b/src/main/tjava/com/r35157/nenjim/hubd/impl/ref/Main.tjava
@@ -2,6 +2,7 @@ package com.r35157.nenjim.hubd.impl.ref;
 
 import com.r35157.libs.jupiter.perps.JupiterPerpsPosition;
 import com.r35157.libs.jupiter.perps.JupiterPerpsService;
+import com.r35157.libs.jupiter.perps.impl.anchoridl.AnchorIdlJupiterPerpsPositionDecoder;
 import com.r35157.libs.jupiter.perps.impl.anchoridl.AnchorIdlJupiterPerpsServiceImpl;
 import com.r35157.libs.solana.SolanaBlockChain;
 import com.r35157.libs.solana.impl.ref.SolanaBlockChainImpl;
@@ -11,7 +12,9 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import java.lang.management.ClassLoadingMXBean;
 import java.lang.management.ManagementFactory;
-
+import com.r35157.libs.jupiter.perps.impl.anchoridl.AnchorIdlJupiterPerpsCustodyDecoder;
+import com.r35157.libs.solana.SolanaAccountInfo;
+import java.math.BigInteger;
 import com.r35157.nenjim.hubd.ctx.ContextManager;
 import com.r35157.nenjim.hubd.journal.JournalManager;
 import com.r35157.nenjim.hubd.impl.ref.JournalManagerImpl;
@@ -23,16 +26,34 @@ public class Main {
 
     // TODO: Consider if we really need a Main class or we just need to move the main method to NenjimHubImpl?
     static void main(String[] args) throws Exception {
-        NenjimHubImpl nenjimHub = new NenjimHubImpl();
+        //NenjimHubImpl nenjimHub = new NenjimHubImpl();
 
-        /*
         SolanaBlockChain sbc = new SolanaBlockChainImpl();
         JupiterPerpsService jupiter = new AnchorIdlJupiterPerpsServiceImpl(sbc);
         ΩSolanaWalletIdΩ walletId = "vj98roDZ7744EBfxyuDFkKpEGCsKQLr7K8UFRumJNHf";
+
         Set<JupiterPerpsPosition> positions = jupiter.getOpenPositions(walletId);
+
+        AnchorIdlJupiterPerpsPositionDecoder positionDecoder = new AnchorIdlJupiterPerpsPositionDecoder();
+        AnchorIdlJupiterPerpsCustodyDecoder custodyDecoder = new AnchorIdlJupiterPerpsCustodyDecoder();
+
+        for (JupiterPerpsPosition position : positions) {
+            SolanaAccountInfo positionAccountInfo = sbc.getAccountInfo(position.positionAccount());
+            ΩSolanaAddressΩ collateralCustodyAccount = positionDecoder.decodeCollateralCustodyAccount(positionAccountInfo);
+            SolanaAccountInfo collateralCustodyAccountInfo = sbc.getAccountInfo(collateralCustodyAccount);
+            BigInteger currentCumulativeInterestRate =custodyDecoder.decodeCurrentCumulativeInterestRate(collateralCustodyAccountInfo);
+            BigInteger cumulativeInterestSnapshot = positionDecoder.decodeCumulativeInterestSnapshot(positionAccountInfo);
+            BigInteger difference = currentCumulativeInterestRate.subtract(cumulativeInterestSnapshot);
+
+            System.out.println("positionAccount: " + position.positionAccount());
+            System.out.println("currentCumulativeInterestRate: " + currentCumulativeInterestRate);
+            System.out.println("cumulativeInterestSnapshot: " + cumulativeInterestSnapshot);
+            System.out.println("difference: " + difference);
+            System.out.println();
+        }
+
         int a=0;
-        */
-        nenjimHub.awaitShutdown();
+        //nenjimHub.awaitShutdown();
 
         /*        try {
             log.info("Auto-starting 2 Nenjim application(s)...");