diff --git a/packages/mesh-core-cst/src/types/cardano-sdk.ts b/packages/mesh-core-cst/src/types/cardano-sdk.ts
index b9ad1403..40ec412a 100644
--- a/packages/mesh-core-cst/src/types/cardano-sdk.ts
+++ b/packages/mesh-core-cst/src/types/cardano-sdk.ts
@@ -286,6 +286,9 @@ export type Metadatum = Cardano.Metadatum;
 export type HexBlob = CardanoHexBlob;
 export const HexBlob = CardanoHexBlob;
 
+export type TxCBOR = Serialization.TxCBOR;
+export const TxCBOR = Serialization.TxCBOR;
+
 export type Ed25519PrivateKey = Crypto.Ed25519PrivateKey;
 export const Ed25519PrivateKey = Crypto.Ed25519PrivateKey;
 
diff --git a/packages/mesh-core-cst/src/utils/index.ts b/packages/mesh-core-cst/src/utils/index.ts
index 8dc511eb..b4f7837e 100644
--- a/packages/mesh-core-cst/src/utils/index.ts
+++ b/packages/mesh-core-cst/src/utils/index.ts
@@ -5,3 +5,4 @@ export * from "./value";
 export * from "./data";
 export * from "./address";
 export * from "./encoding";
+export * from "./witness-set";
diff --git a/packages/mesh-core-cst/src/utils/witness-set.ts b/packages/mesh-core-cst/src/utils/witness-set.ts
new file mode 100644
index 00000000..6a541370
--- /dev/null
+++ b/packages/mesh-core-cst/src/utils/witness-set.ts
@@ -0,0 +1,35 @@
+import {
+  CborSet,
+  HexBlob,
+  Transaction,
+  TransactionWitnessSet,
+  TxCBOR,
+  VkeyWitness,
+} from "../types";
+
+export const addVKeyWitnessSetToTransaction = (
+  txHex: string,
+  vkeyWitnessSet: string,
+): string => {
+  const tx = Transaction.fromCbor(TxCBOR(txHex));
+  const currentWitnessSet = tx.witnessSet();
+  const newVkeyWitnessSet = TransactionWitnessSet.fromCbor(
+    HexBlob(vkeyWitnessSet),
+  );
+
+  const currentVkeyWitnesses = currentWitnessSet.vkeys();
+  const newVkeyWitnesses = newVkeyWitnessSet.vkeys();
+  const allVkeyWitnesses = [
+    ...(currentVkeyWitnesses?.values() ?? []),
+    ...(newVkeyWitnesses?.values() ?? []),
+  ];
+
+  currentWitnessSet.setVkeys(
+    CborSet.fromCore(
+      allVkeyWitnesses.map((vkw) => vkw.toCore()),
+      VkeyWitness.fromCore,
+    ),
+  );
+  tx.setWitnessSet(currentWitnessSet);
+  return tx.toCbor();
+};
diff --git a/packages/mesh-core-cst/test/utils/witness-set.test.ts b/packages/mesh-core-cst/test/utils/witness-set.test.ts
new file mode 100644
index 00000000..97b60dc6
--- /dev/null
+++ b/packages/mesh-core-cst/test/utils/witness-set.test.ts
@@ -0,0 +1,15 @@
+import { addVKeyWitnessSetToTransaction } from "../../src/utils/witness-set";
+
+describe("Witness Set", () => {
+  it("should append witness set vkeys correctly", () => {
+    const tx =
+      "84a40081825820ad91133a2c769247d384c0519206766e755b50847b41504b8555932917e492a90201818258390004845038ee499ee8bc0afe56f688f27b2dd76f230d3698a9afcc1b66e0464447c1f51adaefe1ebfb0dd485a349a70479ced1d198cbdf7fe71a38c5ed05021a00028b21075820bdaa99eb158414dea0a91d6c727e2268574b23efe6e08ab3b841abe8059a030ca0f5d90103a0";
+    const signature =
+      "a1008182582089f4b576f05f5aad99bce0bdd51afe48529772f7561bb2ac9d84a4afbda1ecd658402702ebaab96e33259eacc175edffcf5b74cdb2bc28d8bf0a99e5c3bb4999597828470aa46ea6baf2d3234efc11e81bb7907a992a0ff97c94725e4fe290eef006";
+
+    const newTx = addVKeyWitnessSetToTransaction(tx, signature);
+    expect(newTx).toEqual(
+      "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",
+    );
+  });
+});