diff --git a/src/contracts/bsv20V2.ts b/src/contracts/bsv20V2.ts
index 8bf87e2..53b9616 100644
--- a/src/contracts/bsv20V2.ts
+++ b/src/contracts/bsv20V2.ts
@@ -188,9 +188,9 @@ export abstract class BSV20V2 extends SmartContract {
                 | FTReceiver
             const tokenChangeAmt = Array.isArray(recipients)
                 ? current.getAmt() -
-                  recipients.reduce((acc, receiver) => {
-                      return (acc += receiver.amt)
-                  }, 0n)
+                recipients.reduce((acc, receiver) => {
+                    return (acc += receiver.amt)
+                }, 0n)
                 : current.getAmt() - recipients.amt
             if (tokenChangeAmt < 0n) {
                 throw new Error(`Not enough tokens`)
@@ -316,4 +316,29 @@ export abstract class BSV20V2 extends SmartContract {
         cloned.prependNOPScript(this.getPrependNOPScript())
         return cloned
     }
+
+    /**
+     * recover a `BSV20V2` instance from the transaction
+     * if the contract contains onchain properties of type `HashedMap` or `HashedSet`
+     * it's required to pass all their offchain raw data at this transaction moment
+     * @param tx transaction
+     * @param atOutputIndex output index of `tx`
+     * @param offchainValues the value of offchain properties, the raw data of onchain `HashedMap` and `HashedSet` properties, at this transaction moment
+     */
+    static override fromTx<T extends SmartContract>(
+        this: new (...args: any[]) => T,
+        tx: bsv.Transaction,
+        atOutputIndex: number,
+        offchainValues?: Record<string, any>
+    ): T {
+        const outputScript = tx.outputs[atOutputIndex].script
+        const nopScript = Ordinal.nopScriptFromScript(outputScript)
+        const instance = super.fromTx(
+            tx,
+            atOutputIndex,
+            offchainValues,
+            nopScript
+        )
+        return instance as T
+    }
 }
diff --git a/tests/specs/fromTx.spec.ts b/tests/specs/fromTx.spec.ts
new file mode 100644
index 0000000..9289190
--- /dev/null
+++ b/tests/specs/fromTx.spec.ts
@@ -0,0 +1,72 @@
+import { Addr, PubKey, findSig, fromByteString, toByteString } from "scrypt-ts"
+import { BSV20V1P2PKH, BSV20V2P2PKH, Ordinal } from "../scrypt-ord"
+import { myAddress, myPublicKey } from "../utils/privateKey"
+import { getDefaultSigner } from "../utils/txHelper"
+import { expect, use } from "chai"
+import chaiAsPromised from 'chai-as-promised'
+use(chaiAsPromised)
+
+describe('Test `fromTx`', () => {
+
+    it('BSV20V1P2PKH', async () => {
+        const tick = toByteString('abcd', true)
+        const max = 100n
+        const lim = 10n
+        const dec = 0n
+        const addr = Addr(myAddress.toByteString())
+        // mint token
+        const instance = new BSV20V1P2PKH(tick, max, lim, dec, addr)
+        await instance.connect(getDefaultSigner())
+        await instance.deployToken()
+        const mintTx = await instance.mint(lim)
+        // recover instance from the mint tx
+        const recoveredInstance = BSV20V1P2PKH.fromTx(mintTx, 0)
+        await recoveredInstance.connect(getDefaultSigner())
+        // call
+        const callContract = async () => recoveredInstance.methods.unlock(
+            (sigResps) => findSig(sigResps, myPublicKey),
+            PubKey(myPublicKey.toHex()),
+            {
+                pubKeyOrAddrToSign: myPublicKey,
+                transfer: {
+                    instance: new BSV20V1P2PKH(tick, max, lim, dec, addr),
+                    amt: 1n
+                }
+            }
+        )
+        return expect(callContract()).not.rejected
+    })
+
+    it('BSV20V2P2PKH', async () => {
+        const sym = toByteString('abcd', true)
+        const amt = 100n
+        const dec = 0n
+        const addr = Addr(myAddress.toByteString())
+        // deploy token
+        const instance = new BSV20V2P2PKH(toByteString(''), sym, amt, dec, addr)
+        await instance.connect(getDefaultSigner())
+        instance.prependNOPScript(Ordinal.createDeployV2(
+            fromByteString(instance.sym),
+            instance.max,
+            instance.dec,
+        ))
+        const deployTx = await instance.deploy(1)
+        const tokenId = toByteString(`${deployTx.id}_0`, true)
+        // recover instance from the deploy tx
+        const recoveredInstance = BSV20V2P2PKH.fromTx(deployTx, 0)
+        await recoveredInstance.connect(getDefaultSigner())
+        // call
+        const callContract = async () => recoveredInstance.methods.unlock(
+            (sigResps) => findSig(sigResps, myPublicKey),
+            PubKey(myPublicKey.toHex()),
+            {
+                pubKeyOrAddrToSign: myPublicKey,
+                transfer: {
+                    instance: new BSV20V2P2PKH(tokenId, sym, amt, dec, addr),
+                    amt: 1n
+                }
+            }
+        )
+        return expect(callContract()).not.rejected
+    })
+})