diff --git a/packages/blaze-tx/test/tx.test.ts b/packages/blaze-tx/test/tx.test.ts
new file mode 100644
index 00000000..d7c2e41a
--- /dev/null
+++ b/packages/blaze-tx/test/tx.test.ts
@@ -0,0 +1,91 @@
+import {
+  Address,
+  hardCodedProtocolParams,
+  NetworkId,
+  TransactionId,
+  TransactionInput,
+  TransactionOutput,
+  TransactionUnspentOutput,
+  Value,
+} from '@blaze-cardano/core'
+import * as value from '../src/value'
+import { TxBuilder } from '../src/tx'
+
+function flatten<U>(iterator: IterableIterator<U> | undefined): U[] {
+  if (!iterator) {
+    return []
+  }
+  const result: U[] = []
+  for (const item of iterator) {
+    result.push(item)
+  }
+  return result
+}
+
+const ASSET_NAME_1 = 'ab'.repeat(56 / 2)
+const ASSET_NAME_2 = 'cd'.repeat(56 / 2)
+// const ASSET_NAME_3 = "ef".repeat(56/2)
+
+describe('Transaction Building', () => {
+  it('A complex transaction should balance correctly', async () => {
+    // $hosky
+    const testAddress = Address.fromBech32(
+      'addr1q86ylp637q7hv7a9r387nz8d9zdhem2v06pjyg75fvcmen3rg8t4q3f80r56p93xqzhcup0w7e5heq7lnayjzqau3dfs7yrls5',
+    )
+    const utxos = [
+      new TransactionUnspentOutput(
+        new TransactionInput(TransactionId('0'.repeat(64)), 0n),
+        new TransactionOutput(
+          testAddress,
+          value.makeValue(50_000_000n, [ASSET_NAME_1, 1n], [ASSET_NAME_2, 1n]),
+        ),
+      ),
+      new TransactionUnspentOutput(
+        new TransactionInput(TransactionId('0'.repeat(64)), 0n),
+        new TransactionOutput(
+          testAddress,
+          value.makeValue(40_000_000n, [ASSET_NAME_1, 1n], [ASSET_NAME_2, 1n]),
+        ),
+      ),
+    ]
+    const tx = await new TxBuilder(hardCodedProtocolParams)
+      .addUnspentOutputs(utxos)
+      .setNetworkId(NetworkId.Testnet)
+      .setChangeAddress(testAddress)
+      .payAssets(testAddress, value.makeValue(48_708_444n, [ASSET_NAME_1, 1n]))
+      .complete()
+
+    const inputValue = 
+    // value.merge(
+      tx
+        .body()
+        .inputs()
+        .values()
+        .map((x) =>
+          utxos
+            .find((y) => y.input().toCbor() == x.toCbor())!
+            .output()
+            .amount(),
+        )
+        .reduce(value.merge, value.zero())
+    //   ,new Value(
+    //     flatten(tx.body().withdrawals()?.values()).reduce((x, y) => x + y, 0n),
+    //   ),
+    // )
+
+    const outputValue = value.merge(
+      flatten(tx.body().outputs().values())
+        .map((x) => x.amount())
+        .reduce(value.merge, value.zero()),
+      new Value(tx.body().fee()),
+    )
+
+    console.log("Change: ", tx.body().outputs().at(1)?.amount().coin())
+
+    console.dir(inputValue.toCore(), {depth: null})
+    console.dir(outputValue.toCore(), {depth: null})
+
+    // console.dir(tx.toCore(), {depth: null})
+    expect(inputValue.toCbor()).toEqual(outputValue.toCbor())
+  })
+})