diff --git a/modules/sdk-coin-ada/src/lib/transaction.ts b/modules/sdk-coin-ada/src/lib/transaction.ts
index 21e8bcd3ac..4aa8206641 100644
--- a/modules/sdk-coin-ada/src/lib/transaction.ts
+++ b/modules/sdk-coin-ada/src/lib/transaction.ts
@@ -470,6 +470,40 @@ export class Transaction extends BaseTransaction {
     return this._pledgeDetails;
   }
 
+  /**
+   * Detects whether the parsed transaction carries any Plutus-related content
+   * (script data hash, collateral, reference inputs, plutus datums/scripts/redeemers).
+   * Used to route prebuilt Plutus txs (e.g. RealFi) through the sign-only passthrough
+   * path, which preserves fields the generic builder does not reconstruct.
+   */
+  hasPlutusData(): boolean {
+    if (!this._transaction) {
+      return false;
+    }
+    const body = this._transaction.body();
+    const witnessSet = this._transaction.witness_set();
+    if (
+      body.script_data_hash() !== undefined ||
+      body.collateral() !== undefined ||
+      body.collateral_return() !== undefined ||
+      body.total_collateral() !== undefined ||
+      body.reference_inputs() !== undefined ||
+      witnessSet.plutus_scripts() !== undefined ||
+      witnessSet.plutus_data() !== undefined ||
+      witnessSet.redeemers() !== undefined
+    ) {
+      return true;
+    }
+    const outputs = body.outputs();
+    for (let i = 0; i < outputs.len(); i++) {
+      const output = outputs.get(i);
+      if (output.has_plutus_data() || output.has_script_ref()) {
+        return true;
+      }
+    }
+    return false;
+  }
+
   /**
    * Get transaction fee
    */
diff --git a/modules/sdk-coin-ada/src/lib/transactionBuilder.ts b/modules/sdk-coin-ada/src/lib/transactionBuilder.ts
index 16edafe0a9..4d32f31371 100644
--- a/modules/sdk-coin-ada/src/lib/transactionBuilder.ts
+++ b/modules/sdk-coin-ada/src/lib/transactionBuilder.ts
@@ -576,8 +576,69 @@ export abstract class TransactionBuilder extends BaseTransactionBuilder {
     return this.transaction;
   }
 
+  /**
+   * Sign-only path for prebuilt Plutus transactions (e.g. RealFi order CBOR from WP).
+   *
+   * Does not rebuild body or recompute fees/outputs — reuses the parsed body and
+   * auxiliary data verbatim so Plutus fields survive. Only regenerates vkeys;
+   * other witness content is copied through as-is.
+   */
+  private buildPlutusPassthrough(): Transaction {
+    const originalTx = this._transaction.transaction;
+    const body = originalTx.body();
+    const originalWitnessSet = originalTx.witness_set();
+    const txHash = CardanoWasm.hash_transaction(body);
+
+    const vkeyWitnesses = CardanoWasm.Vkeywitnesses.new();
+    this._signers.forEach((keyPair) => {
+      const prv = keyPair.getKeys().prv as string;
+      const vkeyWitness = CardanoWasm.make_vkey_witness(
+        txHash,
+        CardanoWasm.PrivateKey.from_normal_bytes(Buffer.from(prv, 'hex'))
+      );
+      vkeyWitnesses.add(vkeyWitness);
+    });
+
+    this._transaction.signature.length = 0;
+    this.getAllSignatures().forEach((signature) => {
+      const vkey = CardanoWasm.Vkey.new(CardanoWasm.PublicKey.from_bytes(Buffer.from(signature.publicKey.pub, 'hex')));
+      const ed255Sig = CardanoWasm.Ed25519Signature.from_bytes(signature.signature);
+      vkeyWitnesses.add(CardanoWasm.Vkeywitness.new(vkey, ed255Sig));
+      this._transaction.signature.push(signature.signature.toString('hex'));
+    });
+
+    const witnessSet = CardanoWasm.TransactionWitnessSet.new();
+    witnessSet.set_vkeys(vkeyWitnesses);
+    if (originalWitnessSet.native_scripts() !== undefined) {
+      witnessSet.set_native_scripts(originalWitnessSet.native_scripts()!);
+    }
+    if (originalWitnessSet.bootstraps() !== undefined) {
+      witnessSet.set_bootstraps(originalWitnessSet.bootstraps()!);
+    }
+    if (originalWitnessSet.plutus_scripts() !== undefined) {
+      witnessSet.set_plutus_scripts(originalWitnessSet.plutus_scripts()!);
+    }
+    if (originalWitnessSet.plutus_data() !== undefined) {
+      witnessSet.set_plutus_data(originalWitnessSet.plutus_data()!);
+    }
+    if (originalWitnessSet.redeemers() !== undefined) {
+      witnessSet.set_redeemers(originalWitnessSet.redeemers()!);
+    }
+
+    // Preserve metadata when present — omitting it leaves auxiliary_data_hash dangling.
+    const auxiliaryData = originalTx.auxiliary_data();
+    this._transaction.transaction =
+      auxiliaryData !== undefined
+        ? CardanoWasm.Transaction.new(body, witnessSet, auxiliaryData)
+        : CardanoWasm.Transaction.new(body, witnessSet);
+    return this.transaction;
+  }
+
   /** @inheritdoc */
   protected async buildImplementation(): Promise<Transaction> {
+    if (this._transaction.hasPlutusData()) {
+      return this.buildPlutusPassthrough();
+    }
     if (this._explicitOutputs.length > 0) {
       return this.processExplicitOutputsBuild();
     }
diff --git a/modules/sdk-coin-ada/test/unit/plutusPledgeBuilder.ts b/modules/sdk-coin-ada/test/unit/plutusPledgeBuilder.ts
new file mode 100644
index 0000000000..2c58d66f87
--- /dev/null
+++ b/modules/sdk-coin-ada/test/unit/plutusPledgeBuilder.ts
@@ -0,0 +1,164 @@
+import * as CardanoWasm from '@emurgo/cardano-serialization-lib-nodejs';
+import should from 'should';
+import { coins } from '@bitgo/statics';
+import { KeyPair, Transaction, TransactionBuilderFactory } from '../../src';
+import { privateKeys, rawTx } from '../resources';
+
+const TEST_ADDRESS = 'addr_test1vr8rakm66rcfv4fcxqykg5lf0yv7lsyk9mvapx369jpvtcgfcuk7f';
+
+/**
+ * Builds a synthetic Plutus transaction analogous to CBOR WP would hand BitGoJS
+ * for RealFi pledge (parse -> sign -> re-serialize) flows.
+ */
+function buildPlutusFixtureHex(includeAuxiliaryData = false): string {
+  const addr = CardanoWasm.Address.from_bech32(TEST_ADDRESS);
+
+  const inputs = CardanoWasm.TransactionInputs.new();
+  inputs.add(CardanoWasm.TransactionInput.new(CardanoWasm.TransactionHash.from_bytes(Buffer.alloc(32, 1)), 0));
+
+  const datum = CardanoWasm.PlutusData.new_bytes(Buffer.from('deadbeef', 'hex'));
+
+  const outputs = CardanoWasm.TransactionOutputs.new();
+  const outputBuilder = CardanoWasm.TransactionOutputBuilder.new().with_address(addr).with_plutus_data(datum);
+  const mainOutput = outputBuilder.next().with_coin(CardanoWasm.BigNum.from_str('2000000')).build();
+  outputs.add(mainOutput);
+
+  const body = CardanoWasm.TransactionBody.new_tx_body(inputs, outputs, CardanoWasm.BigNum.from_str('200000'));
+
+  const collateral = CardanoWasm.TransactionInputs.new();
+  collateral.add(CardanoWasm.TransactionInput.new(CardanoWasm.TransactionHash.from_bytes(Buffer.alloc(32, 2)), 0));
+  body.set_collateral(collateral);
+
+  const collateralReturn = CardanoWasm.TransactionOutput.new(
+    addr,
+    CardanoWasm.Value.new(CardanoWasm.BigNum.from_str('1000000'))
+  );
+  body.set_collateral_return(collateralReturn);
+  body.set_total_collateral(CardanoWasm.BigNum.from_str('1000000'));
+
+  const referenceInputs = CardanoWasm.TransactionInputs.new();
+  referenceInputs.add(CardanoWasm.TransactionInput.new(CardanoWasm.TransactionHash.from_bytes(Buffer.alloc(32, 3)), 0));
+  body.set_reference_inputs(referenceInputs);
+  body.set_script_data_hash(CardanoWasm.ScriptDataHash.from_bytes(Buffer.alloc(32, 4)));
+
+  const witnessSet = CardanoWasm.TransactionWitnessSet.new();
+
+  const plutusScripts = CardanoWasm.PlutusScripts.new();
+  plutusScripts.add(CardanoWasm.PlutusScript.new(Buffer.from('510100003222253330033371e00c', 'hex')));
+  witnessSet.set_plutus_scripts(plutusScripts);
+
+  const plutusDataList = CardanoWasm.PlutusList.new();
+  plutusDataList.add(datum);
+  witnessSet.set_plutus_data(plutusDataList);
+
+  const redeemers = CardanoWasm.Redeemers.new();
+  redeemers.add(
+    CardanoWasm.Redeemer.new(
+      CardanoWasm.RedeemerTag.new_spend(),
+      CardanoWasm.BigNum.from_str('0'),
+      datum,
+      CardanoWasm.ExUnits.new(CardanoWasm.BigNum.from_str('1000000'), CardanoWasm.BigNum.from_str('500000'))
+    )
+  );
+  witnessSet.set_redeemers(redeemers);
+
+  let auxiliaryData: CardanoWasm.AuxiliaryData | undefined;
+  if (includeAuxiliaryData) {
+    const metadata = CardanoWasm.GeneralTransactionMetadata.new();
+    metadata.insert(CardanoWasm.BigNum.from_str('674'), CardanoWasm.TransactionMetadatum.new_text('realfi-test'));
+    auxiliaryData = CardanoWasm.AuxiliaryData.new();
+    auxiliaryData.set_metadata(metadata);
+    body.set_auxiliary_data_hash(CardanoWasm.hash_auxiliary_data(auxiliaryData));
+  }
+
+  const tx =
+    auxiliaryData !== undefined
+      ? CardanoWasm.Transaction.new(body, witnessSet, auxiliaryData)
+      : CardanoWasm.Transaction.new(body, witnessSet);
+  return Buffer.from(tx.to_bytes()).toString('hex');
+}
+
+describe('ADA Plutus Passthrough Builder', () => {
+  const plutusFixtureHex = buildPlutusFixtureHex();
+
+  it('should detect plutus data on the parsed transaction', () => {
+    const tx = new Transaction(coins.get('tada'));
+    tx.fromRawTransaction(plutusFixtureHex);
+    tx.hasPlutusData().should.be.true();
+
+    const plainTx = new Transaction(coins.get('tada'));
+    plainTx.fromRawTransaction(rawTx.unsignedNewPledgeTx);
+    plainTx.hasPlutusData().should.be.false();
+  });
+
+  it('should round-trip a plutus transaction byte-for-byte with no new signature', async () => {
+    const factory = new TransactionBuilderFactory(coins.get('tada'));
+    const txBuilder = factory.from(plutusFixtureHex);
+    const tx = (await txBuilder.build()) as Transaction;
+    tx.toBroadcastFormat().should.equal(plutusFixtureHex);
+  });
+
+  it('should preserve plutus fields and produce a valid vkey for the body hash', async () => {
+    const factory = new TransactionBuilderFactory(coins.get('tada'));
+    const txBuilder = factory.from(plutusFixtureHex);
+    txBuilder.sign({ key: privateKeys.prvKey4 });
+    const tx = (await txBuilder.build()) as Transaction;
+    const broadcastHex = tx.toBroadcastFormat();
+    broadcastHex.should.not.equal(plutusFixtureHex);
+
+    const reparsed = CardanoWasm.Transaction.from_bytes(Buffer.from(broadcastHex, 'hex'));
+    const body = reparsed.body();
+    const witnessSet = reparsed.witness_set();
+
+    should.exist(body.collateral());
+    should.exist(body.collateral_return());
+    should.exist(body.total_collateral());
+    should.exist(body.reference_inputs());
+    should.exist(body.script_data_hash());
+    body.outputs().get(0).has_plutus_data().should.be.true();
+
+    should.exist(witnessSet.plutus_scripts());
+    should.exist(witnessSet.plutus_data());
+    should.exist(witnessSet.redeemers());
+
+    const originalTx = CardanoWasm.Transaction.from_bytes(Buffer.from(plutusFixtureHex, 'hex'));
+    body.collateral()!.to_bytes().should.deepEqual(originalTx.body().collateral()!.to_bytes());
+    body.collateral_return()!.to_bytes().should.deepEqual(originalTx.body().collateral_return()!.to_bytes());
+    body.total_collateral()!.to_bytes().should.deepEqual(originalTx.body().total_collateral()!.to_bytes());
+    body.reference_inputs()!.to_bytes().should.deepEqual(originalTx.body().reference_inputs()!.to_bytes());
+    body.script_data_hash()!.to_bytes().should.deepEqual(originalTx.body().script_data_hash()!.to_bytes());
+    witnessSet.plutus_scripts()!.to_bytes().should.deepEqual(originalTx.witness_set().plutus_scripts()!.to_bytes());
+    witnessSet.plutus_data()!.to_bytes().should.deepEqual(originalTx.witness_set().plutus_data()!.to_bytes());
+    witnessSet.redeemers()!.to_bytes().should.deepEqual(originalTx.witness_set().redeemers()!.to_bytes());
+
+    const keyPair = new KeyPair({ prv: privateKeys.prvKey4 });
+    const expected = CardanoWasm.make_vkey_witness(
+      CardanoWasm.hash_transaction(body),
+      CardanoWasm.PrivateKey.from_normal_bytes(Buffer.from(keyPair.getKeys().prv!, 'hex'))
+    );
+    const vkeys = witnessSet.vkeys();
+    should.exist(vkeys);
+    vkeys!.len().should.equal(1);
+    vkeys!.get(0).vkey().public_key().to_hex().should.equal(keyPair.getKeys().pub);
+    vkeys!.get(0).signature().to_hex().should.equal(expected.signature().to_hex());
+  });
+
+  it('should preserve auxiliary data through the passthrough path', async () => {
+    const fixtureWithAux = buildPlutusFixtureHex(true);
+    const factory = new TransactionBuilderFactory(coins.get('tada'));
+    const txBuilder = factory.from(fixtureWithAux);
+    txBuilder.sign({ key: privateKeys.prvKey4 });
+    const tx = (await txBuilder.build()) as Transaction;
+
+    const reparsed = CardanoWasm.Transaction.from_bytes(Buffer.from(tx.toBroadcastFormat(), 'hex'));
+    const original = CardanoWasm.Transaction.from_bytes(Buffer.from(fixtureWithAux, 'hex'));
+    should.exist(reparsed.auxiliary_data());
+    reparsed.auxiliary_data()!.to_bytes().should.deepEqual(original.auxiliary_data()!.to_bytes());
+    should.exist(reparsed.body().auxiliary_data_hash());
+    reparsed
+      .body()
+      .auxiliary_data_hash()!
+      .to_bytes()
+      .should.deepEqual(original.body().auxiliary_data_hash()!.to_bytes());
+  });
+});