Merge pull request #1363 from 0xProject/feat/order-utils/abiEncoder

Add MAP support to order-utils, order-watcher, and types

53 files changed, 1104 insertions, 394 deletions

diff --git a/contracts/protocol/test/asset_proxy/proxies.ts b/contracts/protocol/test/asset_proxy/proxies.ts
index 89c8b390c..bbb44f402 100644
--- a/contracts/protocol/test/asset_proxy/proxies.ts
+++ b/contracts/protocol/test/asset_proxy/proxies.ts
@@ -715,7 +715,7 @@ describe('Asset Transfer Proxies', () => {
                 const erc20AssetData = assetDataUtils.encodeERC20AssetData(erc20TokenA.address);
                 const amounts = [erc20Amount];
                 const nestedAssetData = [erc20AssetData];
-                const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData);
+                const assetData = assetDataUtils.encodeMultiAssetData(amounts, nestedAssetData);
                 const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
                     assetData,
                     fromAddress,
@@ -778,7 +778,7 @@ describe('Asset Transfer Proxies', () => {
                 const erc20AssetData2 = assetDataUtils.encodeERC20AssetData(erc20TokenA.address);
                 const amounts = [erc20Amount1, erc20Amount2];
                 const nestedAssetData = [erc20AssetData1, erc20AssetData2];
-                const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData);
+                const assetData = assetDataUtils.encodeMultiAssetData(amounts, nestedAssetData);
                 const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
                     assetData,
                     fromAddress,
@@ -811,7 +811,7 @@ describe('Asset Transfer Proxies', () => {
                 const erc20AssetData2 = assetDataUtils.encodeERC20AssetData(erc20TokenB.address);
                 const amounts = [erc20Amount1, erc20Amount2];
                 const nestedAssetData = [erc20AssetData1, erc20AssetData2];
-                const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData);
+                const assetData = assetDataUtils.encodeMultiAssetData(amounts, nestedAssetData);
                 const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
                     assetData,
                     fromAddress,
@@ -849,7 +849,7 @@ describe('Asset Transfer Proxies', () => {
                 const erc721AssetData = assetDataUtils.encodeERC721AssetData(erc721TokenA.address, erc721AFromTokenId);
                 const amounts = [erc721Amount];
                 const nestedAssetData = [erc721AssetData];
-                const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData);
+                const assetData = assetDataUtils.encodeMultiAssetData(amounts, nestedAssetData);
                 const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
                     assetData,
                     fromAddress,
@@ -881,7 +881,7 @@ describe('Asset Transfer Proxies', () => {
                 const erc721Amount = new BigNumber(1);
                 const amounts = [erc721Amount, erc721Amount];
                 const nestedAssetData = [erc721AssetData1, erc721AssetData2];
-                const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData);
+                const assetData = assetDataUtils.encodeMultiAssetData(amounts, nestedAssetData);
                 const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
                     assetData,
                     fromAddress,
@@ -913,7 +913,7 @@ describe('Asset Transfer Proxies', () => {
                 const erc721Amount = new BigNumber(1);
                 const amounts = [erc721Amount, erc721Amount];
                 const nestedAssetData = [erc721AssetData1, erc721AssetData2];
-                const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData);
+                const assetData = assetDataUtils.encodeMultiAssetData(amounts, nestedAssetData);
                 const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
                     assetData,
                     fromAddress,
@@ -946,7 +946,7 @@ describe('Asset Transfer Proxies', () => {
                 const erc721AssetData = assetDataUtils.encodeERC721AssetData(erc721TokenA.address, erc721AFromTokenId);
                 const amounts = [erc20Amount, erc721Amount];
                 const nestedAssetData = [erc20AssetData, erc721AssetData];
-                const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData);
+                const assetData = assetDataUtils.encodeMultiAssetData(amounts, nestedAssetData);
                 const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
                     assetData,
                     fromAddress,
@@ -984,10 +984,7 @@ describe('Asset Transfer Proxies', () => {
                 const amounts = [erc20Amount, erc721Amount];
                 const nestedAssetData = [erc20AssetData, erc721AssetData];
                 const extraData = '0102030405060708';
-                const assetData = `${assetDataInterface.MultiAsset.getABIEncodedTransactionData(
-                    amounts,
-                    nestedAssetData,
-                )}${extraData}`;
+                const assetData = `${assetDataUtils.encodeMultiAssetData(amounts, nestedAssetData)}${extraData}`;
                 const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
                     assetData,
                     fromAddress,
@@ -1024,7 +1021,7 @@ describe('Asset Transfer Proxies', () => {
                 const erc20AssetData2 = assetDataUtils.encodeERC20AssetData(erc20TokenB.address);
                 const amounts = [erc20Amount1, erc20Amount2];
                 const nestedAssetData = [erc20AssetData1, erc20AssetData2];
-                const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData);
+                const assetData = assetDataUtils.encodeMultiAssetData(amounts, nestedAssetData);
                 const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
                     assetData,
                     fromAddress,
@@ -1085,7 +1082,7 @@ describe('Asset Transfer Proxies', () => {
                     erc721AssetData3,
                     erc721AssetData4,
                 ];
-                const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData);
+                const assetData = assetDataUtils.encodeMultiAssetData(amounts, nestedAssetData);
                 const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
                     assetData,
                     fromAddress,
@@ -1143,7 +1140,7 @@ describe('Asset Transfer Proxies', () => {
                 const erc721AssetData = assetDataUtils.encodeERC721AssetData(erc721TokenA.address, erc721AFromTokenId);
                 const amounts = [erc20Amount, erc721Amount];
                 const nestedAssetData = [erc20AssetData, erc721AssetData];
-                const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData);
+                const assetData = assetDataUtils.encodeMultiAssetData(amounts, nestedAssetData);
                 const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
                     assetData,
                     fromAddress,
@@ -1169,6 +1166,7 @@ describe('Asset Transfer Proxies', () => {
                 const invalidErc721AssetData = `${invalidProxyId}${erc721AssetData.slice(10)}`;
                 const amounts = [erc20Amount, erc721Amount];
                 const nestedAssetData = [erc20AssetData, invalidErc721AssetData];
+                // HACK: This is used to get around validation built into assetDataUtils
                 const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData);
                 const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
                     assetData,
@@ -1192,6 +1190,7 @@ describe('Asset Transfer Proxies', () => {
                 const erc721AssetData = assetDataUtils.encodeERC721AssetData(erc721TokenA.address, erc721AFromTokenId);
                 const amounts = [erc20Amount];
                 const nestedAssetData = [erc20AssetData, erc721AssetData];
+                // HACK: This is used to get around validation built into assetDataUtils
                 const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData);
                 const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
                     assetData,
@@ -1214,7 +1213,7 @@ describe('Asset Transfer Proxies', () => {
                 const erc20AssetData = assetDataUtils.encodeERC20AssetData(erc20TokenA.address);
                 const amounts = [erc20Amount];
                 const nestedAssetData = [erc20AssetData];
-                const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData);
+                const assetData = assetDataUtils.encodeMultiAssetData(amounts, nestedAssetData);
                 const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
                     assetData,
                     fromAddress,
@@ -1238,6 +1237,7 @@ describe('Asset Transfer Proxies', () => {
                 const erc721AssetData = '0x123456';
                 const amounts = [erc20Amount, erc721Amount];
                 const nestedAssetData = [erc20AssetData, erc721AssetData];
+                // HACK: This is used to get around validation built into assetDataUtils
                 const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData);
                 const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
                     assetData,
@@ -1262,7 +1262,7 @@ describe('Asset Transfer Proxies', () => {
                 const erc721AssetData = assetDataUtils.encodeERC721AssetData(erc721TokenA.address, erc721AFromTokenId);
                 const amounts = [erc20Amount, erc721Amount];
                 const nestedAssetData = [erc20AssetData, erc721AssetData];
-                const assetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(amounts, nestedAssetData);
+                const assetData = assetDataUtils.encodeMultiAssetData(amounts, nestedAssetData);
                 const data = assetProxyInterface.transferFrom.getABIEncodedTransactionData(
                     assetData,
                     fromAddress,
diff --git a/contracts/protocol/test/exchange/core.ts b/contracts/protocol/test/exchange/core.ts
index 9b948f991..42db8623d 100644
--- a/contracts/protocol/test/exchange/core.ts
+++ b/contracts/protocol/test/exchange/core.ts
@@ -1,4 +1,3 @@
-import { artifacts as interfacesArtifacts, IAssetDataContract } from '@0x/contracts-interfaces';
 import {
     chaiSetup,
     constants,
@@ -43,11 +42,6 @@ import { ExchangeWrapper } from '../utils/exchange_wrapper';
 chaiSetup.configure();
 const expect = chai.expect;
 const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
-const assetDataInterface = new IAssetDataContract(
-    interfacesArtifacts.IAssetData.compilerOutput.abi,
-    constants.NULL_ADDRESS,
-    provider,
-);
 // tslint:disable:no-unnecessary-type-assertion
 describe('Exchange core', () => {
     let makerAddress: string;
@@ -777,10 +771,7 @@ describe('Exchange core', () => {
                 assetDataUtils.encodeERC20AssetData(erc20TokenA.address),
                 assetDataUtils.encodeERC20AssetData(erc20TokenB.address),
             ];
-            const makerAssetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(
-                makerAmounts,
-                makerNestedAssetData,
-            );
+            const makerAssetData = assetDataUtils.encodeMultiAssetData(makerAmounts, makerNestedAssetData);
             const makerAssetAmount = new BigNumber(1);
             const takerAssetData = assetDataUtils.encodeERC20AssetData(zrxToken.address);
             const takerAssetAmount = new BigNumber(10);
@@ -830,10 +821,7 @@ describe('Exchange core', () => {
                 assetDataUtils.encodeERC20AssetData(erc20TokenA.address),
                 assetDataUtils.encodeERC20AssetData(erc20TokenB.address),
             ];
-            const makerAssetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(
-                makerAmounts,
-                makerNestedAssetData,
-            );
+            const makerAssetData = assetDataUtils.encodeMultiAssetData(makerAmounts, makerNestedAssetData);
             const makerAssetAmount = new BigNumber(1);
             const takerAmounts = [new BigNumber(10), new BigNumber(1)];
             const takerAssetId = erc721TakerAssetIds[0];
@@ -841,10 +829,7 @@ describe('Exchange core', () => {
                 assetDataUtils.encodeERC20AssetData(zrxToken.address),
                 assetDataUtils.encodeERC721AssetData(erc721Token.address, takerAssetId),
             ];
-            const takerAssetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(
-                takerAmounts,
-                takerNestedAssetData,
-            );
+            const takerAssetData = assetDataUtils.encodeMultiAssetData(takerAmounts, takerNestedAssetData);
             const takerAssetAmount = new BigNumber(1);
             signedOrder = await orderFactory.newSignedOrderAsync({
                 makerAssetData,
@@ -900,10 +885,7 @@ describe('Exchange core', () => {
                 assetDataUtils.encodeERC20AssetData(erc20TokenA.address),
                 assetDataUtils.encodeERC20AssetData(erc20TokenB.address),
             ];
-            const makerAssetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(
-                makerAmounts,
-                makerNestedAssetData,
-            );
+            const makerAssetData = assetDataUtils.encodeMultiAssetData(makerAmounts, makerNestedAssetData);
             const makerAssetAmount = new BigNumber(30);
             const takerAssetData = assetDataUtils.encodeERC20AssetData(zrxToken.address);
             const takerAssetAmount = new BigNumber(10);
@@ -980,10 +962,7 @@ describe('Exchange core', () => {
                 assetDataUtils.encodeERC20AssetData(erc20TokenA.address),
                 assetDataUtils.encodeERC20AssetData(erc20TokenB.address),
             ];
-            const takerAssetData = assetDataInterface.MultiAsset.getABIEncodedTransactionData(
-                takerAmounts,
-                takerNestedAssetData,
-            );
+            const takerAssetData = assetDataUtils.encodeMultiAssetData(takerAmounts, takerNestedAssetData);
             const takerAssetAmount = new BigNumber(30);
             const makerAssetData = assetDataUtils.encodeERC20AssetData(zrxToken.address);
             const makerAssetAmount = new BigNumber(10);
diff --git a/contracts/tokens/src/artifacts/index.ts b/contracts/tokens/src/artifacts/index.ts
index 63b808748..977d01c3e 100644
--- a/contracts/tokens/src/artifacts/index.ts
+++ b/contracts/tokens/src/artifacts/index.ts
@@ -22,6 +22,7 @@ import * as UnlimitedAllowanceToken_v1 from '../../generated-artifacts/Unlimited
 import * as WETH9 from '../../generated-artifacts/WETH9.json';
 import * as ZRXToken from '../../generated-artifacts/ZRXToken.json';
 
+// tslint:disable:no-unnecessary-type-assertion
 export const artifacts = {
     DummyERC20Token: DummyERC20Token as ContractArtifact,
     DummyMultipleReturnERC20Token: DummyMultipleReturnERC20Token as ContractArtifact,
diff --git a/packages/0x.js/CHANGELOG.json b/packages/0x.js/CHANGELOG.json
index 32351ad82..f73de96aa 100644
--- a/packages/0x.js/CHANGELOG.json
+++ b/packages/0x.js/CHANGELOG.json
@@ -1,5 +1,15 @@
 [
     {
+        "version": "3.0.0",
+        "changes": [
+            {
+                "note":
+                    "Export `MultiAssetData`, `MultiAssetDataWithRecursiveDecoding`, `ObjectMap`, and `SingleAssetData` from types. No longer export `AssetData`.",
+                "pr": 1363
+            }
+        ]
+    },
+    {
         "version": "2.0.8",
         "changes": [
             {
diff --git a/packages/0x.js/src/index.ts b/packages/0x.js/src/index.ts
index 2df360b96..d21df0c01 100644
--- a/packages/0x.js/src/index.ts
+++ b/packages/0x.js/src/index.ts
@@ -79,10 +79,13 @@ export {
     OrderStateInvalid,
     OrderState,
     AssetProxyId,
-    AssetData,
+    SingleAssetData,
     ERC20AssetData,
     ERC721AssetData,
+    MultiAssetData,
+    MultiAssetDataWithRecursiveDecoding,
     SignatureType,
+    ObjectMap,
     OrderRelevantState,
     Stats,
 } from '@0x/types';
diff --git a/packages/contract-wrappers/CHANGELOG.json b/packages/contract-wrappers/CHANGELOG.json
index d39027797..581fbdee1 100644
--- a/packages/contract-wrappers/CHANGELOG.json
+++ b/packages/contract-wrappers/CHANGELOG.json
@@ -1,9 +1,13 @@
 [
     {
-        "version": "4.1.4",
+        "version": "4.2.0",
         "changes": [
             {
                 "note": "Add support for Trust Wallet signature denial error"
+            },
+            {
+                "note": "Add balance and allowance queries for `MultiAssetProxy`",
+                "pr": 1363
             }
         ]
     },
diff --git a/packages/contract-wrappers/src/fetchers/asset_balance_and_proxy_allowance_fetcher.ts b/packages/contract-wrappers/src/fetchers/asset_balance_and_proxy_allowance_fetcher.ts
index d10cffe57..1ff130a48 100644
--- a/packages/contract-wrappers/src/fetchers/asset_balance_and_proxy_allowance_fetcher.ts
+++ b/packages/contract-wrappers/src/fetchers/asset_balance_and_proxy_allowance_fetcher.ts
@@ -1,8 +1,7 @@
-// tslint:disable:no-unnecessary-type-assertion
 import { AbstractBalanceAndProxyAllowanceFetcher, assetDataUtils } from '@0x/order-utils';
-import { AssetProxyId, ERC20AssetData, ERC721AssetData } from '@0x/types';
 import { BigNumber } from '@0x/utils';
 import { BlockParamLiteral } from 'ethereum-types';
+import * as _ from 'lodash';
 
 import { ERC20TokenWrapper } from '../contract_wrappers/erc20_token_wrapper';
 import { ERC721TokenWrapper } from '../contract_wrappers/erc721_token_wrapper';
@@ -18,42 +17,45 @@ export class AssetBalanceAndProxyAllowanceFetcher implements AbstractBalanceAndP
     }
     public async getBalanceAsync(assetData: string, userAddress: string): Promise<BigNumber> {
         const decodedAssetData = assetDataUtils.decodeAssetDataOrThrow(assetData);
-        if (decodedAssetData.assetProxyId === AssetProxyId.ERC20) {
-            const decodedERC20AssetData = decodedAssetData as ERC20AssetData;
-            const balance = await this._erc20Token.getBalanceAsync(decodedERC20AssetData.tokenAddress, userAddress, {
+        let balance: BigNumber | undefined;
+        if (assetDataUtils.isERC20AssetData(decodedAssetData)) {
+            balance = await this._erc20Token.getBalanceAsync(decodedAssetData.tokenAddress, userAddress, {
                 defaultBlock: this._stateLayer,
             });
-            return balance;
-        } else {
-            const decodedERC721AssetData = decodedAssetData as ERC721AssetData;
+        } else if (assetDataUtils.isERC721AssetData(decodedAssetData)) {
             const tokenOwner = await this._erc721Token.getOwnerOfAsync(
-                decodedERC721AssetData.tokenAddress,
-                decodedERC721AssetData.tokenId,
+                decodedAssetData.tokenAddress,
+                decodedAssetData.tokenId,
                 {
                     defaultBlock: this._stateLayer,
                 },
             );
-            const balance = tokenOwner === userAddress ? new BigNumber(1) : new BigNumber(0);
-            return balance;
+            balance = tokenOwner === userAddress ? new BigNumber(1) : new BigNumber(0);
+        } else if (assetDataUtils.isMultiAssetData(decodedAssetData)) {
+            // The `balance` for MultiAssetData is the total units of the entire `assetData` that are held by the `userAddress`.
+            for (const [index, nestedAssetDataElement] of decodedAssetData.nestedAssetData.entries()) {
+                const nestedAmountElement = decodedAssetData.amounts[index];
+                const nestedAssetBalance = (await this.getBalanceAsync(
+                    nestedAssetDataElement,
+                    userAddress,
+                )).dividedToIntegerBy(nestedAmountElement);
+                if (_.isUndefined(balance) || nestedAssetBalance.lessThan(balance)) {
+                    balance = nestedAssetBalance;
+                }
+            }
         }
+        return balance as BigNumber;
     }
     public async getProxyAllowanceAsync(assetData: string, userAddress: string): Promise<BigNumber> {
         const decodedAssetData = assetDataUtils.decodeAssetDataOrThrow(assetData);
-        if (decodedAssetData.assetProxyId === AssetProxyId.ERC20) {
-            const decodedERC20AssetData = decodedAssetData as ERC20AssetData;
-            const proxyAllowance = await this._erc20Token.getProxyAllowanceAsync(
-                decodedERC20AssetData.tokenAddress,
-                userAddress,
-                {
-                    defaultBlock: this._stateLayer,
-                },
-            );
-            return proxyAllowance;
-        } else {
-            const decodedERC721AssetData = decodedAssetData as ERC721AssetData;
-
+        let proxyAllowance: BigNumber | undefined;
+        if (assetDataUtils.isERC20AssetData(decodedAssetData)) {
+            proxyAllowance = await this._erc20Token.getProxyAllowanceAsync(decodedAssetData.tokenAddress, userAddress, {
+                defaultBlock: this._stateLayer,
+            });
+        } else if (assetDataUtils.isERC721AssetData(decodedAssetData)) {
             const isApprovedForAll = await this._erc721Token.isProxyApprovedForAllAsync(
-                decodedERC721AssetData.tokenAddress,
+                decodedAssetData.tokenAddress,
                 userAddress,
                 {
                     defaultBlock: this._stateLayer,
@@ -63,15 +65,27 @@ export class AssetBalanceAndProxyAllowanceFetcher implements AbstractBalanceAndP
                 return new BigNumber(this._erc20Token.UNLIMITED_ALLOWANCE_IN_BASE_UNITS);
             } else {
                 const isApproved = await this._erc721Token.isProxyApprovedAsync(
-                    decodedERC721AssetData.tokenAddress,
-                    decodedERC721AssetData.tokenId,
+                    decodedAssetData.tokenAddress,
+                    decodedAssetData.tokenId,
                     {
                         defaultBlock: this._stateLayer,
                     },
                 );
-                const proxyAllowance = isApproved ? new BigNumber(1) : new BigNumber(0);
-                return proxyAllowance;
+                proxyAllowance = isApproved ? new BigNumber(1) : new BigNumber(0);
+            }
+        } else if (assetDataUtils.isMultiAssetData(decodedAssetData)) {
+            // The `proxyAllowance` for MultiAssetData is the total units of the entire `assetData` that the proxies have been approved to spend by the `userAddress`.
+            for (const [index, nestedAssetDataElement] of decodedAssetData.nestedAssetData.entries()) {
+                const nestedAmountElement = decodedAssetData.amounts[index];
+                const nestedAssetAllowance = (await this.getProxyAllowanceAsync(
+                    nestedAssetDataElement,
+                    userAddress,
+                )).dividedToIntegerBy(nestedAmountElement);
+                if (_.isUndefined(proxyAllowance) || nestedAssetAllowance.lessThan(proxyAllowance)) {
+                    proxyAllowance = nestedAssetAllowance;
+                }
             }
         }
+        return proxyAllowance as BigNumber;
     }
 }
diff --git a/packages/fill-scenarios/CHANGELOG.json b/packages/fill-scenarios/CHANGELOG.json
index ca256399a..2c3e261cb 100644
--- a/packages/fill-scenarios/CHANGELOG.json
+++ b/packages/fill-scenarios/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "1.1.0",
+        "changes": [
+            {
+                "note": "Add support for MultiAssetProxy",
+                "pr": 1363
+            }
+        ]
+    },
+    {
         "version": "1.0.16",
         "changes": [
             {
diff --git a/packages/fill-scenarios/src/fill_scenarios.ts b/packages/fill-scenarios/src/fill_scenarios.ts
index 0154bcd0a..ce1f7f9ff 100644
--- a/packages/fill-scenarios/src/fill_scenarios.ts
+++ b/packages/fill-scenarios/src/fill_scenarios.ts
@@ -2,7 +2,7 @@ import { DummyERC20TokenContract, DummyERC721TokenContract, ExchangeContract } f
 import * as artifacts from '@0x/contract-artifacts';
 import { assetDataUtils } from '@0x/order-utils';
 import { orderFactory } from '@0x/order-utils/lib/src/order_factory';
-import { AssetProxyId, ERC721AssetData, OrderWithoutExchangeAddress, SignedOrder } from '@0x/types';
+import { OrderWithoutExchangeAddress, SignedOrder } from '@0x/types';
 import { BigNumber } from '@0x/utils';
 import { Web3Wrapper } from '@0x/web3-wrapper';
 import { Provider } from 'ethereum-types';
@@ -150,39 +150,8 @@ export class FillScenarios {
         feeRecipientAddress: string,
         expirationTimeSeconds?: BigNumber,
     ): Promise<SignedOrder> {
-        const decodedMakerAssetData = assetDataUtils.decodeAssetDataOrThrow(makerAssetData);
-        if (decodedMakerAssetData.assetProxyId === AssetProxyId.ERC20) {
-            await this._increaseERC20BalanceAndAllowanceAsync(
-                decodedMakerAssetData.tokenAddress,
-                makerAddress,
-                makerFillableAmount,
-            );
-        } else {
-            if (!makerFillableAmount.equals(1)) {
-                throw new Error(`ERC721 makerFillableAmount should be equal 1. Found: ${makerFillableAmount}`);
-            }
-            await this._increaseERC721BalanceAndAllowanceAsync(
-                decodedMakerAssetData.tokenAddress,
-                makerAddress,
-                // tslint:disable-next-line:no-unnecessary-type-assertion
-                (decodedMakerAssetData as ERC721AssetData).tokenId,
-            );
-        }
-        const decodedTakerAssetData = assetDataUtils.decodeAssetDataOrThrow(takerAssetData);
-        if (decodedTakerAssetData.assetProxyId === AssetProxyId.ERC20) {
-            const takerTokenAddress = decodedTakerAssetData.tokenAddress;
-            await this._increaseERC20BalanceAndAllowanceAsync(takerTokenAddress, takerAddress, takerFillableAmount);
-        } else {
-            if (!takerFillableAmount.equals(1)) {
-                throw new Error(`ERC721 takerFillableAmount should be equal 1. Found: ${takerFillableAmount}`);
-            }
-            await this._increaseERC721BalanceAndAllowanceAsync(
-                decodedTakerAssetData.tokenAddress,
-                takerAddress,
-                // tslint:disable-next-line:no-unnecessary-type-assertion
-                (decodedMakerAssetData as ERC721AssetData).tokenId,
-            );
-        }
+        await this._increaseBalanceAndAllowanceWithAssetDataAsync(makerAssetData, makerAddress, makerFillableAmount);
+        await this._increaseBalanceAndAllowanceWithAssetDataAsync(takerAssetData, takerAddress, takerFillableAmount);
         // Fees
         await Promise.all([
             this._increaseERC20BalanceAndAllowanceAsync(this._zrxTokenAddress, makerAddress, makerFee),
@@ -298,4 +267,30 @@ export class FillScenarios {
         });
         await this._web3Wrapper.awaitTransactionSuccessAsync(txHash, constants.AWAIT_TRANSACTION_MINED_MS);
     }
+    private async _increaseBalanceAndAllowanceWithAssetDataAsync(
+        assetData: string,
+        userAddress: string,
+        amount: BigNumber,
+    ): Promise<void> {
+        const decodedAssetData = assetDataUtils.decodeAssetDataOrThrow(assetData);
+        if (assetDataUtils.isERC20AssetData(decodedAssetData)) {
+            await this._increaseERC20BalanceAndAllowanceAsync(decodedAssetData.tokenAddress, userAddress, amount);
+        } else if (assetDataUtils.isERC721AssetData(decodedAssetData)) {
+            await this._increaseERC721BalanceAndAllowanceAsync(
+                decodedAssetData.tokenAddress,
+                userAddress,
+                decodedAssetData.tokenId,
+            );
+        } else if (assetDataUtils.isMultiAssetData(decodedAssetData)) {
+            for (const [index, nestedAssetDataElement] of decodedAssetData.nestedAssetData.entries()) {
+                const amountsElement = decodedAssetData.amounts[index];
+                const totalAmount = amount.times(amountsElement);
+                await this._increaseBalanceAndAllowanceWithAssetDataAsync(
+                    nestedAssetDataElement,
+                    userAddress,
+                    totalAmount,
+                );
+            }
+        }
+    }
 }
diff --git a/packages/order-utils/CHANGELOG.json b/packages/order-utils/CHANGELOG.json
index 11889b92e..292f7a57b 100644
--- a/packages/order-utils/CHANGELOG.json
+++ b/packages/order-utils/CHANGELOG.json
@@ -1,5 +1,15 @@
 [
     {
+        "version": "3.1.0",
+        "changes": [
+            {
+                "note":
+                    "Use new ABI encoder, add encoding/decoding logic for MultiAsset assetData, and add information to return values in orderStateUtils",
+                "pr": 1363
+            }
+        ]
+    },
+    {
         "version": "3.0.7",
         "changes": [
             {
diff --git a/packages/order-utils/src/asset_data_utils.ts b/packages/order-utils/src/asset_data_utils.ts
index 9bbef3a23..f314891e2 100644
--- a/packages/order-utils/src/asset_data_utils.ts
+++ b/packages/order-utils/src/asset_data_utils.ts
@@ -1,10 +1,19 @@
-import { AssetData, AssetProxyId, ERC20AssetData, ERC721AssetData } from '@0x/types';
-import { BigNumber } from '@0x/utils';
-import ethAbi = require('ethereumjs-abi');
-import ethUtil = require('ethereumjs-util');
+import {
+    AssetProxyId,
+    ERC20AssetData,
+    ERC721AssetData,
+    MultiAssetData,
+    MultiAssetDataWithRecursiveDecoding,
+    SingleAssetData,
+} from '@0x/types';
+import { AbiEncoder, BigNumber } from '@0x/utils';
+import * as _ from 'lodash';
 
 import { constants } from './constants';
 
+const encodingRules: AbiEncoder.EncodingRules = { shouldOptimize: true };
+const decodingRules: AbiEncoder.DecodingRules = { shouldConvertStructsToObjects: true };
+
 export const assetDataUtils = {
     /**
      * Encodes an ERC20 token address into a hex encoded assetData string, usable in the makerAssetData or
@@ -13,7 +22,10 @@ export const assetDataUtils = {
      * @return The hex encoded assetData string
      */
     encodeERC20AssetData(tokenAddress: string): string {
-        return ethUtil.bufferToHex(ethAbi.simpleEncode('ERC20Token(address)', tokenAddress));
+        const abiEncoder = new AbiEncoder.Method(constants.ERC20_METHOD_ABI);
+        const args = [tokenAddress];
+        const assetData = abiEncoder.encode(args, encodingRules);
+        return assetData;
     },
     /**
      * Decodes an ERC20 assetData hex string into it's corresponding ERC20 tokenAddress & assetProxyId
@@ -21,26 +33,14 @@ export const assetDataUtils = {
      * @return An object containing the decoded tokenAddress & assetProxyId
      */
     decodeERC20AssetData(assetData: string): ERC20AssetData {
-        const data = ethUtil.toBuffer(assetData);
-        if (data.byteLength < constants.ERC20_ASSET_DATA_BYTE_LENGTH) {
-            throw new Error(
-                `Could not decode ERC20 Proxy Data. Expected length of encoded data to be at least ${
-                    constants.ERC20_ASSET_DATA_BYTE_LENGTH
-                }. Got ${data.byteLength}`,
-            );
-        }
-        const assetProxyId = ethUtil.bufferToHex(data.slice(0, constants.SELECTOR_LENGTH));
-        if (assetProxyId !== AssetProxyId.ERC20) {
-            throw new Error(
-                `Could not decode ERC20 Proxy Data. Expected Asset Proxy Id to be ERC20 (${
-                    AssetProxyId.ERC20
-                }), but got ${assetProxyId}`,
-            );
-        }
-        const [tokenAddress] = ethAbi.rawDecode(['address'], data.slice(constants.SELECTOR_LENGTH));
+        assetDataUtils.assertIsERC20AssetData(assetData);
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        const abiEncoder = new AbiEncoder.Method(constants.ERC20_METHOD_ABI);
+        const decodedAssetData = abiEncoder.decode(assetData, decodingRules);
         return {
             assetProxyId,
-            tokenAddress: ethUtil.addHexPrefix(tokenAddress),
+            // TODO(abandeali1): fix return types for `AbiEncoder.Method.decode` so that we can remove type assertion
+            tokenAddress: (decodedAssetData as any).tokenContract,
         };
     },
     /**
@@ -51,14 +51,10 @@ export const assetDataUtils = {
      * @return The hex encoded assetData string
      */
     encodeERC721AssetData(tokenAddress: string, tokenId: BigNumber): string {
-        // TODO: Pass `tokendId` as a BigNumber.
-        return ethUtil.bufferToHex(
-            ethAbi.simpleEncode(
-                'ERC721Token(address,uint256)',
-                tokenAddress,
-                `0x${tokenId.toString(constants.BASE_16)}`,
-            ),
-        );
+        const abiEncoder = new AbiEncoder.Method(constants.ERC721_METHOD_ABI);
+        const args = [tokenAddress, tokenId];
+        const assetData = abiEncoder.encode(args, encodingRules);
+        return assetData;
     },
     /**
      * Decodes an ERC721 assetData hex string into it's corresponding ERC721 tokenAddress, tokenId & assetProxyId
@@ -66,27 +62,99 @@ export const assetDataUtils = {
      * @return An object containing the decoded tokenAddress, tokenId & assetProxyId
      */
     decodeERC721AssetData(assetData: string): ERC721AssetData {
-        const data = ethUtil.toBuffer(assetData);
-        if (data.byteLength < constants.ERC721_ASSET_DATA_MINIMUM_BYTE_LENGTH) {
+        assetDataUtils.assertIsERC721AssetData(assetData);
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        const abiEncoder = new AbiEncoder.Method(constants.ERC721_METHOD_ABI);
+        const decodedAssetData = abiEncoder.decode(assetData, decodingRules);
+        return {
+            assetProxyId,
+            // TODO(abandeali1): fix return types for `AbiEncoder.Method.decode` so that we can remove type assertion
+            tokenAddress: (decodedAssetData as any).tokenContract,
+            tokenId: (decodedAssetData as any).tokenId,
+        };
+    },
+    /**
+     * Encodes assetData for multiple AssetProxies into a single hex encoded assetData string, usable in the makerAssetData or
+     * takerAssetData fields in a 0x order.
+     * @param amounts Amounts of each asset that correspond to a single unit within an order.
+     * @param nestedAssetData assetData strings that correspond to a valid assetProxyId.
+     * @return The hex encoded assetData string
+     */
+    encodeMultiAssetData(amounts: BigNumber[], nestedAssetData: string[]): string {
+        if (amounts.length !== nestedAssetData.length) {
             throw new Error(
-                `Could not decode ERC721 Asset Data. Expected length of encoded data to be at least ${
-                    constants.ERC721_ASSET_DATA_MINIMUM_BYTE_LENGTH
-                }. Got ${data.byteLength}`,
+                `Invalid MultiAsset arguments. Expected length of 'amounts' (${
+                    amounts.length
+                }) to equal length of 'nestedAssetData' (${nestedAssetData.length})`,
             );
         }
-        const assetProxyId = ethUtil.bufferToHex(data.slice(0, constants.SELECTOR_LENGTH));
-        if (assetProxyId !== AssetProxyId.ERC721) {
+        _.forEach(nestedAssetData, assetDataElement => assetDataUtils.validateAssetDataOrThrow(assetDataElement));
+        const abiEncoder = new AbiEncoder.Method(constants.MULTI_ASSET_METHOD_ABI);
+        const args = [amounts, nestedAssetData];
+        const assetData = abiEncoder.encode(args, encodingRules);
+        return assetData;
+    },
+    /**
+     * Decodes a MultiAsset assetData hex string into it's corresponding amounts and nestedAssetData
+     * @param assetData Hex encoded assetData string to decode
+     * @return An object containing the decoded amounts and nestedAssetData
+     */
+    decodeMultiAssetData(assetData: string): MultiAssetData {
+        assetDataUtils.assertIsMultiAssetData(assetData);
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        const abiEncoder = new AbiEncoder.Method(constants.MULTI_ASSET_METHOD_ABI);
+        const decodedAssetData = abiEncoder.decode(assetData, decodingRules);
+        // TODO(abandeali1): fix return types for `AbiEncoder.Method.decode` so that we can remove type assertion
+        const amounts = (decodedAssetData as any).amounts;
+        const nestedAssetData = (decodedAssetData as any).nestedAssetData;
+        if (amounts.length !== nestedAssetData.length) {
             throw new Error(
-                `Could not decode ERC721 Asset Data. Expected Asset Proxy Id to be ERC721 (${
-                    AssetProxyId.ERC721
-                }), but got ${assetProxyId}`,
+                `Invalid MultiAsset assetData. Expected length of 'amounts' (${
+                    amounts.length
+                }) to equal length of 'nestedAssetData' (${nestedAssetData.length})`,
             );
         }
-        const [tokenAddress, tokenId] = ethAbi.rawDecode(['address', 'uint256'], data.slice(constants.SELECTOR_LENGTH));
         return {
             assetProxyId,
-            tokenAddress: ethUtil.addHexPrefix(tokenAddress),
-            tokenId: new BigNumber(tokenId.toString()),
+            amounts,
+            nestedAssetData,
+        };
+    },
+    /**
+     * Decodes a MultiAsset assetData hex string into it's corresponding amounts and decoded nestedAssetData elements (all nested elements are flattened)
+     * @param assetData Hex encoded assetData string to decode
+     * @return An object containing the decoded amounts and nestedAssetData
+     */
+    decodeMultiAssetDataRecursively(assetData: string): MultiAssetDataWithRecursiveDecoding {
+        const decodedAssetData = assetDataUtils.decodeMultiAssetData(assetData);
+        const amounts: any[] = [];
+        const decodedNestedAssetData = _.map(
+            decodedAssetData.nestedAssetData as string[],
+            (nestedAssetDataElement, index) => {
+                const decodedNestedAssetDataElement = assetDataUtils.decodeAssetDataOrThrow(nestedAssetDataElement);
+                if (decodedNestedAssetDataElement.assetProxyId === AssetProxyId.MultiAsset) {
+                    const recursivelyDecodedAssetData = assetDataUtils.decodeMultiAssetDataRecursively(
+                        nestedAssetDataElement,
+                    );
+                    amounts.push(
+                        _.map(recursivelyDecodedAssetData.amounts, amountElement =>
+                            amountElement.times(decodedAssetData.amounts[index]),
+                        ),
+                    );
+                    return recursivelyDecodedAssetData.nestedAssetData;
+                } else {
+                    amounts.push(decodedAssetData.amounts[index]);
+                    return decodedNestedAssetDataElement as SingleAssetData;
+                }
+            },
+        );
+        const flattenedAmounts = _.flattenDeep(amounts);
+        const flattenedDecodedNestedAssetData = _.flattenDeep(decodedNestedAssetData);
+        return {
+            assetProxyId: decodedAssetData.assetProxyId,
+            amounts: flattenedAmounts,
+            // tslint:disable-next-line:no-unnecessary-type-assertion
+            nestedAssetData: flattenedDecodedNestedAssetData as SingleAssetData[],
         };
     },
     /**
@@ -95,24 +163,133 @@ export const assetDataUtils = {
      * @return The assetProxyId
      */
     decodeAssetProxyId(assetData: string): AssetProxyId {
-        const encodedAssetData = ethUtil.toBuffer(assetData);
-        if (encodedAssetData.byteLength < constants.SELECTOR_LENGTH) {
+        if (assetData.length < constants.SELECTOR_CHAR_LENGTH_WITH_PREFIX) {
             throw new Error(
-                `Could not decode assetData. Expected length of encoded data to be at least 4. Got ${
-                    encodedAssetData.byteLength
+                `Could not decode assetData. Expected length of encoded data to be at least 10. Got ${
+                    assetData.length
                 }`,
             );
         }
-        const encodedAssetProxyId = encodedAssetData.slice(0, constants.SELECTOR_LENGTH);
-        const assetProxyId = decodeAssetProxyId(encodedAssetProxyId);
+        const assetProxyId = assetData.slice(0, constants.SELECTOR_CHAR_LENGTH_WITH_PREFIX);
+        if (
+            assetProxyId !== AssetProxyId.ERC20 &&
+            assetProxyId !== AssetProxyId.ERC721 &&
+            assetProxyId !== AssetProxyId.MultiAsset
+        ) {
+            throw new Error(`Invalid assetProxyId: ${assetProxyId}`);
+        }
         return assetProxyId;
     },
     /**
+     * Checks if the decoded asset data is valid ERC20 data
+     * @param decodedAssetData The decoded asset data to check
+     */
+    isERC20AssetData(decodedAssetData: SingleAssetData | MultiAssetData): decodedAssetData is ERC20AssetData {
+        return decodedAssetData.assetProxyId === AssetProxyId.ERC20;
+    },
+    /**
+     * Checks if the decoded asset data is valid ERC721 data
+     * @param decodedAssetData The decoded asset data to check
+     */
+    isERC721AssetData(decodedAssetData: SingleAssetData | MultiAssetData): decodedAssetData is ERC721AssetData {
+        return decodedAssetData.assetProxyId === AssetProxyId.ERC721;
+    },
+    /**
+     * Checks if the decoded asset data is valid MultiAsset data
+     * @param decodedAssetData The decoded asset data to check
+     */
+    isMultiAssetData(decodedAssetData: SingleAssetData | MultiAssetData): decodedAssetData is MultiAssetData {
+        return decodedAssetData.assetProxyId === AssetProxyId.MultiAsset;
+    },
+    /**
+     * Throws if the length or assetProxyId are invalid for the ERC20Proxy.
+     * @param assetData Hex encoded assetData string
+     */
+    assertIsERC20AssetData(assetData: string): void {
+        if (assetData.length < constants.ERC20_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX) {
+            throw new Error(
+                `Could not decode ERC20 Proxy Data. Expected length of encoded data to be at least ${
+                    constants.ERC20_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX
+                }. Got ${assetData.length}`,
+            );
+        }
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        if (assetProxyId !== AssetProxyId.ERC20) {
+            throw new Error(
+                `Could not decode ERC20 assetData. Expected assetProxyId to be ERC20 (${
+                    AssetProxyId.ERC20
+                }), but got ${assetProxyId}`,
+            );
+        }
+    },
+    /**
+     * Throws if the length or assetProxyId are invalid for the ERC721Proxy.
+     * @param assetData Hex encoded assetData string
+     */
+    assertIsERC721AssetData(assetData: string): void {
+        if (assetData.length < constants.ERC721_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX) {
+            throw new Error(
+                `Could not decode ERC721 assetData. Expected length of encoded data to be at least ${
+                    constants.ERC721_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX
+                }. Got ${assetData.length}`,
+            );
+        }
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        if (assetProxyId !== AssetProxyId.ERC721) {
+            throw new Error(
+                `Could not decode ERC721 assetData. Expected assetProxyId to be ERC721 (${
+                    AssetProxyId.ERC721
+                }), but got ${assetProxyId}`,
+            );
+        }
+    },
+    /**
+     * Throws if the length or assetProxyId are invalid for the MultiAssetProxy.
+     * @param assetData Hex encoded assetData string
+     */
+    assertIsMultiAssetData(assetData: string): void {
+        if (assetData.length < constants.MULTI_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX) {
+            throw new Error(
+                `Could not decode MultiAsset assetData. Expected length of encoded data to be at least ${
+                    constants.MULTI_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX
+                }. Got ${assetData.length}`,
+            );
+        }
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        if (assetProxyId !== AssetProxyId.MultiAsset) {
+            throw new Error(
+                `Could not decode MultiAsset assetData. Expected assetProxyId to be MultiAsset (${
+                    AssetProxyId.MultiAsset
+                }), but got ${assetProxyId}`,
+            );
+        }
+    },
+    /**
+     * Throws if the length or assetProxyId are invalid for the corresponding AssetProxy.
+     * @param assetData Hex encoded assetData string
+     */
+    validateAssetDataOrThrow(assetData: string): void {
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        switch (assetProxyId) {
+            case AssetProxyId.ERC20:
+                assetDataUtils.assertIsERC20AssetData(assetData);
+                break;
+            case AssetProxyId.ERC721:
+                assetDataUtils.assertIsERC721AssetData(assetData);
+                break;
+            case AssetProxyId.MultiAsset:
+                assetDataUtils.assertIsMultiAssetData(assetData);
+                break;
+            default:
+                throw new Error(`Unrecognized asset proxy id: ${assetProxyId}`);
+        }
+    },
+    /**
      * Decode any assetData into it's corresponding assetData object
      * @param assetData Hex encoded assetData string to decode
      * @return Either a ERC20 or ERC721 assetData object
      */
-    decodeAssetDataOrThrow(assetData: string): AssetData {
+    decodeAssetDataOrThrow(assetData: string): SingleAssetData | MultiAssetData {
         const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
         switch (assetProxyId) {
             case AssetProxyId.ERC20:
@@ -121,19 +298,11 @@ export const assetDataUtils = {
             case AssetProxyId.ERC721:
                 const erc721AssetData = assetDataUtils.decodeERC721AssetData(assetData);
                 return erc721AssetData;
+            case AssetProxyId.MultiAsset:
+                const multiAssetData = assetDataUtils.decodeMultiAssetData(assetData);
+                return multiAssetData;
             default:
                 throw new Error(`Unrecognized asset proxy id: ${assetProxyId}`);
         }
     },
 };
-
-function decodeAssetProxyId(encodedAssetProxyId: Buffer): AssetProxyId {
-    const hexString = ethUtil.bufferToHex(encodedAssetProxyId);
-    if (hexString === AssetProxyId.ERC20) {
-        return AssetProxyId.ERC20;
-    }
-    if (hexString === AssetProxyId.ERC721) {
-        return AssetProxyId.ERC721;
-    }
-    throw new Error(`Invalid ProxyId: ${hexString}`);
-}
diff --git a/packages/order-utils/src/constants.ts b/packages/order-utils/src/constants.ts
index 10029dcc3..a9a687719 100644
--- a/packages/order-utils/src/constants.ts
+++ b/packages/order-utils/src/constants.ts
@@ -1,16 +1,71 @@
 import { BigNumber } from '@0x/utils';
+import { MethodAbi } from 'ethereum-types';
+
+const ERC20_METHOD_ABI: MethodAbi = {
+    constant: false,
+    inputs: [
+        {
+            name: 'tokenContract',
+            type: 'address',
+        },
+    ],
+    name: 'ERC20Token',
+    outputs: [],
+    payable: false,
+    stateMutability: 'nonpayable',
+    type: 'function',
+};
+
+const ERC721_METHOD_ABI: MethodAbi = {
+    constant: false,
+    inputs: [
+        {
+            name: 'tokenContract',
+            type: 'address',
+        },
+        {
+            name: 'tokenId',
+            type: 'uint256',
+        },
+    ],
+    name: 'ERC721Token',
+    outputs: [],
+    payable: false,
+    stateMutability: 'nonpayable',
+    type: 'function',
+};
+
+const MULTI_ASSET_METHOD_ABI: MethodAbi = {
+    constant: false,
+    inputs: [
+        {
+            name: 'amounts',
+            type: 'uint256[]',
+        },
+        {
+            name: 'nestedAssetData',
+            type: 'bytes[]',
+        },
+    ],
+    name: 'MultiAsset',
+    outputs: [],
+    payable: false,
+    stateMutability: 'nonpayable',
+    type: 'function',
+};
 
 export const constants = {
     NULL_ADDRESS: '0x0000000000000000000000000000000000000000',
     NULL_BYTES: '0x',
+    NULL_ERC20_ASSET_DATA: '0xf47261b00000000000000000000000000000000000000000000000000000000000000000',
     // tslint:disable-next-line:custom-no-magic-numbers
     UNLIMITED_ALLOWANCE_IN_BASE_UNITS: new BigNumber(2).pow(256).minus(1),
     TESTRPC_NETWORK_ID: 50,
     ADDRESS_LENGTH: 20,
-    ERC20_ASSET_DATA_BYTE_LENGTH: 36,
-    ERC721_ASSET_DATA_MINIMUM_BYTE_LENGTH: 53,
-    SELECTOR_LENGTH: 4,
-    BASE_16: 16,
+    ERC20_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX: 74,
+    ERC721_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX: 136,
+    MULTI_ASSET_DATA_MIN_CHAR_LENGTH_WITH_PREFIX: 266,
+    SELECTOR_CHAR_LENGTH_WITH_PREFIX: 10,
     INFINITE_TIMESTAMP_SEC: new BigNumber(2524604400), // Close to infinite
     ZERO_AMOUNT: new BigNumber(0),
     EIP712_DOMAIN_NAME: '0x Protocol',
@@ -48,4 +103,7 @@ export const constants = {
             { name: 'data', type: 'bytes' },
         ],
     },
+    ERC20_METHOD_ABI,
+    ERC721_METHOD_ABI,
+    MULTI_ASSET_METHOD_ABI,
 };
diff --git a/packages/order-utils/src/exchange_transfer_simulator.ts b/packages/order-utils/src/exchange_transfer_simulator.ts
index 7a38b35df..06621fd9e 100644
--- a/packages/order-utils/src/exchange_transfer_simulator.ts
+++ b/packages/order-utils/src/exchange_transfer_simulator.ts
@@ -1,7 +1,8 @@
-import { ExchangeContractErrs } from '@0x/types';
+import { AssetProxyId, ExchangeContractErrs } from '@0x/types';
 import { BigNumber } from '@0x/utils';
 
 import { AbstractBalanceAndProxyAllowanceLazyStore } from './abstract/abstract_balance_and_proxy_allowance_lazy_store';
+import { assetDataUtils } from './asset_data_utils';
 import { constants } from './constants';
 import { TradeSide, TransferType } from './types';
 
@@ -74,24 +75,51 @@ export class ExchangeTransferSimulator {
         tradeSide: TradeSide,
         transferType: TransferType,
     ): Promise<void> {
-        // HACK: When simulating an open order (e.g taker is NULL_ADDRESS), we don't want to adjust balances/
-        // allowances for the taker. We do however, want to increase the balance of the maker since the maker
-        // might be relying on those funds to fill subsequent orders or pay the order's fees.
-        if (from === constants.NULL_ADDRESS && tradeSide === TradeSide.Taker) {
-            await this._increaseBalanceAsync(assetData, to, amountInBaseUnits);
-            return;
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        switch (assetProxyId) {
+            case AssetProxyId.ERC20:
+            case AssetProxyId.ERC721:
+                // HACK: When simulating an open order (e.g taker is NULL_ADDRESS), we don't want to adjust balances/
+                // allowances for the taker. We do however, want to increase the balance of the maker since the maker
+                // might be relying on those funds to fill subsequent orders or pay the order's fees.
+                if (from === constants.NULL_ADDRESS && tradeSide === TradeSide.Taker) {
+                    await this._increaseBalanceAsync(assetData, to, amountInBaseUnits);
+                    return;
+                }
+                const balance = await this._store.getBalanceAsync(assetData, from);
+                const proxyAllowance = await this._store.getProxyAllowanceAsync(assetData, from);
+                if (proxyAllowance.lessThan(amountInBaseUnits)) {
+                    ExchangeTransferSimulator._throwValidationError(
+                        FailureReason.ProxyAllowance,
+                        tradeSide,
+                        transferType,
+                    );
+                }
+                if (balance.lessThan(amountInBaseUnits)) {
+                    ExchangeTransferSimulator._throwValidationError(FailureReason.Balance, tradeSide, transferType);
+                }
+                await this._decreaseProxyAllowanceAsync(assetData, from, amountInBaseUnits);
+                await this._decreaseBalanceAsync(assetData, from, amountInBaseUnits);
+                await this._increaseBalanceAsync(assetData, to, amountInBaseUnits);
+                break;
+            case AssetProxyId.MultiAsset:
+                const decodedAssetData = assetDataUtils.decodeMultiAssetData(assetData);
+                for (const [index, nestedAssetDataElement] of decodedAssetData.nestedAssetData.entries()) {
+                    const amountsElement = decodedAssetData.amounts[index];
+                    const totalAmount = amountInBaseUnits.times(amountsElement);
+                    await this.transferFromAsync(
+                        nestedAssetDataElement,
+                        from,
+                        to,
+                        totalAmount,
+                        tradeSide,
+                        transferType,
+                    );
+                }
+                break;
+            default:
+                break;
         }
-        const balance = await this._store.getBalanceAsync(assetData, from);
-        const proxyAllowance = await this._store.getProxyAllowanceAsync(assetData, from);
-        if (proxyAllowance.lessThan(amountInBaseUnits)) {
-            ExchangeTransferSimulator._throwValidationError(FailureReason.ProxyAllowance, tradeSide, transferType);
-        }
-        if (balance.lessThan(amountInBaseUnits)) {
-            ExchangeTransferSimulator._throwValidationError(FailureReason.Balance, tradeSide, transferType);
-        }
-        await this._decreaseProxyAllowanceAsync(assetData, from, amountInBaseUnits);
-        await this._decreaseBalanceAsync(assetData, from, amountInBaseUnits);
-        await this._increaseBalanceAsync(assetData, to, amountInBaseUnits);
     }
     private async _decreaseProxyAllowanceAsync(
         assetData: string,
diff --git a/packages/order-utils/src/index.ts b/packages/order-utils/src/index.ts
index e70d43efb..2150a02e4 100644
--- a/packages/order-utils/src/index.ts
+++ b/packages/order-utils/src/index.ts
@@ -34,11 +34,14 @@ export {
     OrderRelevantState,
     OrderState,
     ECSignature,
-    AssetData,
+    SingleAssetData,
     ERC20AssetData,
     ERC721AssetData,
+    MultiAssetData,
+    MultiAssetDataWithRecursiveDecoding,
     AssetProxyId,
     SignatureType,
+    ObjectMap,
     OrderStateValid,
     OrderStateInvalid,
     ExchangeContractErrs,
diff --git a/packages/order-utils/src/order_state_utils.ts b/packages/order-utils/src/order_state_utils.ts
index fe0d6c773..389419587 100644
--- a/packages/order-utils/src/order_state_utils.ts
+++ b/packages/order-utils/src/order_state_utils.ts
@@ -1,5 +1,6 @@
 import {
     ExchangeContractErrs,
+    ObjectMap,
     OrderRelevantState,
     OrderState,
     OrderStateInvalid,
@@ -7,9 +8,11 @@ import {
     SignedOrder,
 } from '@0x/types';
 import { BigNumber } from '@0x/utils';
+import * as _ from 'lodash';
 
 import { AbstractBalanceAndProxyAllowanceFetcher } from './abstract/abstract_balance_and_proxy_allowance_fetcher';
 import { AbstractOrderFilledCancelledFetcher } from './abstract/abstract_order_filled_cancelled_fetcher';
+import { assetDataUtils } from './asset_data_utils';
 import { orderHashUtils } from './order_hash';
 import { OrderValidationUtils } from './order_validation_utils';
 import { RemainingFillableCalculator } from './remaining_fillable_calculator';
@@ -18,7 +21,9 @@ import { utils } from './utils';
 interface SidedOrderRelevantState {
     isMakerSide: boolean;
     traderBalance: BigNumber;
+    traderIndividualBalances: ObjectMap<BigNumber>;
     traderProxyAllowance: BigNumber;
+    traderIndividualProxyAllowances: ObjectMap<BigNumber>;
     traderFeeBalance: BigNumber;
     traderFeeProxyAllowance: BigNumber;
     filledTakerAssetAmount: BigNumber;
@@ -121,7 +126,9 @@ export class OrderStateUtils {
         const sidedOrderRelevantState = {
             isMakerSide: true,
             traderBalance: orderRelevantState.makerBalance,
+            traderIndividualBalances: orderRelevantState.makerIndividualBalances,
             traderProxyAllowance: orderRelevantState.makerProxyAllowance,
+            traderIndividualProxyAllowances: orderRelevantState.makerIndividualProxyAllowances,
             traderFeeBalance: orderRelevantState.makerFeeBalance,
             traderFeeProxyAllowance: orderRelevantState.makerFeeProxyAllowance,
             filledTakerAssetAmount: orderRelevantState.filledTakerAssetAmount,
@@ -165,7 +172,9 @@ export class OrderStateUtils {
 
         const orderRelevantState = {
             makerBalance: sidedOrderRelevantState.traderBalance,
+            makerIndividualBalances: sidedOrderRelevantState.traderIndividualBalances,
             makerProxyAllowance: sidedOrderRelevantState.traderProxyAllowance,
+            makerIndividualProxyAllowances: sidedOrderRelevantState.traderIndividualProxyAllowances,
             makerFeeBalance: sidedOrderRelevantState.traderFeeBalance,
             makerFeeProxyAllowance: sidedOrderRelevantState.traderFeeProxyAllowance,
             filledTakerAssetAmount: sidedOrderRelevantState.filledTakerAssetAmount,
@@ -236,10 +245,12 @@ export class OrderStateUtils {
         const isAssetZRX = assetData === zrxAssetData;
 
         const traderBalance = await this._balanceAndProxyAllowanceFetcher.getBalanceAsync(assetData, traderAddress);
+        const traderIndividualBalances = await this._getAssetBalancesAsync(assetData, traderAddress);
         const traderProxyAllowance = await this._balanceAndProxyAllowanceFetcher.getProxyAllowanceAsync(
             assetData,
             traderAddress,
         );
+        const traderIndividualProxyAllowances = await this._getAssetProxyAllowancesAsync(assetData, traderAddress);
         const traderFeeBalance = await this._balanceAndProxyAllowanceFetcher.getBalanceAsync(
             zrxAssetData,
             traderAddress,
@@ -278,7 +289,9 @@ export class OrderStateUtils {
         const sidedOrderRelevantState = {
             isMakerSide,
             traderBalance,
+            traderIndividualBalances,
             traderProxyAllowance,
+            traderIndividualProxyAllowances,
             traderFeeBalance,
             traderFeeProxyAllowance,
             filledTakerAssetAmount,
@@ -287,4 +300,47 @@ export class OrderStateUtils {
         };
         return sidedOrderRelevantState;
     }
+    private async _getAssetBalancesAsync(
+        assetData: string,
+        traderAddress: string,
+        initialBalances: ObjectMap<BigNumber> = {},
+    ): Promise<ObjectMap<BigNumber>> {
+        const decodedAssetData = assetDataUtils.decodeAssetDataOrThrow(assetData);
+        let balances: ObjectMap<BigNumber> = { ...initialBalances };
+        if (assetDataUtils.isERC20AssetData(decodedAssetData) || assetDataUtils.isERC721AssetData(decodedAssetData)) {
+            const balance = await this._balanceAndProxyAllowanceFetcher.getBalanceAsync(assetData, traderAddress);
+            const tokenAddress = decodedAssetData.tokenAddress;
+            balances[tokenAddress] = _.isUndefined(initialBalances[tokenAddress])
+                ? balance
+                : balances[tokenAddress].add(balance);
+        } else if (assetDataUtils.isMultiAssetData(decodedAssetData)) {
+            for (const assetDataElement of decodedAssetData.nestedAssetData) {
+                balances = await this._getAssetBalancesAsync(assetDataElement, traderAddress, balances);
+            }
+        }
+        return balances;
+    }
+    private async _getAssetProxyAllowancesAsync(
+        assetData: string,
+        traderAddress: string,
+        initialAllowances: ObjectMap<BigNumber> = {},
+    ): Promise<ObjectMap<BigNumber>> {
+        const decodedAssetData = assetDataUtils.decodeAssetDataOrThrow(assetData);
+        let allowances: ObjectMap<BigNumber> = { ...initialAllowances };
+        if (assetDataUtils.isERC20AssetData(decodedAssetData) || assetDataUtils.isERC721AssetData(decodedAssetData)) {
+            const allowance = await this._balanceAndProxyAllowanceFetcher.getProxyAllowanceAsync(
+                assetData,
+                traderAddress,
+            );
+            const tokenAddress = decodedAssetData.tokenAddress;
+            allowances[tokenAddress] = _.isUndefined(initialAllowances[tokenAddress])
+                ? allowance
+                : allowances[tokenAddress].add(allowance);
+        } else if (assetDataUtils.isMultiAssetData(decodedAssetData)) {
+            for (const assetDataElement of decodedAssetData.nestedAssetData) {
+                allowances = await this._getAssetBalancesAsync(assetDataElement, traderAddress, allowances);
+            }
+        }
+        return allowances;
+    }
 }
diff --git a/packages/order-utils/src/store/balance_and_proxy_allowance_lazy_store.ts b/packages/order-utils/src/store/balance_and_proxy_allowance_lazy_store.ts
index f42a76d0c..ae3e36238 100644
--- a/packages/order-utils/src/store/balance_and_proxy_allowance_lazy_store.ts
+++ b/packages/order-utils/src/store/balance_and_proxy_allowance_lazy_store.ts
@@ -119,7 +119,7 @@ export class BalanceAndProxyAllowanceLazyStore implements AbstractBalanceAndProx
     public deleteAllERC721ProxyAllowance(tokenAddress: string, userAddress: string): void {
         for (const assetData in this._proxyAllowance) {
             if (this._proxyAllowance.hasOwnProperty(assetData)) {
-                const decodedAssetData = assetDataUtils.decodeAssetDataOrThrow(assetData);
+                const decodedAssetData = assetDataUtils.decodeERC721AssetData(assetData);
                 if (
                     decodedAssetData.assetProxyId === AssetProxyId.ERC721 &&
                     decodedAssetData.tokenAddress === tokenAddress &&
diff --git a/packages/order-utils/test/asset_data_utils_test.ts b/packages/order-utils/test/asset_data_utils_test.ts
index f175b7a38..c498c5a00 100644
--- a/packages/order-utils/test/asset_data_utils_test.ts
+++ b/packages/order-utils/test/asset_data_utils_test.ts
@@ -1,6 +1,6 @@
 import * as chai from 'chai';
 
-import { ERC20AssetData, ERC721AssetData } from '@0x/types';
+import { AssetProxyId, ERC721AssetData } from '@0x/types';
 import { BigNumber } from '@0x/utils';
 
 import { assetDataUtils } from '../src/asset_data_utils';
@@ -10,41 +10,101 @@ import { chaiSetup } from './utils/chai_setup';
 chaiSetup.configure();
 const expect = chai.expect;
 
-const KNOWN_ENCODINGS = [
-    {
-        address: '0x1dc4c1cefef38a777b15aa20260a54e584b16c48',
-        assetData: '0xf47261b00000000000000000000000001dc4c1cefef38a777b15aa20260a54e584b16c48',
-    },
-    {
-        address: '0x1dc4c1cefef38a777b15aa20260a54e584b16c48',
-        tokenId: new BigNumber(1),
-        assetData:
-            '0x025717920000000000000000000000001dc4c1cefef38a777b15aa20260a54e584b16c480000000000000000000000000000000000000000000000000000000000000001',
-    },
-];
-
-const ERC20_ASSET_PROXY_ID = '0xf47261b0';
-const ERC721_ASSET_PROXY_ID = '0x02571792';
+const KNOWN_ERC20_ENCODING = {
+    address: '0x1dc4c1cefef38a777b15aa20260a54e584b16c48',
+    assetData: '0xf47261b00000000000000000000000001dc4c1cefef38a777b15aa20260a54e584b16c48',
+};
+const KNOWN_ERC721_ENCODING = {
+    address: '0x1dc4c1cefef38a777b15aa20260a54e584b16c48',
+    tokenId: new BigNumber(1),
+    assetData:
+        '0x025717920000000000000000000000001dc4c1cefef38a777b15aa20260a54e584b16c480000000000000000000000000000000000000000000000000000000000000001',
+};
+const KNOWN_MULTI_ASSET_ENCODING = {
+    amounts: [new BigNumber(1), new BigNumber(1)],
+    nestedAssetData: [KNOWN_ERC20_ENCODING.assetData, KNOWN_ERC721_ENCODING.assetData],
+    assetData:
+        '0x94cfcdd7000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000a00000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000a00000000000000000000000000000000000000000000000000000000000000024f47261b00000000000000000000000001dc4c1cefef38a777b15aa20260a54e584b16c48000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000044025717920000000000000000000000001dc4c1cefef38a777b15aa20260a54e584b16c48000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000',
+};
 
 describe('assetDataUtils', () => {
     it('should encode ERC20', () => {
-        const assetData = assetDataUtils.encodeERC20AssetData(KNOWN_ENCODINGS[0].address);
-        expect(assetData).to.equal(KNOWN_ENCODINGS[0].assetData);
+        const assetData = assetDataUtils.encodeERC20AssetData(KNOWN_ERC20_ENCODING.address);
+        expect(assetData).to.equal(KNOWN_ERC20_ENCODING.assetData);
     });
     it('should decode ERC20', () => {
-        const assetData: ERC20AssetData = assetDataUtils.decodeERC20AssetData(KNOWN_ENCODINGS[0].assetData);
-        expect(assetData.tokenAddress).to.equal(KNOWN_ENCODINGS[0].address);
-        expect(assetData.assetProxyId).to.equal(ERC20_ASSET_PROXY_ID);
+        const decodedAssetData = assetDataUtils.decodeERC20AssetData(KNOWN_ERC20_ENCODING.assetData);
+        expect(decodedAssetData.tokenAddress).to.equal(KNOWN_ERC20_ENCODING.address);
+        expect(decodedAssetData.assetProxyId).to.equal(AssetProxyId.ERC20);
     });
     it('should encode ERC721', () => {
-        const assetData = assetDataUtils.encodeERC721AssetData(KNOWN_ENCODINGS[1].address, KNOWN_ENCODINGS[1]
-            .tokenId as BigNumber);
-        expect(assetData).to.equal(KNOWN_ENCODINGS[1].assetData);
+        const assetData = assetDataUtils.encodeERC721AssetData(
+            KNOWN_ERC721_ENCODING.address,
+            KNOWN_ERC721_ENCODING.tokenId,
+        );
+        expect(assetData).to.equal(KNOWN_ERC721_ENCODING.assetData);
     });
     it('should decode ERC721', () => {
-        const assetData: ERC721AssetData = assetDataUtils.decodeERC721AssetData(KNOWN_ENCODINGS[1].assetData);
-        expect(assetData.tokenAddress).to.equal(KNOWN_ENCODINGS[1].address);
-        expect(assetData.assetProxyId).to.equal(ERC721_ASSET_PROXY_ID);
-        expect(assetData.tokenId).to.be.bignumber.equal(KNOWN_ENCODINGS[1].tokenId);
+        const decodedAssetData = assetDataUtils.decodeERC721AssetData(KNOWN_ERC721_ENCODING.assetData);
+        expect(decodedAssetData.tokenAddress).to.equal(KNOWN_ERC721_ENCODING.address);
+        expect(decodedAssetData.assetProxyId).to.equal(AssetProxyId.ERC721);
+        expect(decodedAssetData.tokenId).to.be.bignumber.equal(KNOWN_ERC721_ENCODING.tokenId);
+    });
+    it('should encode ERC20 and ERC721 multiAssetData', () => {
+        const assetData = assetDataUtils.encodeMultiAssetData(
+            KNOWN_MULTI_ASSET_ENCODING.amounts,
+            KNOWN_MULTI_ASSET_ENCODING.nestedAssetData,
+        );
+        expect(assetData).to.equal(KNOWN_MULTI_ASSET_ENCODING.assetData);
+    });
+    it('should decode ERC20 and ERC721 multiAssetData', () => {
+        const decodedAssetData = assetDataUtils.decodeMultiAssetData(KNOWN_MULTI_ASSET_ENCODING.assetData);
+        expect(decodedAssetData.assetProxyId).to.equal(AssetProxyId.MultiAsset);
+        expect(decodedAssetData.amounts).to.deep.equal(KNOWN_MULTI_ASSET_ENCODING.amounts);
+        expect(decodedAssetData.nestedAssetData).to.deep.equal(KNOWN_MULTI_ASSET_ENCODING.nestedAssetData);
+    });
+    it('should recursively decode ERC20 and ERC721 multiAssetData', () => {
+        const decodedAssetData = assetDataUtils.decodeMultiAssetDataRecursively(KNOWN_MULTI_ASSET_ENCODING.assetData);
+        expect(decodedAssetData.assetProxyId).to.equal(AssetProxyId.MultiAsset);
+        expect(decodedAssetData.amounts).to.deep.equal(KNOWN_MULTI_ASSET_ENCODING.amounts);
+        const decodedErc20AssetData = decodedAssetData.nestedAssetData[0];
+        // tslint:disable-next-line:no-unnecessary-type-assertion
+        const decodedErc721AssetData = decodedAssetData.nestedAssetData[1] as ERC721AssetData;
+        expect(decodedErc20AssetData.tokenAddress).to.equal(KNOWN_ERC20_ENCODING.address);
+        expect(decodedErc20AssetData.assetProxyId).to.equal(AssetProxyId.ERC20);
+        expect(decodedErc721AssetData.tokenAddress).to.equal(KNOWN_ERC721_ENCODING.address);
+        expect(decodedErc721AssetData.assetProxyId).to.equal(AssetProxyId.ERC721);
+        expect(decodedErc721AssetData.tokenId).to.be.bignumber.equal(KNOWN_ERC721_ENCODING.tokenId);
+    });
+    it('should recursively decode nested assetData within multiAssetData', () => {
+        const amounts = [new BigNumber(1), new BigNumber(1), new BigNumber(2)];
+        const nestedAssetData = [
+            KNOWN_ERC20_ENCODING.assetData,
+            KNOWN_ERC721_ENCODING.assetData,
+            KNOWN_MULTI_ASSET_ENCODING.assetData,
+        ];
+        const assetData = assetDataUtils.encodeMultiAssetData(amounts, nestedAssetData);
+        const decodedAssetData = assetDataUtils.decodeMultiAssetDataRecursively(assetData);
+        expect(decodedAssetData.assetProxyId).to.equal(AssetProxyId.MultiAsset);
+        const expectedAmounts = [new BigNumber(1), new BigNumber(1), new BigNumber(2), new BigNumber(2)];
+        expect(decodedAssetData.amounts).to.deep.equal(expectedAmounts);
+        const expectedLength = 4;
+        expect(decodedAssetData.nestedAssetData.length).to.be.equal(expectedLength);
+        const decodedErc20AssetData1 = decodedAssetData.nestedAssetData[0];
+        // tslint:disable-next-line:no-unnecessary-type-assertion
+        const decodedErc721AssetData1 = decodedAssetData.nestedAssetData[1] as ERC721AssetData;
+        const decodedErc20AssetData2 = decodedAssetData.nestedAssetData[2];
+        // tslint:disable-next-line:no-unnecessary-type-assertion
+        const decodedErc721AssetData2 = decodedAssetData.nestedAssetData[3] as ERC721AssetData;
+        expect(decodedErc20AssetData1.tokenAddress).to.equal(KNOWN_ERC20_ENCODING.address);
+        expect(decodedErc20AssetData1.assetProxyId).to.equal(AssetProxyId.ERC20);
+        expect(decodedErc721AssetData1.tokenAddress).to.equal(KNOWN_ERC721_ENCODING.address);
+        expect(decodedErc721AssetData1.assetProxyId).to.equal(AssetProxyId.ERC721);
+        expect(decodedErc721AssetData1.tokenId).to.be.bignumber.equal(KNOWN_ERC721_ENCODING.tokenId);
+        expect(decodedErc20AssetData2.tokenAddress).to.equal(KNOWN_ERC20_ENCODING.address);
+        expect(decodedErc20AssetData2.assetProxyId).to.equal(AssetProxyId.ERC20);
+        expect(decodedErc721AssetData2.tokenAddress).to.equal(KNOWN_ERC721_ENCODING.address);
+        expect(decodedErc721AssetData2.assetProxyId).to.equal(AssetProxyId.ERC721);
+        expect(decodedErc721AssetData2.tokenId).to.be.bignumber.equal(KNOWN_ERC721_ENCODING.tokenId);
     });
 });
diff --git a/packages/order-utils/test/utils/test_order_factory.ts b/packages/order-utils/test/utils/test_order_factory.ts
index 145332674..4efe0b38e 100644
--- a/packages/order-utils/test/utils/test_order_factory.ts
+++ b/packages/order-utils/test/utils/test_order_factory.ts
@@ -7,9 +7,9 @@ import { orderFactory } from '../../src/order_factory';
 const BASE_TEST_ORDER: Order = orderFactory.createOrder(
     constants.NULL_ADDRESS,
     constants.ZERO_AMOUNT,
-    constants.NULL_ADDRESS,
+    constants.NULL_ERC20_ASSET_DATA,
     constants.ZERO_AMOUNT,
-    constants.NULL_ADDRESS,
+    constants.NULL_ERC20_ASSET_DATA,
     constants.NULL_ADDRESS,
 );
 const BASE_TEST_SIGNED_ORDER: SignedOrder = {
diff --git a/packages/order-watcher/CHANGELOG.json b/packages/order-watcher/CHANGELOG.json
index 304dc45fd..4cfecd034 100644
--- a/packages/order-watcher/CHANGELOG.json
+++ b/packages/order-watcher/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.4.0",
+        "changes": [
+            {
+                "note": "Add support for `MultiAssetProxy`",
+                "pr": 1363
+            }
+        ]
+    },
+    {
         "version": "2.3.0",
         "changes": [
             {
diff --git a/packages/order-watcher/src/index.ts b/packages/order-watcher/src/index.ts
index e275a0c6a..1f4e5eff1 100644
--- a/packages/order-watcher/src/index.ts
+++ b/packages/order-watcher/src/index.ts
@@ -7,6 +7,7 @@ export {
     OrderStateInvalid,
     OrderState,
     ExchangeContractErrs,
+    ObjectMap,
     OrderRelevantState,
     Stats,
 } from '@0x/types';
diff --git a/packages/order-watcher/src/order_watcher/dependent_order_hashes_tracker.ts b/packages/order-watcher/src/order_watcher/dependent_order_hashes_tracker.ts
index a956a94db..d1085014c 100644
--- a/packages/order-watcher/src/order_watcher/dependent_order_hashes_tracker.ts
+++ b/packages/order-watcher/src/order_watcher/dependent_order_hashes_tracker.ts
@@ -1,6 +1,5 @@
-// tslint:disable:no-unnecessary-type-assertion
 import { assetDataUtils, orderHashUtils } from '@0x/order-utils';
-import { AssetProxyId, ERC20AssetData, ERC721AssetData, SignedOrder } from '@0x/types';
+import { AssetProxyId, SignedOrder } from '@0x/types';
 import { BigNumber } from '@0x/utils';
 import * as _ from 'lodash';
 
@@ -62,35 +61,18 @@ export class DependentOrderHashesTracker {
         return dependentOrderHashes;
     }
     public addToDependentOrderHashes(signedOrder: SignedOrder): void {
-        const decodedMakerAssetData = assetDataUtils.decodeAssetDataOrThrow(signedOrder.makerAssetData);
-        if (decodedMakerAssetData.assetProxyId === AssetProxyId.ERC20) {
-            this._addToERC20DependentOrderHashes(signedOrder, (decodedMakerAssetData as ERC20AssetData).tokenAddress);
-        } else {
-            this._addToERC721DependentOrderHashes(
-                signedOrder,
-                (decodedMakerAssetData as ERC721AssetData).tokenAddress,
-                (decodedMakerAssetData as ERC721AssetData).tokenId,
-            );
-        }
+        this._addAssetDataToDependentOrderHashes(signedOrder, signedOrder.makerAssetData);
         this._addToERC20DependentOrderHashes(signedOrder, this._zrxTokenAddress);
         this._addToMakerDependentOrderHashes(signedOrder);
     }
     public removeFromDependentOrderHashes(signedOrder: SignedOrder): void {
-        const decodedMakerAssetData = assetDataUtils.decodeAssetDataOrThrow(signedOrder.makerAssetData);
-        if (decodedMakerAssetData.assetProxyId === AssetProxyId.ERC20) {
-            this._removeFromERC20DependentOrderhashes(
-                signedOrder,
-                (decodedMakerAssetData as ERC20AssetData).tokenAddress,
-            );
-        } else {
-            this._removeFromERC721DependentOrderhashes(
-                signedOrder,
-                (decodedMakerAssetData as ERC721AssetData).tokenAddress,
-                (decodedMakerAssetData as ERC721AssetData).tokenId,
-            );
-        }
+        this._removeAssetDataFromDependentOrderHashes(signedOrder, signedOrder.makerAssetData);
         // If makerToken === ZRX then we already removed it and we don't need to remove it again.
-        if ((decodedMakerAssetData as ERC20AssetData).tokenAddress !== this._zrxTokenAddress) {
+        const decodedMakerAssetData = assetDataUtils.decodeAssetDataOrThrow(signedOrder.makerAssetData);
+        if (
+            assetDataUtils.isERC20AssetData(decodedMakerAssetData) &&
+            decodedMakerAssetData.tokenAddress !== this._zrxTokenAddress
+        ) {
             this._removeFromERC20DependentOrderhashes(signedOrder, this._zrxTokenAddress);
         }
         this._removeFromMakerDependentOrderhashes(signedOrder);
@@ -167,6 +149,18 @@ export class DependentOrderHashesTracker {
             tokenId.toString()
         ].add(orderHash);
     }
+    private _addAssetDataToDependentOrderHashes(signedOrder: SignedOrder, assetData: string): void {
+        const decodedAssetData = assetDataUtils.decodeAssetDataOrThrow(assetData);
+        if (assetDataUtils.isERC20AssetData(decodedAssetData)) {
+            this._addToERC20DependentOrderHashes(signedOrder, decodedAssetData.tokenAddress);
+        } else if (assetDataUtils.isERC721AssetData(decodedAssetData)) {
+            this._addToERC721DependentOrderHashes(signedOrder, decodedAssetData.tokenAddress, decodedAssetData.tokenId);
+        } else if (assetDataUtils.isMultiAssetData(decodedAssetData)) {
+            _.each(decodedAssetData.nestedAssetData, nestedAssetDataElement =>
+                this._addAssetDataToDependentOrderHashes(signedOrder, nestedAssetDataElement),
+            );
+        }
+    }
     private _addToMakerDependentOrderHashes(signedOrder: SignedOrder): void {
         const orderHash = orderHashUtils.getOrderHashHex(signedOrder);
         if (_.isUndefined(this._orderHashesByMakerAddress[signedOrder.makerAddress])) {
@@ -230,4 +224,20 @@ export class DependentOrderHashesTracker {
             delete this._orderHashesByMakerAddress[signedOrder.makerAddress];
         }
     }
+    private _removeAssetDataFromDependentOrderHashes(signedOrder: SignedOrder, assetData: string): void {
+        const decodedAssetData = assetDataUtils.decodeAssetDataOrThrow(assetData);
+        if (assetDataUtils.isERC20AssetData(decodedAssetData)) {
+            this._removeFromERC20DependentOrderhashes(signedOrder, decodedAssetData.tokenAddress);
+        } else if (assetDataUtils.isERC721AssetData(decodedAssetData)) {
+            this._removeFromERC721DependentOrderhashes(
+                signedOrder,
+                decodedAssetData.tokenAddress,
+                decodedAssetData.tokenId,
+            );
+        } else if (assetDataUtils.isMultiAssetData(decodedAssetData)) {
+            _.each(decodedAssetData.nestedAssetData, nestedAssetDataElement =>
+                this._removeAssetDataFromDependentOrderHashes(signedOrder, nestedAssetDataElement),
+            );
+        }
+    }
 }
diff --git a/packages/order-watcher/src/order_watcher/order_watcher.ts b/packages/order-watcher/src/order_watcher/order_watcher.ts
index 96c5ca7b4..a06fd0cfe 100644
--- a/packages/order-watcher/src/order_watcher/order_watcher.ts
+++ b/packages/order-watcher/src/order_watcher/order_watcher.ts
@@ -161,14 +161,7 @@ export class OrderWatcher {
         this._dependentOrderHashesTracker.addToDependentOrderHashes(signedOrder);
 
         const orderAssetDatas = [signedOrder.makerAssetData, signedOrder.takerAssetData];
-        _.each(orderAssetDatas, assetData => {
-            const decodedAssetData = assetDataUtils.decodeAssetDataOrThrow(assetData);
-            if (decodedAssetData.assetProxyId === AssetProxyId.ERC20) {
-                this._collisionResistantAbiDecoder.addERC20Token(decodedAssetData.tokenAddress);
-            } else if (decodedAssetData.assetProxyId === AssetProxyId.ERC721) {
-                this._collisionResistantAbiDecoder.addERC721Token(decodedAssetData.tokenAddress);
-            }
-        });
+        _.each(orderAssetDatas, assetData => this._addAssetDataToAbiDecoder(assetData));
     }
     /**
      * Removes an order from the orderWatcher
@@ -236,31 +229,71 @@ export class OrderWatcher {
             await this._emitRevalidateOrdersAsync([orderHash]);
         }
     }
+    private _addAssetDataToAbiDecoder(assetData: string): void {
+        const decodedAssetData = assetDataUtils.decodeAssetDataOrThrow(assetData);
+        if (assetDataUtils.isERC20AssetData(decodedAssetData)) {
+            this._collisionResistantAbiDecoder.addERC20Token(decodedAssetData.tokenAddress);
+        } else if (assetDataUtils.isERC721AssetData(decodedAssetData)) {
+            this._collisionResistantAbiDecoder.addERC721Token(decodedAssetData.tokenAddress);
+        } else if (assetDataUtils.isMultiAssetData(decodedAssetData)) {
+            _.each(decodedAssetData.nestedAssetData, nestedAssetDataElement =>
+                this._addAssetDataToAbiDecoder(nestedAssetDataElement),
+            );
+        }
+    }
+    private _deleteLazyStoreBalance(assetData: string, userAddress: string): void {
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        switch (assetProxyId) {
+            case AssetProxyId.ERC20:
+            case AssetProxyId.ERC721:
+                this._balanceAndProxyAllowanceLazyStore.deleteBalance(assetData, userAddress);
+                break;
+            case AssetProxyId.MultiAsset:
+                const decodedAssetData = assetDataUtils.decodeMultiAssetData(assetData);
+                _.each(decodedAssetData.nestedAssetData, nestedAssetDataElement =>
+                    this._deleteLazyStoreBalance(nestedAssetDataElement, userAddress),
+                );
+                break;
+            default:
+                break;
+        }
+    }
+    private _deleteLazyStoreProxyAllowance(assetData: string, userAddress: string): void {
+        const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
+        switch (assetProxyId) {
+            case AssetProxyId.ERC20:
+            case AssetProxyId.ERC721:
+                this._balanceAndProxyAllowanceLazyStore.deleteProxyAllowance(assetData, userAddress);
+                break;
+            case AssetProxyId.MultiAsset:
+                const decodedAssetData = assetDataUtils.decodeMultiAssetData(assetData);
+                _.each(decodedAssetData.nestedAssetData, nestedAssetDataElement =>
+                    this._deleteLazyStoreProxyAllowance(nestedAssetDataElement, userAddress),
+                );
+                break;
+            default:
+                break;
+        }
+    }
     private _cleanupOrderRelatedState(orderHash: string): void {
         const signedOrder = this._orderByOrderHash[orderHash];
 
         this._orderFilledCancelledLazyStore.deleteFilledTakerAmount(orderHash);
         this._orderFilledCancelledLazyStore.deleteIsCancelled(orderHash);
 
-        this._balanceAndProxyAllowanceLazyStore.deleteBalance(signedOrder.makerAssetData, signedOrder.makerAddress);
-        this._balanceAndProxyAllowanceLazyStore.deleteProxyAllowance(
-            signedOrder.makerAssetData,
-            signedOrder.makerAddress,
-        );
-        this._balanceAndProxyAllowanceLazyStore.deleteBalance(signedOrder.takerAssetData, signedOrder.takerAddress);
-        this._balanceAndProxyAllowanceLazyStore.deleteProxyAllowance(
-            signedOrder.takerAssetData,
-            signedOrder.takerAddress,
-        );
+        this._deleteLazyStoreBalance(signedOrder.makerAssetData, signedOrder.makerAddress);
+        this._deleteLazyStoreProxyAllowance(signedOrder.makerAssetData, signedOrder.makerAddress);
+        this._deleteLazyStoreBalance(signedOrder.takerAssetData, signedOrder.takerAddress);
+        this._deleteLazyStoreProxyAllowance(signedOrder.takerAssetData, signedOrder.takerAddress);
 
         const zrxAssetData = this._orderFilledCancelledLazyStore.getZRXAssetData();
         if (!signedOrder.makerFee.isZero()) {
-            this._balanceAndProxyAllowanceLazyStore.deleteBalance(zrxAssetData, signedOrder.makerAddress);
-            this._balanceAndProxyAllowanceLazyStore.deleteProxyAllowance(zrxAssetData, signedOrder.makerAddress);
+            this._deleteLazyStoreBalance(zrxAssetData, signedOrder.makerAddress);
+            this._deleteLazyStoreProxyAllowance(zrxAssetData, signedOrder.makerAddress);
         }
         if (!signedOrder.takerFee.isZero()) {
-            this._balanceAndProxyAllowanceLazyStore.deleteBalance(zrxAssetData, signedOrder.takerAddress);
-            this._balanceAndProxyAllowanceLazyStore.deleteProxyAllowance(zrxAssetData, signedOrder.takerAddress);
+            this._deleteLazyStoreBalance(zrxAssetData, signedOrder.takerAddress);
+            this._deleteLazyStoreProxyAllowance(zrxAssetData, signedOrder.takerAddress);
         }
     }
     private _onOrderExpired(orderHash: string): void {
@@ -302,7 +335,7 @@ export class OrderWatcher {
                     // Invalidate cache
                     const args = decodedLog.args as ERC20TokenApprovalEventArgs;
                     const tokenAssetData = assetDataUtils.encodeERC20AssetData(decodedLog.address);
-                    this._balanceAndProxyAllowanceLazyStore.deleteProxyAllowance(tokenAssetData, args._owner);
+                    this._deleteLazyStoreProxyAllowance(tokenAssetData, args._owner);
                     // Revalidate orders
                     const orderHashes = this._dependentOrderHashesTracker.getDependentOrderHashesByAssetDataByMaker(
                         args._owner,
@@ -315,7 +348,7 @@ export class OrderWatcher {
                     // Invalidate cache
                     const args = decodedLog.args as ERC721TokenApprovalEventArgs;
                     const tokenAssetData = assetDataUtils.encodeERC721AssetData(decodedLog.address, args._tokenId);
-                    this._balanceAndProxyAllowanceLazyStore.deleteProxyAllowance(tokenAssetData, args._owner);
+                    this._deleteLazyStoreProxyAllowance(tokenAssetData, args._owner);
                     // Revalidate orders
                     const orderHashes = this._dependentOrderHashesTracker.getDependentOrderHashesByAssetDataByMaker(
                         args._owner,
@@ -333,8 +366,8 @@ export class OrderWatcher {
                     // Invalidate cache
                     const args = decodedLog.args as ERC20TokenTransferEventArgs;
                     const tokenAssetData = assetDataUtils.encodeERC20AssetData(decodedLog.address);
-                    this._balanceAndProxyAllowanceLazyStore.deleteBalance(tokenAssetData, args._from);
-                    this._balanceAndProxyAllowanceLazyStore.deleteBalance(tokenAssetData, args._to);
+                    this._deleteLazyStoreBalance(tokenAssetData, args._from);
+                    this._deleteLazyStoreBalance(tokenAssetData, args._to);
                     // Revalidate orders
                     const orderHashes = this._dependentOrderHashesTracker.getDependentOrderHashesByAssetDataByMaker(
                         args._from,
@@ -347,8 +380,8 @@ export class OrderWatcher {
                     // Invalidate cache
                     const args = decodedLog.args as ERC721TokenTransferEventArgs;
                     const tokenAssetData = assetDataUtils.encodeERC721AssetData(decodedLog.address, args._tokenId);
-                    this._balanceAndProxyAllowanceLazyStore.deleteBalance(tokenAssetData, args._from);
-                    this._balanceAndProxyAllowanceLazyStore.deleteBalance(tokenAssetData, args._to);
+                    this._deleteLazyStoreBalance(tokenAssetData, args._from);
+                    this._deleteLazyStoreBalance(tokenAssetData, args._to);
                     // Revalidate orders
                     const orderHashes = this._dependentOrderHashesTracker.getDependentOrderHashesByAssetDataByMaker(
                         args._from,
@@ -375,7 +408,7 @@ export class OrderWatcher {
                 // Invalidate cache
                 const args = decodedLog.args as WETH9DepositEventArgs;
                 const tokenAssetData = assetDataUtils.encodeERC20AssetData(decodedLog.address);
-                this._balanceAndProxyAllowanceLazyStore.deleteBalance(tokenAssetData, args._owner);
+                this._deleteLazyStoreBalance(tokenAssetData, args._owner);
                 // Revalidate orders
                 const orderHashes = this._dependentOrderHashesTracker.getDependentOrderHashesByAssetDataByMaker(
                     args._owner,
@@ -388,7 +421,7 @@ export class OrderWatcher {
                 // Invalidate cache
                 const args = decodedLog.args as WETH9WithdrawalEventArgs;
                 const tokenAssetData = assetDataUtils.encodeERC20AssetData(decodedLog.address);
-                this._balanceAndProxyAllowanceLazyStore.deleteBalance(tokenAssetData, args._owner);
+                this._deleteLazyStoreBalance(tokenAssetData, args._owner);
                 // Revalidate orders
                 const orderHashes = this._dependentOrderHashesTracker.getDependentOrderHashesByAssetDataByMaker(
                     args._owner,
diff --git a/packages/order-watcher/test/order_watcher_test.ts b/packages/order-watcher/test/order_watcher_test.ts
index 271e5dec5..41dc884d5 100644
--- a/packages/order-watcher/test/order_watcher_test.ts
+++ b/packages/order-watcher/test/order_watcher_test.ts
@@ -675,5 +675,213 @@ describe('OrderWatcher', () => {
                 })().catch(done);
             });
         });
+        describe('multiAsset', async () => {
+            const tokenId = new BigNumber(42);
+            const [makerErc721TokenAddress] = tokenUtils.getDummyERC721TokenAddresses();
+            const makerErc721AssetData = assetDataUtils.encodeERC721AssetData(makerErc721TokenAddress, tokenId);
+            const fillableErc721Amount = new BigNumber(1);
+            const [makerErc20TokenAddress] = tokenUtils.getDummyERC20TokenAddresses();
+            const makerErc20AssetData = assetDataUtils.encodeERC20AssetData(makerErc20TokenAddress);
+            const fillableErc20Amount = new BigNumber(2);
+            const multiAssetAmounts = [fillableErc721Amount, fillableErc20Amount];
+            const nestedAssetData = [makerErc721AssetData, makerErc20AssetData];
+            const makerMultiAssetData = assetDataUtils.encodeMultiAssetData(multiAssetAmounts, nestedAssetData);
+            it('should emit orderStateInvalid when maker allowance of ERC721 token set to 0 for watched order', (done: DoneCallback) => {
+                (async () => {
+                    signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                        makerMultiAssetData,
+                        takerAssetData,
+                        makerAddress,
+                        takerAddress,
+                        fillableErc721Amount,
+                    );
+                    const orderHash = orderHashUtils.getOrderHashHex(signedOrder);
+                    await orderWatcher.addOrderAsync(signedOrder);
+                    const callback = callbackErrorReporter.reportNodeCallbackErrors(done)((orderState: OrderState) => {
+                        expect(orderState.isValid).to.be.false();
+                        const invalidOrderState = orderState as OrderStateInvalid;
+                        expect(invalidOrderState.orderHash).to.be.equal(orderHash);
+                        expect(invalidOrderState.error).to.be.equal(ExchangeContractErrs.InsufficientMakerAllowance);
+                    });
+                    orderWatcher.subscribe(callback);
+                    await contractWrappers.erc721Token.setApprovalAsync(
+                        makerErc721TokenAddress,
+                        constants.NULL_ADDRESS,
+                        tokenId,
+                    );
+                })().catch(done);
+            });
+            it('should emit orderStateInvalid when maker allowance for all of ERC721 token set to 0 for watched order', (done: DoneCallback) => {
+                (async () => {
+                    signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                        makerMultiAssetData,
+                        takerAssetData,
+                        makerAddress,
+                        takerAddress,
+                        fillableErc721Amount,
+                    );
+                    await contractWrappers.erc721Token.setApprovalAsync(
+                        makerErc721TokenAddress,
+                        constants.NULL_ADDRESS,
+                        tokenId,
+                    );
+                    let isApproved = true;
+                    await contractWrappers.erc721Token.setProxyApprovalForAllAsync(
+                        makerErc721TokenAddress,
+                        makerAddress,
+                        isApproved,
+                    );
+                    const orderHash = orderHashUtils.getOrderHashHex(signedOrder);
+                    await orderWatcher.addOrderAsync(signedOrder);
+                    const callback = callbackErrorReporter.reportNodeCallbackErrors(done)((orderState: OrderState) => {
+                        expect(orderState.isValid).to.be.false();
+                        const invalidOrderState = orderState as OrderStateInvalid;
+                        expect(invalidOrderState.orderHash).to.be.equal(orderHash);
+                        expect(invalidOrderState.error).to.be.equal(ExchangeContractErrs.InsufficientMakerAllowance);
+                    });
+                    orderWatcher.subscribe(callback);
+                    isApproved = false;
+                    await contractWrappers.erc721Token.setProxyApprovalForAllAsync(
+                        makerErc721TokenAddress,
+                        makerAddress,
+                        isApproved,
+                    );
+                })().catch(done);
+            });
+            it('should emit orderStateInvalid when maker moves ERC721 backing watched order', (done: DoneCallback) => {
+                (async () => {
+                    signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                        makerMultiAssetData,
+                        takerAssetData,
+                        makerAddress,
+                        takerAddress,
+                        fillableErc721Amount,
+                    );
+                    const orderHash = orderHashUtils.getOrderHashHex(signedOrder);
+                    await orderWatcher.addOrderAsync(signedOrder);
+                    const callback = callbackErrorReporter.reportNodeCallbackErrors(done)((orderState: OrderState) => {
+                        expect(orderState.isValid).to.be.false();
+                        const invalidOrderState = orderState as OrderStateInvalid;
+                        expect(invalidOrderState.orderHash).to.be.equal(orderHash);
+                        expect(invalidOrderState.error).to.be.equal(ExchangeContractErrs.InsufficientMakerBalance);
+                    });
+                    orderWatcher.subscribe(callback);
+                    await contractWrappers.erc721Token.transferFromAsync(
+                        makerErc721TokenAddress,
+                        coinbase,
+                        makerAddress,
+                        tokenId,
+                    );
+                })().catch(done);
+            });
+            it('should emit orderStateInvalid when maker allowance of ERC20 token set to 0 for watched order', (done: DoneCallback) => {
+                (async () => {
+                    signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                        makerMultiAssetData,
+                        takerAssetData,
+                        makerAddress,
+                        takerAddress,
+                        fillableErc721Amount,
+                    );
+                    const orderHash = orderHashUtils.getOrderHashHex(signedOrder);
+                    await orderWatcher.addOrderAsync(signedOrder);
+                    const callback = callbackErrorReporter.reportNodeCallbackErrors(done)((orderState: OrderState) => {
+                        expect(orderState.isValid).to.be.false();
+                        const invalidOrderState = orderState as OrderStateInvalid;
+                        expect(invalidOrderState.orderHash).to.be.equal(orderHash);
+                        expect(invalidOrderState.error).to.be.equal(ExchangeContractErrs.InsufficientMakerAllowance);
+                    });
+                    orderWatcher.subscribe(callback);
+                    await contractWrappers.erc20Token.setProxyAllowanceAsync(
+                        makerErc20TokenAddress,
+                        makerAddress,
+                        new BigNumber(0),
+                    );
+                })().catch(done);
+            });
+            it('should not emit an orderState event when irrelevant ERC20 Transfer event received', (done: DoneCallback) => {
+                (async () => {
+                    signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                        makerMultiAssetData,
+                        takerAssetData,
+                        makerAddress,
+                        takerAddress,
+                        fillableAmount,
+                    );
+                    await orderWatcher.addOrderAsync(signedOrder);
+                    const callback = callbackErrorReporter.reportNodeCallbackErrors(done)((_orderState: OrderState) => {
+                        throw new Error('OrderState callback fired for irrelevant order');
+                    });
+                    orderWatcher.subscribe(callback);
+                    const notTheMaker = userAddresses[0];
+                    const anyRecipient = takerAddress;
+                    const transferAmount = new BigNumber(2);
+                    await contractWrappers.erc20Token.transferAsync(
+                        makerTokenAddress,
+                        notTheMaker,
+                        anyRecipient,
+                        transferAmount,
+                    );
+                    setTimeout(() => {
+                        done();
+                    }, TIMEOUT_MS);
+                })().catch(done);
+            });
+            it('should emit orderStateInvalid when makerAddress moves ERC20 balance backing watched order', (done: DoneCallback) => {
+                (async () => {
+                    signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                        makerMultiAssetData,
+                        takerAssetData,
+                        makerAddress,
+                        takerAddress,
+                        fillableAmount,
+                    );
+                    const orderHash = orderHashUtils.getOrderHashHex(signedOrder);
+                    await orderWatcher.addOrderAsync(signedOrder);
+                    const callback = callbackErrorReporter.reportNodeCallbackErrors(done)((orderState: OrderState) => {
+                        expect(orderState.isValid).to.be.false();
+                        const invalidOrderState = orderState as OrderStateInvalid;
+                        expect(invalidOrderState.orderHash).to.be.equal(orderHash);
+                        expect(invalidOrderState.error).to.be.equal(ExchangeContractErrs.InsufficientMakerBalance);
+                    });
+                    orderWatcher.subscribe(callback);
+                    const anyRecipient = takerAddress;
+                    const makerBalance = await contractWrappers.erc20Token.getBalanceAsync(
+                        makerTokenAddress,
+                        makerAddress,
+                    );
+                    await contractWrappers.erc20Token.transferAsync(
+                        makerTokenAddress,
+                        makerAddress,
+                        anyRecipient,
+                        makerBalance,
+                    );
+                })().catch(done);
+            });
+            // TODO(abandeali1): The following test will fail until the MAP has been deployed and activated.
+            it.skip('should emit orderStateInvalid when watched order fully filled', (done: DoneCallback) => {
+                (async () => {
+                    signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                        makerMultiAssetData,
+                        takerAssetData,
+                        makerAddress,
+                        takerAddress,
+                        fillableAmount,
+                    );
+                    const orderHash = orderHashUtils.getOrderHashHex(signedOrder);
+                    await orderWatcher.addOrderAsync(signedOrder);
+
+                    const callback = callbackErrorReporter.reportNodeCallbackErrors(done)((orderState: OrderState) => {
+                        expect(orderState.isValid).to.be.false();
+                        const invalidOrderState = orderState as OrderStateInvalid;
+                        expect(invalidOrderState.orderHash).to.be.equal(orderHash);
+                        expect(invalidOrderState.error).to.be.equal(ExchangeContractErrs.OrderRemainingFillAmountZero);
+                    });
+                    orderWatcher.subscribe(callback);
+
+                    await contractWrappers.exchange.fillOrderAsync(signedOrder, fillableAmount, takerAddress);
+                })().catch(done);
+            });
+        });
     });
 }); // tslint:disable:max-file-line-count
diff --git a/packages/order-watcher/test/order_watcher_web_socket_server_test.ts b/packages/order-watcher/test/order_watcher_web_socket_server_test.ts
index 578e0de61..6894f42fb 100644
--- a/packages/order-watcher/test/order_watcher_web_socket_server_test.ts
+++ b/packages/order-watcher/test/order_watcher_web_socket_server_test.ts
@@ -26,7 +26,7 @@ interface WsMessage {
     data: string;
 }
 
-describe.only('OrderWatcherWebSocketServer', async () => {
+describe('OrderWatcherWebSocketServer', async () => {
     let contractWrappers: ContractWrappers;
     let wsServer: OrderWatcherWebSocketServer;
     let wsClient: WebSocket.w3cwebsocket;
diff --git a/packages/pipeline/package.json b/packages/pipeline/package.json
index a40f3d21c..ab73642ec 100644
--- a/packages/pipeline/package.json
+++ b/packages/pipeline/package.json
@@ -44,7 +44,7 @@
         "@0x/contract-artifacts": "^1.0.1",
         "@0x/contract-wrappers": "^3.0.0",
         "@0x/dev-utils": "^1.0.21",
-        "@0x/order-utils": "^2.0.0",
+        "@0x/order-utils": "^3.0.7",
         "@0x/subproviders": "^2.1.8",
         "@0x/types": "^1.4.1",
         "@0x/utils": "^2.0.8",
diff --git a/packages/pipeline/src/entities/token_order.ts b/packages/pipeline/src/entities/token_order.ts
index 4b8f0abc3..2709747cb 100644
--- a/packages/pipeline/src/entities/token_order.ts
+++ b/packages/pipeline/src/entities/token_order.ts
@@ -1,7 +1,6 @@
 import { BigNumber } from '@0x/utils';
 import { Column, Entity, PrimaryColumn } from 'typeorm';
 
-import { OrderType } from '../types';
 import { bigNumberTransformer, numberToBigIntTransformer } from '../utils';
 
 @Entity({ name: 'token_orderbook_snapshots', schema: 'raw' })
@@ -11,7 +10,7 @@ export class TokenOrderbookSnapshot {
     @PrimaryColumn({ name: 'source' })
     public source!: string;
     @PrimaryColumn({ name: 'order_type' })
-    public orderType!: OrderType;
+    public orderType!: string;
     @PrimaryColumn({ name: 'price', type: 'numeric', transformer: bigNumberTransformer })
     public price!: BigNumber;
     @PrimaryColumn({ name: 'base_asset_symbol' })
diff --git a/packages/pipeline/src/parsers/ddex_orders/index.ts b/packages/pipeline/src/parsers/ddex_orders/index.ts
index d7b97efbe..eeb9c9d5b 100644
--- a/packages/pipeline/src/parsers/ddex_orders/index.ts
+++ b/packages/pipeline/src/parsers/ddex_orders/index.ts
@@ -23,8 +23,12 @@ export function parseDdexOrders(
 ): TokenOrder[] {
     const aggregatedBids = aggregateOrders(ddexOrderbook.bids);
     const aggregatedAsks = aggregateOrders(ddexOrderbook.asks);
-    const parsedBids = aggregatedBids.map(order => parseDdexOrder(ddexMarket, observedTimestamp, 'bid', source, order));
-    const parsedAsks = aggregatedAsks.map(order => parseDdexOrder(ddexMarket, observedTimestamp, 'ask', source, order));
+    const parsedBids = aggregatedBids.map(order =>
+        parseDdexOrder(ddexMarket, observedTimestamp, OrderType.Bid, source, order),
+    );
+    const parsedAsks = aggregatedAsks.map(order =>
+        parseDdexOrder(ddexMarket, observedTimestamp, OrderType.Ask, source, order),
+    );
     return parsedBids.concat(parsedAsks);
 }
 
diff --git a/packages/pipeline/src/parsers/events/exchange_events.ts b/packages/pipeline/src/parsers/events/exchange_events.ts
index e18106c75..9c4a5f89a 100644
--- a/packages/pipeline/src/parsers/events/exchange_events.ts
+++ b/packages/pipeline/src/parsers/events/exchange_events.ts
@@ -5,7 +5,7 @@ import { LogWithDecodedArgs } from 'ethereum-types';
 import * as R from 'ramda';
 
 import { ExchangeCancelEvent, ExchangeCancelUpToEvent, ExchangeFillEvent } from '../../entities';
-import { bigNumbertoStringOrNull } from '../../utils';
+import { bigNumbertoStringOrNull, convertAssetProxyIdToType } from '../../utils';
 
 /**
  * Parses raw event logs for a fill event and returns an array of
@@ -40,9 +40,7 @@ export const parseExchangeCancelUpToEvents: (
  */
 export function _convertToExchangeFillEvent(eventLog: LogWithDecodedArgs<ExchangeFillEventArgs>): ExchangeFillEvent {
     const makerAssetData = assetDataUtils.decodeAssetDataOrThrow(eventLog.args.makerAssetData);
-    const makerAssetType = makerAssetData.assetProxyId === AssetProxyId.ERC20 ? 'erc20' : 'erc721';
     const takerAssetData = assetDataUtils.decodeAssetDataOrThrow(eventLog.args.takerAssetData);
-    const takerAssetType = takerAssetData.assetProxyId === AssetProxyId.ERC20 ? 'erc20' : 'erc721';
     const exchangeFillEvent = new ExchangeFillEvent();
     exchangeFillEvent.contractAddress = eventLog.address as string;
     exchangeFillEvent.blockNumber = eventLog.blockNumber as number;
@@ -59,16 +57,24 @@ export function _convertToExchangeFillEvent(eventLog: LogWithDecodedArgs<Exchang
     exchangeFillEvent.takerFeePaid = eventLog.args.takerFeePaid;
     exchangeFillEvent.orderHash = eventLog.args.orderHash;
     exchangeFillEvent.rawMakerAssetData = eventLog.args.makerAssetData;
-    exchangeFillEvent.makerAssetType = makerAssetType;
+    // tslint:disable-next-line:no-unnecessary-type-assertion
+    exchangeFillEvent.makerAssetType = convertAssetProxyIdToType(makerAssetData.assetProxyId as AssetProxyId);
     exchangeFillEvent.makerAssetProxyId = makerAssetData.assetProxyId;
-    exchangeFillEvent.makerTokenAddress = makerAssetData.tokenAddress;
+    // HACK(abandeali1): this event schema currently does not support multiple maker/taker assets, so we store the first token address from the MultiAssetProxy assetData
+    exchangeFillEvent.makerTokenAddress = assetDataUtils.isMultiAssetData(makerAssetData)
+        ? assetDataUtils.decodeMultiAssetDataRecursively(eventLog.args.makerAssetData).nestedAssetData[0].tokenAddress
+        : makerAssetData.tokenAddress;
     // tslint has a false positive here. Type assertion is required.
     // tslint:disable-next-line:no-unnecessary-type-assertion
     exchangeFillEvent.makerTokenId = bigNumbertoStringOrNull((makerAssetData as ERC721AssetData).tokenId);
     exchangeFillEvent.rawTakerAssetData = eventLog.args.takerAssetData;
-    exchangeFillEvent.takerAssetType = takerAssetType;
+    // tslint:disable-next-line:no-unnecessary-type-assertion
+    exchangeFillEvent.takerAssetType = convertAssetProxyIdToType(takerAssetData.assetProxyId as AssetProxyId);
     exchangeFillEvent.takerAssetProxyId = takerAssetData.assetProxyId;
-    exchangeFillEvent.takerTokenAddress = takerAssetData.tokenAddress;
+    // HACK(abandeali1): this event schema currently does not support multiple maker/taker assets, so we store the first token address from the MultiAssetProxy assetData
+    exchangeFillEvent.takerTokenAddress = assetDataUtils.isMultiAssetData(takerAssetData)
+        ? assetDataUtils.decodeMultiAssetDataRecursively(eventLog.args.takerAssetData).nestedAssetData[0].tokenAddress
+        : takerAssetData.tokenAddress;
     // tslint:disable-next-line:no-unnecessary-type-assertion
     exchangeFillEvent.takerTokenId = bigNumbertoStringOrNull((takerAssetData as ERC721AssetData).tokenId);
     return exchangeFillEvent;
@@ -83,9 +89,7 @@ export function _convertToExchangeCancelEvent(
     eventLog: LogWithDecodedArgs<ExchangeCancelEventArgs>,
 ): ExchangeCancelEvent {
     const makerAssetData = assetDataUtils.decodeAssetDataOrThrow(eventLog.args.makerAssetData);
-    const makerAssetType = makerAssetData.assetProxyId === AssetProxyId.ERC20 ? 'erc20' : 'erc721';
     const takerAssetData = assetDataUtils.decodeAssetDataOrThrow(eventLog.args.takerAssetData);
-    const takerAssetType = takerAssetData.assetProxyId === AssetProxyId.ERC20 ? 'erc20' : 'erc721';
     const exchangeCancelEvent = new ExchangeCancelEvent();
     exchangeCancelEvent.contractAddress = eventLog.address as string;
     exchangeCancelEvent.blockNumber = eventLog.blockNumber as number;
@@ -98,15 +102,23 @@ export function _convertToExchangeCancelEvent(
     exchangeCancelEvent.senderAddress = eventLog.args.senderAddress;
     exchangeCancelEvent.orderHash = eventLog.args.orderHash;
     exchangeCancelEvent.rawMakerAssetData = eventLog.args.makerAssetData;
-    exchangeCancelEvent.makerAssetType = makerAssetType;
+    // tslint:disable-next-line:no-unnecessary-type-assertion
+    exchangeCancelEvent.makerAssetType = convertAssetProxyIdToType(makerAssetData.assetProxyId as AssetProxyId);
     exchangeCancelEvent.makerAssetProxyId = makerAssetData.assetProxyId;
-    exchangeCancelEvent.makerTokenAddress = makerAssetData.tokenAddress;
+    // HACK(abandeali1): this event schema currently does not support multiple maker/taker assets, so we store the first token address from the MultiAssetProxy assetData
+    exchangeCancelEvent.makerTokenAddress = assetDataUtils.isMultiAssetData(makerAssetData)
+        ? assetDataUtils.decodeMultiAssetDataRecursively(eventLog.args.makerAssetData).nestedAssetData[0].tokenAddress
+        : makerAssetData.tokenAddress;
     // tslint:disable-next-line:no-unnecessary-type-assertion
     exchangeCancelEvent.makerTokenId = bigNumbertoStringOrNull((makerAssetData as ERC721AssetData).tokenId);
     exchangeCancelEvent.rawTakerAssetData = eventLog.args.takerAssetData;
-    exchangeCancelEvent.takerAssetType = takerAssetType;
+    // tslint:disable-next-line:no-unnecessary-type-assertion
+    exchangeCancelEvent.takerAssetType = convertAssetProxyIdToType(takerAssetData.assetProxyId as AssetProxyId);
     exchangeCancelEvent.takerAssetProxyId = takerAssetData.assetProxyId;
-    exchangeCancelEvent.takerTokenAddress = takerAssetData.tokenAddress;
+    // HACK(abandeali1): this event schema currently does not support multiple maker/taker assets, so we store the first token address from the MultiAssetProxy assetData
+    exchangeCancelEvent.takerTokenAddress = assetDataUtils.isMultiAssetData(takerAssetData)
+        ? assetDataUtils.decodeMultiAssetDataRecursively(eventLog.args.takerAssetData).nestedAssetData[0].tokenAddress
+        : takerAssetData.tokenAddress;
     // tslint:disable-next-line:no-unnecessary-type-assertion
     exchangeCancelEvent.takerTokenId = bigNumbertoStringOrNull((takerAssetData as ERC721AssetData).tokenId);
     return exchangeCancelEvent;
diff --git a/packages/pipeline/src/parsers/idex_orders/index.ts b/packages/pipeline/src/parsers/idex_orders/index.ts
index dfe27455c..14b871195 100644
--- a/packages/pipeline/src/parsers/idex_orders/index.ts
+++ b/packages/pipeline/src/parsers/idex_orders/index.ts
@@ -2,7 +2,7 @@ import { BigNumber } from '@0x/utils';
 
 import { aggregateOrders } from '../utils';
 
-import { IdexOrder, IdexOrderbook, IdexOrderParam } from '../../data_sources/idex';
+import { IdexOrderbook, IdexOrderParam } from '../../data_sources/idex';
 import { TokenOrderbookSnapshot as TokenOrder } from '../../entities';
 import { OrderType } from '../../types';
 
@@ -21,7 +21,9 @@ export function parseIdexOrders(idexOrderbook: IdexOrderbook, observedTimestamp:
     const idexBidOrder = idexOrderbook.bids[0];
     const parsedBids =
         aggregatedBids.length > 0
-            ? aggregatedBids.map(order => parseIdexOrder(idexBidOrder.params, observedTimestamp, 'bid', source, order))
+            ? aggregatedBids.map(order =>
+                  parseIdexOrder(idexBidOrder.params, observedTimestamp, OrderType.Bid, source, order),
+              )
             : [];
 
     const aggregatedAsks = aggregateOrders(idexOrderbook.asks);
@@ -29,7 +31,9 @@ export function parseIdexOrders(idexOrderbook: IdexOrderbook, observedTimestamp:
     const idexAskOrder = idexOrderbook.asks[0];
     const parsedAsks =
         aggregatedAsks.length > 0
-            ? aggregatedAsks.map(order => parseIdexOrder(idexAskOrder.params, observedTimestamp, 'ask', source, order))
+            ? aggregatedAsks.map(order =>
+                  parseIdexOrder(idexAskOrder.params, observedTimestamp, OrderType.Ask, source, order),
+              )
             : [];
     return parsedBids.concat(parsedAsks);
 }
@@ -62,7 +66,7 @@ export function parseIdexOrder(
     tokenOrder.baseVolume = amount;
     tokenOrder.quoteVolume = price.times(amount);
 
-    if (orderType === 'bid') {
+    if (orderType === OrderType.Bid) {
         tokenOrder.baseAssetSymbol = idexOrderParam.buySymbol;
         tokenOrder.baseAssetAddress = idexOrderParam.tokenBuy;
         tokenOrder.quoteAssetSymbol = idexOrderParam.sellSymbol;
diff --git a/packages/pipeline/src/parsers/oasis_orders/index.ts b/packages/pipeline/src/parsers/oasis_orders/index.ts
index 13997f31b..b71fb65b9 100644
--- a/packages/pipeline/src/parsers/oasis_orders/index.ts
+++ b/packages/pipeline/src/parsers/oasis_orders/index.ts
@@ -23,13 +23,13 @@ export function parseOasisOrders(
     observedTimestamp: number,
     source: string,
 ): TokenOrder[] {
-    const aggregatedBids = aggregateOrders(R.filter(R.propEq('act', 'bid'), oasisOrderbook));
-    const aggregatedAsks = aggregateOrders(R.filter(R.propEq('act', 'ask'), oasisOrderbook));
+    const aggregatedBids = aggregateOrders(R.filter(R.propEq('act', OrderType.Bid), oasisOrderbook));
+    const aggregatedAsks = aggregateOrders(R.filter(R.propEq('act', OrderType.Ask), oasisOrderbook));
     const parsedBids = aggregatedBids.map(order =>
-        parseOasisOrder(oasisMarket, observedTimestamp, 'bid', source, order),
+        parseOasisOrder(oasisMarket, observedTimestamp, OrderType.Bid, source, order),
     );
     const parsedAsks = aggregatedAsks.map(order =>
-        parseOasisOrder(oasisMarket, observedTimestamp, 'ask', source, order),
+        parseOasisOrder(oasisMarket, observedTimestamp, OrderType.Ask, source, order),
     );
     return parsedBids.concat(parsedAsks);
 }
diff --git a/packages/pipeline/src/parsers/paradex_orders/index.ts b/packages/pipeline/src/parsers/paradex_orders/index.ts
index 5ceeb64a4..85990dae4 100644
--- a/packages/pipeline/src/parsers/paradex_orders/index.ts
+++ b/packages/pipeline/src/parsers/paradex_orders/index.ts
@@ -21,10 +21,10 @@ export function parseParadexOrders(
     source: string,
 ): TokenOrder[] {
     const parsedBids = paradexOrderbookResponse.bids.map(order =>
-        parseParadexOrder(paradexMarket, observedTimestamp, 'bid', source, order),
+        parseParadexOrder(paradexMarket, observedTimestamp, OrderType.Bid, source, order),
     );
     const parsedAsks = paradexOrderbookResponse.asks.map(order =>
-        parseParadexOrder(paradexMarket, observedTimestamp, 'ask', source, order),
+        parseParadexOrder(paradexMarket, observedTimestamp, OrderType.Ask, source, order),
     );
     return parsedBids.concat(parsedAsks);
 }
diff --git a/packages/pipeline/src/parsers/sra_orders/index.ts b/packages/pipeline/src/parsers/sra_orders/index.ts
index ef8901e40..13fe632a4 100644
--- a/packages/pipeline/src/parsers/sra_orders/index.ts
+++ b/packages/pipeline/src/parsers/sra_orders/index.ts
@@ -4,7 +4,7 @@ import { AssetProxyId, ERC721AssetData } from '@0x/types';
 import * as R from 'ramda';
 
 import { SraOrder } from '../../entities';
-import { bigNumbertoStringOrNull } from '../../utils';
+import { bigNumbertoStringOrNull, convertAssetProxyIdToType } from '../../utils';
 
 /**
  * Parses a raw order response from an SRA endpoint and returns an array of
@@ -22,9 +22,7 @@ export function parseSraOrders(rawOrdersResponse: OrdersResponse): SraOrder[] {
 export function _convertToEntity(apiOrder: APIOrder): SraOrder {
     // TODO(albrow): refactor out common asset data decoding code.
     const makerAssetData = assetDataUtils.decodeAssetDataOrThrow(apiOrder.order.makerAssetData);
-    const makerAssetType = makerAssetData.assetProxyId === AssetProxyId.ERC20 ? 'erc20' : 'erc721';
     const takerAssetData = assetDataUtils.decodeAssetDataOrThrow(apiOrder.order.takerAssetData);
-    const takerAssetType = takerAssetData.assetProxyId === AssetProxyId.ERC20 ? 'erc20' : 'erc721';
 
     const sraOrder = new SraOrder();
     sraOrder.exchangeAddress = apiOrder.order.exchangeAddress;
@@ -43,16 +41,24 @@ export function _convertToEntity(apiOrder: APIOrder): SraOrder {
     sraOrder.signature = apiOrder.order.signature;
 
     sraOrder.rawMakerAssetData = apiOrder.order.makerAssetData;
-    sraOrder.makerAssetType = makerAssetType;
+    // tslint:disable-next-line:no-unnecessary-type-assertion
+    sraOrder.makerAssetType = convertAssetProxyIdToType(makerAssetData.assetProxyId as AssetProxyId);
     sraOrder.makerAssetProxyId = makerAssetData.assetProxyId;
-    sraOrder.makerTokenAddress = makerAssetData.tokenAddress;
+    // HACK(abandeali1): this event schema currently does not support multiple maker/taker assets, so we store the first token address from the MultiAssetProxy assetData
+    sraOrder.makerTokenAddress = assetDataUtils.isMultiAssetData(makerAssetData)
+        ? assetDataUtils.decodeMultiAssetDataRecursively(apiOrder.order.makerAssetData).nestedAssetData[0].tokenAddress
+        : makerAssetData.tokenAddress;
     // tslint has a false positive here. Type assertion is required.
     // tslint:disable-next-line:no-unnecessary-type-assertion
     sraOrder.makerTokenId = bigNumbertoStringOrNull((makerAssetData as ERC721AssetData).tokenId);
     sraOrder.rawTakerAssetData = apiOrder.order.takerAssetData;
-    sraOrder.takerAssetType = takerAssetType;
+    // tslint:disable-next-line:no-unnecessary-type-assertion
+    sraOrder.takerAssetType = convertAssetProxyIdToType(takerAssetData.assetProxyId as AssetProxyId);
     sraOrder.takerAssetProxyId = takerAssetData.assetProxyId;
-    sraOrder.takerTokenAddress = takerAssetData.tokenAddress;
+    // HACK(abandeali1): this event schema currently does not support multiple maker/taker assets, so we store the first token address from the MultiAssetProxy assetData
+    sraOrder.takerTokenAddress = assetDataUtils.isMultiAssetData(takerAssetData)
+        ? assetDataUtils.decodeMultiAssetDataRecursively(apiOrder.order.takerAssetData).nestedAssetData[0].tokenAddress
+        : takerAssetData.tokenAddress;
     // tslint:disable-next-line:no-unnecessary-type-assertion
     sraOrder.takerTokenId = bigNumbertoStringOrNull((takerAssetData as ERC721AssetData).tokenId);
 
diff --git a/packages/pipeline/src/types.ts b/packages/pipeline/src/types.ts
index e02b42a40..5f2121807 100644
--- a/packages/pipeline/src/types.ts
+++ b/packages/pipeline/src/types.ts
@@ -1,2 +1,9 @@
-export type AssetType = 'erc20' | 'erc721';
-export type OrderType = 'bid' | 'ask';
+export enum AssetType {
+    ERC20 = 'erc20',
+    ERC721 = 'erc721',
+    MultiAsset = 'multiAsset',
+}
+export enum OrderType {
+    Bid = 'bid',
+    Ask = 'ask',
+}
diff --git a/packages/pipeline/src/utils/transformers/asset_proxy_id_types.ts b/packages/pipeline/src/utils/transformers/asset_proxy_id_types.ts
new file mode 100644
index 000000000..2cd05a616
--- /dev/null
+++ b/packages/pipeline/src/utils/transformers/asset_proxy_id_types.ts
@@ -0,0 +1,20 @@
+import { AssetProxyId } from '@0x/types';
+
+import { AssetType } from '../../types';
+
+/**
+ * Converts an assetProxyId to its string equivalent
+ * @param assetProxyId Id of AssetProxy
+ */
+export function convertAssetProxyIdToType(assetProxyId: AssetProxyId): AssetType {
+    switch (assetProxyId) {
+        case AssetProxyId.ERC20:
+            return AssetType.ERC20;
+        case AssetProxyId.ERC721:
+            return AssetType.ERC721;
+        case AssetProxyId.MultiAsset:
+            return AssetType.MultiAsset;
+        default:
+            throw new Error(`${assetProxyId} not a supported assetProxyId`);
+    }
+}
diff --git a/packages/pipeline/src/utils/transformers/index.ts b/packages/pipeline/src/utils/transformers/index.ts
index 232c1c5de..31a4c9223 100644
--- a/packages/pipeline/src/utils/transformers/index.ts
+++ b/packages/pipeline/src/utils/transformers/index.ts
@@ -1,2 +1,3 @@
 export * from './big_number';
 export * from './number_to_bigint';
+export * from './asset_proxy_id_types';
diff --git a/packages/pipeline/test/parsers/ddex_orders/index_test.ts b/packages/pipeline/test/parsers/ddex_orders/index_test.ts
index 4a4a86bf8..f30e86b02 100644
--- a/packages/pipeline/test/parsers/ddex_orders/index_test.ts
+++ b/packages/pipeline/test/parsers/ddex_orders/index_test.ts
@@ -31,13 +31,13 @@ describe('ddex_orders', () => {
                 amountDecimals: 0,
             };
             const observedTimestamp: number = Date.now();
-            const orderType: OrderType = 'bid';
+            const orderType: OrderType = OrderType.Bid;
             const source: string = 'ddex';
 
             const expected = new TokenOrder();
             expected.source = 'ddex';
             expected.observedTimestamp = observedTimestamp;
-            expected.orderType = 'bid';
+            expected.orderType = OrderType.Bid;
             expected.price = new BigNumber(0.5);
             // ddex currently confuses base and quote assets.
             // Switch them to maintain our internal consistency.
diff --git a/packages/pipeline/test/parsers/events/exchange_events_test.ts b/packages/pipeline/test/parsers/events/exchange_events_test.ts
index 5d4b185a5..956ad9ef8 100644
--- a/packages/pipeline/test/parsers/events/exchange_events_test.ts
+++ b/packages/pipeline/test/parsers/events/exchange_events_test.ts
@@ -6,6 +6,7 @@ import 'mocha';
 
 import { ExchangeFillEvent } from '../../../src/entities';
 import { _convertToExchangeFillEvent } from '../../../src/parsers/events/exchange_events';
+import { AssetType } from '../../../src/types';
 import { chaiSetup } from '../../utils/chai_setup';
 
 chaiSetup.configure();
@@ -62,12 +63,12 @@ describe('exchange_events', () => {
             expected.takerFeePaid = new BigNumber('12345');
             expected.orderHash = '0xab12ed2cbaa5615ab690b9da75a46e53ddfcf3f1a68655b5fe0d94c75a1aac4a';
             expected.rawMakerAssetData = '0xf47261b0000000000000000000000000c02aaa39b223fe8d0a0e5c4f27ead9083c756cc2';
-            expected.makerAssetType = 'erc20';
+            expected.makerAssetType = AssetType.ERC20;
             expected.makerAssetProxyId = '0xf47261b0';
             expected.makerTokenAddress = '0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2';
             expected.makerTokenId = null;
             expected.rawTakerAssetData = '0xf47261b0000000000000000000000000e41d2489571d322189246dafa5ebde1f4699f498';
-            expected.takerAssetType = 'erc20';
+            expected.takerAssetType = AssetType.ERC20;
             expected.takerAssetProxyId = '0xf47261b0';
             expected.takerTokenAddress = '0xe41d2489571d322189246dafa5ebde1f4699f498';
             expected.takerTokenId = null;
diff --git a/packages/pipeline/test/parsers/idex_orders/index_test.ts b/packages/pipeline/test/parsers/idex_orders/index_test.ts
index d54ecb9a8..48b019732 100644
--- a/packages/pipeline/test/parsers/idex_orders/index_test.ts
+++ b/packages/pipeline/test/parsers/idex_orders/index_test.ts
@@ -31,13 +31,13 @@ describe('idex_orders', () => {
                 user: '0x212345667543456435324564345643453453333',
             };
             const observedTimestamp: number = Date.now();
-            const orderType: OrderType = 'bid';
+            const orderType: OrderType = OrderType.Bid;
             const source: string = 'idex';
 
             const expected = new TokenOrder();
             expected.source = 'idex';
             expected.observedTimestamp = observedTimestamp;
-            expected.orderType = 'bid';
+            expected.orderType = OrderType.Bid;
             expected.price = new BigNumber(0.5);
             expected.baseAssetSymbol = 'ABC';
             expected.baseAssetAddress = '0x0000000000000000000000000000000000000000';
@@ -65,13 +65,13 @@ describe('idex_orders', () => {
                 user: '0x212345667543456435324564345643453453333',
             };
             const observedTimestamp: number = Date.now();
-            const orderType: OrderType = 'ask';
+            const orderType: OrderType = OrderType.Ask;
             const source: string = 'idex';
 
             const expected = new TokenOrder();
             expected.source = 'idex';
             expected.observedTimestamp = observedTimestamp;
-            expected.orderType = 'ask';
+            expected.orderType = OrderType.Ask;
             expected.price = new BigNumber(0.5);
             expected.baseAssetSymbol = 'ABC';
             expected.baseAssetAddress = '0x0000000000000000000000000000000000000000';
diff --git a/packages/pipeline/test/parsers/oasis_orders/index_test.ts b/packages/pipeline/test/parsers/oasis_orders/index_test.ts
index 433bfb665..401fedff8 100644
--- a/packages/pipeline/test/parsers/oasis_orders/index_test.ts
+++ b/packages/pipeline/test/parsers/oasis_orders/index_test.ts
@@ -27,13 +27,13 @@ describe('oasis_orders', () => {
                 low: 0,
             };
             const observedTimestamp: number = Date.now();
-            const orderType: OrderType = 'bid';
+            const orderType: OrderType = OrderType.Bid;
             const source: string = 'oasis';
 
             const expected = new TokenOrder();
             expected.source = 'oasis';
             expected.observedTimestamp = observedTimestamp;
-            expected.orderType = 'bid';
+            expected.orderType = OrderType.Bid;
             expected.price = new BigNumber(0.5);
             expected.baseAssetSymbol = 'DEF';
             expected.baseAssetAddress = null;
diff --git a/packages/pipeline/test/parsers/paradex_orders/index_test.ts b/packages/pipeline/test/parsers/paradex_orders/index_test.ts
index 6b811b90d..c5dd8751b 100644
--- a/packages/pipeline/test/parsers/paradex_orders/index_test.ts
+++ b/packages/pipeline/test/parsers/paradex_orders/index_test.ts
@@ -32,13 +32,13 @@ describe('paradex_orders', () => {
                 quoteTokenAddress: '0x0000000000000000000000000000000000000000',
             };
             const observedTimestamp: number = Date.now();
-            const orderType: OrderType = 'bid';
+            const orderType: OrderType = OrderType.Bid;
             const source: string = 'paradex';
 
             const expected = new TokenOrder();
             expected.source = 'paradex';
             expected.observedTimestamp = observedTimestamp;
-            expected.orderType = 'bid';
+            expected.orderType = OrderType.Bid;
             expected.price = new BigNumber(0.1245);
             expected.baseAssetSymbol = 'DEF';
             expected.baseAssetAddress = '0xb45df06e38540a675fdb5b598abf2c0dbe9d6b81';
diff --git a/packages/pipeline/test/parsers/sra_orders/index_test.ts b/packages/pipeline/test/parsers/sra_orders/index_test.ts
index ee2842ef3..838171a72 100644
--- a/packages/pipeline/test/parsers/sra_orders/index_test.ts
+++ b/packages/pipeline/test/parsers/sra_orders/index_test.ts
@@ -5,6 +5,7 @@ import 'mocha';
 
 import { SraOrder } from '../../../src/entities';
 import { _convertToEntity } from '../../../src/parsers/sra_orders';
+import { AssetType } from '../../../src/types';
 import { chaiSetup } from '../../utils/chai_setup';
 
 chaiSetup.configure();
@@ -50,12 +51,12 @@ describe('sra_orders', () => {
             expected.signature =
                 '0x1b5a5d672b0d647b5797387ccbb89d822d5d2e873346b014f4ff816ff0783f2a7a0d2824d2d7042ec8ea375bc7f870963e1cb8248f1db03ddf125e27b5963aa11f03';
             expected.rawMakerAssetData = '0xf47261b0000000000000000000000000c02aaa39b223fe8d0a0e5c4f27ead9083c756cc2';
-            expected.makerAssetType = 'erc20';
+            expected.makerAssetType = AssetType.ERC20;
             expected.makerAssetProxyId = '0xf47261b0';
             expected.makerTokenAddress = '0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2';
             expected.makerTokenId = null;
             expected.rawTakerAssetData = '0xf47261b000000000000000000000000042d6622dece394b54999fbd73d108123806f6a18';
-            expected.takerAssetType = 'erc20';
+            expected.takerAssetType = AssetType.ERC20;
             expected.takerAssetProxyId = '0xf47261b0';
             expected.takerTokenAddress = '0x42d6622dece394b54999fbd73d108123806f6a18';
             expected.takerTokenId = null;
diff --git a/packages/types/CHANGELOG.json b/packages/types/CHANGELOG.json
index f1cd2f18e..fdb421e79 100644
--- a/packages/types/CHANGELOG.json
+++ b/packages/types/CHANGELOG.json
@@ -18,6 +18,10 @@
             {
                 "note": "Add RevertReasons for DutchAuction contract",
                 "pr": 1225
+            },
+            {
+                "note": "Add MultiAsset types",
+                "pr": 1363
             }
         ],
         "timestamp": 1544570656
diff --git a/packages/types/src/index.ts b/packages/types/src/index.ts
index 4470dd501..472b56dc2 100644
--- a/packages/types/src/index.ts
+++ b/packages/types/src/index.ts
@@ -110,7 +110,9 @@ export type DoneCallback = (err?: Error) => void;
 
 export interface OrderRelevantState {
     makerBalance: BigNumber;
+    makerIndividualBalances: ObjectMap<BigNumber>;
     makerProxyAllowance: BigNumber;
+    makerIndividualProxyAllowances: ObjectMap<BigNumber>;
     makerFeeBalance: BigNumber;
     makerFeeProxyAllowance: BigNumber;
     filledTakerAssetAmount: BigNumber;
@@ -155,6 +157,7 @@ export enum SignatureType {
 export enum AssetProxyId {
     ERC20 = '0xf47261b0',
     ERC721 = '0x02571792',
+    MultiAsset = '0x94cfcdd7',
 }
 
 export interface ERC20AssetData {
@@ -168,7 +171,21 @@ export interface ERC721AssetData {
     tokenId: BigNumber;
 }
 
-export type AssetData = ERC20AssetData | ERC721AssetData;
+export type SingleAssetData = ERC20AssetData | ERC721AssetData;
+
+export interface MultiAssetData {
+    assetProxyId: string;
+    amounts: BigNumber[];
+    nestedAssetData: string[];
+}
+
+export interface MultiAssetDataWithRecursiveDecoding {
+    assetProxyId: string;
+    amounts: BigNumber[];
+    nestedAssetData: SingleAssetData[];
+}
+
+export type AssetData = SingleAssetData | MultiAssetData | MultiAssetDataWithRecursiveDecoding;
 
 // TODO: DRY. These should be extracted from contract code.
 export enum RevertReason {
diff --git a/packages/utils/CHANGELOG.json b/packages/utils/CHANGELOG.json
index 605151fb6..eb94da8d6 100644
--- a/packages/utils/CHANGELOG.json
+++ b/packages/utils/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.1.1",
+        "changes": [
+            {
+                "note": "Add `should` prefix to names of properties in EncodingRules and DecodingRules",
+                "pr": 1363
+            }
+        ]
+    },
+    {
         "version": "2.1.0",
         "changes": [
             {
diff --git a/packages/utils/src/abi_encoder/abstract_data_types/types/set.ts b/packages/utils/src/abi_encoder/abstract_data_types/types/set.ts
index 089d04659..00059a4b6 100644
--- a/packages/utils/src/abi_encoder/abstract_data_types/types/set.ts
+++ b/packages/utils/src/abi_encoder/abstract_data_types/types/set.ts
@@ -62,7 +62,7 @@ export abstract class AbstractSetDataType extends DataType {
         // Create a new scope in the calldata, before descending into the members of this set.
         calldata.startScope();
         let value: any[] | object;
-        if (rules.structsAsObjects && !this._isArray) {
+        if (rules.shouldConvertStructsToObjects && !this._isArray) {
             // Construct an object with values for each member of the set.
             value = {};
             _.each(this._memberIndexByName, (idx: number, key: string) => {
diff --git a/packages/utils/src/abi_encoder/calldata/calldata.ts b/packages/utils/src/abi_encoder/calldata/calldata.ts
index 5f3eee94a..b08fb71ce 100644
--- a/packages/utils/src/abi_encoder/calldata/calldata.ts
+++ b/packages/utils/src/abi_encoder/calldata/calldata.ts
@@ -49,7 +49,7 @@ export class Calldata {
             throw new Error('expected root');
         }
         // Optimize, if flag set
-        if (this._rules.optimize) {
+        if (this._rules.shouldOptimize) {
             this._optimize();
         }
         // Set offsets
@@ -60,7 +60,9 @@ export class Calldata {
             offset += block.getSizeInBytes();
         }
         // Generate hex string
-        const hexString = this._rules.annotate ? this._toHumanReadableCallData() : this._toEvmCompatibeCallDataHex();
+        const hexString = this._rules.shouldAnnotate
+            ? this._toHumanReadableCallData()
+            : this._toEvmCompatibeCallDataHex();
         return hexString;
     }
     /**
diff --git a/packages/utils/src/abi_encoder/utils/constants.ts b/packages/utils/src/abi_encoder/utils/constants.ts
index 2f43ba04d..36de2dd4f 100644
--- a/packages/utils/src/abi_encoder/utils/constants.ts
+++ b/packages/utils/src/abi_encoder/utils/constants.ts
@@ -11,7 +11,7 @@ export const constants = {
     HEX_SELECTOR_BYTE_OFFSET_IN_CALLDATA: 0,
     // Disable no-object-literal-type-assertion so we can enforce cast
     /* tslint:disable no-object-literal-type-assertion */
-    DEFAULT_DECODING_RULES: { structsAsObjects: false } as DecodingRules,
-    DEFAULT_ENCODING_RULES: { optimize: true, annotate: false } as EncodingRules,
+    DEFAULT_DECODING_RULES: { shouldConvertStructsToObjects: false } as DecodingRules,
+    DEFAULT_ENCODING_RULES: { shouldOptimize: true, shouldAnnotate: false } as EncodingRules,
     /* tslint:enable no-object-literal-type-assertion */
 };
diff --git a/packages/utils/src/abi_encoder/utils/rules.ts b/packages/utils/src/abi_encoder/utils/rules.ts
index 31471e97a..c8d83c3ba 100644
--- a/packages/utils/src/abi_encoder/utils/rules.ts
+++ b/packages/utils/src/abi_encoder/utils/rules.ts
@@ -1,8 +1,8 @@
 export interface DecodingRules {
-    structsAsObjects: boolean;
+    shouldConvertStructsToObjects: boolean;
 }
 
 export interface EncodingRules {
-    optimize?: boolean;
-    annotate?: boolean;
+    shouldOptimize?: boolean;
+    shouldAnnotate?: boolean;
 }
diff --git a/packages/utils/test/abi_encoder/evm_data_types_test.ts b/packages/utils/test/abi_encoder/evm_data_types_test.ts
index 7185851a8..55d582d10 100644
--- a/packages/utils/test/abi_encoder/evm_data_types_test.ts
+++ b/packages/utils/test/abi_encoder/evm_data_types_test.ts
@@ -10,7 +10,7 @@ chaiSetup.configure();
 const expect = chai.expect;
 
 describe('ABI Encoder: EVM Data Type Encoding/Decoding', () => {
-    const encodingRules: AbiEncoder.EncodingRules = { optimize: false }; // optimizer is tested separately.
+    const encodingRules: AbiEncoder.EncodingRules = { shouldOptimize: false }; // optimizer is tested separately.
     describe('Array', () => {
         it('Fixed size; Static elements', async () => {
             // Create DataType object
@@ -194,7 +194,7 @@ describe('ABI Encoder: EVM Data Type Encoding/Decoding', () => {
                 '0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffb0000000000000000000000000000000000000000000000000000000000000001';
             expect(encodedArgs).to.be.equal(expectedEncodedArgs);
             // Decode Encoded Args and validate result
-            const decodingRules: AbiEncoder.DecodingRules = { structsAsObjects: true };
+            const decodingRules: AbiEncoder.DecodingRules = { shouldConvertStructsToObjects: true };
             const decodedArgs = dataType.decode(encodedArgs, decodingRules);
             expect(decodedArgs).to.be.deep.equal(args);
         });
@@ -214,7 +214,7 @@ describe('ABI Encoder: EVM Data Type Encoding/Decoding', () => {
                 '0x00000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000080000000000000000000000000000000000000000000000000000000000000000d48656c6c6f2c20576f726c6421000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000008abcdef0123456789000000000000000000000000000000000000000000000000';
             expect(encodedArgs).to.be.equal(expectedEncodedArgs);
             // Decode Encoded Args and validate result
-            const decodingRules: AbiEncoder.DecodingRules = { structsAsObjects: true };
+            const decodingRules: AbiEncoder.DecodingRules = { shouldConvertStructsToObjects: true };
             const decodedArgs = dataType.decode(encodedArgs, decodingRules);
             expect(decodedArgs).to.be.deep.equal(args);
         });
@@ -234,7 +234,7 @@ describe('ABI Encoder: EVM Data Type Encoding/Decoding', () => {
                 '0x00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002';
             expect(encodedArgs).to.be.equal(expectedEncodedArgs);
             // Decode Encoded Args and validate result
-            const decodingRules: AbiEncoder.DecodingRules = { structsAsObjects: true };
+            const decodingRules: AbiEncoder.DecodingRules = { shouldConvertStructsToObjects: true };
             const decodedArgs = dataType.decode(encodedArgs, decodingRules);
             expect(decodedArgs).to.be.deep.equal(args);
         });
@@ -254,7 +254,7 @@ describe('ABI Encoder: EVM Data Type Encoding/Decoding', () => {
                 '0x0000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002';
             expect(encodedArgs).to.be.equal(expectedEncodedArgs);
             // Decode Encoded Args and validate result
-            const decodingRules: AbiEncoder.DecodingRules = { structsAsObjects: true };
+            const decodingRules: AbiEncoder.DecodingRules = { shouldConvertStructsToObjects: true };
             const decodedArgs = dataType.decode(encodedArgs, decodingRules);
             expect(decodedArgs).to.be.deep.equal(args);
         });
@@ -276,7 +276,7 @@ describe('ABI Encoder: EVM Data Type Encoding/Decoding', () => {
                 '0x0102030400000000000000000000000000000000000000000000000000000000050607080000000000000000000000000000000000000000000000000000000009101112000000000000000000000000000000000000000000000000000000001314151600000000000000000000000000000000000000000000000000000000';
             expect(encodedArgs).to.be.equal(expectedEncodedArgs);
             // Decode Encoded Args and validate result
-            const decodingRules: AbiEncoder.DecodingRules = { structsAsObjects: true };
+            const decodingRules: AbiEncoder.DecodingRules = { shouldConvertStructsToObjects: true };
             const decodedArgs = dataType.decode(encodedArgs, decodingRules);
             expect(decodedArgs).to.be.deep.equal(args);
         });
@@ -298,7 +298,7 @@ describe('ABI Encoder: EVM Data Type Encoding/Decoding', () => {
                 '0x000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000000004010203040000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000040506070800000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000000004091011120000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000041314151600000000000000000000000000000000000000000000000000000000';
             expect(encodedArgs).to.be.equal(expectedEncodedArgs);
             // Decode Encoded Args and validate result
-            const decodingRules: AbiEncoder.DecodingRules = { structsAsObjects: true };
+            const decodingRules: AbiEncoder.DecodingRules = { shouldConvertStructsToObjects: true };
             const decodedArgs = dataType.decode(encodedArgs, decodingRules);
             expect(decodedArgs).to.be.deep.equal(args);
         });
@@ -328,7 +328,7 @@ describe('ABI Encoder: EVM Data Type Encoding/Decoding', () => {
                 '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';
             expect(encodedArgs).to.be.equal(expectedEncodedArgs);
             // Decode Encoded Args and validate result
-            const decodingRules: AbiEncoder.DecodingRules = { structsAsObjects: true };
+            const decodingRules: AbiEncoder.DecodingRules = { shouldConvertStructsToObjects: true };
             const decodedArgs = dataType.decode(encodedArgs, decodingRules);
             expect(decodedArgs).to.be.deep.equal(args);
         });
diff --git a/packages/utils/test/abi_encoder/methods_test.ts b/packages/utils/test/abi_encoder/methods_test.ts
index 837020883..a0525967e 100644
--- a/packages/utils/test/abi_encoder/methods_test.ts
+++ b/packages/utils/test/abi_encoder/methods_test.ts
@@ -10,7 +10,7 @@ chaiSetup.configure();
 const expect = chai.expect;
 
 describe('ABI Encoder: Method Encoding / Decoding', () => {
-    const encodingRules: AbiEncoder.EncodingRules = { optimize: false }; // optimizer is tested separately.
+    const encodingRules: AbiEncoder.EncodingRules = { shouldOptimize: false }; // optimizer is tested separately.
     it('Types with default widths', async () => {
         // Generate calldata
         const method = new AbiEncoder.Method(AbiSamples.typesWithDefaultWidthsAbi);
@@ -360,7 +360,7 @@ describe('ABI Encoder: Method Encoding / Decoding', () => {
             '0x4b49031c000000000000000000000000000000000000000000000000000000000000007f000000000000000000000000000000000000000000000000000000000000000e0000000000000000000000000000000000000000000000000000000000000036000000000000000000000000000000000000000000000000000000000000012000000000000000000000000000000000000000000000000000000000000002800000000000000000000000000000000000000000000000000000000000000440000000000000000000000000000000000000000000000000000000000000088000000000000000000000000000000000000000000000000000000000000009800000000000000000000000000000000000000000000000000000000000000ae0000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000a00000000000000000000000000000000000000000000000000000000000000034746865206c6974746c6520706970696e67207069706572207069706564206120706970696e6720706970706572207061707065720000000000000000000000000000000000000000000000000000000000000000000000000000000000000081746865206b6964206b6e6f777320686f7720746f20777269746520706f656d732c20776861742063616e204920736179202d2d2049206775657373207468657265732061206c6f74204920636f756c642073617920746f2074727920746f2066696c6c2074686973206c696e6520776974682061206c6f74206f6620746578742e000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000003000000000000000000000000000000000000000000000000000000000000006000000000000000000000000000000000000000000000000000000000000000a0000000000000000000000000000000000000000000000000000000000000014000000000000000000000000000000000000000000000000000000000000000163874563783498732482743928742389723894723984700000000000000000000000000000000000000000000000000000000000000000000000000000000006e72834723982374239847239847298472489274987489742847289472394874987498478743294237434923473298472398423748923748923748923472389472894789474893742894728947389427498237432987423894723894732894723894372498237498237428934723980000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000027283473298473248923749238742398742398472894729843278942374982374892374892743982000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000003000000000000000000000000000000000000000000000000000000000000006000000000000000000000000000000000000000000000000000000000000002800000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000000500000000000000000000000000000000000000000000000000000000000000a000000000000000000000000000000000000000000000000000000000000000e00000000000000000000000000000000000000000000000000000000000000120000000000000000000000000000000000000000000000000000000000000018000000000000000000000000000000000000000000000000000000000000001c0000000000000000000000000000000000000000000000000000000000000000b736f6d6520737472696e670000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000013736f6d6520616e6f7468657220737472696e67000000000000000000000000000000000000000000000000000000000000000000000000000000000000000024746865726520617265206a75737420746f6f206d616e7920737472696e6773757020696e0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000046865726500000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002079616c6c2067686f6e6e61206d616b65206d65206c6f7365206d79206d696e640000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000a00000000000000000000000000000000000000000000000000000000000000034746865206c6974746c6520706970696e67207069706572207069706564206120706970696e6720706970706572207061707065720000000000000000000000000000000000000000000000000000000000000000000000000000000000000081746865206b6964206b6e6f777320686f7720746f20777269746520706f656d732c20776861742063616e204920736179202d2d2049206775657373207468657265732061206c6f74204920636f756c642073617920746f2074727920746f2066696c6c2074686973206c696e6520776974682061206c6f74206f6620746578742e00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000f0ac511500000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000081746865206b6964206b6e6f777320686f7720746f20777269746520706f656d732c20776861742063616e204920736179202d2d2049206775657373207468657265732061206c6f74204920636f756c642073617920746f2074727920746f2066696c6c2074686973206c696e6520776974682061206c6f74206f6620746578742e0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000003d69d500000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000000100000000000000000000000000e41d2489571d322189246dafa5ebde1f4699f498000000000000000000000000000000000000000000000000000000000000004e616b64686a61736a6b646861736a6b6c647368646a6168646b6a73616864616a6b73646873616a6b646873616a6b646861646a6b617368646a6b73616468616a6b646873616a6b64687361646a6b000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002829384723894723843743289742389472398473289472348927489274894738427428947389facdea0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000001a0000000000000000000000000000000000000000000000000000000000089b51500000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000000100000000000000000000000000746dafa5ebde1f4699f4981d3221892e41d24895000000000000000000000000000000000000000000000000000000000000004e6b73646873616a6b646873616a6b646861646a6b617368646a6b73616468616a6b646873616a6b64687361646a6b616b64686a61736a6b646861736a6b6c647368646a6168646b6a73616864616a000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002829384723894398473289472348927489272384374328974238947274894738427428947389facde100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000fa3150000000000000000000000000000000000000000000000000000000000000080000000000000000000000000000000000000000000000000000000000000010000000000000000000000000089571d322189e415ebde1f4699f498d24246dafa000000000000000000000000000000000000000000000000000000000000004e73646873616a6b646873616a6b646861646a6b617368646a616b64686a61736a6b646861736a6b6c647368646a6168646b6a73616864616a6b6b73616468616a6b646873616a6b64687361646a6b000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002838947238437432829384729742389472398473289472348927489274894738427428947389facdef000000000000000000000000000000000000000000000000';
         expect(calldata).to.be.equal(expectedCalldata);
         // Validate decoding
-        const decodedValue = method.decode(calldata, { structsAsObjects: true });
+        const decodedValue = method.decode(calldata, { shouldConvertStructsToObjects: true });
         expect(decodedValue).to.be.deep.equal(args);
     });
 });
diff --git a/packages/utils/test/abi_encoder/optimizer_test.ts b/packages/utils/test/abi_encoder/optimizer_test.ts
index 18aa6549a..ee0654ec3 100644
--- a/packages/utils/test/abi_encoder/optimizer_test.ts
+++ b/packages/utils/test/abi_encoder/optimizer_test.ts
@@ -10,7 +10,7 @@ chaiSetup.configure();
 const expect = chai.expect;
 
 describe('ABI Encoder: Optimized Method Encoding/Decoding', () => {
-    const encodingRules: AbiEncoder.EncodingRules = { optimize: true };
+    const encodingRules: AbiEncoder.EncodingRules = { shouldOptimize: true };
     it('Duplicate Dynamic Arrays with Static Elements', async () => {
         // Generate calldata
         const method = new AbiEncoder.Method(OptimizedAbis.duplicateDynamicArraysWithStaticElements);
@@ -206,7 +206,7 @@ describe('ABI Encoder: Optimized Method Encoding/Decoding', () => {
         const twoDimArray2 = twoDimArray1;
         const args = [twoDimArray1, twoDimArray2];
         // Validata calldata
-        const optimizedCalldata = method.encode(args, { optimize: false });
+        const optimizedCalldata = method.encode(args, { shouldOptimize: false });
         const expectedOptimizedCalldata =
             '0x0d28c4f9000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000002c0000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000120000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000080000000000000000000000000000000000000000000000000000000000000000548656c6c6f0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000005576f726c640000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000003000000000000000000000000000000000000000000000000000000000000006000000000000000000000000000000000000000000000000000000000000000a000000000000000000000000000000000000000000000000000000000000000e00000000000000000000000000000000000000000000000000000000000000003466f6f00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000003426172000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000035a61610000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000120000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000080000000000000000000000000000000000000000000000000000000000000000548656c6c6f0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000005576f726c640000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000003000000000000000000000000000000000000000000000000000000000000006000000000000000000000000000000000000000000000000000000000000000a000000000000000000000000000000000000000000000000000000000000000e00000000000000000000000000000000000000000000000000000000000000003466f6f00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000003426172000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000035a61610000000000000000000000000000000000000000000000000000000000';
         expect(optimizedCalldata).to.be.equal(expectedOptimizedCalldata);
diff --git a/packages/utils/test/abi_encoder/return_values_test.ts b/packages/utils/test/abi_encoder/return_values_test.ts
index a8cdd6ca3..104c7f5db 100644
--- a/packages/utils/test/abi_encoder/return_values_test.ts
+++ b/packages/utils/test/abi_encoder/return_values_test.ts
@@ -10,7 +10,7 @@ chaiSetup.configure();
 const expect = chai.expect;
 
 describe('ABI Encoder: Return Value Encoding/Decoding', () => {
-    const encodingRules: AbiEncoder.EncodingRules = { optimize: false }; // optimizer is tested separately.
+    const encodingRules: AbiEncoder.EncodingRules = { shouldOptimize: false }; // optimizer is tested separately.
     it('No Return Value', async () => {
         // Decode return value
         const method = new AbiEncoder.Method(ReturnValueAbis.noReturnValues);
diff --git a/yarn.lock b/yarn.lock
index 0953cbc74..b86969e3b 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -507,7 +507,7 @@
     lodash "^4.17.5"
     uuid "^3.1.0"
 
-"@0x/order-utils@^2.0.0", "@0x/order-utils@^2.0.1":
+"@0x/order-utils@^2.0.1":
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/@0x/order-utils/-/order-utils-2.0.1.tgz#8c46d7aeb9e2cce54a0822824c12427cbe5f7eb4"
   dependencies:
@@ -2100,10 +2100,6 @@ aes-js@^0.2.3:
   version "0.2.4"
   resolved "https://registry.yarnpkg.com/aes-js/-/aes-js-0.2.4.tgz#94b881ab717286d015fa219e08fb66709dda5a3d"
 
-aes-js@^3.1.1:
-  version "3.1.2"
-  resolved "https://registry.npmjs.org/aes-js/-/aes-js-3.1.2.tgz#db9aabde85d5caabbfc0d4f2a4446960f627146a"
-
 agent-base@4, agent-base@^4.1.0, agent-base@~4.2.0:
   version "4.2.1"
   resolved "https://registry.yarnpkg.com/agent-base/-/agent-base-4.2.1.tgz#d89e5999f797875674c07d87f260fc41e83e8ca9"
@@ -3669,7 +3665,7 @@ bs-logger@0.x:
   dependencies:
     fast-json-stable-stringify "^2.0.0"
 
-bs58@=4.0.1, bs58@^4.0.0:
+bs58@=4.0.1:
   version "4.0.1"
   resolved "https://registry.yarnpkg.com/bs58/-/bs58-4.0.1.tgz#be161e76c354f6f788ae4071f63f34e8c4f0a42a"
   dependencies:
@@ -3692,14 +3688,6 @@ bs58check@^1.0.8:
     bs58 "^3.1.0"
     create-hash "^1.1.0"
 
-bs58check@^2.1.2:
-  version "2.1.2"
-  resolved "https://registry.npmjs.org/bs58check/-/bs58check-2.1.2.tgz#53b018291228d82a5aa08e7d796fdafda54aebfc"
-  dependencies:
-    bs58 "^4.0.0"
-    create-hash "^1.1.0"
-    safe-buffer "^5.1.2"
-
 bser@^2.0.0:
   version "2.0.0"
   resolved "https://registry.npmjs.org/bser/-/bser-2.0.0.tgz#9ac78d3ed5d915804fd87acb158bc797147a1719"
@@ -6410,19 +6398,6 @@ ethereumjs-wallet@0.6.0:
     utf8 "^2.1.1"
     uuid "^2.0.1"
 
-ethereumjs-wallet@~0.6.0:
-  version "0.6.2"
-  resolved "https://registry.npmjs.org/ethereumjs-wallet/-/ethereumjs-wallet-0.6.2.tgz#67244b6af3e8113b53d709124b25477b64aeccda"
-  dependencies:
-    aes-js "^3.1.1"
-    bs58check "^2.1.2"
-    ethereumjs-util "^5.2.0"
-    hdkey "^1.0.0"
-    safe-buffer "^5.1.2"
-    scrypt.js "^0.2.0"
-    utf8 "^3.0.0"
-    uuid "^3.3.2"
-
 ethers@~4.0.4:
   version "4.0.4"
   resolved "https://registry.yarnpkg.com/ethers/-/ethers-4.0.4.tgz#d3f85e8b27f4b59537e06526439b0fb15b44dc65"
@@ -7339,7 +7314,7 @@ ganache-core@0xProject/ganache-core#monorepo-dep:
     ethereumjs-tx "0xProject/ethereumjs-tx#fake-tx-include-signature-by-default"
     ethereumjs-util "^5.2.0"
     ethereumjs-vm "2.3.5"
-    ethereumjs-wallet "~0.6.0"
+    ethereumjs-wallet "0.6.0"
     fake-merkle-patricia-tree "~1.0.1"
     heap "~0.2.6"
     js-scrypt "^0.2.0"
@@ -8077,14 +8052,6 @@ hdkey@^0.7.0, hdkey@^0.7.1:
     coinstring "^2.0.0"
     secp256k1 "^3.0.1"
 
-hdkey@^1.0.0:
-  version "1.1.0"
-  resolved "https://registry.npmjs.org/hdkey/-/hdkey-1.1.0.tgz#e74e7b01d2c47f797fa65d1d839adb7a44639f29"
-  dependencies:
-    coinstring "^2.0.0"
-    safe-buffer "^5.1.1"
-    secp256k1 "^3.0.1"
-
 he@1.1.1:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/he/-/he-1.1.1.tgz#93410fd21b009735151f8868c2f271f3427e23fd"
@@ -16679,10 +16646,6 @@ utf8@^2.1.1:
   version "2.1.2"
   resolved "https://registry.yarnpkg.com/utf8/-/utf8-2.1.2.tgz#1fa0d9270e9be850d9b05027f63519bf46457d96"
 
-utf8@^3.0.0:
-  version "3.0.0"
-  resolved "https://registry.npmjs.org/utf8/-/utf8-3.0.0.tgz#f052eed1364d696e769ef058b183df88c87f69d1"
-
 util-deprecate@~1.0.1:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/util-deprecate/-/util-deprecate-1.0.2.tgz#450d4dc9fa70de732762fbd2d4a28981419a0ccf"