Merge pull request #413 from 0xProject/feature/ethers-contracts

abi-gen V2 abi and ethers-contracts

77 files changed, 729 insertions, 543 deletions

diff --git a/packages/0x.js/CHANGELOG.md b/packages/0x.js/CHANGELOG.md
index 2710788e0..b882a1b31 100644
--- a/packages/0x.js/CHANGELOG.md
+++ b/packages/0x.js/CHANGELOG.md
@@ -4,6 +4,7 @@
 
     * Validate and lowercase all addresses in public methods (#373)
     * Improve validation to force passing contract addresses on private networks (#385)
+    * Change `LogErrorContractEventArgs.errorId` type from `BigNumber` to `number` (#413)
     * Rename all public `_unsubscribeAll` methods to `unsubscribeAll` (#415)
 
 ## v0.32.2 - _February 9, 2018_
diff --git a/packages/0x.js/contract_templates/partials/call.handlebars b/packages/0x.js/contract_templates/partials/call.handlebars
deleted file mode 100644
index 0475136f0..000000000
--- a/packages/0x.js/contract_templates/partials/call.handlebars
+++ /dev/null
@@ -1,15 +0,0 @@
-public {{this.name}} = {
-    async callAsync(
-    {{> typed_params inputs=inputs}}
-        defaultBlock?: Web3.BlockParam,
-    ): Promise<{{> return_type outputs=outputs}}> {
-        const self = this as {{contractName}}Contract;
-        const result = await promisify<{{> return_type outputs=outputs}}>(
-            self._web3ContractInstance.{{this.name}}.call,
-            self._web3ContractInstance,
-        )(
-            {{> params inputs=inputs}}
-        );
-        return result;
-    },
-};
diff --git a/packages/0x.js/contract_templates/partials/return_type.handlebars b/packages/0x.js/contract_templates/partials/return_type.handlebars
deleted file mode 100644
index 383961a40..000000000
--- a/packages/0x.js/contract_templates/partials/return_type.handlebars
+++ /dev/null
@@ -1,6 +0,0 @@
-{{#singleReturnValue}}
-{{#returnType outputs.0.type}}{{/returnType}}
-{{/singleReturnValue}}
-{{^singleReturnValue}}
-[{{#each outputs}}{{#returnType type}}{{/returnType}}{{#unless @last}}, {{/unless}}{{/each}}]
-{{/singleReturnValue}}
diff --git a/packages/0x.js/contract_templates/partials/typed_params.handlebars b/packages/0x.js/contract_templates/partials/typed_params.handlebars
deleted file mode 100644
index 3ea4b2e95..000000000
--- a/packages/0x.js/contract_templates/partials/typed_params.handlebars
+++ /dev/null
@@ -1,3 +0,0 @@
-{{#each inputs}}
-    {{name}}: {{#parameterType type}}{{/parameterType}},
-{{/each}}
diff --git a/packages/0x.js/package.json b/packages/0x.js/package.json
index 4fb0eb6ac..96ba28b75 100644
--- a/packages/0x.js/package.json
+++ b/packages/0x.js/package.json
@@ -17,7 +17,7 @@
         "build": "run-p build:umd:prod build:commonjs; exit 0;",
         "docs:json": "typedoc --excludePrivate --excludeExternals --target ES5 --json $JSON_FILE_PATH $PROJECT_DIR",
         "upload_docs_json": "aws s3 cp generated_docs/index.json $S3_URL --profile 0xproject --grants read=uri=http://acs.amazonaws.com/groups/global/AllUsers --content-type application/json",
-        "generate_contract_wrappers": "node ../abi-gen/lib/index.js --abis 'src/artifacts/@(Exchange|Token|TokenTransferProxy|EtherToken|TokenRegistry|DummyToken).json' --template contract_templates/contract.handlebars --partials 'contract_templates/partials/**/*.handlebars' --output src/contract_wrappers/generated",
+        "generate_contract_wrappers": "node ../abi-gen/lib/index.js --abis 'src/artifacts/@(Exchange|Token|TokenTransferProxy|EtherToken|TokenRegistry|DummyToken).json' --template ../contract_templates/contract.handlebars --partials '../contract_templates/partials/**/*.handlebars' --output src/contract_wrappers/generated --backend ethers && prettier --write 'src/contract_wrappers/generated/**.ts'",
         "lint": "tslint --project . 'src/**/*.ts' 'test/**/*.ts'",
         "test:circleci": "run-s test:coverage report_test_coverage",
         "test": "run-s clean test:commonjs",
@@ -77,6 +77,7 @@
         "types-bn": "^0.0.1",
         "typescript": "2.7.1",
         "web3-provider-engine": "^13.0.1",
+        "ethers-typescript-typings": "^0.0.1",
         "web3-typescript-typings": "^0.9.11",
         "webpack": "^3.1.0"
     },
@@ -88,6 +89,7 @@
         "@0xproject/web3-wrapper": "^0.1.14",
         "bintrees": "^1.0.2",
         "bn.js": "^4.11.8",
+        "ethers-contracts": "^2.2.1",
         "ethereumjs-abi": "^0.6.4",
         "ethereumjs-blockstream": "^2.0.6",
         "ethereumjs-util": "^5.1.1",
diff --git a/packages/0x.js/src/contract_wrappers/contract_wrapper.ts b/packages/0x.js/src/contract_wrappers/contract_wrapper.ts
index b313273b5..ad7727de5 100644
--- a/packages/0x.js/src/contract_wrappers/contract_wrapper.ts
+++ b/packages/0x.js/src/contract_wrappers/contract_wrapper.ts
@@ -108,10 +108,10 @@ export class ContractWrapper {
         const logWithDecodedArgs = this._abiDecoder.tryToDecodeLogOrNoop(log);
         return logWithDecodedArgs;
     }
-    protected async _instantiateContractIfExistsAsync(
+    protected async _getContractAbiAndAddressFromArtifactsAsync(
         artifact: Artifact,
         addressIfExists?: string,
-    ): Promise<Web3.ContractInstance> {
+    ): Promise<[Web3.ContractAbi, string]> {
         let contractAddress: string;
         if (_.isUndefined(addressIfExists)) {
             if (_.isUndefined(artifact.networks[this._networkId])) {
@@ -125,8 +125,8 @@ export class ContractWrapper {
         if (!doesContractExist) {
             throw new Error(CONTRACT_NAME_TO_NOT_FOUND_ERROR[artifact.contract_name]);
         }
-        const contractInstance = this._web3Wrapper.getContractInstance(artifact.abi, contractAddress);
-        return contractInstance;
+        const abiAndAddress: [Web3.ContractAbi, string] = [artifact.abi, contractAddress];
+        return abiAndAddress;
     }
     protected _getContractAddress(artifact: Artifact, addressIfExists?: string): string {
         if (_.isUndefined(addressIfExists)) {
diff --git a/packages/0x.js/src/contract_wrappers/ether_token_wrapper.ts b/packages/0x.js/src/contract_wrappers/ether_token_wrapper.ts
index 4807eff33..42f8213a2 100644
--- a/packages/0x.js/src/contract_wrappers/ether_token_wrapper.ts
+++ b/packages/0x.js/src/contract_wrappers/ether_token_wrapper.ts
@@ -187,11 +187,11 @@ export class EtherTokenWrapper extends ContractWrapper {
         if (!_.isUndefined(etherTokenContract)) {
             return etherTokenContract;
         }
-        const web3ContractInstance = await this._instantiateContractIfExistsAsync(
+        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
             artifacts.EtherTokenArtifact,
             etherTokenAddress,
         );
-        const contractInstance = new EtherTokenContract(web3ContractInstance, this._web3Wrapper.getContractDefaults());
+        const contractInstance = new EtherTokenContract(this._web3Wrapper, abi, address);
         etherTokenContract = contractInstance;
         this._etherTokenContractsByAddress[etherTokenAddress] = etherTokenContract;
         return etherTokenContract;
diff --git a/packages/0x.js/src/contract_wrappers/exchange_wrapper.ts b/packages/0x.js/src/contract_wrappers/exchange_wrapper.ts
index 6bafc84c1..20b46c6bc 100644
--- a/packages/0x.js/src/contract_wrappers/exchange_wrapper.ts
+++ b/packages/0x.js/src/contract_wrappers/exchange_wrapper.ts
@@ -108,8 +108,10 @@ export class ExchangeWrapper extends ContractWrapper {
 
         const exchangeContract = await this._getExchangeContractAsync();
         const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
+        const txData = {};
         let unavailableTakerTokenAmount = await exchangeContract.getUnavailableTakerTokenAmount.callAsync(
             orderHash,
+            txData,
             defaultBlock,
         );
         // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
@@ -127,7 +129,8 @@ export class ExchangeWrapper extends ContractWrapper {
 
         const exchangeContract = await this._getExchangeContractAsync();
         const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
-        let fillAmountInBaseUnits = await exchangeContract.filled.callAsync(orderHash, defaultBlock);
+        const txData = {};
+        let fillAmountInBaseUnits = await exchangeContract.filled.callAsync(orderHash, txData, defaultBlock);
         // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
         fillAmountInBaseUnits = new BigNumber(fillAmountInBaseUnits);
         return fillAmountInBaseUnits;
@@ -144,7 +147,8 @@ export class ExchangeWrapper extends ContractWrapper {
 
         const exchangeContract = await this._getExchangeContractAsync();
         const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
-        let cancelledAmountInBaseUnits = await exchangeContract.cancelled.callAsync(orderHash, defaultBlock);
+        const txData = {};
+        let cancelledAmountInBaseUnits = await exchangeContract.cancelled.callAsync(orderHash, txData, defaultBlock);
         // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
         cancelledAmountInBaseUnits = new BigNumber(cancelledAmountInBaseUnits);
         return cancelledAmountInBaseUnits;
@@ -858,7 +862,7 @@ export class ExchangeWrapper extends ContractWrapper {
         });
         if (!_.isUndefined(errLog)) {
             const logArgs = (errLog as LogWithDecodedArgs<LogErrorContractEventArgs>).args;
-            const errCode = logArgs.errorId.toNumber();
+            const errCode = logArgs.errorId;
             const errMessage = this._exchangeContractErrCodesToMsg[errCode];
             throw new Error(errMessage);
         }
@@ -906,11 +910,11 @@ export class ExchangeWrapper extends ContractWrapper {
         if (!_.isUndefined(this._exchangeContractIfExists)) {
             return this._exchangeContractIfExists;
         }
-        const web3ContractInstance = await this._instantiateContractIfExistsAsync(
+        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
             artifacts.ExchangeArtifact,
             this._contractAddressIfExists,
         );
-        const contractInstance = new ExchangeContract(web3ContractInstance, this._web3Wrapper.getContractDefaults());
+        const contractInstance = new ExchangeContract(this._web3Wrapper, abi, address);
         this._exchangeContractIfExists = contractInstance;
         return this._exchangeContractIfExists;
     }
diff --git a/packages/0x.js/src/contract_wrappers/generated/.gitignore b/packages/0x.js/src/contract_wrappers/generated/.gitignore
index 834808b48..72e8ffc0d 100644
--- a/packages/0x.js/src/contract_wrappers/generated/.gitignore
+++ b/packages/0x.js/src/contract_wrappers/generated/.gitignore
@@ -1,6 +1 @@
-dummy_token.ts
-ether_token.ts
-exchange.ts
-token_registry.ts
-token_transfer_proxy.ts
-token.ts
+*
diff --git a/packages/0x.js/src/contract_wrappers/generated/base_contract.ts b/packages/0x.js/src/contract_wrappers/generated/base_contract.ts
deleted file mode 100644
index d8fac7eea..000000000
--- a/packages/0x.js/src/contract_wrappers/generated/base_contract.ts
+++ /dev/null
@@ -1,33 +0,0 @@
-import {TxData, TxDataPayable} from '@0xproject/types';
-import * as _ from 'lodash';
-import * as Web3 from 'web3';
-
-export class BaseContract {
-    protected _web3ContractInstance: Web3.ContractInstance;
-    protected _defaults: Partial<TxData>;
-    protected async _applyDefaultsToTxDataAsync<T extends TxData|TxDataPayable>(
-        txData: T,
-        estimateGasAsync?: (txData: T) => Promise<number>,
-    ): Promise<TxData> {
-        // Gas amount sourced with the following priorities:
-        // 1. Optional param passed in to public method call
-        // 2. Global config passed in at library instantiation
-        // 3. Gas estimate calculation + safety margin
-        const removeUndefinedProperties = _.pickBy;
-        const txDataWithDefaults = {
-            ...removeUndefinedProperties(this._defaults),
-            ...removeUndefinedProperties(txData as any),
-            // HACK: TS can't prove that T is spreadable.
-            // Awaiting https://github.com/Microsoft/TypeScript/pull/13288 to be merged
-        };
-        if (_.isUndefined(txDataWithDefaults.gas) && !_.isUndefined(estimateGasAsync)) {
-            const estimatedGas = await estimateGasAsync(txData);
-            txDataWithDefaults.gas = estimatedGas;
-        }
-        return txDataWithDefaults;
-    }
-    constructor(web3ContractInstance: Web3.ContractInstance, defaults: Partial<TxData>) {
-        this._web3ContractInstance = web3ContractInstance;
-        this._defaults = defaults;
-    }
-}
diff --git a/packages/0x.js/src/contract_wrappers/token_registry_wrapper.ts b/packages/0x.js/src/contract_wrappers/token_registry_wrapper.ts
index f0ae5f33c..e1806c6f2 100644
--- a/packages/0x.js/src/contract_wrappers/token_registry_wrapper.ts
+++ b/packages/0x.js/src/contract_wrappers/token_registry_wrapper.ts
@@ -23,7 +23,7 @@ export class TokenRegistryWrapper extends ContractWrapper {
             address: metadata[0],
             name: metadata[1],
             symbol: metadata[2],
-            decimals: metadata[3].toNumber(),
+            decimals: metadata[3],
         };
         return token;
     }
@@ -50,7 +50,8 @@ export class TokenRegistryWrapper extends ContractWrapper {
     public async getTokenAddressesAsync(): Promise<string[]> {
         const tokenRegistryContract = await this._getTokenRegistryContractAsync();
         const addresses = await tokenRegistryContract.getTokenAddresses.callAsync();
-        return addresses;
+        const lowerCaseAddresses = _.map(addresses, address => address.toLowerCase());
+        return lowerCaseAddresses;
     }
     /**
      * Retrieves a token by address currently listed in the Token Registry smart contract
@@ -116,14 +117,11 @@ export class TokenRegistryWrapper extends ContractWrapper {
         if (!_.isUndefined(this._tokenRegistryContractIfExists)) {
             return this._tokenRegistryContractIfExists;
         }
-        const web3ContractInstance = await this._instantiateContractIfExistsAsync(
+        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
             artifacts.TokenRegistryArtifact,
             this._contractAddressIfExists,
         );
-        const contractInstance = new TokenRegistryContract(
-            web3ContractInstance,
-            this._web3Wrapper.getContractDefaults(),
-        );
+        const contractInstance = new TokenRegistryContract(this._web3Wrapper, abi, address);
         this._tokenRegistryContractIfExists = contractInstance;
         return this._tokenRegistryContractIfExists;
     }
diff --git a/packages/0x.js/src/contract_wrappers/token_transfer_proxy_wrapper.ts b/packages/0x.js/src/contract_wrappers/token_transfer_proxy_wrapper.ts
index f0cbf364d..211c7dfb4 100644
--- a/packages/0x.js/src/contract_wrappers/token_transfer_proxy_wrapper.ts
+++ b/packages/0x.js/src/contract_wrappers/token_transfer_proxy_wrapper.ts
@@ -59,14 +59,11 @@ export class TokenTransferProxyWrapper extends ContractWrapper {
         if (!_.isUndefined(this._tokenTransferProxyContractIfExists)) {
             return this._tokenTransferProxyContractIfExists;
         }
-        const web3ContractInstance = await this._instantiateContractIfExistsAsync(
+        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
             artifacts.TokenTransferProxyArtifact,
             this._contractAddressIfExists,
         );
-        const contractInstance = new TokenTransferProxyContract(
-            web3ContractInstance,
-            this._web3Wrapper.getContractDefaults(),
-        );
+        const contractInstance = new TokenTransferProxyContract(this._web3Wrapper, abi, address);
         this._tokenTransferProxyContractIfExists = contractInstance;
         return this._tokenTransferProxyContractIfExists;
     }
diff --git a/packages/0x.js/src/contract_wrappers/token_wrapper.ts b/packages/0x.js/src/contract_wrappers/token_wrapper.ts
index 11a7670c0..0f688cb71 100644
--- a/packages/0x.js/src/contract_wrappers/token_wrapper.ts
+++ b/packages/0x.js/src/contract_wrappers/token_wrapper.ts
@@ -51,7 +51,8 @@ export class TokenWrapper extends ContractWrapper {
 
         const tokenContract = await this._getTokenContractAsync(normalizedTokenAddress);
         const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
-        let balance = await tokenContract.balanceOf.callAsync(normalizedOwnerAddress, defaultBlock);
+        const txData = {};
+        let balance = await tokenContract.balanceOf.callAsync(normalizedOwnerAddress, txData, defaultBlock);
         // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
         balance = new BigNumber(balance);
         return balance;
@@ -146,9 +147,11 @@ export class TokenWrapper extends ContractWrapper {
 
         const tokenContract = await this._getTokenContractAsync(normalizedTokenAddress);
         const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
+        const txData = {};
         let allowanceInBaseUnits = await tokenContract.allowance.callAsync(
             normalizedOwnerAddress,
             normalizedSpenderAddress,
+            txData,
             defaultBlock,
         );
         // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
@@ -419,11 +422,11 @@ export class TokenWrapper extends ContractWrapper {
         if (!_.isUndefined(tokenContract)) {
             return tokenContract;
         }
-        const web3ContractInstance = await this._instantiateContractIfExistsAsync(
+        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
             artifacts.TokenArtifact,
             normalizedTokenAddress,
         );
-        const contractInstance = new TokenContract(web3ContractInstance, this._web3Wrapper.getContractDefaults());
+        const contractInstance = new TokenContract(this._web3Wrapper, abi, address);
         tokenContract = contractInstance;
         this._tokenContractsByAddress[normalizedTokenAddress] = tokenContract;
         return tokenContract;
diff --git a/packages/0x.js/src/types.ts b/packages/0x.js/src/types.ts
index 0a3037258..2f17e30c2 100644
--- a/packages/0x.js/src/types.ts
+++ b/packages/0x.js/src/types.ts
@@ -127,7 +127,7 @@ export interface SignedOrder extends Order {
 }
 
 //                          [address, name, symbol, decimals, ipfsHash, swarmHash]
-export type TokenMetadata = [string, string, string, BigNumber, string, string];
+export type TokenMetadata = [string, string, string, number, string, string];
 
 export interface Token {
     name: string;
diff --git a/packages/0x.js/test/utils/fill_scenarios.ts b/packages/0x.js/test/utils/fill_scenarios.ts
index 1a61487f4..8b1308298 100644
--- a/packages/0x.js/test/utils/fill_scenarios.ts
+++ b/packages/0x.js/test/utils/fill_scenarios.ts
@@ -35,12 +35,8 @@ export class FillScenarios {
         const web3Wrapper = (this._zeroEx as any)._web3Wrapper as Web3Wrapper;
         for (const token of this._tokens) {
             if (token.symbol !== 'ZRX' && token.symbol !== 'WETH') {
-                const contractInstance = web3Wrapper.getContractInstance(
-                    artifacts.DummyTokenArtifact.abi,
-                    token.address,
-                );
                 const defaults = {};
-                const dummyToken = new DummyTokenContract(contractInstance, defaults);
+                const dummyToken = new DummyTokenContract(web3Wrapper, artifacts.DummyTokenArtifact.abi, token.address);
                 const tokenSupply = ZeroEx.toBaseUnitAmount(INITIAL_COINBASE_TOKEN_SUPPLY_IN_UNITS, token.decimals);
                 const txHash = await dummyToken.setBalance.sendTransactionAsync(this._coinbase, tokenSupply, {
                     from: this._coinbase,
diff --git a/packages/0x.js/tsconfig.json b/packages/0x.js/tsconfig.json
index 117f51e83..a6b5c71c2 100644
--- a/packages/0x.js/tsconfig.json
+++ b/packages/0x.js/tsconfig.json
@@ -9,6 +9,7 @@
         "./test/**/*",
         "../../node_modules/types-bn/index.d.ts",
         "../../node_modules/types-ethereumjs-util/index.d.ts",
+        "../../node_modules/ethers-typescript-typings/index.d.ts",
         "../../node_modules/web3-typescript-typings/index.d.ts",
         "../../node_modules/chai-typescript-typings/index.d.ts",
         "../../node_modules/chai-as-promised-typescript-typings/index.d.ts"
diff --git a/packages/abi-gen/CHANGELOG.md b/packages/abi-gen/CHANGELOG.md
index c86d6fb55..d9198d3ed 100644
--- a/packages/abi-gen/CHANGELOG.md
+++ b/packages/abi-gen/CHANGELOG.md
@@ -1,5 +1,11 @@
 # CHANGELOG
 
+## v0.2.3 - _TBD, 2018_
+
+    * Add a `backend` parameter that allows you to specify the Ethereum library you use in your templates (`web3` or `ethers`). Ethers auto-converts small ints to numbers whereas Web3 doesn't. Defaults to `web3` (#413)
+    * Add support for [tuple types](https://solidity.readthedocs.io/en/develop/abi-spec.html#handling-tuple-types) (#413)
+    * Add `hasReturnValue` to context data (#413)
+
 ## v0.2.1 - _February 9, 2018_
 
     * Fix publishing issue where .npmignore was not properly excluding undesired content (#389)
diff --git a/packages/abi-gen/src/index.ts b/packages/abi-gen/src/index.ts
index bc5a974a9..7c29f7d1d 100644
--- a/packages/abi-gen/src/index.ts
+++ b/packages/abi-gen/src/index.ts
@@ -11,13 +11,14 @@ import * as yargs from 'yargs';
 import toSnakeCase = require('to-snake-case');
 import * as Web3 from 'web3';
 
-import { ContextData, ParamKind } from './types';
+import { ContextData, ContractsBackend, ParamKind } from './types';
 import { utils } from './utils';
 
 const ABI_TYPE_CONSTRUCTOR = 'constructor';
 const ABI_TYPE_METHOD = 'function';
 const ABI_TYPE_EVENT = 'event';
 const DEFAULT_NETWORK_ID = 50;
+const DEFAULT_BACKEND = 'web3';
 
 const args = yargs
     .option('abis', {
@@ -43,6 +44,12 @@ const args = yargs
         demandOption: true,
         normalize: true,
     })
+    .option('backend', {
+        describe: `The backing Ethereum library your app uses. Either 'web3' or 'ethers'. Ethers auto-converts small ints to numbers whereas Web3 doesn't.`,
+        type: 'string',
+        choices: [ContractsBackend.Web3, ContractsBackend.Ethers],
+        default: DEFAULT_BACKEND,
+    })
     .option('network-id', {
         describe: 'ID of the network where contract ABIs are nested in artifacts',
         type: 'number',
@@ -73,8 +80,8 @@ function writeOutputFile(name: string, renderedTsCode: string): void {
     utils.log(`Created: ${chalk.bold(filePath)}`);
 }
 
-Handlebars.registerHelper('parameterType', utils.solTypeToTsType.bind(utils, ParamKind.Input));
-Handlebars.registerHelper('returnType', utils.solTypeToTsType.bind(utils, ParamKind.Output));
+Handlebars.registerHelper('parameterType', utils.solTypeToTsType.bind(utils, ParamKind.Input, args.backend));
+Handlebars.registerHelper('returnType', utils.solTypeToTsType.bind(utils, ParamKind.Output, args.backend));
 
 if (args.partials) {
     registerPartials(args.partials);
@@ -129,6 +136,7 @@ for (const abiFileName of abiFileNames) {
         const methodData = {
             ...methodAbi,
             singleReturnValue: methodAbi.outputs.length === 1,
+            hasReturnValue: methodAbi.outputs.length !== 0,
         };
         return methodData;
     });
diff --git a/packages/abi-gen/src/types.ts b/packages/abi-gen/src/types.ts
index e82ab824b..deddb1857 100644
--- a/packages/abi-gen/src/types.ts
+++ b/packages/abi-gen/src/types.ts
@@ -12,8 +12,14 @@ export enum AbiType {
     Fallback = 'fallback',
 }
 
+export enum ContractsBackend {
+    Web3 = 'web3',
+    Ethers = 'ethers',
+}
+
 export interface Method extends Web3.MethodAbi {
     singleReturnValue: boolean;
+    hasReturnValue: boolean;
 }
 
 export interface ContextData {
diff --git a/packages/abi-gen/src/utils.ts b/packages/abi-gen/src/utils.ts
index 14255643a..3e4ff619a 100644
--- a/packages/abi-gen/src/utils.ts
+++ b/packages/abi-gen/src/utils.ts
@@ -3,17 +3,23 @@ import * as _ from 'lodash';
 import * as path from 'path';
 import * as Web3 from 'web3';
 
-import { AbiType, ParamKind } from './types';
+import { AbiType, ContractsBackend, ParamKind } from './types';
 
 export const utils = {
-    solTypeToTsType(paramKind: ParamKind, solType: string): string {
+    solTypeToTsType(
+        paramKind: ParamKind,
+        backend: ContractsBackend,
+        solType: string,
+        components?: Web3.DataItem[],
+    ): string {
         const trailingArrayRegex = /\[\d*\]$/;
         if (solType.match(trailingArrayRegex)) {
             const arrayItemSolType = solType.replace(trailingArrayRegex, '');
-            const arrayItemTsType = utils.solTypeToTsType(paramKind, arrayItemSolType);
-            const arrayTsType = utils.isUnionType(arrayItemTsType)
-                ? `Array<${arrayItemTsType}>`
-                : `${arrayItemTsType}[]`;
+            const arrayItemTsType = utils.solTypeToTsType(paramKind, backend, arrayItemSolType, components);
+            const arrayTsType =
+                utils.isUnionType(arrayItemTsType) || utils.isObjectType(arrayItemTsType)
+                    ? `Array<${arrayItemTsType}>`
+                    : `${arrayItemTsType}[]`;
             return arrayTsType;
         } else {
             const solTypeRegexToTsType = [
@@ -24,25 +30,49 @@ export const utils = {
                 { regex: '^bytes\\d*$', tsType: 'string' },
             ];
             if (paramKind === ParamKind.Input) {
-                // web3 allows to pass those an non-bignumbers and that's nice
-                // but it always returns stuff as BigNumbers
+                // web3 and ethers allow to pass those as numbers instead of bignumbers
                 solTypeRegexToTsType.unshift({
                     regex: '^u?int(8|16|32)?$',
                     tsType: 'number|BigNumber',
                 });
             }
+            if (backend === ContractsBackend.Ethers && paramKind === ParamKind.Output) {
+                // ethers-contracts automatically converts small BigNumbers to numbers
+                solTypeRegexToTsType.unshift({
+                    regex: '^u?int(8|16|32|48)?$',
+                    tsType: 'number',
+                });
+            }
             for (const regexAndTxType of solTypeRegexToTsType) {
                 const { regex, tsType } = regexAndTxType;
                 if (solType.match(regex)) {
                     return tsType;
                 }
             }
+            const TUPLE_TYPE_REGEX = '^tuple$';
+            if (solType.match(TUPLE_TYPE_REGEX)) {
+                const componentsType = _.map(components, component => {
+                    const componentValueType = utils.solTypeToTsType(
+                        paramKind,
+                        backend,
+                        component.type,
+                        component.components,
+                    );
+                    const componentType = `${component.name}: ${componentValueType}`;
+                    return componentType;
+                });
+                const tsType = `{${componentsType}}`;
+                return tsType;
+            }
             throw new Error(`Unknown Solidity type found: ${solType}`);
         }
     },
     isUnionType(tsType: string): boolean {
         return tsType === 'number|BigNumber';
     },
+    isObjectType(tsType: string): boolean {
+        return /^{.*}$/.test(tsType);
+    },
     log(...args: any[]): void {
         console.log(...args); // tslint:disable-line:no-console
     },
diff --git a/packages/0x.js/contract_templates/contract.handlebars b/packages/contract_templates/contract.handlebars
index 33699b8a7..b5c2dd9f2 100644
--- a/packages/0x.js/contract_templates/contract.handlebars
+++ b/packages/contract_templates/contract.handlebars
@@ -1,15 +1,16 @@
 /**
  * This file is auto-generated using abi-gen. Don't edit directly.
- * Templates can be found at https://github.com/0xProject/0x.js/tree/development/packages/0x.js/contract_templates.
+ * Templates can be found at https://github.com/0xProject/0x.js/tree/development/packages/contract_templates.
  */
 // tslint:disable:no-consecutive-blank-lines
 // tslint:disable-next-line:no-unused-variable
 import { TxData, TxDataPayable } from '@0xproject/types';
 import { BigNumber, classUtils, promisify } from '@0xproject/utils';
+import { BaseContract, Web3Wrapper } from '@0xproject/web3-wrapper';
+import * as ethersContracts from 'ethers-contracts';
+import * as _ from 'lodash';
 import * as Web3 from 'web3';
 
-import {BaseContract} from './base_contract';
-
 {{#if events}}
 export type {{contractName}}ContractEventArgs =
 {{#each events}}
@@ -28,6 +29,7 @@ export enum {{contractName}}Events {
 {{/each}}
 {{/if}}
 
+// tslint:disable:no-parameter-reassignment
 export class {{contractName}}Contract extends BaseContract {
 {{#each methods}}
     {{#this.constant}}
@@ -37,8 +39,8 @@ export class {{contractName}}Contract extends BaseContract {
     {{> tx contractName=../contractName}}
     {{/this.constant}}
 {{/each}}
-    constructor(web3ContractInstance: Web3.ContractInstance, defaults: Partial<TxData>) {
-        super(web3ContractInstance, defaults);
-        classUtils.bindAll(this, ['_web3ContractInstance', '_defaults']);
+    constructor(web3Wrapper: Web3Wrapper, abi: Web3.ContractAbi, address: string) {
+        super(web3Wrapper, abi, address);
+        classUtils.bindAll(this, ['_ethersInterface', 'address', 'abi', '_web3Wrapper']);
     }
 } // tslint:disable:max-file-line-count
diff --git a/packages/contract_templates/partials/call.handlebars b/packages/contract_templates/partials/call.handlebars
new file mode 100644
index 000000000..cfb9bea82
--- /dev/null
+++ b/packages/contract_templates/partials/call.handlebars
@@ -0,0 +1,3 @@
+public {{this.name}} = {
+    {{> callAsync}}
+};
diff --git a/packages/contract_templates/partials/callAsync.handlebars b/packages/contract_templates/partials/callAsync.handlebars
new file mode 100644
index 000000000..93d347145
--- /dev/null
+++ b/packages/contract_templates/partials/callAsync.handlebars
@@ -0,0 +1,30 @@
+{{#hasReturnValue}}
+async callAsync(
+{{> typed_params inputs=inputs}}
+{{#this.payable}}
+    txData: TxDataPayable = {},
+{{/this.payable}}
+{{^this.payable}}
+    txData: TxData = {},
+{{/this.payable}}
+    defaultBlock?: Web3.BlockParam,
+): Promise<{{> return_type outputs=outputs}}> {
+    const self = this as {{contractName}}Contract;
+    const inputAbi = _.find(this.abi, {name: '{{this.name}}'}).inputs;
+    [{{> params inputs=inputs}}] = BaseContract._transformABIData(inputAbi, [{{> params inputs=inputs}}], BaseContract._bigNumberToString.bind(this));
+    const encodedData = self._ethersInterface.functions.{{this.name}}(
+        {{> params inputs=inputs}}
+    ).data;
+    const callData = await self._applyDefaultsToTxDataAsync(
+        {
+            data: encodedData,
+        }
+    )
+    const rawCallResult = await self._web3Wrapper.callAsync(callData, defaultBlock);
+    const outputAbi = _.find(this.abi, {name: '{{this.name}}'}).outputs as Web3.DataItem[];
+    const outputParamsTypes = _.map(outputAbi, 'type');
+    let resultArray = ethersContracts.Interface.decodeParams(outputParamsTypes, rawCallResult) as any;
+    resultArray = BaseContract._transformABIData(outputAbi, resultArray, BaseContract._lowercaseAddress.bind(this));
+    return resultArray{{#singleReturnValue}}[0]{{/singleReturnValue}};
+},
+{{/hasReturnValue}}
diff --git a/packages/0x.js/contract_templates/partials/event.handlebars b/packages/contract_templates/partials/event.handlebars
index 6d68d4c0f..3c6100e4f 100644
--- a/packages/0x.js/contract_templates/partials/event.handlebars
+++ b/packages/contract_templates/partials/event.handlebars
@@ -1,5 +1,5 @@
 export interface {{name}}ContractEventArgs {
     {{#each inputs}}
-    {{name}}: {{#returnType type}}{{/returnType}};
+    {{name}}: {{#returnType type components}}{{/returnType}};
     {{/each}}
 }
diff --git a/packages/0x.js/contract_templates/partials/params.handlebars b/packages/contract_templates/partials/params.handlebars
index ac5d4ae85..ac5d4ae85 100644
--- a/packages/0x.js/contract_templates/partials/params.handlebars
+++ b/packages/contract_templates/partials/params.handlebars
diff --git a/packages/contract_templates/partials/return_type.handlebars b/packages/contract_templates/partials/return_type.handlebars
new file mode 100644
index 000000000..9dd509953
--- /dev/null
+++ b/packages/contract_templates/partials/return_type.handlebars
@@ -0,0 +1,10 @@
+{{#if outputs.length}}
+{{#singleReturnValue}}
+{{#returnType outputs.0.type components}}{{/returnType}}
+{{/singleReturnValue}}
+{{^singleReturnValue}}
+[{{#each outputs}}{{#returnType type components}}{{/returnType}}{{#unless @last}}, {{/unless}}{{/each}}]
+{{/singleReturnValue}}
+{{else}}
+void
+{{/if}}
diff --git a/packages/0x.js/contract_templates/partials/tx.handlebars b/packages/contract_templates/partials/tx.handlebars
index 9df83266a..347a482d6 100644
--- a/packages/0x.js/contract_templates/partials/tx.handlebars
+++ b/packages/contract_templates/partials/tx.handlebars
@@ -9,19 +9,22 @@ public {{this.name}} = {
     {{/this.payable}}
     ): Promise<string> {
         const self = this as {{contractName}}Contract;
+        const inputAbi = _.find(this.abi, {name: '{{this.name}}'}).inputs;
+        [{{> params inputs=inputs}}] = BaseContract._transformABIData(inputAbi, [{{> params inputs=inputs}}], BaseContract._bigNumberToString.bind(this));
+        const encodedData = this._ethersInterface.functions.{{this.name}}(
+            {{> params inputs=inputs}}
+        ).data
         const txDataWithDefaults = await self._applyDefaultsToTxDataAsync(
-            txData,
+            {
+                ...txData,
+                data: encodedData,
+            },
             self.{{this.name}}.estimateGasAsync.bind(
                 self,
                 {{> params inputs=inputs}}
             ),
         );
-        const txHash = await promisify<string>(
-            self._web3ContractInstance.{{this.name}}, self._web3ContractInstance,
-        )(
-            {{> params inputs=inputs}}
-            txDataWithDefaults,
-        );
+        const txHash = await this._web3Wrapper.sendTransactionAsync(txDataWithDefaults);
         return txHash;
     },
     async estimateGasAsync(
@@ -29,15 +32,16 @@ public {{this.name}} = {
         txData: TxData = {},
     ): Promise<number> {
         const self = this as {{contractName}}Contract;
-        const txDataWithDefaults = await self._applyDefaultsToTxDataAsync(
-            txData,
-        );
-        const gas = await promisify<number>(
-            self._web3ContractInstance.{{this.name}}.estimateGas, self._web3ContractInstance,
-        )(
+        const encodedData = this._ethersInterface.functions.{{this.name}}(
             {{> params inputs=inputs}}
-            txDataWithDefaults,
+        ).data
+        const txDataWithDefaults = await self._applyDefaultsToTxDataAsync(
+            {
+                ...txData,
+                data: encodedData,
+            }
         );
+        const gas = await this._web3Wrapper.estimateGasAsync(txDataWithDefaults);
         return gas;
     },
     getABIEncodedTransactionData(
@@ -45,7 +49,10 @@ public {{this.name}} = {
         txData: TxData = {},
     ): string {
         const self = this as {{contractName}}Contract;
-        const abiEncodedTransactionData = self._web3ContractInstance.{{this.name}}.getData();
+        const abiEncodedTransactionData = this._ethersInterface.functions.{{this.name}}(
+            {{> params inputs=inputs}}
+        ).data
         return abiEncodedTransactionData;
     },
+    {{> callAsync}}
 };
diff --git a/packages/contract_templates/partials/typed_params.handlebars b/packages/contract_templates/partials/typed_params.handlebars
new file mode 100644
index 000000000..c100e58f7
--- /dev/null
+++ b/packages/contract_templates/partials/typed_params.handlebars
@@ -0,0 +1,3 @@
+{{#each inputs}}
+    {{name}}: {{#parameterType type components}}{{/parameterType}},
+{{/each}}
diff --git a/packages/contracts/contract_templates/contract.handlebars b/packages/contracts/contract_templates/contract.handlebars
deleted file mode 100644
index afb9708e9..000000000
--- a/packages/contracts/contract_templates/contract.handlebars
+++ /dev/null
@@ -1,26 +0,0 @@
-/**
- * This file is auto-generated using abi-gen. Don't edit directly.
- * Templates can be found at https://github.com/0xProject/0x.js/tree/development/packages/abi-gen-templates.
- */
-// tslint:disable:async-suffix member-ordering no-consecutive-blank-lines
-// tslint:disable-next-line:no-unused-variable
-import { TxData, TxDataPayable } from '@0xproject/types';
-import { BigNumber, classUtils, promisify } from '@0xproject/utils';
-import * as Web3 from 'web3';
-
-import {BaseContract} from './base_contract';
-
-export class {{contractName}}Contract extends BaseContract {
-{{#each methods}}
-    {{#this.constant}}
-    {{> call contractName=../contractName}}
-    {{/this.constant}}
-    {{^this.constant}}
-    {{> tx contractName=../contractName}}
-    {{/this.constant}}
-{{/each}}
-    constructor(web3ContractInstance: Web3.ContractInstance, defaults?: Partial<TxData>) {
-        super(web3ContractInstance, defaults);
-        classUtils.bindAll(this, ['_web3ContractInstance', '_defaults']);
-    }
-} // tslint:disable:max-file-line-count
diff --git a/packages/contracts/contract_templates/partials/call.handlebars b/packages/contracts/contract_templates/partials/call.handlebars
deleted file mode 100644
index 82a45b40e..000000000
--- a/packages/contracts/contract_templates/partials/call.handlebars
+++ /dev/null
@@ -1,10 +0,0 @@
-public async {{this.name}}(
-{{> typed_params inputs=inputs}}
-    defaultBlock?: Web3.BlockParam,
-): Promise<{{> return_type outputs=outputs}}> {
-    const self = this as {{contractName}}Contract;
-    const result = await self._web3ContractInstance.{{this.name}}.call(
-        {{> params inputs=inputs}}
-    );
-    return result;
-}
diff --git a/packages/contracts/contract_templates/partials/params.handlebars b/packages/contracts/contract_templates/partials/params.handlebars
deleted file mode 100644
index ac5d4ae85..000000000
--- a/packages/contracts/contract_templates/partials/params.handlebars
+++ /dev/null
@@ -1,3 +0,0 @@
-{{#each inputs}}
-{{name}},
-{{/each}}
diff --git a/packages/contracts/contract_templates/partials/return_type.handlebars b/packages/contracts/contract_templates/partials/return_type.handlebars
deleted file mode 100644
index 40a5dd8b0..000000000
--- a/packages/contracts/contract_templates/partials/return_type.handlebars
+++ /dev/null
@@ -1,10 +0,0 @@
-{{#if outputs.length}}
-{{#singleReturnValue}}
-{{#returnType outputs.0.type}}{{/returnType}}
-{{/singleReturnValue}}
-{{^singleReturnValue}}
-[{{#each outputs}}{{#returnType type}}{{/returnType}}{{#unless @last}}, {{/unless}}{{/each}}]
-{{/singleReturnValue}}
-{{else}}
-void
-{{/if}}
diff --git a/packages/contracts/contract_templates/partials/tx.handlebars b/packages/contracts/contract_templates/partials/tx.handlebars
deleted file mode 100644
index 69ae982d6..000000000
--- a/packages/contracts/contract_templates/partials/tx.handlebars
+++ /dev/null
@@ -1,36 +0,0 @@
-public {{this.name}} = {
-    async sendTransactionAsync(
-    {{> typed_params inputs=inputs}}
-    {{#this.payable}}
-        txData: TxDataPayable = {},
-    {{/this.payable}}
-    {{^this.payable}}
-        txData: TxData = {},
-    {{/this.payable}}
-    ): Promise<string> {
-        const self = this as {{contractName}}Contract;
-        const txDataWithDefaults = await self._applyDefaultsToTxDataAsync(txData);
-        const txHash = await self._web3ContractInstance.{{this.name}}(
-            {{> params inputs=inputs}}
-            txDataWithDefaults,
-        );
-        return txHash;
-    },
-    async callAsync(
-    {{> typed_params inputs=inputs}}
-    {{#this.payable}}
-        txData: TxDataPayable = {},
-    {{/this.payable}}
-    {{^this.payable}}
-        txData: TxData = {},
-    {{/this.payable}}
-    ): Promise<{{> return_type outputs=outputs}}> {
-        const self = this as {{contractName}}Contract;
-        const txDataWithDefaults = await self._applyDefaultsToTxDataAsync(txData);
-        const returnValue = await self._web3ContractInstance.{{this.name}}.call(
-            {{> params inputs=inputs}}
-            txDataWithDefaults,
-        );
-        return returnValue;
-    },
-};
diff --git a/packages/contracts/contract_templates/partials/typed_params.handlebars b/packages/contracts/contract_templates/partials/typed_params.handlebars
deleted file mode 100644
index 3ea4b2e95..000000000
--- a/packages/contracts/contract_templates/partials/typed_params.handlebars
+++ /dev/null
@@ -1,3 +0,0 @@
-{{#each inputs}}
-    {{name}}: {{#parameterType type}}{{/parameterType}},
-{{/each}}
diff --git a/packages/contracts/package.json b/packages/contracts/package.json
index 0a3a6fc84..8159ba244 100644
--- a/packages/contracts/package.json
+++ b/packages/contracts/package.json
@@ -17,7 +17,7 @@
         "compile:comment": "Yarn workspaces do not link binaries correctly so we need to reference them directly https://github.com/yarnpkg/yarn/issues/3846",
         "compile": "node ../deployer/lib/src/cli.js compile --contracts ${npm_package_config_contracts} --contracts-dir src/contracts --artifacts-dir src/artifacts",
         "clean": "shx rm -rf ./lib",
-        "generate_contract_wrappers": "node ../abi-gen/lib/index.js --abis 'src/artifacts/@(DummyToken|TokenTransferProxy|Exchange|TokenRegistry|MultiSigWallet|MultiSigWalletWithTimeLock|MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress|TokenRegistry|ZRXToken).json' --template contract_templates/contract.handlebars --partials 'contract_templates/partials/**/*.handlebars' --output src/contract_wrappers/generated",
+        "generate_contract_wrappers": "node ../abi-gen/lib/index.js --abis 'src/artifacts/@(DummyToken|TokenTransferProxy|Exchange|TokenRegistry|MultiSigWallet|MultiSigWalletWithTimeLock|MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress|TokenRegistry|ZRXToken).json' --template ../contract_templates/contract.handlebars --partials '../contract_templates/partials/**/*.handlebars' --output src/contract_wrappers/generated --backend ethers && prettier --write 'src/contract_wrappers/generated/**.ts'",
         "migrate": "node ../deployer/lib/src/cli.js migrate",
         "lint": "tslint --project . 'migrations/**/*.ts' 'test/**/*.ts' 'util/**/*.ts' 'deploy/**/*.ts'",
         "test:circleci": "yarn test"
@@ -58,6 +58,7 @@
         "types-bn": "^0.0.1",
         "types-ethereumjs-util": "0xProject/types-ethereumjs-util",
         "typescript": "2.7.1",
+        "ethers-typescript-typings": "^0.0.1",
         "web3-typescript-typings": "^0.9.11",
         "yargs": "^10.0.3"
     },
@@ -72,6 +73,7 @@
         "bn.js": "^4.11.8",
         "ethereumjs-abi": "^0.6.4",
         "ethereumjs-util": "^5.1.1",
+        "ethers-contracts": "^2.2.1",
         "isomorphic-fetch": "^2.2.1",
         "lodash": "^4.17.4",
         "request": "^2.81.0",
diff --git a/packages/contracts/src/contract_wrappers/generated/.gitignore b/packages/contracts/src/contract_wrappers/generated/.gitignore
index b976a8737..72e8ffc0d 100644
--- a/packages/contracts/src/contract_wrappers/generated/.gitignore
+++ b/packages/contracts/src/contract_wrappers/generated/.gitignore
@@ -1,8 +1 @@
-dummy_token.ts
-exchange.ts
-multi_sig_wallet_with_time_lock_except_remove_authorized_address.ts
-multi_sig_wallet_with_time_lock.ts
-multi_sig_wallet.ts
-token_registry.ts
-token_transfer_proxy.ts
-zrx_token.ts
+*
diff --git a/packages/contracts/src/contract_wrappers/generated/base_contract.ts b/packages/contracts/src/contract_wrappers/generated/base_contract.ts
deleted file mode 100644
index 2d77b3ab1..000000000
--- a/packages/contracts/src/contract_wrappers/generated/base_contract.ts
+++ /dev/null
@@ -1,35 +0,0 @@
-import {TxData, TxDataPayable} from '@0xproject/types';
-import * as _ from 'lodash';
-import * as Web3 from 'web3';
-
-export class BaseContract {
-    public address: string;
-    protected _web3ContractInstance: Web3.ContractInstance;
-    protected _defaults: Partial<TxData>;
-    protected async _applyDefaultsToTxDataAsync<T extends TxData|TxDataPayable>(
-        txData: T,
-        estimateGasAsync?: (txData: T) => Promise<number>,
-    ): Promise<TxData> {
-        // Gas amount sourced with the following priorities:
-        // 1. Optional param passed in to public method call
-        // 2. Global config passed in at library instantiation
-        // 3. Gas estimate calculation + safety margin
-        const removeUndefinedProperties = _.pickBy;
-        const txDataWithDefaults = {
-            ...removeUndefinedProperties(this._defaults),
-            ...removeUndefinedProperties(txData as any),
-            // HACK: TS can't prove that T is spreadable.
-            // Awaiting https://github.com/Microsoft/TypeScript/pull/13288 to be merged
-        };
-        if (_.isUndefined(txDataWithDefaults.gas) && !_.isUndefined(estimateGasAsync)) {
-            const estimatedGas = await estimateGasAsync(txData);
-            txDataWithDefaults.gas = estimatedGas;
-        }
-        return txDataWithDefaults;
-    }
-    constructor(web3ContractInstance: Web3.ContractInstance, defaults?: Partial<TxData>) {
-        this.address = web3ContractInstance.address;
-        this._web3ContractInstance = web3ContractInstance;
-        this._defaults = defaults || {};
-    }
-}
diff --git a/packages/contracts/test/exchange/core.ts b/packages/contracts/test/exchange/core.ts
index 9cfc68418..303d745aa 100644
--- a/packages/contracts/test/exchange/core.ts
+++ b/packages/contracts/test/exchange/core.ts
@@ -1,12 +1,4 @@
-import {
-    LogCancelContractEventArgs,
-    LogErrorContractEventArgs,
-    LogFillContractEventArgs,
-    LogWithDecodedArgs,
-    SignedOrder,
-    TransactionReceiptWithDecodedLogs,
-    ZeroEx,
-} from '0x.js';
+import { LogWithDecodedArgs, SignedOrder, TransactionReceiptWithDecodedLogs, ZeroEx } from '0x.js';
 import { BlockchainLifecycle, devConstants, web3Factory } from '@0xproject/dev-utils';
 import { BigNumber } from '@0xproject/utils';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
@@ -15,7 +7,12 @@ import ethUtil = require('ethereumjs-util');
 import * as Web3 from 'web3';
 
 import { DummyTokenContract } from '../../src/contract_wrappers/generated/dummy_token';
-import { ExchangeContract } from '../../src/contract_wrappers/generated/exchange';
+import {
+    ExchangeContract,
+    LogCancelContractEventArgs,
+    LogErrorContractEventArgs,
+    LogFillContractEventArgs,
+} from '../../src/contract_wrappers/generated/exchange';
 import { TokenTransferProxyContract } from '../../src/contract_wrappers/generated/token_transfer_proxy';
 import { Balances } from '../../util/balances';
 import { constants } from '../../util/constants';
@@ -63,16 +60,20 @@ describe('Exchange', () => {
             deployer.deployAsync(ContractName.DummyToken),
             deployer.deployAsync(ContractName.DummyToken),
         ]);
-        rep = new DummyTokenContract(repInstance);
-        dgd = new DummyTokenContract(dgdInstance);
-        zrx = new DummyTokenContract(zrxInstance);
+        rep = new DummyTokenContract(web3Wrapper, repInstance.abi, repInstance.address);
+        dgd = new DummyTokenContract(web3Wrapper, dgdInstance.abi, dgdInstance.address);
+        zrx = new DummyTokenContract(web3Wrapper, zrxInstance.abi, zrxInstance.address);
         const tokenTransferProxyInstance = await deployer.deployAsync(ContractName.TokenTransferProxy);
-        tokenTransferProxy = new TokenTransferProxyContract(tokenTransferProxyInstance);
+        tokenTransferProxy = new TokenTransferProxyContract(
+            web3Wrapper,
+            tokenTransferProxyInstance.abi,
+            tokenTransferProxyInstance.address,
+        );
         const exchangeInstance = await deployer.deployAsync(ContractName.Exchange, [
             zrx.address,
             tokenTransferProxy.address,
         ]);
-        exchange = new ExchangeContract(exchangeInstance);
+        exchange = new ExchangeContract(web3Wrapper, exchangeInstance.abi, exchangeInstance.address);
         await tokenTransferProxy.addAuthorizedAddress.sendTransactionAsync(exchange.address, { from: accounts[0] });
         zeroEx = new ZeroEx(web3.currentProvider, {
             exchangeContractAddress: exchange.address,
@@ -650,7 +651,7 @@ describe('Exchange', () => {
 
         it('should not change balances if makerTokenAddress is ZRX, makerTokenAmount + makerFee > maker allowance, \
                 and shouldThrowOnInsufficientBalanceOrAllowance = false', async () => {
-            const makerZRXAllowance = await zrx.allowance(maker, tokenTransferProxy.address);
+            const makerZRXAllowance = await zrx.allowance.callAsync(maker, tokenTransferProxy.address);
             signedOrder = await orderFactory.newSignedOrderAsync({
                 makerTokenAddress: zrx.address,
                 makerTokenAmount: new BigNumber(makerZRXAllowance),
@@ -676,7 +677,7 @@ describe('Exchange', () => {
 
         it('should not change balances if takerTokenAddress is ZRX, takerTokenAmount + takerFee > taker allowance, \
                 and shouldThrowOnInsufficientBalanceOrAllowance = false', async () => {
-            const takerZRXAllowance = await zrx.allowance(taker, tokenTransferProxy.address);
+            const takerZRXAllowance = await zrx.allowance.callAsync(taker, tokenTransferProxy.address);
             signedOrder = await orderFactory.newSignedOrderAsync({
                 takerTokenAddress: zrx.address,
                 takerTokenAmount: new BigNumber(takerZRXAllowance),
@@ -723,7 +724,7 @@ describe('Exchange', () => {
             const res = await exWrapper.fillOrderAsync(signedOrder, taker);
             expect(res.logs).to.have.length(1);
             const log = res.logs[0] as LogWithDecodedArgs<LogErrorContractEventArgs>;
-            const errCode = log.args.errorId.toNumber();
+            const errCode = log.args.errorId;
             expect(errCode).to.be.equal(ExchangeContractErrs.ERROR_ORDER_EXPIRED);
         });
 
@@ -734,7 +735,7 @@ describe('Exchange', () => {
             const res = await exWrapper.fillOrderAsync(signedOrder, taker);
             expect(res.logs).to.have.length(1);
             const log = res.logs[0] as LogWithDecodedArgs<LogErrorContractEventArgs>;
-            const errCode = log.args.errorId.toNumber();
+            const errCode = log.args.errorId;
             expect(errCode).to.be.equal(ExchangeContractErrs.ERROR_ORDER_FULLY_FILLED_OR_CANCELLED);
         });
     });
@@ -862,7 +863,7 @@ describe('Exchange', () => {
             const res = await exWrapper.cancelOrderAsync(signedOrder, maker);
             expect(res.logs).to.have.length(1);
             const log = res.logs[0] as LogWithDecodedArgs<LogErrorContractEventArgs>;
-            const errCode = log.args.errorId.toNumber();
+            const errCode = log.args.errorId;
             expect(errCode).to.be.equal(ExchangeContractErrs.ERROR_ORDER_FULLY_FILLED_OR_CANCELLED);
         });
 
@@ -874,7 +875,7 @@ describe('Exchange', () => {
             const res = await exWrapper.cancelOrderAsync(signedOrder, maker);
             expect(res.logs).to.have.length(1);
             const log = res.logs[0] as LogWithDecodedArgs<LogErrorContractEventArgs>;
-            const errCode = log.args.errorId.toNumber();
+            const errCode = log.args.errorId;
             expect(errCode).to.be.equal(ExchangeContractErrs.ERROR_ORDER_EXPIRED);
         });
     });
diff --git a/packages/contracts/test/exchange/helpers.ts b/packages/contracts/test/exchange/helpers.ts
index 5fe00225e..9869c2155 100644
--- a/packages/contracts/test/exchange/helpers.ts
+++ b/packages/contracts/test/exchange/helpers.ts
@@ -5,7 +5,12 @@ import { Web3Wrapper } from '@0xproject/web3-wrapper';
 import * as chai from 'chai';
 import ethUtil = require('ethereumjs-util');
 
-import { ExchangeContract } from '../../src/contract_wrappers/generated/exchange';
+import {
+    ExchangeContract,
+    LogCancelContractEventArgs,
+    LogErrorContractEventArgs,
+    LogFillContractEventArgs,
+} from '../../src/contract_wrappers/generated/exchange';
 import { constants } from '../../util/constants';
 import { ExchangeWrapper } from '../../util/exchange_wrapper';
 import { OrderFactory } from '../../util/order_factory';
@@ -42,7 +47,7 @@ describe('Exchange', () => {
             zrx.address,
             tokenTransferProxy.address,
         ]);
-        const exchange = new ExchangeContract(exchangeInstance);
+        const exchange = new ExchangeContract(web3Wrapper, exchangeInstance.abi, exchangeInstance.address);
         await tokenTransferProxy.addAuthorizedAddress(exchange.address, { from: accounts[0] });
         const zeroEx = new ZeroEx(web3.currentProvider, { networkId: constants.TESTRPC_NETWORK_ID });
         exchangeWrapper = new ExchangeWrapper(exchange, zeroEx);
@@ -50,8 +55,8 @@ describe('Exchange', () => {
             exchangeContractAddress: exchange.address,
             maker,
             feeRecipient,
-            makerToken: rep.address,
-            takerToken: dgd.address,
+            makerTokenAddress: rep.address,
+            takerTokenAddress: dgd.address,
             makerTokenAmount: ZeroEx.toBaseUnitAmount(new BigNumber(100), 18),
             takerTokenAmount: ZeroEx.toBaseUnitAmount(new BigNumber(200), 18),
             makerFee: ZeroEx.toBaseUnitAmount(new BigNumber(1), 18),
diff --git a/packages/contracts/test/exchange/wrapper.ts b/packages/contracts/test/exchange/wrapper.ts
index bf5a89222..4ea40cb59 100644
--- a/packages/contracts/test/exchange/wrapper.ts
+++ b/packages/contracts/test/exchange/wrapper.ts
@@ -7,7 +7,12 @@ import * as _ from 'lodash';
 import * as Web3 from 'web3';
 
 import { DummyTokenContract } from '../../src/contract_wrappers/generated/dummy_token';
-import { ExchangeContract } from '../../src/contract_wrappers/generated/exchange';
+import {
+    ExchangeContract,
+    LogCancelContractEventArgs,
+    LogErrorContractEventArgs,
+    LogFillContractEventArgs,
+} from '../../src/contract_wrappers/generated/exchange';
 import { TokenRegistryContract } from '../../src/contract_wrappers/generated/token_registry';
 import { TokenTransferProxyContract } from '../../src/contract_wrappers/generated/token_transfer_proxy';
 import { Balances } from '../../util/balances';
@@ -55,18 +60,26 @@ describe('Exchange', () => {
             deployer.deployAsync(ContractName.DummyToken),
             deployer.deployAsync(ContractName.DummyToken),
         ]);
-        rep = new DummyTokenContract(repInstance);
-        dgd = new DummyTokenContract(dgdInstance);
-        zrx = new DummyTokenContract(zrxInstance);
+        rep = new DummyTokenContract(web3Wrapper, repInstance.abi, repInstance.address);
+        dgd = new DummyTokenContract(web3Wrapper, dgdInstance.abi, dgdInstance.address);
+        zrx = new DummyTokenContract(web3Wrapper, zrxInstance.abi, zrxInstance.address);
         const tokenRegistryInstance = await deployer.deployAsync(ContractName.TokenRegistry);
-        tokenRegistry = new TokenRegistryContract(tokenRegistryInstance);
+        tokenRegistry = new TokenRegistryContract(
+            web3Wrapper,
+            tokenRegistryInstance.abi,
+            tokenRegistryInstance.address,
+        );
         const tokenTransferProxyInstance = await deployer.deployAsync(ContractName.TokenTransferProxy);
-        tokenTransferProxy = new TokenTransferProxyContract(tokenTransferProxyInstance);
+        tokenTransferProxy = new TokenTransferProxyContract(
+            web3Wrapper,
+            tokenTransferProxyInstance.abi,
+            tokenTransferProxyInstance.address,
+        );
         const exchangeInstance = await deployer.deployAsync(ContractName.Exchange, [
             zrx.address,
             tokenTransferProxy.address,
         ]);
-        exchange = new ExchangeContract(exchangeInstance);
+        exchange = new ExchangeContract(web3Wrapper, exchangeInstance.abi, exchangeInstance.address);
         await tokenTransferProxy.addAuthorizedAddress.sendTransactionAsync(exchange.address, { from: accounts[0] });
         const zeroEx = new ZeroEx(web3.currentProvider, { networkId: constants.TESTRPC_NETWORK_ID });
         exWrapper = new ExchangeWrapper(exchange, zeroEx);
diff --git a/packages/contracts/test/multi_sig_with_time_lock.ts b/packages/contracts/test/multi_sig_with_time_lock.ts
index 6812cb09f..a726814e4 100644
--- a/packages/contracts/test/multi_sig_with_time_lock.ts
+++ b/packages/contracts/test/multi_sig_with_time_lock.ts
@@ -59,10 +59,14 @@ describe('MultiSigWalletWithTimeLock', () => {
                     SIGNATURES_REQUIRED,
                     0,
                 ]);
-                multiSig = new MultiSigWalletWithTimeLockContract(multiSigInstance);
+                multiSig = new MultiSigWalletWithTimeLockContract(
+                    web3Wrapper,
+                    multiSigInstance.abi,
+                    multiSigInstance.address,
+                );
                 multiSigWrapper = new MultiSigWrapper((multiSig as any) as MultiSigWalletContract);
 
-                const secondsTimeLocked = await multiSig.secondsTimeLocked();
+                const secondsTimeLocked = await multiSig.secondsTimeLocked.callAsync();
                 initialSecondsTimeLocked = secondsTimeLocked.toNumber();
             });
             it('should throw when not called by wallet', async () => {
@@ -113,7 +117,7 @@ describe('MultiSigWalletWithTimeLock', () => {
                 const blockNum = await web3Wrapper.getBlockNumberAsync();
                 const blockInfo = await web3Wrapper.getBlockAsync(blockNum);
                 const timestamp = new BigNumber(blockInfo.timestamp);
-                const confirmationTimeBigNum = new BigNumber(await multiSig.confirmationTimes(txId));
+                const confirmationTimeBigNum = new BigNumber(await multiSig.confirmationTimes.callAsync(txId));
 
                 expect(timestamp).to.be.bignumber.equal(confirmationTimeBigNum);
             });
@@ -141,7 +145,7 @@ describe('MultiSigWalletWithTimeLock', () => {
                 const res = await zeroEx.awaitTransactionMinedAsync(txHash);
                 expect(res.logs).to.have.length(2);
 
-                const secondsTimeLocked = new BigNumber(await multiSig.secondsTimeLocked());
+                const secondsTimeLocked = new BigNumber(await multiSig.secondsTimeLocked.callAsync());
                 expect(secondsTimeLocked).to.be.bignumber.equal(SECONDS_TIME_LOCKED);
             });
         });
@@ -152,10 +156,14 @@ describe('MultiSigWalletWithTimeLock', () => {
                     SIGNATURES_REQUIRED,
                     SECONDS_TIME_LOCKED,
                 ]);
-                multiSig = new MultiSigWalletWithTimeLockContract(multiSigInstance);
+                multiSig = new MultiSigWalletWithTimeLockContract(
+                    web3Wrapper,
+                    multiSigInstance.abi,
+                    multiSigInstance.address,
+                );
                 multiSigWrapper = new MultiSigWrapper((multiSig as any) as MultiSigWalletContract);
 
-                const secondsTimeLocked = await multiSig.secondsTimeLocked();
+                const secondsTimeLocked = await multiSig.secondsTimeLocked.callAsync();
                 initialSecondsTimeLocked = secondsTimeLocked.toNumber();
                 const destination = multiSig.address;
                 const from = owners[0];
@@ -187,7 +195,7 @@ describe('MultiSigWalletWithTimeLock', () => {
                 await rpc.increaseTimeAsync(SECONDS_TIME_LOCKED.toNumber());
                 await multiSig.executeTransaction.sendTransactionAsync(txId, { from: owners[0] });
 
-                const secondsTimeLocked = new BigNumber(await multiSig.secondsTimeLocked());
+                const secondsTimeLocked = new BigNumber(await multiSig.secondsTimeLocked.callAsync());
                 expect(secondsTimeLocked).to.be.bignumber.equal(newSecondsTimeLocked);
             });
         });
diff --git a/packages/contracts/test/multi_sig_with_time_lock_except_remove_auth_addr.ts b/packages/contracts/test/multi_sig_with_time_lock_except_remove_auth_addr.ts
index 7e9d44730..c0299e1e1 100644
--- a/packages/contracts/test/multi_sig_with_time_lock_except_remove_auth_addr.ts
+++ b/packages/contracts/test/multi_sig_with_time_lock_except_remove_auth_addr.ts
@@ -49,7 +49,11 @@ describe('MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress', () => {
         [authorizedAddress, unauthorizedAddress] = accounts;
         const initialOwner = accounts[0];
         const tokenTransferProxyInstance = await deployer.deployAsync(ContractName.TokenTransferProxy);
-        tokenTransferProxy = new TokenTransferProxyContract(tokenTransferProxyInstance);
+        tokenTransferProxy = new TokenTransferProxyContract(
+            web3Wrapper,
+            tokenTransferProxyInstance.abi,
+            tokenTransferProxyInstance.address,
+        );
         await tokenTransferProxy.addAuthorizedAddress.sendTransactionAsync(authorizedAddress, {
             from: initialOwner,
         });
@@ -57,7 +61,11 @@ describe('MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress', () => {
             ContractName.MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress,
             [owners, requiredApprovals, SECONDS_TIME_LOCKED, tokenTransferProxy.address],
         );
-        multiSig = new MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddressContract(multiSigInstance);
+        multiSig = new MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddressContract(
+            web3Wrapper,
+            multiSigInstance.abi,
+            multiSigInstance.address,
+        );
         await tokenTransferProxy.transferOwnership.sendTransactionAsync(multiSig.address, {
             from: initialOwner,
         });
@@ -74,12 +82,14 @@ describe('MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress', () => {
     describe('isFunctionRemoveAuthorizedAddress', () => {
         it('should throw if data is not for removeAuthorizedAddress', async () => {
             const data = MultiSigWrapper.encodeFnArgs('addAuthorizedAddress', PROXY_ABI, [owners[0]]);
-            return expect(multiSig.isFunctionRemoveAuthorizedAddress(data)).to.be.rejectedWith(constants.REVERT);
+            return expect(multiSig.isFunctionRemoveAuthorizedAddress.callAsync(data)).to.be.rejectedWith(
+                constants.REVERT,
+            );
         });
 
         it('should return true if data is for removeAuthorizedAddress', async () => {
             const data = MultiSigWrapper.encodeFnArgs('removeAuthorizedAddress', PROXY_ABI, [owners[0]]);
-            const isFunctionRemoveAuthorizedAddress = await multiSig.isFunctionRemoveAuthorizedAddress(data);
+            const isFunctionRemoveAuthorizedAddress = await multiSig.isFunctionRemoveAuthorizedAddress.callAsync(data);
             expect(isFunctionRemoveAuthorizedAddress).to.be.true();
         });
     });
@@ -114,7 +124,7 @@ describe('MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress', () => {
             const log = abiDecoder.tryToDecodeLogOrNoop(res.logs[0]) as LogWithDecodedArgs<SubmissionContractEventArgs>;
             const txId = log.args.transactionId;
             await multiSig.confirmTransaction.sendTransactionAsync(txId, { from: owners[1] });
-            const isConfirmed = await multiSig.isConfirmed(txId);
+            const isConfirmed = await multiSig.isConfirmed.callAsync(txId);
             expect(isConfirmed).to.be.true();
 
             return expect(
@@ -133,7 +143,7 @@ describe('MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress', () => {
             const log = abiDecoder.tryToDecodeLogOrNoop(res.logs[0]) as LogWithDecodedArgs<SubmissionContractEventArgs>;
             const txId = log.args.transactionId;
             await multiSig.confirmTransaction.sendTransactionAsync(txId, { from: owners[1] });
-            const isConfirmed = await multiSig.isConfirmed(txId);
+            const isConfirmed = await multiSig.isConfirmed.callAsync(txId);
             expect(isConfirmed).to.be.true();
 
             return expect(
@@ -152,10 +162,10 @@ describe('MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress', () => {
             const log = abiDecoder.tryToDecodeLogOrNoop(res.logs[0]) as LogWithDecodedArgs<SubmissionContractEventArgs>;
             const txId = log.args.transactionId;
             await multiSig.confirmTransaction.sendTransactionAsync(txId, { from: owners[1] });
-            const isConfirmed = await multiSig.isConfirmed(txId);
+            const isConfirmed = await multiSig.isConfirmed.callAsync(txId);
             expect(isConfirmed).to.be.true();
             await multiSig.executeRemoveAuthorizedAddress.sendTransactionAsync(txId, { from: owners[1] });
-            const isAuthorized = await tokenTransferProxy.authorized(authorizedAddress);
+            const isAuthorized = await tokenTransferProxy.authorized.callAsync(authorizedAddress);
             expect(isAuthorized).to.be.false();
         });
 
@@ -170,10 +180,10 @@ describe('MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress', () => {
             const log = abiDecoder.tryToDecodeLogOrNoop(res.logs[0]) as LogWithDecodedArgs<SubmissionContractEventArgs>;
             const txId = log.args.transactionId;
             await multiSig.confirmTransaction.sendTransactionAsync(txId, { from: owners[1] });
-            const isConfirmed = await multiSig.isConfirmed(txId);
+            const isConfirmed = await multiSig.isConfirmed.callAsync(txId);
             expect(isConfirmed).to.be.true();
             await multiSig.executeRemoveAuthorizedAddress.sendTransactionAsync(txId, { from: owners[1] });
-            const tx = await multiSig.transactions(txId);
+            const tx = await multiSig.transactions.callAsync(txId);
             const isExecuted = tx[3];
             expect(isExecuted).to.be.true();
             return expect(
diff --git a/packages/contracts/test/token_registry.ts b/packages/contracts/test/token_registry.ts
index 867282d2c..eee14ad9f 100644
--- a/packages/contracts/test/token_registry.ts
+++ b/packages/contracts/test/token_registry.ts
@@ -31,7 +31,7 @@ describe('TokenRegistry', () => {
         owner = accounts[0];
         notOwner = accounts[1];
         const tokenRegInstance = await deployer.deployAsync(ContractName.TokenRegistry);
-        tokenReg = new TokenRegistryContract(tokenRegInstance);
+        tokenReg = new TokenRegistryContract(web3Wrapper, tokenRegInstance.abi, tokenRegInstance.address);
         tokenRegWrapper = new TokenRegWrapper(tokenReg);
     });
     beforeEach(async () => {
diff --git a/packages/contracts/test/token_transfer_proxy/auth.ts b/packages/contracts/test/token_transfer_proxy/auth.ts
index 9d453b079..4f497dd0d 100644
--- a/packages/contracts/test/token_transfer_proxy/auth.ts
+++ b/packages/contracts/test/token_transfer_proxy/auth.ts
@@ -25,7 +25,11 @@ describe('TokenTransferProxy', () => {
         owner = address = accounts[0];
         notOwner = accounts[1];
         const tokenTransferProxyInstance = await deployer.deployAsync(ContractName.TokenTransferProxy);
-        tokenTransferProxy = new TokenTransferProxyContract(tokenTransferProxyInstance);
+        tokenTransferProxy = new TokenTransferProxyContract(
+            web3Wrapper,
+            tokenTransferProxyInstance.abi,
+            tokenTransferProxyInstance.address,
+        );
     });
     beforeEach(async () => {
         await blockchainLifecycle.startAsync();
@@ -41,7 +45,7 @@ describe('TokenTransferProxy', () => {
         });
         it('should allow owner to add an authorized address', async () => {
             await tokenTransferProxy.addAuthorizedAddress.sendTransactionAsync(address, { from: owner });
-            const isAuthorized = await tokenTransferProxy.authorized(address);
+            const isAuthorized = await tokenTransferProxy.authorized.callAsync(address);
             expect(isAuthorized).to.be.true();
         });
         it('should throw if owner attempts to authorize a duplicate address', async () => {
@@ -67,7 +71,7 @@ describe('TokenTransferProxy', () => {
             await tokenTransferProxy.removeAuthorizedAddress.sendTransactionAsync(address, {
                 from: owner,
             });
-            const isAuthorized = await tokenTransferProxy.authorized(address);
+            const isAuthorized = await tokenTransferProxy.authorized.callAsync(address);
             expect(isAuthorized).to.be.false();
         });
 
@@ -82,19 +86,19 @@ describe('TokenTransferProxy', () => {
 
     describe('getAuthorizedAddresses', () => {
         it('should return all authorized addresses', async () => {
-            const initial = await tokenTransferProxy.getAuthorizedAddresses();
+            const initial = await tokenTransferProxy.getAuthorizedAddresses.callAsync();
             expect(initial).to.have.length(0);
             await tokenTransferProxy.addAuthorizedAddress.sendTransactionAsync(address, {
                 from: owner,
             });
-            const afterAdd = await tokenTransferProxy.getAuthorizedAddresses();
+            const afterAdd = await tokenTransferProxy.getAuthorizedAddresses.callAsync();
             expect(afterAdd).to.have.length(1);
             expect(afterAdd).to.include(address);
 
             await tokenTransferProxy.removeAuthorizedAddress.sendTransactionAsync(address, {
                 from: owner,
             });
-            const afterRemove = await tokenTransferProxy.getAuthorizedAddresses();
+            const afterRemove = await tokenTransferProxy.getAuthorizedAddresses.callAsync();
             expect(afterRemove).to.have.length(0);
         });
     });
diff --git a/packages/contracts/test/token_transfer_proxy/transfer_from.ts b/packages/contracts/test/token_transfer_proxy/transfer_from.ts
index c35a7276a..6b86a0e97 100644
--- a/packages/contracts/test/token_transfer_proxy/transfer_from.ts
+++ b/packages/contracts/test/token_transfer_proxy/transfer_from.ts
@@ -33,9 +33,13 @@ describe('TokenTransferProxy', () => {
         accounts = await web3Wrapper.getAvailableAddressesAsync();
         owner = notAuthorized = accounts[0];
         const tokenTransferProxyInstance = await deployer.deployAsync(ContractName.TokenTransferProxy);
-        tokenTransferProxy = new TokenTransferProxyContract(tokenTransferProxyInstance);
+        tokenTransferProxy = new TokenTransferProxyContract(
+            web3Wrapper,
+            tokenTransferProxyInstance.abi,
+            tokenTransferProxyInstance.address,
+        );
         const repInstance = await deployer.deployAsync(ContractName.DummyToken);
-        rep = new DummyTokenContract(repInstance);
+        rep = new DummyTokenContract(web3Wrapper, repInstance.abi, repInstance.address);
 
         dmyBalances = new Balances([rep], [accounts[0], accounts[1]]);
         await Promise.all([
diff --git a/packages/contracts/test/unlimited_allowance_token.ts b/packages/contracts/test/unlimited_allowance_token.ts
index f0a66e76b..03eb581ad 100644
--- a/packages/contracts/test/unlimited_allowance_token.ts
+++ b/packages/contracts/test/unlimited_allowance_token.ts
@@ -35,7 +35,7 @@ describe('UnlimitedAllowanceToken', () => {
         owner = accounts[0];
         spender = accounts[1];
         const tokenInstance = await deployer.deployAsync(ContractName.DummyToken);
-        token = new DummyTokenContract(tokenInstance);
+        token = new DummyTokenContract(web3Wrapper, tokenInstance.abi, tokenInstance.address);
         await token.mint.sendTransactionAsync(MAX_MINT_VALUE, { from: owner });
         tokenAddress = token.address;
     });
diff --git a/packages/contracts/test/zrx_token.ts b/packages/contracts/test/zrx_token.ts
index 1610ada12..4ccc66b36 100644
--- a/packages/contracts/test/zrx_token.ts
+++ b/packages/contracts/test/zrx_token.ts
@@ -36,7 +36,7 @@ describe('ZRXToken', () => {
             networkId: constants.TESTRPC_NETWORK_ID,
         });
         const zrxInstance = await deployer.deployAsync(ContractName.ZRXToken);
-        zrx = new ZRXTokenContract(zrxInstance);
+        zrx = new ZRXTokenContract(web3Wrapper, zrxInstance.abi, zrxInstance.address);
         zrxAddress = zrx.address;
         MAX_UINT = zeroEx.token.UNLIMITED_ALLOWANCE_IN_BASE_UNITS;
     });
@@ -48,25 +48,25 @@ describe('ZRXToken', () => {
     });
     describe('constants', () => {
         it('should have 18 decimals', async () => {
-            const decimals = new BigNumber(await zrx.decimals());
+            const decimals = new BigNumber(await zrx.decimals.callAsync());
             const expectedDecimals = 18;
             expect(decimals).to.be.bignumber.equal(expectedDecimals);
         });
 
         it('should have a total supply of 1 billion tokens', async () => {
-            const totalSupply = new BigNumber(await zrx.totalSupply());
+            const totalSupply = new BigNumber(await zrx.totalSupply.callAsync());
             const expectedTotalSupply = 1000000000;
             expect(ZeroEx.toUnitAmount(totalSupply, 18)).to.be.bignumber.equal(expectedTotalSupply);
         });
 
         it('should be named 0x Protocol Token', async () => {
-            const name = await zrx.name();
+            const name = await zrx.name.callAsync();
             const expectedName = '0x Protocol Token';
             expect(name).to.be.equal(expectedName);
         });
 
         it('should have the symbol ZRX', async () => {
-            const symbol = await zrx.symbol();
+            const symbol = await zrx.symbol.callAsync();
             const expectedSymbol = 'ZRX';
             expect(symbol).to.be.equal(expectedSymbol);
         });
@@ -75,7 +75,7 @@ describe('ZRXToken', () => {
     describe('constructor', () => {
         it('should initialize owner balance to totalSupply', async () => {
             const ownerBalance = await zeroEx.token.getBalanceAsync(zrxAddress, owner);
-            const totalSupply = new BigNumber(await zrx.totalSupply());
+            const totalSupply = new BigNumber(await zrx.totalSupply.callAsync());
             expect(totalSupply).to.be.bignumber.equal(ownerBalance);
         });
     });
diff --git a/packages/contracts/tsconfig.json b/packages/contracts/tsconfig.json
index b618ca4e7..490531eeb 100644
--- a/packages/contracts/tsconfig.json
+++ b/packages/contracts/tsconfig.json
@@ -11,6 +11,7 @@
         "../../node_modules/types-ethereumjs-util/index.d.ts",
         "../../node_modules/chai-typescript-typings/index.d.ts",
         "../../node_modules/web3-typescript-typings/index.d.ts",
+        "../../node_modules/ethers-typescript-typings/index.d.ts",
         "../../node_modules/chai-as-promised-typescript-typings/index.d.ts",
         "../../node_modules/types-ethereumjs-util/index.d.ts",
         "../../node_modules/types-bn/index.d.ts",
diff --git a/packages/contracts/util/balances.ts b/packages/contracts/util/balances.ts
index 0abc305d8..d03d4b3c5 100644
--- a/packages/contracts/util/balances.ts
+++ b/packages/contracts/util/balances.ts
@@ -17,7 +17,7 @@ export class Balances {
         const balancesByOwner: BalancesByOwner = {};
         for (const tokenContractInstance of this._tokenContractInstances) {
             for (const ownerAddress of this._ownerAddresses) {
-                let balance = await tokenContractInstance.balanceOf(ownerAddress);
+                let balance = await tokenContractInstance.balanceOf.callAsync(ownerAddress);
                 balance = new BigNumber(balance);
                 if (_.isUndefined(balancesByOwner[ownerAddress])) {
                     balancesByOwner[ownerAddress] = {};
diff --git a/packages/contracts/util/exchange_wrapper.ts b/packages/contracts/util/exchange_wrapper.ts
index 03d04629d..f016067fe 100644
--- a/packages/contracts/util/exchange_wrapper.ts
+++ b/packages/contracts/util/exchange_wrapper.ts
@@ -186,11 +186,11 @@ export class ExchangeWrapper {
     public async getOrderHashAsync(signedOrder: SignedOrder): Promise<string> {
         const shouldThrowOnInsufficientBalanceOrAllowance = false;
         const params = signedOrderUtils.getOrderAddressesAndValues(signedOrder);
-        const orderHash = await this._exchange.getOrderHash(params.orderAddresses, params.orderValues);
+        const orderHash = await this._exchange.getOrderHash.callAsync(params.orderAddresses, params.orderValues);
         return orderHash;
     }
     public async isValidSignatureAsync(signedOrder: SignedOrder): Promise<boolean> {
-        const isValidSignature = await this._exchange.isValidSignature(
+        const isValidSignature = await this._exchange.isValidSignature.callAsync(
             signedOrder.maker,
             ZeroEx.getOrderHashHex(signedOrder),
             signedOrder.ecSignature.v,
@@ -204,7 +204,7 @@ export class ExchangeWrapper {
         denominator: BigNumber,
         target: BigNumber,
     ): Promise<boolean> {
-        const isRoundingError = await this._exchange.isRoundingError(numerator, denominator, target);
+        const isRoundingError = await this._exchange.isRoundingError.callAsync(numerator, denominator, target);
         return isRoundingError;
     }
     public async getPartialAmountAsync(
@@ -212,7 +212,9 @@ export class ExchangeWrapper {
         denominator: BigNumber,
         target: BigNumber,
     ): Promise<BigNumber> {
-        const partialAmount = new BigNumber(await this._exchange.getPartialAmount(numerator, denominator, target));
+        const partialAmount = new BigNumber(
+            await this._exchange.getPartialAmount.callAsync(numerator, denominator, target),
+        );
         return partialAmount;
     }
 }
diff --git a/packages/contracts/util/token_registry_wrapper.ts b/packages/contracts/util/token_registry_wrapper.ts
index d0af17103..d78c8a64e 100644
--- a/packages/contracts/util/token_registry_wrapper.ts
+++ b/packages/contracts/util/token_registry_wrapper.ts
@@ -22,36 +22,36 @@ export class TokenRegWrapper {
         return tx;
     }
     public async getTokenMetaDataAsync(tokenAddress: string) {
-        const data = await this._tokenReg.getTokenMetaData(tokenAddress);
+        const data = await this._tokenReg.getTokenMetaData.callAsync(tokenAddress);
         const token: Token = {
             address: data[0],
             name: data[1],
             symbol: data[2],
-            decimals: data[3].toNumber(),
+            decimals: data[3],
             ipfsHash: data[4],
             swarmHash: data[5],
         };
         return token;
     }
     public async getTokenByNameAsync(tokenName: string) {
-        const data = await this._tokenReg.getTokenByName(tokenName);
+        const data = await this._tokenReg.getTokenByName.callAsync(tokenName);
         const token: Token = {
             address: data[0],
             name: data[1],
             symbol: data[2],
-            decimals: data[3].toNumber(),
+            decimals: data[3],
             ipfsHash: data[4],
             swarmHash: data[5],
         };
         return token;
     }
     public async getTokenBySymbolAsync(tokenSymbol: string) {
-        const data = await this._tokenReg.getTokenBySymbol(tokenSymbol);
+        const data = await this._tokenReg.getTokenBySymbol.callAsync(tokenSymbol);
         const token: Token = {
             address: data[0],
             name: data[1],
             symbol: data[2],
-            decimals: data[3].toNumber(),
+            decimals: data[3],
             ipfsHash: data[4],
             swarmHash: data[5],
         };
diff --git a/packages/contracts/util/types.ts b/packages/contracts/util/types.ts
index 65bc26f79..d6e4c587d 100644
--- a/packages/contracts/util/types.ts
+++ b/packages/contracts/util/types.ts
@@ -41,8 +41,8 @@ export interface DefaultOrderParams {
     exchangeContractAddress: string;
     maker: string;
     feeRecipient: string;
-    makerToken: string;
-    takerToken: string;
+    makerTokenAddress: string;
+    takerTokenAddress: string;
     makerTokenAmount: BigNumber;
     takerTokenAmount: BigNumber;
     makerFee: BigNumber;
diff --git a/packages/deployer/package.json b/packages/deployer/package.json
index f969e4eda..2a6668fa6 100644
--- a/packages/deployer/package.json
+++ b/packages/deployer/package.json
@@ -36,6 +36,7 @@
         "tslint": "5.8.0",
         "types-bn": "^0.0.1",
         "typescript": "2.7.1",
+        "ethers-typescript-typings": "^0.0.1",
         "web3-typescript-typings": "^0.9.11"
     },
     "dependencies": {
diff --git a/packages/deployer/src/cli.ts b/packages/deployer/src/cli.ts
index ba156ac20..c976e8f97 100644
--- a/packages/deployer/src/cli.ts
+++ b/packages/deployer/src/cli.ts
@@ -10,8 +10,8 @@ import { constants } from './utils/constants';
 import { CliOptions, CompilerOptions, DeployerOptions } from './utils/types';
 
 const DEFAULT_OPTIMIZER_ENABLED = false;
-const DEFAULT_CONTRACTS_DIR = path.resolve('src');
-const DEFAULT_ARTIFACTS_DIR = path.resolve('artifacts');
+const DEFAULT_CONTRACTS_DIR = path.resolve('src/contracts');
+const DEFAULT_ARTIFACTS_DIR = path.resolve('src/artifacts');
 const DEFAULT_NETWORK_ID = 50;
 const DEFAULT_JSONRPC_PORT = 8545;
 const DEFAULT_GAS_PRICE = (10 ** 9 * 2).toString();
@@ -100,6 +100,9 @@ async function onDeployCommand(argv: CliOptions): Promise<void> {
  */
 function getContractsSetFromList(contracts: string): Set<string> {
     const specifiedContracts = new Set();
+    if (contracts === '*') {
+        return new Set(['*']);
+    }
     const contractsArray = contracts.split(',');
     _.forEach(contractsArray, contractName => {
         const fileName = `${contractName}${constants.SOLIDITY_FILE_EXTENSION}`;
diff --git a/packages/deployer/src/deployer.ts b/packages/deployer/src/deployer.ts
index 021645fd1..6710bcc85 100644
--- a/packages/deployer/src/deployer.ts
+++ b/packages/deployer/src/deployer.ts
@@ -174,7 +174,7 @@ export class Deployer {
         const block = await this.web3Wrapper.getBlockAsync('latest');
         let gas: number;
         try {
-            const gasEstimate: number = await this.web3Wrapper.estimateGasAsync(data);
+            const gasEstimate: number = await this.web3Wrapper.estimateGasAsync({ data });
             gas = Math.min(gasEstimate + EXTRA_GAS, block.gasLimit);
         } catch (err) {
             gas = block.gasLimit;
diff --git a/packages/deployer/tsconfig.json b/packages/deployer/tsconfig.json
index 4e1edb510..897446b66 100644
--- a/packages/deployer/tsconfig.json
+++ b/packages/deployer/tsconfig.json
@@ -11,6 +11,7 @@
         "../../node_modules/types-bn/index.d.ts",
         "../../node_modules/types-ethereumjs-util/index.d.ts",
         "../../node_modules/chai-typescript-typings/index.d.ts",
+        "../../node_modules/ethers-typescript-typings/index.d.ts",
         "../../node_modules/web3-typescript-typings/index.d.ts"
     ]
 }
diff --git a/packages/dev-utils/tsconfig.json b/packages/dev-utils/tsconfig.json
index ace978fea..1ed3fbc9c 100644
--- a/packages/dev-utils/tsconfig.json
+++ b/packages/dev-utils/tsconfig.json
@@ -8,6 +8,7 @@
         "./test/**/*",
         "../../node_modules/types-bn/index.d.ts",
         "../../node_modules/chai-typescript-typings/index.d.ts",
+        "../../node_modules/ethers-typescript-typings/index.d.ts",
         "../../node_modules/web3-typescript-typings/index.d.ts",
         "../../node_modules/types-ethereumjs-util/index.d.ts"
     ]
diff --git a/packages/ethers-typescript-typings/.npmignore b/packages/ethers-typescript-typings/.npmignore
new file mode 100644
index 000000000..104d718ed
--- /dev/null
+++ b/packages/ethers-typescript-typings/.npmignore
@@ -0,0 +1,3 @@
+.*
+yarn-error.log
+/scripts/
diff --git a/packages/ethers-typescript-typings/CHANGELOG.md b/packages/ethers-typescript-typings/CHANGELOG.md
new file mode 100644
index 000000000..d67d5c73d
--- /dev/null
+++ b/packages/ethers-typescript-typings/CHANGELOG.md
@@ -0,0 +1,5 @@
+# CHANGELOG
+
+## v0.0.1 - _TBD, 2018_
+
+    * Initial types (#413)
diff --git a/packages/ethers-typescript-typings/README.md b/packages/ethers-typescript-typings/README.md
new file mode 100644
index 000000000..56ce5f138
--- /dev/null
+++ b/packages/ethers-typescript-typings/README.md
@@ -0,0 +1,49 @@
+## ethers-typescript-typings
+
+There currently isn't an official [Ethers][ethers]
+type definition included in the [DefinitelyTyped][definitelytyped] project.
+Until that happens, we will continue to improve our own type definition.
+If it get's close to comprehensive, we'll add it to [DefinitelyTyped][definitelytyped].
+
+[ethers]: https://github.com/ethers-io/ethers.js
+[definitelytyped]: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+## Installation
+
+```bash
+yarn add -D ethers-typescript-typings
+```
+
+## Usage
+
+Add the following line within an `include` section of your `tsconfig.json`
+
+```json
+"./node_modules/ethers-typescript-typings/index.d.ts"
+```
+
+## Contributing
+
+We strongly encourage that the community help us make improvements and determine the future direction of the protocol. To report bugs within this package, please create an issue in this repository.
+
+Please read our [contribution guidelines](../../CONTRIBUTING.md) before getting started.
+
+### Install Dependencies
+
+If you don't have yarn workspaces enabled (Yarn < v1.0) - enable them:
+
+```bash
+yarn config set workspaces-experimental true
+```
+
+Then install dependencies
+
+```bash
+yarn install
+```
+
+### Lint
+
+```bash
+yarn lint
+```
diff --git a/packages/ethers-typescript-typings/index.d.ts b/packages/ethers-typescript-typings/index.d.ts
new file mode 100644
index 000000000..e5d38819e
--- /dev/null
+++ b/packages/ethers-typescript-typings/index.d.ts
@@ -0,0 +1,28 @@
+declare module 'ethers-contracts' {
+    export interface TransactionDescription {
+        name: string;
+        signature: string;
+        sighash: string;
+        data: string;
+    }
+    export interface CallDescription extends TransactionDescription {
+        parse: (...args: any[]) => any;
+    }
+    export interface FunctionDescription {
+        (...params: any[]): TransactionDescription | CallDescription;
+        inputs: { names: string[]; types: string[] };
+        outputs: { names: string[]; types: string[] };
+    }
+    export interface EventDescription {
+        parse: (...args: any[]) => any;
+        inputs: { names: string[]; types: string[] };
+        signature: string;
+        topic: string;
+    }
+    export class Interface {
+        public functions: { [functionName: string]: FunctionDescription };
+        public events: { [eventName: string]: EventDescription };
+        public static decodeParams(types: string[], data: string): any[];
+        constructor(abi: any);
+    }
+}
diff --git a/packages/ethers-typescript-typings/package.json b/packages/ethers-typescript-typings/package.json
new file mode 100644
index 000000000..0e6f517c8
--- /dev/null
+++ b/packages/ethers-typescript-typings/package.json
@@ -0,0 +1,28 @@
+{
+    "name": "ethers-typescript-typings",
+    "version": "0.0.1",
+    "description": "Typescript type definitions for ethers.js",
+    "main": "index.d.ts",
+    "types": "index.d.ts",
+    "scripts": {
+        "lint": "tslint index.d.ts"
+    },
+    "repository": {
+        "type": "git",
+        "url": "git+https://github.com/0xProject/0x.js.git"
+    },
+    "author": "Fabio Berger",
+    "contributors": [
+        "Leonid Logvinov <logvinov.leon@gmail.com>"
+    ],
+    "license": "Apache-2.0",
+    "bugs": {
+        "url": "https://github.com/0xProject/0x.js/issues"
+    },
+    "homepage": "https://github.com/0xProject/0x.js/packages/ethers-typescript-typings#readme",
+    "devDependencies": {
+        "tslint": "5.8.0",
+        "tslint-config-0xproject": "^0.0.2",
+        "typescript": "2.7.1"
+    }
+}
diff --git a/packages/ethers-typescript-typings/scripts/postpublish.js b/packages/ethers-typescript-typings/scripts/postpublish.js
new file mode 100644
index 000000000..b3e5407c8
--- /dev/null
+++ b/packages/ethers-typescript-typings/scripts/postpublish.js
@@ -0,0 +1,5 @@
+const postpublish_utils = require('../../../scripts/postpublish_utils');
+const packageJSON = require('../package.json');
+
+const subPackageName = packageJSON.name;
+postpublish_utils.standardPostPublishAsync(subPackageName);
\ No newline at end of file
diff --git a/packages/ethers-typescript-typings/tslint.json b/packages/ethers-typescript-typings/tslint.json
new file mode 100644
index 000000000..9a93a1f74
--- /dev/null
+++ b/packages/ethers-typescript-typings/tslint.json
@@ -0,0 +1,3 @@
+{
+    "extends": ["tslint-config-0xproject"]
+}
diff --git a/packages/types/CHANGELOG.md b/packages/types/CHANGELOG.md
index b1cb721d2..a4f293d60 100644
--- a/packages/types/CHANGELOG.md
+++ b/packages/types/CHANGELOG.md
@@ -1,5 +1,10 @@
 # CHANGELOG
 
+## v0.2.4 - _TBD, 2018_
+
+    * Add `data` to `TxData` (#413)
+    * Add `number` as an option to `ContractEventArg` (#413)
+
 ## v0.2.1 - _February 9, 2018_
 
     * Fix publishing issue where .npmignore was not properly excluding undesired content (#389)
diff --git a/packages/types/src/index.ts b/packages/types/src/index.ts
index cb17936f7..6242d4268 100644
--- a/packages/types/src/index.ts
+++ b/packages/types/src/index.ts
@@ -2,6 +2,7 @@ import { BigNumber } from 'bignumber.js';
 import * as Web3 from 'web3';
 
 export interface TxData {
+    data?: string;
     from?: string;
     gas?: number;
     gasPrice?: BigNumber;
@@ -38,7 +39,7 @@ export enum AbiType {
     Fallback = 'fallback',
 }
 
-export type ContractEventArg = string | BigNumber;
+export type ContractEventArg = string | BigNumber | number;
 
 export interface DecodedLogArgs {
     [argName: string]: ContractEventArg;
diff --git a/packages/utils/CHANGELOG.md b/packages/utils/CHANGELOG.md
index 19ee80e4f..81792bee8 100644
--- a/packages/utils/CHANGELOG.md
+++ b/packages/utils/CHANGELOG.md
@@ -1,5 +1,9 @@
 # CHANGELOG
 
+## v0.4.0 - _TBD, 2018_
+
+    * Use `ethers-contracts` as a backend to decode event args (#413)
+
 ## v0.3.2 - _February 9, 2018_
 
     * Fix publishing issue where .npmignore was not properly excluding undesired content (#389)
diff --git a/packages/utils/package.json b/packages/utils/package.json
index 14ccabcf4..4f63aa4ce 100644
--- a/packages/utils/package.json
+++ b/packages/utils/package.json
@@ -26,11 +26,13 @@
         "shx": "^0.2.2",
         "tslint": "5.8.0",
         "typescript": "2.7.1",
+        "ethers-typescript-typings": "^0.0.1",
         "web3-typescript-typings": "^0.9.11"
     },
     "dependencies": {
         "@0xproject/types": "^0.2.3",
         "bignumber.js": "~4.1.0",
+        "ethers-contracts": "^2.2.1",
         "js-sha3": "^0.7.0",
         "lodash": "^4.17.4",
         "web3": "^0.20.0"
diff --git a/packages/utils/src/abi_decoder.ts b/packages/utils/src/abi_decoder.ts
index 368973b1b..2b496eb17 100644
--- a/packages/utils/src/abi_decoder.ts
+++ b/packages/utils/src/abi_decoder.ts
@@ -1,7 +1,7 @@
 import { AbiType, DecodedLogArgs, LogWithDecodedArgs, RawLog, SolidityTypes } from '@0xproject/types';
+import * as ethersContracts from 'ethers-contracts';
 import * as _ from 'lodash';
 import * as Web3 from 'web3';
-import * as SolidityCoder from 'web3/lib/solidity/coder';
 
 import { BigNumber } from './configured_bignumber';
 
@@ -27,31 +27,29 @@ export class AbiDecoder {
         if (_.isUndefined(event)) {
             return log;
         }
+        const ethersInterface = new ethersContracts.Interface([event]);
         const logData = log.data;
         const decodedParams: DecodedLogArgs = {};
-        let dataIndex = 0;
         let topicsIndex = 1;
 
         const nonIndexedInputs = _.filter(event.inputs, input => !input.indexed);
         const dataTypes = _.map(nonIndexedInputs, input => input.type);
-        const decodedData = SolidityCoder.decodeParams(dataTypes, logData.slice('0x'.length));
+        const decodedData = ethersInterface.events[event.name].parse(log.data);
 
         let failedToDecode = false;
-        _.forEach(event.inputs, (param: Web3.EventParameter) => {
+        _.forEach(event.inputs, (param: Web3.EventParameter, i: number) => {
             // Indexed parameters are stored in topics. Non-indexed ones in decodedData
-            let value: BigNumber | string = param.indexed ? log.topics[topicsIndex++] : decodedData[dataIndex++];
+            let value: BigNumber | string | number = param.indexed ? log.topics[topicsIndex++] : decodedData[i];
             if (_.isUndefined(value)) {
                 failedToDecode = true;
                 return;
             }
             if (param.type === SolidityTypes.Address) {
                 value = AbiDecoder._padZeros(new BigNumber(value).toString(16));
-            } else if (
-                param.type === SolidityTypes.Uint256 ||
-                param.type === SolidityTypes.Uint8 ||
-                param.type === SolidityTypes.Uint
-            ) {
+            } else if (param.type === SolidityTypes.Uint256 || param.type === SolidityTypes.Uint) {
                 value = new BigNumber(value);
+            } else if (param.type === SolidityTypes.Uint8) {
+                value = new BigNumber(value).toNumber();
             }
             decodedParams[param.name] = value;
         });
@@ -67,11 +65,14 @@ export class AbiDecoder {
         }
     }
     private _addABI(abiArray: Web3.AbiDefinition[]): void {
+        if (_.isUndefined(abiArray)) {
+            return;
+        }
+        const ethersInterface = new ethersContracts.Interface(abiArray);
         _.map(abiArray, (abi: Web3.AbiDefinition) => {
             if (abi.type === AbiType.Event) {
-                const signature = `${abi.name}(${_.map(abi.inputs, input => input.type).join(',')})`;
-                const signatureHash = new Web3().sha3(signature);
-                this._methodIds[signatureHash] = abi;
+                const topic = ethersInterface.events[abi.name].topic;
+                this._methodIds[topic] = abi;
             }
         });
         this._savedABIs = this._savedABIs.concat(abiArray);
diff --git a/packages/utils/src/globals.d.ts b/packages/utils/src/globals.d.ts
deleted file mode 100644
index ade9e59db..000000000
--- a/packages/utils/src/globals.d.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-declare module 'web3/lib/solidity/coder' {
-    const decodeParams: (types: string[], data: string) => any[];
-}
diff --git a/packages/utils/tsconfig.json b/packages/utils/tsconfig.json
index 3d967d05f..8114d99cd 100644
--- a/packages/utils/tsconfig.json
+++ b/packages/utils/tsconfig.json
@@ -3,5 +3,9 @@
     "compilerOptions": {
         "outDir": "lib"
     },
-    "include": ["./src/**/*", "../../node_modules/web3-typescript-typings/index.d.ts"]
+    "include": [
+        "./src/**/*",
+        "../../node_modules/web3-typescript-typings/index.d.ts",
+        "../../node_modules/ethers-typescript-typings/index.d.ts"
+    ]
 }
diff --git a/packages/web3-wrapper/CHANGELOG.md b/packages/web3-wrapper/CHANGELOG.md
index 387aafb3a..eef665d24 100644
--- a/packages/web3-wrapper/CHANGELOG.md
+++ b/packages/web3-wrapper/CHANGELOG.md
@@ -1,9 +1,12 @@
 # CHANGELOG
 
-## v0.2.XX - _TBD_ 2018
+## v0.2.0 _TBD, 2018_
 
-    *  Ensure all returned user addresses are lowercase (#373)
+    * Ensure all returned user addresses are lowercase (#373)
+    * Add `web3Wrapper.callAsync` (#413)
+    * Make `web3Wrapper.estimateGas` accept whole `txData` instead of `data` (#413)
+    * Remove `web3Wrapper.getContractInstance` (#413)
 
-## v0.1.12 - _February 9, 2018_
+## v0.1.12 _February 9, 2018_
 
     * Fix publishing issue where .npmignore was not properly excluding undesired content (#389)
diff --git a/packages/web3-wrapper/package.json b/packages/web3-wrapper/package.json
index 8f87bb118..e827842b0 100644
--- a/packages/web3-wrapper/package.json
+++ b/packages/web3-wrapper/package.json
@@ -26,11 +26,13 @@
         "shx": "^0.2.2",
         "tslint": "5.8.0",
         "typescript": "2.7.1",
+        "ethers-typescript-typings": "^0.0.1",
         "web3-typescript-typings": "^0.9.11"
     },
     "dependencies": {
         "@0xproject/types": "^0.2.3",
         "@0xproject/utils": "^0.3.4",
+        "ethers-contracts": "^2.2.1",
         "lodash": "^4.17.4",
         "web3": "^0.20.0"
     }
diff --git a/packages/web3-wrapper/src/base_contract.ts b/packages/web3-wrapper/src/base_contract.ts
new file mode 100644
index 000000000..997ce97d3
--- /dev/null
+++ b/packages/web3-wrapper/src/base_contract.ts
@@ -0,0 +1,69 @@
+import { TxData, TxDataPayable } from '@0xproject/types';
+import * as ethersContracts from 'ethers-contracts';
+import * as _ from 'lodash';
+import * as Web3 from 'web3';
+
+import { Web3Wrapper } from './web3_wrapper';
+
+export class BaseContract {
+    protected _ethersInterface: ethersContracts.Interface;
+    protected _web3Wrapper: Web3Wrapper;
+    public abi: Web3.ContractAbi;
+    public address: string;
+    protected static _transformABIData(
+        abis: Web3.DataItem[],
+        values: any[],
+        transformation: (type: string, value: any) => any,
+    ): any {
+        return _.map(values, (value: any, i: number) =>
+            BaseContract._transformTypedData(abis[i].type, value, transformation),
+        );
+    }
+    protected static _lowercaseAddress(type: string, value: string): string {
+        return type === 'address' ? value.toLowerCase() : value;
+    }
+    protected static _bigNumberToString(type: string, value: string): string {
+        return _.isObject(value) && (value as any).isBigNumber ? value.toString() : value;
+    }
+    private static _transformTypedData(
+        type: string,
+        values: any,
+        transformation: (type: string, value: any) => any,
+    ): any {
+        const trailingArrayRegex = /\[\d*\]$/;
+        if (type.match(trailingArrayRegex)) {
+            const arrayItemType = type.replace(trailingArrayRegex, '');
+            return _.map(values, value => this._transformTypedData(arrayItemType, value, transformation));
+        } else {
+            return transformation(type, values);
+        }
+    }
+    protected async _applyDefaultsToTxDataAsync<T extends Partial<TxData | TxDataPayable>>(
+        txData: T,
+        estimateGasAsync?: (txData: T) => Promise<number>,
+    ): Promise<TxData> {
+        // Gas amount sourced with the following priorities:
+        // 1. Optional param passed in to public method call
+        // 2. Global config passed in at library instantiation
+        // 3. Gas estimate calculation + safety margin
+        const removeUndefinedProperties = _.pickBy;
+        const txDataWithDefaults = {
+            to: this.address,
+            ...removeUndefinedProperties(this._web3Wrapper.getContractDefaults()),
+            ...removeUndefinedProperties(txData as any),
+            // HACK: TS can't prove that T is spreadable.
+            // Awaiting https://github.com/Microsoft/TypeScript/pull/13288 to be merged
+        };
+        if (_.isUndefined(txDataWithDefaults.gas) && !_.isUndefined(estimateGasAsync)) {
+            const estimatedGas = await estimateGasAsync(txData);
+            txDataWithDefaults.gas = estimatedGas;
+        }
+        return txDataWithDefaults;
+    }
+    constructor(web3Wrapper: Web3Wrapper, abi: Web3.ContractAbi, address: string) {
+        this._web3Wrapper = web3Wrapper;
+        this.abi = abi;
+        this.address = address;
+        this._ethersInterface = new ethersContracts.Interface(abi);
+    }
+}
diff --git a/packages/web3-wrapper/src/index.ts b/packages/web3-wrapper/src/index.ts
index 7f3452c98..56dfa227c 100644
--- a/packages/web3-wrapper/src/index.ts
+++ b/packages/web3-wrapper/src/index.ts
@@ -1,179 +1,2 @@
-import { TransactionReceipt, TxData } from '@0xproject/types';
-import { BigNumber, promisify } from '@0xproject/utils';
-import * as _ from 'lodash';
-import * as Web3 from 'web3';
-
-interface RawLogEntry {
-    logIndex: string | null;
-    transactionIndex: string | null;
-    transactionHash: string;
-    blockHash: string | null;
-    blockNumber: string | null;
-    address: string;
-    data: string;
-    topics: string[];
-}
-
-export class Web3Wrapper {
-    private _web3: Web3;
-    private _defaults: Partial<TxData>;
-    private _jsonRpcRequestId: number;
-    constructor(provider: Web3.Provider, defaults?: Partial<TxData>) {
-        if (_.isUndefined((provider as any).sendAsync)) {
-            // Web3@1.0 provider doesn't support synchronous http requests,
-            // so it only has an async `send` method, instead of a `send` and `sendAsync` in web3@0.x.x`
-            // We re-assign the send method so that Web3@1.0 providers work with 0x.js
-            (provider as any).sendAsync = (provider as any).send;
-        }
-        this._web3 = new Web3();
-        this._web3.setProvider(provider);
-        this._defaults = defaults || {};
-        this._jsonRpcRequestId = 0;
-    }
-    public getContractDefaults(): Partial<TxData> {
-        return this._defaults;
-    }
-    public setProvider(provider: Web3.Provider) {
-        this._web3.setProvider(provider);
-    }
-    public isAddress(address: string): boolean {
-        return this._web3.isAddress(address);
-    }
-    public async isSenderAddressAvailableAsync(senderAddress: string): Promise<boolean> {
-        const addresses = await this.getAvailableAddressesAsync();
-        const normalizedAddress = senderAddress.toLowerCase();
-        return _.includes(addresses, normalizedAddress);
-    }
-    public async getNodeVersionAsync(): Promise<string> {
-        const nodeVersion = await promisify<string>(this._web3.version.getNode)();
-        return nodeVersion;
-    }
-    public async getNetworkIdAsync(): Promise<number> {
-        const networkIdStr = await promisify<string>(this._web3.version.getNetwork)();
-        const networkId = _.parseInt(networkIdStr);
-        return networkId;
-    }
-    public async getTransactionReceiptAsync(txHash: string): Promise<TransactionReceipt> {
-        const transactionReceipt = await promisify<TransactionReceipt>(this._web3.eth.getTransactionReceipt)(txHash);
-        if (!_.isNull(transactionReceipt)) {
-            transactionReceipt.status = this._normalizeTxReceiptStatus(transactionReceipt.status);
-        }
-        return transactionReceipt;
-    }
-    public getCurrentProvider(): Web3.Provider {
-        return this._web3.currentProvider;
-    }
-    public toWei(ethAmount: BigNumber): BigNumber {
-        const balanceWei = this._web3.toWei(ethAmount, 'ether');
-        return balanceWei;
-    }
-    public async getBalanceInWeiAsync(owner: string): Promise<BigNumber> {
-        let balanceInWei = await promisify<BigNumber>(this._web3.eth.getBalance)(owner);
-        // Rewrap in a new BigNumber
-        balanceInWei = new BigNumber(balanceInWei);
-        return balanceInWei;
-    }
-    public async doesContractExistAtAddressAsync(address: string): Promise<boolean> {
-        const code = await promisify<string>(this._web3.eth.getCode)(address);
-        // Regex matches 0x0, 0x00, 0x in order to accommodate poorly implemented clients
-        const codeIsEmpty = /^0x0{0,40}$/i.test(code);
-        return !codeIsEmpty;
-    }
-    public async signTransactionAsync(address: string, message: string): Promise<string> {
-        const signData = await promisify<string>(this._web3.eth.sign)(address, message);
-        return signData;
-    }
-    public async getBlockNumberAsync(): Promise<number> {
-        const blockNumber = await promisify<number>(this._web3.eth.getBlockNumber)();
-        return blockNumber;
-    }
-    public async getBlockAsync(blockParam: string | Web3.BlockParam): Promise<Web3.BlockWithoutTransactionData> {
-        const block = await promisify<Web3.BlockWithoutTransactionData>(this._web3.eth.getBlock)(blockParam);
-        return block;
-    }
-    public async getBlockTimestampAsync(blockParam: string | Web3.BlockParam): Promise<number> {
-        const { timestamp } = await this.getBlockAsync(blockParam);
-        return timestamp;
-    }
-    public async getAvailableAddressesAsync(): Promise<string[]> {
-        const addresses = await promisify<string[]>(this._web3.eth.getAccounts)();
-        const normalizedAddresses = _.map(addresses, address => address.toLowerCase());
-        return normalizedAddresses;
-    }
-    public async getLogsAsync(filter: Web3.FilterObject): Promise<Web3.LogEntry[]> {
-        let fromBlock = filter.fromBlock;
-        if (_.isNumber(fromBlock)) {
-            fromBlock = this._web3.toHex(fromBlock);
-        }
-        let toBlock = filter.toBlock;
-        if (_.isNumber(toBlock)) {
-            toBlock = this._web3.toHex(toBlock);
-        }
-        const serializedFilter = {
-            ...filter,
-            fromBlock,
-            toBlock,
-        };
-        const payload = {
-            jsonrpc: '2.0',
-            id: this._jsonRpcRequestId++,
-            method: 'eth_getLogs',
-            params: [serializedFilter],
-        };
-        const rawLogs = await this._sendRawPayloadAsync<RawLogEntry[]>(payload);
-        const formattedLogs = _.map(rawLogs, this._formatLog.bind(this));
-        return formattedLogs;
-    }
-    public getContractFromAbi(abi: Web3.ContractAbi): Web3.Contract<any> {
-        const web3Contract = this._web3.eth.contract(abi);
-        return web3Contract;
-    }
-    public getContractInstance(abi: Web3.ContractAbi, address: string): Web3.ContractInstance {
-        const web3ContractInstance = this.getContractFromAbi(abi).at(address);
-        return web3ContractInstance;
-    }
-    public async estimateGasAsync(data: string): Promise<number> {
-        const gas = await promisify<number>(this._web3.eth.estimateGas)({ data });
-        return gas;
-    }
-    public async sendTransactionAsync(txData: Web3.TxData): Promise<string> {
-        const txHash = await promisify<string>(this._web3.eth.sendTransaction)(txData);
-        return txHash;
-    }
-    private async _sendRawPayloadAsync<A>(payload: Web3.JSONRPCRequestPayload): Promise<A> {
-        const sendAsync = this._web3.currentProvider.sendAsync.bind(this._web3.currentProvider);
-        const response = await promisify<Web3.JSONRPCResponsePayload>(sendAsync)(payload);
-        const result = response.result;
-        return result;
-    }
-    private _normalizeTxReceiptStatus(status: undefined | null | string | 0 | 1): null | 0 | 1 {
-        // Transaction status might have four values
-        // undefined - Testrpc and other old clients
-        // null - New clients on old transactions
-        // number - Parity
-        // hex - Geth
-        if (_.isString(status)) {
-            return this._web3.toDecimal(status) as 0 | 1;
-        } else if (_.isUndefined(status)) {
-            return null;
-        } else {
-            return status;
-        }
-    }
-    private _formatLog(rawLog: RawLogEntry): Web3.LogEntry {
-        const formattedLog = {
-            ...rawLog,
-            logIndex: this._hexToDecimal(rawLog.logIndex),
-            blockNumber: this._hexToDecimal(rawLog.blockNumber),
-            transactionIndex: this._hexToDecimal(rawLog.transactionIndex),
-        };
-        return formattedLog;
-    }
-    private _hexToDecimal(hex: string | null): number | null {
-        if (_.isNull(hex)) {
-            return null;
-        }
-        const decimal = this._web3.toDecimal(hex);
-        return decimal;
-    }
-}
+export { Web3Wrapper } from './web3_wrapper';
+export { BaseContract } from './base_contract';
diff --git a/packages/web3-wrapper/src/web3_wrapper.ts b/packages/web3-wrapper/src/web3_wrapper.ts
new file mode 100644
index 000000000..a07805344
--- /dev/null
+++ b/packages/web3-wrapper/src/web3_wrapper.ts
@@ -0,0 +1,179 @@
+import { TransactionReceipt, TxData } from '@0xproject/types';
+import { BigNumber, promisify } from '@0xproject/utils';
+import * as _ from 'lodash';
+import * as Web3 from 'web3';
+
+interface RawLogEntry {
+    logIndex: string | null;
+    transactionIndex: string | null;
+    transactionHash: string;
+    blockHash: string | null;
+    blockNumber: string | null;
+    address: string;
+    data: string;
+    topics: string[];
+}
+
+export class Web3Wrapper {
+    private _web3: Web3;
+    private _defaults: Partial<TxData>;
+    private _jsonRpcRequestId: number;
+    constructor(provider: Web3.Provider, defaults?: Partial<TxData>) {
+        if (_.isUndefined((provider as any).sendAsync)) {
+            // Web3@1.0 provider doesn't support synchronous http requests,
+            // so it only has an async `send` method, instead of a `send` and `sendAsync` in web3@0.x.x`
+            // We re-assign the send method so that Web3@1.0 providers work with 0x.js
+            (provider as any).sendAsync = (provider as any).send;
+        }
+        this._web3 = new Web3();
+        this._web3.setProvider(provider);
+        this._defaults = defaults || {};
+        this._jsonRpcRequestId = 0;
+    }
+    public getContractDefaults(): Partial<TxData> {
+        return this._defaults;
+    }
+    public setProvider(provider: Web3.Provider) {
+        this._web3.setProvider(provider);
+    }
+    public isAddress(address: string): boolean {
+        return this._web3.isAddress(address);
+    }
+    public async isSenderAddressAvailableAsync(senderAddress: string): Promise<boolean> {
+        const addresses = await this.getAvailableAddressesAsync();
+        const normalizedAddress = senderAddress.toLowerCase();
+        return _.includes(addresses, normalizedAddress);
+    }
+    public async getNodeVersionAsync(): Promise<string> {
+        const nodeVersion = await promisify<string>(this._web3.version.getNode)();
+        return nodeVersion;
+    }
+    public async getNetworkIdAsync(): Promise<number> {
+        const networkIdStr = await promisify<string>(this._web3.version.getNetwork)();
+        const networkId = _.parseInt(networkIdStr);
+        return networkId;
+    }
+    public async getTransactionReceiptAsync(txHash: string): Promise<TransactionReceipt> {
+        const transactionReceipt = await promisify<TransactionReceipt>(this._web3.eth.getTransactionReceipt)(txHash);
+        if (!_.isNull(transactionReceipt)) {
+            transactionReceipt.status = this._normalizeTxReceiptStatus(transactionReceipt.status);
+        }
+        return transactionReceipt;
+    }
+    public getCurrentProvider(): Web3.Provider {
+        return this._web3.currentProvider;
+    }
+    public toWei(ethAmount: BigNumber): BigNumber {
+        const balanceWei = this._web3.toWei(ethAmount, 'ether');
+        return balanceWei;
+    }
+    public async getBalanceInWeiAsync(owner: string): Promise<BigNumber> {
+        let balanceInWei = await promisify<BigNumber>(this._web3.eth.getBalance)(owner);
+        // Rewrap in a new BigNumber
+        balanceInWei = new BigNumber(balanceInWei);
+        return balanceInWei;
+    }
+    public async doesContractExistAtAddressAsync(address: string): Promise<boolean> {
+        const code = await promisify<string>(this._web3.eth.getCode)(address);
+        // Regex matches 0x0, 0x00, 0x in order to accommodate poorly implemented clients
+        const codeIsEmpty = /^0x0{0,40}$/i.test(code);
+        return !codeIsEmpty;
+    }
+    public async signTransactionAsync(address: string, message: string): Promise<string> {
+        const signData = await promisify<string>(this._web3.eth.sign)(address, message);
+        return signData;
+    }
+    public async getBlockNumberAsync(): Promise<number> {
+        const blockNumber = await promisify<number>(this._web3.eth.getBlockNumber)();
+        return blockNumber;
+    }
+    public async getBlockAsync(blockParam: string | Web3.BlockParam): Promise<Web3.BlockWithoutTransactionData> {
+        const block = await promisify<Web3.BlockWithoutTransactionData>(this._web3.eth.getBlock)(blockParam);
+        return block;
+    }
+    public async getBlockTimestampAsync(blockParam: string | Web3.BlockParam): Promise<number> {
+        const { timestamp } = await this.getBlockAsync(blockParam);
+        return timestamp;
+    }
+    public async getAvailableAddressesAsync(): Promise<string[]> {
+        const addresses = await promisify<string[]>(this._web3.eth.getAccounts)();
+        const normalizedAddresses = _.map(addresses, address => address.toLowerCase());
+        return normalizedAddresses;
+    }
+    public async getLogsAsync(filter: Web3.FilterObject): Promise<Web3.LogEntry[]> {
+        let fromBlock = filter.fromBlock;
+        if (_.isNumber(fromBlock)) {
+            fromBlock = this._web3.toHex(fromBlock);
+        }
+        let toBlock = filter.toBlock;
+        if (_.isNumber(toBlock)) {
+            toBlock = this._web3.toHex(toBlock);
+        }
+        const serializedFilter = {
+            ...filter,
+            fromBlock,
+            toBlock,
+        };
+        const payload = {
+            jsonrpc: '2.0',
+            id: this._jsonRpcRequestId++,
+            method: 'eth_getLogs',
+            params: [serializedFilter],
+        };
+        const rawLogs = await this._sendRawPayloadAsync<RawLogEntry[]>(payload);
+        const formattedLogs = _.map(rawLogs, this._formatLog.bind(this));
+        return formattedLogs;
+    }
+    public getContractFromAbi(abi: Web3.ContractAbi): Web3.Contract<any> {
+        const web3Contract = this._web3.eth.contract(abi);
+        return web3Contract;
+    }
+    public async estimateGasAsync(txData: Partial<Web3.TxData>): Promise<number> {
+        const gas = await promisify<number>(this._web3.eth.estimateGas)(txData);
+        return gas;
+    }
+    public async callAsync(callData: Web3.CallData, defaultBlock?: Web3.BlockParam): Promise<string> {
+        const rawCalllResult = await promisify<string>(this._web3.eth.call)(callData, defaultBlock);
+        return rawCalllResult;
+    }
+    public async sendTransactionAsync(txData: Web3.TxData): Promise<string> {
+        const txHash = await promisify<string>(this._web3.eth.sendTransaction)(txData);
+        return txHash;
+    }
+    private async _sendRawPayloadAsync<A>(payload: Web3.JSONRPCRequestPayload): Promise<A> {
+        const sendAsync = this._web3.currentProvider.sendAsync.bind(this._web3.currentProvider);
+        const response = await promisify<Web3.JSONRPCResponsePayload>(sendAsync)(payload);
+        const result = response.result;
+        return result;
+    }
+    private _normalizeTxReceiptStatus(status: undefined | null | string | 0 | 1): null | 0 | 1 {
+        // Transaction status might have four values
+        // undefined - Testrpc and other old clients
+        // null - New clients on old transactions
+        // number - Parity
+        // hex - Geth
+        if (_.isString(status)) {
+            return this._web3.toDecimal(status) as 0 | 1;
+        } else if (_.isUndefined(status)) {
+            return null;
+        } else {
+            return status;
+        }
+    }
+    private _formatLog(rawLog: RawLogEntry): Web3.LogEntry {
+        const formattedLog = {
+            ...rawLog,
+            logIndex: this._hexToDecimal(rawLog.logIndex),
+            blockNumber: this._hexToDecimal(rawLog.blockNumber),
+            transactionIndex: this._hexToDecimal(rawLog.transactionIndex),
+        };
+        return formattedLog;
+    }
+    private _hexToDecimal(hex: string | null): number | null {
+        if (_.isNull(hex)) {
+            return null;
+        }
+        const decimal = this._web3.toDecimal(hex);
+        return decimal;
+    }
+}
diff --git a/packages/web3-wrapper/tsconfig.json b/packages/web3-wrapper/tsconfig.json
index 3d967d05f..7bae7f9f0 100644
--- a/packages/web3-wrapper/tsconfig.json
+++ b/packages/web3-wrapper/tsconfig.json
@@ -3,5 +3,9 @@
     "compilerOptions": {
         "outDir": "lib"
     },
-    "include": ["./src/**/*", "../../node_modules/web3-typescript-typings/index.d.ts"]
+    "include": [
+        "./src/**/*",
+        "../../node_modules/ethers-typescript-typings/index.d.ts",
+        "../../node_modules/web3-typescript-typings/index.d.ts"
+    ]
 }