diff --git a/web3.js/examples/budget-timestamp.js b/web3.js/examples/budget-timestamp.js
index 8d1fa8c802..b70bd68248 100644
--- a/web3.js/examples/budget-timestamp.js
+++ b/web3.js/examples/budget-timestamp.js
@@ -13,7 +13,7 @@ const contractState = new solanaWeb3.Account();
 
 let url;
 url = 'http://localhost:8899';
-const connection = new solanaWeb3.Connection(url);
+const connection = new solanaWeb3.Connection(url, 'recent');
 
 function showBalance() {
   console.log(`\n== Account State`);
@@ -50,9 +50,9 @@ function confirmTransaction(signature) {
 }
 
 function airDrop() {
-  console.log(`\n== Requesting airdrop of 100 to ${account1.publicKey}`);
+  console.log(`\n== Requesting airdrop of 100000 to ${account1.publicKey}`);
   return connection
-    .requestAirdrop(account1.publicKey, 100)
+    .requestAirdrop(account1.publicKey, 100000)
     .then(confirmTransaction);
 }
 
diff --git a/web3.js/examples/budget-two-approvers.js b/web3.js/examples/budget-two-approvers.js
index a9e679fd0f..5d50279a96 100644
--- a/web3.js/examples/budget-two-approvers.js
+++ b/web3.js/examples/budget-two-approvers.js
@@ -16,7 +16,7 @@ const approver2 = new solanaWeb3.Account();
 let url;
 url = 'http://localhost:8899';
 //url = 'http://testnet.solana.com:8899';
-const connection = new solanaWeb3.Connection(url);
+const connection = new solanaWeb3.Connection(url, 'recent');
 
 function getTransactionFee() {
   return connection.getRecentBlockhash().then(response => {
@@ -59,7 +59,7 @@ function confirmTransaction(signature) {
 }
 
 function airDrop(feeCalculator) {
-  const airdrop = 100 + 3 * feeCalculator.targetLamportsPerSignature;
+  const airdrop = 100 + 5 * feeCalculator.targetLamportsPerSignature;
   console.log(`\n== Requesting airdrop of ${airdrop} to ${account1.publicKey}`);
   return connection
     .requestAirdrop(account1.publicKey, airdrop)
diff --git a/web3.js/module.flow.js b/web3.js/module.flow.js
index 57f91cc57a..bab7e4cc44 100644
--- a/web3.js/module.flow.js
+++ b/web3.js/module.flow.js
@@ -47,6 +47,8 @@ declare module '@solana/web3.js' {
   /* TODO */
 
   // === src/connection.js ===
+  declare export type Commitment = 'max' | 'recent';
+
   declare export type AccountInfo = {
     executable: boolean,
     owner: PublicKey,
@@ -104,28 +106,39 @@ declare module '@solana/web3.js' {
   };
 
   declare export class Connection {
-    constructor(endpoint: string): Connection;
-    getAccountInfo(publicKey: PublicKey): Promise<AccountInfo>;
+    constructor(endpoint: string, commitment: ?Commitment): Connection;
+    getAccountInfo(
+      publicKey: PublicKey,
+      commitment: ?Commitment,
+    ): Promise<AccountInfo>;
     getProgramAccounts(
       programId: PublicKey,
+      commitment: ?Commitment,
     ): Promise<Array<[PublicKey, AccountInfo]>>;
-    getBalance(publicKey: PublicKey): Promise<number>;
+    getBalance(publicKey: PublicKey, commitment: ?Commitment): Promise<number>;
     getClusterNodes(): Promise<Array<ContactInfo>>;
-    getVoteAccounts(): Promise<VoteAccountStatus>;
-    confirmTransaction(signature: TransactionSignature): Promise<boolean>;
-    getSlot(): Promise<number>;
-    getSlotLeader(): Promise<string>;
+    getVoteAccounts(commitment: ?Commitment): Promise<VoteAccountStatus>;
+    confirmTransaction(
+      signature: TransactionSignature,
+      commitment: ?Commitment,
+    ): Promise<boolean>;
+    getSlot(commitment: ?Commitment): Promise<number>;
+    getSlotLeader(commitment: ?Commitment): Promise<string>;
     getSignatureStatus(
       signature: TransactionSignature,
+      commitment: ?Commitment,
     ): Promise<SignatureSuccess | TransactionError | null>;
-    getTransactionCount(): Promise<number>;
-    getTotalSupply(): Promise<number>;
-    getInflation(): Promise<Inflation>;
+    getTransactionCount(commitment: ?Commitment): Promise<number>;
+    getTotalSupply(commitment: ?Commitment): Promise<number>;
+    getInflation(commitment: ?Commitment): Promise<Inflation>;
     getEpochSchedule(): Promise<EpochSchedule>;
-    getRecentBlockhash(): Promise<[Blockhash, FeeCalculator]>;
+    getRecentBlockhash(
+      commitment: ?Commitment,
+    ): Promise<[Blockhash, FeeCalculator]>;
     requestAirdrop(
       to: PublicKey,
       amount: number,
+      commitment: ?Commitment,
     ): Promise<TransactionSignature>;
     sendTransaction(
       transaction: Transaction,
@@ -287,10 +300,17 @@ declare module '@solana/web3.js' {
     ...signers: Array<Account>
   ): Promise<TransactionSignature>;
 
+  declare export function sendAndConfirmRecentTransaction(
+    connection: Connection,
+    transaction: Transaction,
+    ...signers: Array<Account>
+  ): Promise<TransactionSignature>;
+
   // === src/util/send-and-confirm-raw-transaction.js ===
   declare export function sendAndConfirmRawTransaction(
     connection: Connection,
     wireTransaction: Buffer,
+    commitment: ?Commitment,
   ): Promise<TransactionSignature>;
 
   // === src/util/testnet.js ===
diff --git a/web3.js/src/connection.js b/web3.js/src/connection.js
index 4a8ac2b1a8..ee59088d82 100644
--- a/web3.js/src/connection.js
+++ b/web3.js/src/connection.js
@@ -18,6 +18,15 @@ import type {TransactionSignature} from './transaction';
 
 type RpcRequest = (methodName: string, args: Array<any>) => any;
 
+/**
+ * The level of commitment desired when querying state
+ *   'max':    Query the most recent block which has reached max voter lockout
+ *   'recent': Query the most recent block
+ *
+ * @typedef {'max' | 'recent'} Commitment
+ */
+export type Commitment = 'max' | 'recent';
+
 /**
  * Information describing a cluster node
  *
@@ -488,6 +497,7 @@ export class Connection {
   _rpcWebSocket: RpcWebSocketClient;
   _rpcWebSocketConnected: boolean = false;
 
+  _commitment: ?Commitment;
   _blockhashInfo: {
     recentBlockhash: Blockhash | null,
     seconds: number,
@@ -505,11 +515,13 @@ export class Connection {
    * Establish a JSON RPC connection
    *
    * @param endpoint URL to the fullnode JSON RPC endpoint
+   * @param commitment optional default commitment level
    */
-  constructor(endpoint: string) {
+  constructor(endpoint: string, commitment: ?Commitment) {
     let url = urlParse(endpoint);
 
     this._rpcRequest = createRpcRequest(url.href);
+    this._commitment = commitment;
     this._blockhashInfo = {
       recentBlockhash: null,
       seconds: -1,
@@ -542,10 +554,12 @@ export class Connection {
   /**
    * Fetch the balance for the specified public key
    */
-  async getBalance(publicKey: PublicKey): Promise<number> {
-    const unsafeRes = await this._rpcRequest('getBalance', [
-      publicKey.toBase58(),
-    ]);
+  async getBalance(
+    publicKey: PublicKey,
+    commitment: ?Commitment,
+  ): Promise<number> {
+    const args = this._argsWithCommitment([publicKey.toBase58()], commitment);
+    const unsafeRes = await this._rpcRequest('getBalance', args);
     const res = GetBalanceRpcResult(unsafeRes);
     if (res.error) {
       throw new Error(res.error.message);
@@ -557,10 +571,12 @@ export class Connection {
   /**
    * Fetch all the account info for the specified public key
    */
-  async getAccountInfo(publicKey: PublicKey): Promise<AccountInfo> {
-    const unsafeRes = await this._rpcRequest('getAccountInfo', [
-      publicKey.toBase58(),
-    ]);
+  async getAccountInfo(
+    publicKey: PublicKey,
+    commitment: ?Commitment,
+  ): Promise<AccountInfo> {
+    const args = this._argsWithCommitment([publicKey.toBase58()], commitment);
+    const unsafeRes = await this._rpcRequest('getAccountInfo', args);
     const res = GetAccountInfoRpcResult(unsafeRes);
     if (res.error) {
       throw new Error(res.error.message);
@@ -582,10 +598,10 @@ export class Connection {
    */
   async getProgramAccounts(
     programId: PublicKey,
+    commitment: ?Commitment,
   ): Promise<Array<PublicKeyAndAccount>> {
-    const unsafeRes = await this._rpcRequest('getProgramAccounts', [
-      programId.toBase58(),
-    ]);
+    const args = this._argsWithCommitment([programId.toBase58()], commitment);
+    const unsafeRes = await this._rpcRequest('getProgramAccounts', args);
     const res = GetProgramAccountsRpcResult(unsafeRes);
     if (res.error) {
       throw new Error(res.error.message);
@@ -610,8 +626,12 @@ export class Connection {
   /**
    * Confirm the transaction identified by the specified signature
    */
-  async confirmTransaction(signature: TransactionSignature): Promise<boolean> {
-    const unsafeRes = await this._rpcRequest('confirmTransaction', [signature]);
+  async confirmTransaction(
+    signature: TransactionSignature,
+    commitment: ?Commitment,
+  ): Promise<boolean> {
+    const args = this._argsWithCommitment([signature], commitment);
+    const unsafeRes = await this._rpcRequest('confirmTransaction', args);
     const res = ConfirmTransactionRpcResult(unsafeRes);
     if (res.error) {
       throw new Error(res.error.message);
@@ -654,8 +674,9 @@ export class Connection {
   /**
    * Return the list of nodes that are currently participating in the cluster
    */
-  async getVoteAccounts(): Promise<VoteAccountStatus> {
-    const unsafeRes = await this._rpcRequest('getVoteAccounts', []);
+  async getVoteAccounts(commitment: ?Commitment): Promise<VoteAccountStatus> {
+    const args = this._argsWithCommitment([], commitment);
+    const unsafeRes = await this._rpcRequest('getVoteAccounts', args);
     const res = GetVoteAccounts(unsafeRes);
     //const res = unsafeRes;
     if (res.error) {
@@ -668,8 +689,9 @@ export class Connection {
   /**
    * Fetch the current slot that the node is processing
    */
-  async getSlot(): Promise<number> {
-    const unsafeRes = await this._rpcRequest('getSlot', []);
+  async getSlot(commitment: ?Commitment): Promise<number> {
+    const args = this._argsWithCommitment([], commitment);
+    const unsafeRes = await this._rpcRequest('getSlot', args);
     const res = GetSlot(unsafeRes);
     if (res.error) {
       throw new Error(res.error.message);
@@ -681,8 +703,9 @@ export class Connection {
   /**
    * Fetch the current slot leader of the cluster
    */
-  async getSlotLeader(): Promise<string> {
-    const unsafeRes = await this._rpcRequest('getSlotLeader', []);
+  async getSlotLeader(commitment: ?Commitment): Promise<string> {
+    const args = this._argsWithCommitment([], commitment);
+    const unsafeRes = await this._rpcRequest('getSlotLeader', args);
     const res = GetSlotLeader(unsafeRes);
     if (res.error) {
       throw new Error(res.error.message);
@@ -696,8 +719,10 @@ export class Connection {
    */
   async getSignatureStatus(
     signature: TransactionSignature,
+    commitment: ?Commitment,
   ): Promise<SignatureSuccess | TransactionError | null> {
-    const unsafeRes = await this._rpcRequest('getSignatureStatus', [signature]);
+    const args = this._argsWithCommitment([signature], commitment);
+    const unsafeRes = await this._rpcRequest('getSignatureStatus', args);
     const res = GetSignatureStatusRpcResult(unsafeRes);
     if (res.error) {
       throw new Error(res.error.message);
@@ -709,8 +734,9 @@ export class Connection {
   /**
    * Fetch the current transaction count of the cluster
    */
-  async getTransactionCount(): Promise<number> {
-    const unsafeRes = await this._rpcRequest('getTransactionCount', []);
+  async getTransactionCount(commitment: ?Commitment): Promise<number> {
+    const args = this._argsWithCommitment([], commitment);
+    const unsafeRes = await this._rpcRequest('getTransactionCount', args);
     const res = GetTransactionCountRpcResult(unsafeRes);
     if (res.error) {
       throw new Error(res.error.message);
@@ -722,8 +748,9 @@ export class Connection {
   /**
    * Fetch the current total currency supply of the cluster in lamports
    */
-  async getTotalSupply(): Promise<number> {
-    const unsafeRes = await this._rpcRequest('getTotalSupply', []);
+  async getTotalSupply(commitment: ?Commitment): Promise<number> {
+    const args = this._argsWithCommitment([], commitment);
+    const unsafeRes = await this._rpcRequest('getTotalSupply', args);
     const res = GetTotalSupplyRpcResult(unsafeRes);
     if (res.error) {
       throw new Error(res.error.message);
@@ -735,8 +762,9 @@ export class Connection {
   /**
    * Fetch the cluster Inflation parameters
    */
-  async getInflation(): Promise<GetInflationRpcResult> {
-    const unsafeRes = await this._rpcRequest('getInflation', []);
+  async getInflation(commitment: ?Commitment): Promise<GetInflationRpcResult> {
+    const args = this._argsWithCommitment([], commitment);
+    const unsafeRes = await this._rpcRequest('getInflation', args);
     const res = GetInflationRpcResult(unsafeRes);
     if (res.error) {
       throw new Error(res.error.message);
@@ -748,8 +776,9 @@ export class Connection {
   /**
    * Fetch the Epoch Info parameters
    */
-  async getEpochInfo(): Promise<GetEpochInfoRpcResult> {
-    const unsafeRes = await this._rpcRequest('getEpochInfo', []);
+  async getEpochInfo(commitment: ?Commitment): Promise<GetEpochInfoRpcResult> {
+    const args = this._argsWithCommitment([], commitment);
+    const unsafeRes = await this._rpcRequest('getEpochInfo', args);
     const res = GetEpochInfoRpcResult(unsafeRes);
     if (res.error) {
       throw new Error(res.error.message);
@@ -775,10 +804,14 @@ export class Connection {
    * Fetch the minimum balance needed to exempt an account of `dataLength`
    * size from rent
    */
-  async getMinimumBalanceForRentExemption(dataLength: number): Promise<number> {
+  async getMinimumBalanceForRentExemption(
+    dataLength: number,
+    commitment: ?Commitment,
+  ): Promise<number> {
+    const args = this._argsWithCommitment([dataLength], commitment);
     const unsafeRes = await this._rpcRequest(
       'getMinimumBalanceForRentExemption',
-      [dataLength],
+      args,
     );
     const res = GetMinimumBalanceForRentExemptionRpcResult(unsafeRes);
     if (res.error) {
@@ -792,8 +825,11 @@ export class Connection {
   /**
    * Fetch a recent blockhash from the cluster
    */
-  async getRecentBlockhash(): Promise<BlockhashAndFeeCalculator> {
-    const unsafeRes = await this._rpcRequest('getRecentBlockhash', []);
+  async getRecentBlockhash(
+    commitment: ?Commitment,
+  ): Promise<BlockhashAndFeeCalculator> {
+    const args = this._argsWithCommitment([], commitment);
+    const unsafeRes = await this._rpcRequest('getRecentBlockhash', args);
 
     // Legacy v0.16 response.  TODO: Remove in September 2019
     try {
@@ -823,17 +859,15 @@ export class Connection {
   async requestAirdrop(
     to: PublicKey,
     amount: number,
+    commitment: ?Commitment,
   ): Promise<TransactionSignature> {
-    const unsafeRes = await this._rpcRequest('requestAirdrop', [
-      to.toBase58(),
-      amount,
-    ]);
+    const args = this._argsWithCommitment([to.toBase58(), amount], commitment);
+    const unsafeRes = await this._rpcRequest('requestAirdrop', args);
     const res = RequestAirdropRpcResult(unsafeRes);
     if (res.error) {
       throw new Error(res.error.message);
     }
     assert(typeof res.result !== 'undefined');
-    await sleep(500);
     return res.result;
   }
 
@@ -1170,4 +1204,12 @@ export class Connection {
       throw new Error(`Unknown account change id: ${id}`);
     }
   }
+
+  _argsWithCommitment(args: Array<any>, override: ?Commitment): Array<any> {
+    const commitment = override || this._commitment;
+    if (commitment) {
+      args.push({commitment});
+    }
+    return args;
+  }
 }
diff --git a/web3.js/src/util/send-and-confirm-raw-transaction.js b/web3.js/src/util/send-and-confirm-raw-transaction.js
index ec405fca65..e1c0c6df1a 100644
--- a/web3.js/src/util/send-and-confirm-raw-transaction.js
+++ b/web3.js/src/util/send-and-confirm-raw-transaction.js
@@ -1,6 +1,7 @@
 // @flow
 
 import {Connection} from '../connection';
+import type {Commitment} from '../connection';
 import {sleep} from './sleep';
 import type {TransactionSignature} from '../transaction';
 import {DEFAULT_TICKS_PER_SLOT, NUM_TICKS_PER_SECOND} from '../timing';
@@ -11,6 +12,7 @@ import {DEFAULT_TICKS_PER_SLOT, NUM_TICKS_PER_SECOND} from '../timing';
 export async function sendAndConfirmRawTransaction(
   connection: Connection,
   rawTransaction: Buffer,
+  commitment: ?Commitment,
 ): Promise<TransactionSignature> {
   const start = Date.now();
   let signature = await connection.sendRawTransaction(rawTransaction);
@@ -19,7 +21,7 @@ export async function sendAndConfirmRawTransaction(
   let status = null;
   let statusRetries = 6;
   for (;;) {
-    status = await connection.getSignatureStatus(signature);
+    status = await connection.getSignatureStatus(signature, commitment);
     if (status) {
       break;
     }
diff --git a/web3.js/src/util/send-and-confirm-transaction.js b/web3.js/src/util/send-and-confirm-transaction.js
index 48d16b6a3f..f3ed5a3122 100644
--- a/web3.js/src/util/send-and-confirm-transaction.js
+++ b/web3.js/src/util/send-and-confirm-transaction.js
@@ -3,12 +3,29 @@
 import invariant from 'assert';
 
 import {Connection} from '../connection';
+import type {Commitment} from '../connection';
 import {Transaction} from '../transaction';
 import {sleep} from './sleep';
 import type {Account} from '../account';
 import type {TransactionSignature} from '../transaction';
 import {DEFAULT_TICKS_PER_SLOT, NUM_TICKS_PER_SECOND} from '../timing';
 
+/**
+ * Sign, send and confirm a transaction with recent commitment level
+ */
+export async function sendAndConfirmRecentTransaction(
+  connection: Connection,
+  transaction: Transaction,
+  ...signers: Array<Account>
+): Promise<TransactionSignature> {
+  return await _sendAndConfirmTransaction(
+    connection,
+    transaction,
+    signers,
+    'recent',
+  );
+}
+
 /**
  * Sign, send and confirm a transaction
  */
@@ -16,6 +33,15 @@ export async function sendAndConfirmTransaction(
   connection: Connection,
   transaction: Transaction,
   ...signers: Array<Account>
+): Promise<TransactionSignature> {
+  return await _sendAndConfirmTransaction(connection, transaction, signers);
+}
+
+async function _sendAndConfirmTransaction(
+  connection: Connection,
+  transaction: Transaction,
+  signers: Array<Account>,
+  commitment: ?Commitment,
 ): Promise<TransactionSignature> {
   let sendRetries = 10;
   let signature;
@@ -27,7 +53,7 @@ export async function sendAndConfirmTransaction(
     let status = null;
     let statusRetries = 6;
     for (;;) {
-      status = await connection.getSignatureStatus(signature);
+      status = await connection.getSignatureStatus(signature, commitment);
       if (status) {
         break;
       }
diff --git a/web3.js/test/bpf-loader.test.js b/web3.js/test/bpf-loader.test.js
index b69c5bd0dc..3eeeb065e4 100644
--- a/web3.js/test/bpf-loader.test.js
+++ b/web3.js/test/bpf-loader.test.js
@@ -27,7 +27,7 @@ test('load BPF C program', async () => {
 
   const data = await fs.readFile('test/fixtures/noop-c/noop.so');
 
-  const connection = new Connection(url);
+  const connection = new Connection(url, 'recent');
   const [, feeCalculator] = await connection.getRecentBlockhash();
   const fees =
     feeCalculator.lamportsPerSignature *
@@ -52,7 +52,7 @@ test('load BPF Rust program', async () => {
     'test/fixtures/noop-rust/solana_bpf_rust_noop.so',
   );
 
-  const connection = new Connection(url);
+  const connection = new Connection(url, 'recent');
   const [, feeCalculator] = await connection.getRecentBlockhash();
   const fees =
     feeCalculator.lamportsPerSignature *
diff --git a/web3.js/test/connection.test.js b/web3.js/test/connection.test.js
index 95863cfd6c..59b6715f2b 100644
--- a/web3.js/test/connection.test.js
+++ b/web3.js/test/connection.test.js
@@ -15,7 +15,7 @@ import {url} from './url';
 import {sleep} from '../src/util/sleep';
 
 if (!mockRpcEnabled) {
-  // The default of 5 seconds is too slow for live testing sometimes
+  // Testing max commitment level takes around 20s to complete
   jest.setTimeout(30000);
 }
 
@@ -51,7 +51,7 @@ test('get program accounts', async () => {
     return;
   }
 
-  const connection = new Connection(url);
+  const connection = new Connection(url, 'recent');
   const account0 = new Account();
   const account1 = new Account();
   const programId = new Account();
@@ -171,18 +171,18 @@ test('get inflation', async () => {
 });
 
 test('get epoch info', async () => {
-  const connection = new Connection(url);
+  const connection = new Connection(url, 'recent');
 
   mockRpc.push([
     url,
     {
       method: 'getEpochInfo',
-      params: [],
+      params: [{commitment: 'recent'}],
     },
     {
       error: null,
       result: {
-        epoch: 1,
+        epoch: 0,
         slotIndex: 1,
         slotsInEpoch: 8192,
         absoluteSlot: 1,
@@ -194,7 +194,7 @@ test('get epoch info', async () => {
 
   for (const key of ['epoch', 'slotIndex', 'slotsInEpoch', 'absoluteSlot']) {
     expect(epochInfo).toHaveProperty(key);
-    expect(epochInfo[key]).toBeGreaterThan(0);
+    expect(epochInfo[key]).toBeGreaterThanOrEqual(0);
   }
 });
 
@@ -434,13 +434,13 @@ test('get recent blockhash', async () => {
 
 test('request airdrop', async () => {
   const account = new Account();
-  const connection = new Connection(url);
+  const connection = new Connection(url, 'recent');
 
   mockRpc.push([
     url,
     {
       method: 'requestAirdrop',
-      params: [account.publicKey.toBase58(), 40],
+      params: [account.publicKey.toBase58(), 40, {commitment: 'recent'}],
     },
     {
       error: null,
@@ -452,7 +452,7 @@ test('request airdrop', async () => {
     url,
     {
       method: 'requestAirdrop',
-      params: [account.publicKey.toBase58(), 2],
+      params: [account.publicKey.toBase58(), 2, {commitment: 'recent'}],
     },
     {
       error: null,
@@ -464,7 +464,7 @@ test('request airdrop', async () => {
     url,
     {
       method: 'getBalance',
-      params: [account.publicKey.toBase58()],
+      params: [account.publicKey.toBase58(), {commitment: 'recent'}],
     },
     {
       error: null,
@@ -482,7 +482,7 @@ test('request airdrop', async () => {
     url,
     {
       method: 'getAccountInfo',
-      params: [account.publicKey.toBase58()],
+      params: [account.publicKey.toBase58(), {commitment: 'recent'}],
     },
     {
       error: null,
@@ -534,16 +534,54 @@ test('request airdrop', async () => {
   expect(accountInfo.owner).toEqual(SystemProgram.programId);
 });
 
-test('transaction', async () => {
-  const accountFrom = new Account();
-  const accountTo = new Account();
-  const connection = new Connection(url);
+// expected to take around 20s
+test('request airdrop - max commitment', async () => {
+  const account = new Account();
+  const connection = new Connection(url, 'max');
 
   mockRpc.push([
     url,
     {
       method: 'requestAirdrop',
-      params: [accountFrom.publicKey.toBase58(), 100010],
+      params: [account.publicKey.toBase58(), 40, {commitment: 'max'}],
+    },
+    {
+      error: null,
+      result:
+        '1WE5w4B7v59x6qjyC4FbG2FEKYKQfvsJwqSxNVmtMjT8TQ31hsZieDHcSgqzxiAoTL56n2w5TncjqEKjLhtF4Vk',
+    },
+  ]);
+  mockRpc.push([
+    url,
+    {
+      method: 'getBalance',
+      params: [account.publicKey.toBase58(), {commitment: 'max'}],
+    },
+    {
+      error: null,
+      result: 40,
+    },
+  ]);
+
+  await connection.requestAirdrop(account.publicKey, 40);
+  const balance = await connection.getBalance(account.publicKey);
+  expect(balance).toBe(40);
+});
+
+test('transaction', async () => {
+  const accountFrom = new Account();
+  const accountTo = new Account();
+  const connection = new Connection(url, 'recent');
+
+  mockRpc.push([
+    url,
+    {
+      method: 'requestAirdrop',
+      params: [
+        accountFrom.publicKey.toBase58(),
+        100010,
+        {commitment: 'recent'},
+      ],
     },
     {
       error: null,
@@ -555,7 +593,7 @@ test('transaction', async () => {
     url,
     {
       method: 'getBalance',
-      params: [accountFrom.publicKey.toBase58()],
+      params: [accountFrom.publicKey.toBase58(), {commitment: 'recent'}],
     },
     {
       error: null,
@@ -569,7 +607,7 @@ test('transaction', async () => {
     url,
     {
       method: 'requestAirdrop',
-      params: [accountTo.publicKey.toBase58(), 21],
+      params: [accountTo.publicKey.toBase58(), 21, {commitment: 'recent'}],
     },
     {
       error: null,
@@ -581,7 +619,7 @@ test('transaction', async () => {
     url,
     {
       method: 'getBalance',
-      params: [accountTo.publicKey.toBase58()],
+      params: [accountTo.publicKey.toBase58(), {commitment: 'recent'}],
     },
     {
       error: null,
@@ -591,7 +629,7 @@ test('transaction', async () => {
   await connection.requestAirdrop(accountTo.publicKey, 21);
   expect(await connection.getBalance(accountTo.publicKey)).toBe(21);
 
-  mockGetRecentBlockhash();
+  mockGetRecentBlockhash('recent');
   mockRpc.push([
     url,
     {
@@ -617,6 +655,7 @@ test('transaction', async () => {
       method: 'confirmTransaction',
       params: [
         '3WE5w4B7v59x6qjyC4FbG2FEKYKQfvsJwqSxNVmtMjT8TQ31hsZieDHcSgqzxiAoTL56n2w5TncjqEKjLhtF4Vk',
+        {commitment: 'recent'},
       ],
     },
     {
@@ -642,6 +681,7 @@ test('transaction', async () => {
       method: 'getSignatureStatus',
       params: [
         '3WE5w4B7v59x6qjyC4FbG2FEKYKQfvsJwqSxNVmtMjT8TQ31hsZieDHcSgqzxiAoTL56n2w5TncjqEKjLhtF4Vk',
+        {commitment: 'recent'},
       ],
     },
     {
@@ -657,7 +697,7 @@ test('transaction', async () => {
     url,
     {
       method: 'getBalance',
-      params: [accountFrom.publicKey.toBase58()],
+      params: [accountFrom.publicKey.toBase58(), {commitment: 'recent'}],
     },
     {
       error: null,
@@ -674,7 +714,7 @@ test('transaction', async () => {
     url,
     {
       method: 'getBalance',
-      params: [accountTo.publicKey.toBase58()],
+      params: [accountTo.publicKey.toBase58(), {commitment: 'recent'}],
     },
     {
       error: null,
@@ -692,7 +732,7 @@ test('multi-instruction transaction', async () => {
 
   const accountFrom = new Account();
   const accountTo = new Account();
-  const connection = new Connection(url);
+  const connection = new Connection(url, 'recent');
 
   await connection.requestAirdrop(accountFrom.publicKey, SOL_LAMPORTS);
   expect(await connection.getBalance(accountFrom.publicKey)).toBe(SOL_LAMPORTS);
@@ -743,7 +783,7 @@ test('account change notification', async () => {
     return;
   }
 
-  const connection = new Connection(url);
+  const connection = new Connection(url, 'recent');
   const owner = new Account();
   const programAccount = new Account();
 
@@ -755,11 +795,16 @@ test('account change notification', async () => {
   );
 
   await connection.requestAirdrop(owner.publicKey, SOL_LAMPORTS);
-  await Loader.load(connection, owner, programAccount, BpfLoader.programId, [
-    1,
-    2,
-    3,
-  ]);
+  try {
+    await Loader.load(connection, owner, programAccount, BpfLoader.programId, [
+      1,
+      2,
+      3,
+    ]);
+  } catch (err) {
+    await connection.removeAccountChangeListener(subscriptionId);
+    throw err;
+  }
 
   // Wait for mockCallback to receive a call
   let i = 0;
@@ -788,7 +833,7 @@ test('program account change notification', async () => {
     return;
   }
 
-  const connection = new Connection(url);
+  const connection = new Connection(url, 'recent');
   const owner = new Account();
   const programAccount = new Account();
 
@@ -809,11 +854,16 @@ test('program account change notification', async () => {
   );
 
   await connection.requestAirdrop(owner.publicKey, SOL_LAMPORTS);
-  await Loader.load(connection, owner, programAccount, BpfLoader.programId, [
-    1,
-    2,
-    3,
-  ]);
+  try {
+    await Loader.load(connection, owner, programAccount, BpfLoader.programId, [
+      1,
+      2,
+      3,
+    ]);
+  } catch (err) {
+    await connection.removeProgramAccountChangeListener(subscriptionId);
+    throw err;
+  }
 
   // Wait for mockCallback to receive a call
   let i = 0;
diff --git a/web3.js/test/mockrpc/get-recent-blockhash.js b/web3.js/test/mockrpc/get-recent-blockhash.js
index 138f17c817..c85ed41aad 100644
--- a/web3.js/test/mockrpc/get-recent-blockhash.js
+++ b/web3.js/test/mockrpc/get-recent-blockhash.js
@@ -1,17 +1,22 @@
 // @flow
 
 import {Account} from '../../src';
+import type {Commitment} from '../../src/connection';
 import {url} from '../url';
 import {mockRpc} from '../__mocks__/node-fetch';
 
-export function mockGetRecentBlockhash() {
+export function mockGetRecentBlockhash(commitment: ?Commitment) {
   const recentBlockhash = new Account();
+  const params = [];
+  if (commitment) {
+    params.push({commitment});
+  }
 
   mockRpc.push([
     url,
     {
       method: 'getRecentBlockhash',
-      params: [],
+      params,
     },
     {
       error: null,
diff --git a/web3.js/test/transaction-payer.test.js b/web3.js/test/transaction-payer.test.js
index 5b8e68e0f2..d488682a13 100644
--- a/web3.js/test/transaction-payer.test.js
+++ b/web3.js/test/transaction-payer.test.js
@@ -14,13 +14,17 @@ test('transaction-payer', async () => {
   const accountPayer = new Account();
   const accountFrom = new Account();
   const accountTo = new Account();
-  const connection = new Connection(url);
+  const connection = new Connection(url, 'recent');
 
   mockRpc.push([
     url,
     {
       method: 'requestAirdrop',
-      params: [accountPayer.publicKey.toBase58(), SOL_LAMPORTS],
+      params: [
+        accountPayer.publicKey.toBase58(),
+        SOL_LAMPORTS,
+        {commitment: 'recent'},
+      ],
     },
     {
       error: null,
@@ -34,7 +38,7 @@ test('transaction-payer', async () => {
     url,
     {
       method: 'requestAirdrop',
-      params: [accountFrom.publicKey.toBase58(), 12],
+      params: [accountFrom.publicKey.toBase58(), 12, {commitment: 'recent'}],
     },
     {
       error: null,
@@ -48,7 +52,7 @@ test('transaction-payer', async () => {
     url,
     {
       method: 'requestAirdrop',
-      params: [accountTo.publicKey.toBase58(), 21],
+      params: [accountTo.publicKey.toBase58(), 21, {commitment: 'recent'}],
     },
     {
       error: null,
@@ -58,7 +62,7 @@ test('transaction-payer', async () => {
   ]);
   await connection.requestAirdrop(accountTo.publicKey, 21);
 
-  mockGetRecentBlockhash();
+  mockGetRecentBlockhash('recent');
   mockRpc.push([
     url,
     {
@@ -89,6 +93,7 @@ test('transaction-payer', async () => {
       method: 'confirmTransaction',
       params: [
         '3WE5w4B7v59x6qjyC4FbG2FEKYKQfvsJwqSxNVmtMjT8TQ31hsZieDHcSgqzxiAoTL56n2w5TncjqEKjLhtF4Vk',
+        {commitment: 'recent'},
       ],
     },
     {
@@ -114,6 +119,7 @@ test('transaction-payer', async () => {
       method: 'getSignatureStatus',
       params: [
         '3WE5w4B7v59x6qjyC4FbG2FEKYKQfvsJwqSxNVmtMjT8TQ31hsZieDHcSgqzxiAoTL56n2w5TncjqEKjLhtF4Vk',
+        {commitment: 'recent'},
       ],
     },
     {
@@ -129,7 +135,7 @@ test('transaction-payer', async () => {
     url,
     {
       method: 'getBalance',
-      params: [accountPayer.publicKey.toBase58()],
+      params: [accountPayer.publicKey.toBase58(), {commitment: 'recent'}],
     },
     {
       error: null,
@@ -148,7 +154,7 @@ test('transaction-payer', async () => {
     url,
     {
       method: 'getBalance',
-      params: [accountFrom.publicKey.toBase58()],
+      params: [accountFrom.publicKey.toBase58(), {commitment: 'recent'}],
     },
     {
       error: null,