diff --git a/web3.js/bin/localnet.sh b/web3.js/bin/localnet.sh
index 8085e7e6ab..a06d1c3ba5 100755
--- a/web3.js/bin/localnet.sh
+++ b/web3.js/bin/localnet.sh
@@ -10,7 +10,7 @@ channel=$(
     } catch (err) {
       p = require("../package.json");
     }
-    p["solana-channel"]
+    p["testnetDefaultChannel"]
   '
 )
 
diff --git a/web3.js/module.flow.js b/web3.js/module.flow.js
index 6fda94fbf9..c000b541d1 100644
--- a/web3.js/module.flow.js
+++ b/web3.js/module.flow.js
@@ -262,4 +262,7 @@ declare module '@solana/web3.js' {
     connection: Connection,
     wireTransaction: Buffer,
   ): Promise<TransactionSignature>;
+
+  // === src/util/testnet.js ===
+  declare export function testnetChannelEndpoint(channel?: string): string;
 }
diff --git a/web3.js/package.json b/web3.js/package.json
index ed3aa3bab7..c684b68c57 100644
--- a/web3.js/package.json
+++ b/web3.js/package.json
@@ -24,7 +24,7 @@
   "bin": {
     "solana-localnet": "bin/localnet.sh"
   },
-  "solana-channel": "beta",
+  "testnetDefaultChannel": "beta",
   "files": [
     "/bin",
     "/doc",
@@ -37,7 +37,7 @@
   "scripts": {
     "bpf-sdk:install": "set -ex; npm run bpf-sdk:fetch; npm run bpf-sdk:extract",
     "bpf-sdk:extract": "test -d bpf-sdk || tar jxvf bpf-sdk.tar.bz2",
-    "bpf-sdk:fetch": "test -f bpf-sdk.tar.bz2 || curl http://solana-sdk.s3.amazonaws.com/$npm_package_solana_channel/bpf-sdk.tar.bz2 -o bpf-sdk.tar.bz2",
+    "bpf-sdk:fetch": "test -f bpf-sdk.tar.bz2 || curl http://solana-sdk.s3.amazonaws.com/$npm_package_testnetDefaultChannel/bpf-sdk.tar.bz2 -o bpf-sdk.tar.bz2",
     "bpf-sdk:remove-symlinks": "find bpf-sdk -type l -print -exec cp {} {}.tmp \\; -exec mv {}.tmp {} \\;",
     "build": "cross-env NODE_ENV=production rollup -c",
     "clean": "rimraf ./coverage ./lib",
@@ -55,8 +55,8 @@
     "lint:watch": "watch 'npm run lint:fix' . --wait=1 --ignoreDirectoryPattern=/doc/",
     "localnet:down": "bin/localnet.sh down",
     "localnet:logs": "bin/localnet.sh logs -f",
-    "localnet:up": "bin/localnet.sh up $npm_package_solana_channel",
-    "localnet:update": "bin/localnet.sh update $npm_package_solana_channel",
+    "localnet:up": "bin/localnet.sh up $npm_package_testnetDefaultChannel",
+    "localnet:update": "bin/localnet.sh update $npm_package_testnetDefaultChannel",
     "ok": "set -ex; npm run lint; npm run flow; npm run test; npm run doc",
     "prepare": "set -ex; npm run clean; npm run bpf-sdk:install; npm run build; rm -rf bpf-sdk; npm rum bpf-sdk:extract; npm run bpf-sdk:remove-symlinks",
     "pretty": "prettier --write '{,{examples,src,test}/**/}*.js'",
diff --git a/web3.js/src/index.js b/web3.js/src/index.js
index 6c67c54334..dcf627ef3d 100644
--- a/web3.js/src/index.js
+++ b/web3.js/src/index.js
@@ -13,3 +13,4 @@ export {sendAndConfirmTransaction} from './util/send-and-confirm-transaction';
 export {
   sendAndConfirmRawTransaction,
 } from './util/send-and-confirm-raw-transaction';
+export {testnetChannelEndpoint} from './util/testnet';
diff --git a/web3.js/src/transaction.js b/web3.js/src/transaction.js
index 876fd7ca4a..9ac3353794 100644
--- a/web3.js/src/transaction.js
+++ b/web3.js/src/transaction.js
@@ -168,11 +168,13 @@ export class Transaction {
         programIds.push(programId);
       }
 
-      instruction.keys.map(key => key.toString()).forEach(key => {
-        if (!keys.includes(key)) {
-          keys.push(key);
-        }
-      });
+      instruction.keys
+        .map(key => key.toString())
+        .forEach(key => {
+          if (!keys.includes(key)) {
+            keys.push(key);
+          }
+        });
     });
 
     const instructions = this.instructions.map(instruction => {
diff --git a/web3.js/src/util/testnet.js b/web3.js/src/util/testnet.js
new file mode 100644
index 0000000000..f10c7ba991
--- /dev/null
+++ b/web3.js/src/util/testnet.js
@@ -0,0 +1,27 @@
+//@flow
+
+import {testnetDefaultChannel} from '../../package.json';
+
+/**
+ * @private
+ */
+const endpoint = {
+  edge: 'https://api.edge.testnet.solana.com',
+  beta: 'https://api.beta.testnet.solana.com',
+  stable: 'https://api.testnet.solana.com',
+};
+
+/**
+ * Retrieves the RPC endpoint URL for the specified testnet release
+ * channel
+ */
+export function testnetChannelEndpoint(channel?: string): string {
+  if (!channel) {
+    return endpoint[testnetDefaultChannel];
+  }
+
+  if (endpoint[channel]) {
+    return endpoint[channel];
+  }
+  throw new Error(`Unknown channel: ${channel}`);
+}
diff --git a/web3.js/test/testnet.test.js b/web3.js/test/testnet.test.js
new file mode 100644
index 0000000000..4a7dc9c309
--- /dev/null
+++ b/web3.js/test/testnet.test.js
@@ -0,0 +1,18 @@
+// @flow
+import {testnetChannelEndpoint} from '../src/util/testnet';
+
+test('invalid', () => {
+  expect(() => {
+    testnetChannelEndpoint('abc123');
+  }).toThrow();
+});
+
+test('edge', () => {
+  expect(testnetChannelEndpoint('edge')).toEqual(
+    'https://api.edge.testnet.solana.com',
+  );
+});
+
+test('default', () => {
+  testnetChannelEndpoint(); // Should not throw
+});
diff --git a/web3.js/test/url.js b/web3.js/test/url.js
index a26789d4c4..59bef47d5d 100644
--- a/web3.js/test/url.js
+++ b/web3.js/test/url.js
@@ -6,8 +6,12 @@
 
 export const url = 'http://localhost:8899/';
 
-//export const url = 'http://edge.testnet.solana.com:8899/';
-//export const url = 'http://beta.edge.testnet.solana.com:8899/';
+/*
+export const url = 'http://edge.testnet.solana.com:8899/';
+export const url = 'http://beta.testnet.solana.com:8899/';
+export const url = 'http://testnet.solana.com:8899/';
 
-//export const url = 'http://testnet.solana.com:8899/';
-//export const url = 'https://api.testnet.solana.com/';
+export const url = 'https://api.edge.testnet.solana.com/';
+export const url = 'https://api.beta.testnet.solana.com/';
+export const url = 'https://api.testnet.solana.com/';
+*/