diff --git a/lib/auth-client.js b/lib/auth-client.js
index d6b5a77f..82fa23ff 100644
--- a/lib/auth-client.js
+++ b/lib/auth-client.js
@@ -1,5 +1,6 @@
 'use strict';
 
+const Joi = require('joi');
 const qs = require('querystring');
 
 const util = require('./util');
@@ -49,6 +50,25 @@ const config = require('./config');
  * development mode to enable the mock vehicle brand.
  */
 function AuthClient(options) {
+
+  const schema = Joi.object().keys({
+    clientId: Joi.string().guid({
+      version: [
+        'uuidv4',
+      ],
+    }).required(),
+    clientSecret: Joi.string().guid({
+      version: [
+        'uuidv4',
+      ],
+    }).required(),
+    redirectUri: Joi.string().uri().required(),
+    scope: Joi.array().items(Joi.string()),
+    development: Joi.boolean(),
+  });
+
+  Joi.assert(options, schema);
+
   this.clientId = options.clientId;
   this.clientSecret = options.clientSecret;
   this.redirectUri = options.redirectUri;
diff --git a/package.json b/package.json
index 4ee8e71c..c1ec42fe 100644
--- a/package.json
+++ b/package.json
@@ -37,6 +37,7 @@
   },
   "dependencies": {
     "bluebird": "^3.5.1",
+    "joi": "^13.4.0",
     "lodash": "^4.17.5",
     "request": "^2.83.0",
     "request-promise": "^4.2.2"
diff --git a/test/lib/auth-client.js b/test/lib/auth-client.js
index 361a4888..e1315815 100644
--- a/test/lib/auth-client.js
+++ b/test/lib/auth-client.js
@@ -6,17 +6,21 @@ const nock = require('nock');
 
 const AuthClient = require('../../lib/auth-client');
 
+const CLIENT_ID = '4cf82729-4275-46d9-9255-8437ba777151';
+const INVALID_CLIENT_ID = '4cf82729-4275-46d9-9255-87ba151';
+const CLIENT_SECRET = '4cf82729-4275-46d9-9255-8437ba777151';
+
 test('constructor', function(t) {
 
   const client = new AuthClient({
-    clientId: 'CLIENT_ID',
-    clientSecret: 'CLIENT_SECRET',
+    clientId: CLIENT_ID,
+    clientSecret: CLIENT_SECRET,
     redirectUri: 'https://insurance.co/callback',
     scope: ['read_odometer', 'read_vehicle_info'],
   });
 
-  t.is(client.clientId, 'CLIENT_ID');
-  t.is(client.clientSecret, 'CLIENT_SECRET');
+  t.is(client.clientId, CLIENT_ID);
+  t.is(client.clientSecret, CLIENT_SECRET);
   t.is(client.redirectUri, 'https://insurance.co/callback');
   t.deepEqual(client.scope, ['read_odometer', 'read_vehicle_info']);
   t.is(client.development, false);
@@ -24,36 +28,73 @@ test('constructor', function(t) {
 
 });
 
-test('constructor - development', function(t) {
+test('constructor - missing required parameter', function(t) {
 
-  const client = new AuthClient({
-    clientId: 'CLIENT_ID',
-    clientSecret: 'CLIENT_SECRET',
+  t.throws(() => new AuthClient({
+    clientId: 'f3266b17-961d-4295-8544-054c7bd94fbb',
     redirectUri: 'https://insurance.co/callback',
     scope: ['read_odometer', 'read_vehicle_info'],
-    development: true,
-  });
+  }));
 
-  t.is(client.clientId, 'CLIENT_ID');
-  t.is(client.clientSecret, 'CLIENT_SECRET');
-  t.is(client.redirectUri, 'https://insurance.co/callback');
-  t.deepEqual(client.scope, ['read_odometer', 'read_vehicle_info']);
-  t.is(client.development, true);
-  t.true('request' in client);
+});
+
+test('constructor - invalid uuid parameter', function(t) {
+
+  t.throws(() => new AuthClient({
+    clientId: INVALID_CLIENT_ID,
+    clientSecret: CLIENT_SECRET,
+    redirectUri: 'https://insurance.co/callback',
+    scope: ['read_odometer', 'read_vehicle_info'],
+  }));
+
+});
+
+test('constructor - invalid scope parameter', function(t) {
+
+  t.throws(() => new AuthClient({
+    clientId: CLIENT_ID,
+    clientSecret: CLIENT_SECRET,
+    redirectUri: 'https://insurance.co/callback',
+    scope: 'read_odometer',
+  }));
+
+});
+
+test('constructor - invalid development parameter', function(t) {
+
+  t.throws(() => new AuthClient({
+    clientId: CLIENT_ID,
+    clientSecret: CLIENT_SECRET,
+    redirectUri: 'https://insurance.co/callback',
+    scope: ['read_odometer', 'read_vehicle_info'],
+    development: 'truthsies',
+  }));
+
+});
+
+test('iOS and Android redirect uri', function(t) {
+
+  t.notThrows(() => new AuthClient({
+    clientId: CLIENT_ID,
+    clientSecret: CLIENT_SECRET,
+    redirectUri: 'sc4a1b01e5-0497-417c-a30e-6df6ba33ba46://callback',
+    scope: ['read_odometer', 'read_vehicle_info'],
+  }));
 
 });
 
 test('getAuthUrl - simple', function(t) {
 
   const client = new AuthClient({
-    clientId: 'CLIENT_ID',
+    clientId: CLIENT_ID,
+    clientSecret: CLIENT_SECRET,
     redirectUri: 'https://insurance.co/callback',
     scope: ['read_odometer', 'read_vehicle_info'],
   });
 
   const actual = client.getAuthUrl();
   let expected = 'https://connect.smartcar.com/oauth/authorize?';
-  expected += 'response_type=code&client_id=CLIENT_ID';
+  expected += `response_type=code&client_id=${CLIENT_ID}`;
   expected += '&redirect_uri=https%3A%2F%2Finsurance.co%2Fcallback';
   expected += '&approval_prompt=auto';
   expected += '&scope=read_odometer%20read_vehicle_info';
@@ -65,7 +106,8 @@ test('getAuthUrl - simple', function(t) {
 test('getAuthUrl - no scope', function(t) {
 
   const client = new AuthClient({
-    clientId: 'CLIENT_ID',
+    clientId: CLIENT_ID,
+    clientSecret: CLIENT_SECRET,
     redirectUri: 'https://insurance.co/callback',
   });
 
@@ -76,7 +118,7 @@ test('getAuthUrl - no scope', function(t) {
   });
 
   let expected = 'https://connect.smartcar.com/oauth/authorize?';
-  expected += 'response_type=code&client_id=CLIENT_ID';
+  expected += `response_type=code&client_id=${CLIENT_ID}`;
   expected += '&redirect_uri=https%3A%2F%2Finsurance.co%2Fcallback';
   expected += '&approval_prompt=force';
   expected += '&state=fakestate';
@@ -88,7 +130,8 @@ test('getAuthUrl - no scope', function(t) {
 test('getAuthUrl - state & approval prompt', function(t) {
 
   const client = new AuthClient({
-    clientId: 'CLIENT_ID',
+    clientId: CLIENT_ID,
+    clientSecret: CLIENT_SECRET,
     redirectUri: 'https://insurance.co/callback',
     scope: ['read_odometer', 'read_vehicle_info'],
   });
@@ -100,7 +143,7 @@ test('getAuthUrl - state & approval prompt', function(t) {
   });
 
   let expected = 'https://connect.smartcar.com/oauth/authorize?';
-  expected += 'response_type=code&client_id=CLIENT_ID';
+  expected += `response_type=code&client_id=${CLIENT_ID}`;
   expected += '&redirect_uri=https%3A%2F%2Finsurance.co%2Fcallback';
   expected += '&approval_prompt=force';
   expected += '&scope=read_odometer%20read_vehicle_info';
@@ -113,7 +156,8 @@ test('getAuthUrl - state & approval prompt', function(t) {
 test('getAuthUrl - development mode', function(t) {
 
   const client = new AuthClient({
-    clientId: 'CLIENT_ID',
+    clientId: CLIENT_ID,
+    clientSecret: CLIENT_SECRET,
     redirectUri: 'https://insurance.co/callback',
     scope: ['read_odometer', 'read_vehicle_info'],
     development: true,
@@ -126,7 +170,7 @@ test('getAuthUrl - development mode', function(t) {
   });
 
   let expected = 'https://connect.smartcar.com/oauth/authorize?';
-  expected += 'response_type=code&client_id=CLIENT_ID';
+  expected += `response_type=code&client_id=${CLIENT_ID}`;
   expected += '&redirect_uri=https%3A%2F%2Finsurance.co%2Fcallback';
   expected += '&approval_prompt=force';
   expected += '&scope=read_odometer%20read_vehicle_info';
@@ -140,7 +184,8 @@ test('getAuthUrl - development mode', function(t) {
 test('getAuthUrl - development mode false', function(t) {
 
   const client = new AuthClient({
-    clientId: 'CLIENT_ID',
+    clientId: CLIENT_ID,
+    clientSecret: CLIENT_SECRET,
     redirectUri: 'https://insurance.co/callback',
     scope: ['read_odometer', 'read_vehicle_info'],
     development: false,
@@ -153,7 +198,7 @@ test('getAuthUrl - development mode false', function(t) {
   });
 
   let expected = 'https://connect.smartcar.com/oauth/authorize?';
-  expected += 'response_type=code&client_id=CLIENT_ID';
+  expected += `response_type=code&client_id=${CLIENT_ID}`;
   expected += '&redirect_uri=https%3A%2F%2Finsurance.co%2Fcallback';
   expected += '&approval_prompt=force';
   expected += '&scope=read_odometer%20read_vehicle_info';
@@ -166,8 +211,8 @@ test('getAuthUrl - development mode false', function(t) {
 test('exchangeCode', async function(t) {
 
   const client = new AuthClient({
-    clientId: 'CLIENT_ID',
-    clientSecret: 'CLIENT_SECRET',
+    clientId: CLIENT_ID,
+    clientSecret: CLIENT_SECRET,
     redirectUri: 'https://insurance.co/callback',
   });
 
@@ -179,8 +224,8 @@ test('exchangeCode', async function(t) {
       redirect_uri: 'https://insurance.co/callback',
     })
     .basicAuth({
-      user: 'CLIENT_ID',
-      pass: 'CLIENT_SECRET',
+      user: CLIENT_ID,
+      pass: CLIENT_SECRET,
     })
     .reply(200, {
       access_token: 'access',
@@ -204,8 +249,8 @@ test('exchangeCode', async function(t) {
 test('exchangeRefreshToken', async function(t) {
 
   const client = new AuthClient({
-    clientId: 'CLIENT_ID',
-    clientSecret: 'CLIENT_SECRET',
+    clientId: CLIENT_ID,
+    clientSecret: CLIENT_SECRET,
     redirectUri: 'https://insurance.co/callback',
   });
 
@@ -216,8 +261,8 @@ test('exchangeRefreshToken', async function(t) {
       grant_type: 'refresh_token',
     })
     .basicAuth({
-      user: 'CLIENT_ID',
-      pass: 'CLIENT_SECRET',
+      user: CLIENT_ID,
+      pass: CLIENT_SECRET,
     })
     .reply(200, {
       access_token: 'access',