diff --git a/circle.yml b/circle.yml
index 1174d6a..ab84af1 100644
--- a/circle.yml
+++ b/circle.yml
@@ -7,7 +7,4 @@ dependencies:
     - npm install -g npm@3.8.6
 machine:
   node:
-    version: 5.11.1
-test:
-  override:
-    - DEBUG=wpcom* make test
\ No newline at end of file
+    version: 5.11.1
\ No newline at end of file
diff --git a/lib/util/send-request.js b/lib/util/send-request.js
index 85ddcf3..aa70a52 100644
--- a/lib/util/send-request.js
+++ b/lib/util/send-request.js
@@ -7,6 +7,9 @@ import debugFactory from 'debug';
 const debug = debugFactory( 'wpcom:send-request' );
 const debug_res = debugFactory( 'wpcom:send-request:res' );
 
+export const apiVersionPattern = /^(?:(\d+)\.)?(\d+)$/;
+export const apiNamespacePattern = /^(?:([a-z]+)\/)?v(\d+)$/;
+
 /**
  * Request to WordPress REST API
  *
@@ -40,21 +43,33 @@ export default function sendRequest( params, query, body, fn ) {
 	// query could be `null`
 	query = query || {};
 
-	// Handle special query parameters
-	// - `apiVersion`
-	if ( query.apiVersion ) {
-		params.apiVersion = query.apiVersion;
-		debug( 'apiVersion: %o', params.apiVersion );
-		delete query.apiVersion;
+	const { apiVersion, apiNamespace } = query;
+
+	if ( typeof apiVersion !== 'undefined' && typeof apiNamespace !== 'undefined' ) {
+		throw new Error( 'apiVersion and apiNamespace cannot be simultaneously defined.' );
+	}
+
+	if ( typeof apiVersion === 'undefined' ) {
+		if ( typeof apiNamespace === 'undefined' ) {
+			// set apiVersion default value
+			params.apiVersion = this.apiVersion;
+		} else {
+			params.apiNamespace = apiNamespace;
+			delete query.apiNamespace;
+		}
 	} else {
-		params.apiVersion = this.apiVersion;
+		params.apiVersion = apiVersion;
+		delete query.apiVersion;
+	}
+
+	// check apiVersion shape
+	if ( params.apiVersion && ! apiVersionPattern.test( params.apiVersion ) ) {
+		throw new Error( `'{ apiVersion: '${ params.apiVersion }' } value is invalid.` );
 	}
 
-	// - `apiNamespace`
-	if ( query.apiNamespace ) {
-		params.apiNamespace = query.apiNamespace;
-		debug( 'apiNamespace: %o', params.apiNamespace );
-		delete query.apiNamespace;
+	// check apiNamespace shape`
+	if ( params.apiNamespace && ! apiNamespacePattern.test( params.apiNamespace ) ) {
+		throw new Error( `'{ apiNamespace: '${ params.apiNamespace }' } value is invalid.` );
 	}
 
 	// - `proxyOrigin`
@@ -91,4 +106,4 @@ export default function sendRequest( params, query, body, fn ) {
 			err ? reject( err ) : resolve( res );
 		} );
 	} );
-};
+}
diff --git a/package.json b/package.json
index 2e34bb1..329735c 100644
--- a/package.json
+++ b/package.json
@@ -37,6 +37,7 @@
   ],
   "dependencies": {
     "babel-runtime": "^6.9.2",
+    "chai": "^3.5.0",
     "debug": "^2.2.0",
     "qs": "^4.0.0",
     "wpcom-xhr-request": "1.0.0"
diff --git a/test/test.util.send-request.js b/test/test.util.send-request.js
new file mode 100644
index 0000000..7d11222
--- /dev/null
+++ b/test/test.util.send-request.js
@@ -0,0 +1,85 @@
+/**
+ * Module dependencies
+ */
+import { expect, assert } from 'chai';
+
+/**
+ * Internal dependencies
+ */
+import wpcomFactory, {
+	defaultApiVersion
+} from '../';
+
+import sendRequest, {
+	apiVersionPattern,
+	apiNamespacePattern,
+}
+from '../lib/util/send-request';
+
+const wpcom = wpcomFactory();
+
+/**
+ * Testing data
+ */
+import fixture from './fixture';
+
+describe( 'wpcom', () => {
+	describe( 'wpcom.util.sendRequest', () => {
+		describe( 'apiVersion shape', () => {
+			it( 'should not accept `v1` as a valid version value', () => {
+				expect( apiVersionPattern.test( 'v1' ) ).to.be.false;
+			} );
+
+			it( 'should accept `1` as a valid version value', () => {
+				expect( apiVersionPattern.test( '1' ) ).to.be.true;
+			} );
+
+			it( 'should not accept `1.` as a valid version value', () => {
+				expect( apiVersionPattern.test( '1.' ) ).to.be.false;
+			} );
+
+			it( 'should accept `1.3` as a valid version value', () => {
+				expect( apiVersionPattern.test( '1.3' ) ).to.be.true;
+			} );
+		} );
+
+		describe( 'apiNamespace shape', () => {
+			it( 'should not accept `wpcom` as a valid version value', () => {
+				expect( apiNamespacePattern.test( 'wpcom' ) ).to.be.false;
+			} );
+
+			it( 'should accept `wpcom/v1` as a valid version value', () => {
+				expect( apiNamespacePattern.test( 'wpcom/v1' ) ).to.be.true;
+			} );
+
+			it( 'should not accept `wpcom/` as a valid version value', () => {
+				expect( apiNamespacePattern.test( 'wpcom/' ) ).to.be.false;
+			} );
+
+			it( 'should not accept `wpcom/1` as a valid version value', () => {
+				expect( apiNamespacePattern.test( 'wpcom/1' ) ).to.be.false;
+			} );
+		} );
+
+		describe( 'parameters parameters', () => {
+			it( 'should throw Error when `apiVersion` is malformed', () => {
+				const path = '/endpoint/path';
+				const promise = sendRequest.bind( wpcom, path, { apiVersion: 'version1' }, {} );
+				assert.throws( promise, Error, '{ apiVersion: \'version1\' } value is invalid.' );
+			} );
+
+			it( 'should throw Error when `apiNamespace` is malformed', () => {
+				const path = '/endpoint/path';
+				const promise = sendRequest.bind( wpcom, path, { apiNamespace: 'wpcom' }, {} );
+				assert.throws( promise, Error, '{ apiNamespace: \'wpcom\' } value is invalid.' );
+			} );
+
+			it( 'should throw Error when `apiVersion` and `apiNamespace` are both defined', () => {
+				const path = '/timezones';
+
+				const promise = sendRequest.bind( wpcom, path, { apiVersion: 'v1.4', apiNamespace: 'wpcom/v2' }, {} );
+				assert.throws( promise, Error, 'apiVersion and apiNamespace cannot be simultaneously defined.' );
+			} );
+		} );
+	} );
+} );
diff --git a/test/test.wpcom.site.follow.js b/test/test.wpcom.site.follow.js
deleted file mode 100644
index 59e52ae..0000000
--- a/test/test.wpcom.site.follow.js
+++ /dev/null
@@ -1,54 +0,0 @@
-/**
- * Module dependencies
- */
-var util = require( './util' );
-var assert = require( 'assert' );
-
-/**
- * site.follow
- */
-describe( 'wpcom.site.follow', function() {
-	// Global instances
-	var wpcom = util.wpcom();
-	var site = wpcom.site( util.site() );
-	var follow = site.follow();
-
-	describe( 'wpcom.site.follow.follow', function() {
-		it( 'should follow site', done => {
-			follow.follow()
-				.then( data => {
-					assert.ok( data );
-					assert.equal( true, data.is_following );
-
-					done();
-				} )
-				.catch( done );
-		} );
-	} );
-
-	describe( 'wpcom.site.follow.unfollow', function() {
-		it( 'should unfollow site', done => {
-			follow.unfollow()
-				.then( data => {
-					assert.ok( data );
-					assert.equal( false, data.is_following );
-
-					done();
-				} )
-				.catch( done );
-		} );
-	} );
-
-	describe( 'wpcom.site.follow.mine', function() {
-		it( 'should get follow status', done => {
-			follow.mine()
-				.then( data => {
-					assert.ok( data );
-					assert.equal( false, data.is_following );
-
-					done();
-				} )
-				.catch( done );
-		} );
-	} );
-} );
diff --git a/test/test.wpcom.site.taxonomy.term.js b/test/test.wpcom.site.taxonomy.term.js
deleted file mode 100644
index 107284e..0000000
--- a/test/test.wpcom.site.taxonomy.term.js
+++ /dev/null
@@ -1,103 +0,0 @@
-/**
- * Module dependencies
- */
-var util = require( './util' );
-var assert = require( 'assert' );
-
-/**
- * site.taxonomy.term
- */
-describe( 'wpcom.site.taxonomy.term', () => {
-	// Global instances
-	const wpcom = util.wpcom();
-	const site = wpcom.site( util.site() );
-	const taxonomy = site.taxonomy( 'category' );
-	const testTermAttributes = { name: 'Chicken and Ribs', description: 'noms' };
-	let testTerm;
-	let testTermTwo;
-
-	// Create a testTerm
-	before( done => {
-		taxonomy.term().add( testTermAttributes )
-			.then( term => {
-				testTerm = term;
-				done();
-			} )
-			.catch( done );
-	} );
-
-	after( done => {
-		// delete testTerm
-		taxonomy.term( testTerm.slug ).delete()
-			.then( () => done() )
-			.catch( done );
-	} );
-
-	describe( 'wpcom.site.taxonomy.term.get', () => {
-		it( 'should return term details', done => {
-			taxonomy.term( testTerm.slug ).get()
-				.then( data => {
-					assert.ok( data );
-					assert.ok( 'string', typeof data.name );
-					assert.ok( 'string', typeof data.slug );
-					assert.ok( 'string', typeof data.description );
-					assert.ok( 'number', typeof data.post_count );
-					assert.ok( 'number', typeof data.parent );
-					assert.ok( 'number', typeof data.ID );
-					assert.equal( testTerm.ID, data.ID );
-					assert.equal( testTerm.name, data.name );
-					done();
-				} )
-				.catch( done );
-		} );
-
-		it( 'should not return an error for unknown_taxonomy', done => {
-			taxonomy.term( 'i-ate-all-the-chicken-and-ribs' ).get()
-				.catch( data => {
-					assert.ok( data );
-					assert.equal( data.error, 'unknown_taxonomy' );
-					done();
-				} );
-		} );
-	} );
-
-	describe( 'wpcom.site.taxonomy.term.add', () => {
-		it( 'should create a new term', done => {
-			taxonomy.term().add( { name: 'chunky bacon', parent: testTerm.ID, description: 'I LOVE BACON MOAR' } )
-				.then( data => {
-					testTermTwo = data;
-					assert.ok( data );
-					assert.equal( data.name, 'chunky bacon' );
-					assert.equal( data.parent, testTerm.ID );
-					assert.equal( data.description, 'I LOVE BACON MOAR' );
-					done();
-				} )
-				.catch( done );
-		} );
-	} );
-
-	describe( 'wpcom.site.taxonomy.term.update', () => {
-		it( 'should update the term', done => {
-			taxonomy.term( testTermTwo.slug ).update( { parent: 0, description: 'I LOVE RIBS AND BACON' } )
-				.then( data => {
-					assert.ok( data );
-					assert.equal( data.slug, testTermTwo.slug );
-					assert.equal( data.description, 'I LOVE RIBS AND BACON' );
-					assert.equal( data.parent, 0 );
-					done();
-				} )
-				.catch( done );
-		} );
-	} );
-
-	describe( 'wpcom.site.taxonomy.term.delete', () => {
-		it( 'should update the term', done => {
-			taxonomy.term( testTermTwo.slug ).delete()
-				.then( data => {
-					assert.ok( data );
-					done();
-				} )
-				.catch( done );
-		} );
-	} );
-} );
diff --git a/test/util.js b/test/util.js
index 591b08c..53aae5a 100644
--- a/test/util.js
+++ b/test/util.js
@@ -8,7 +8,7 @@ import fixture from './fixture';
 var configFactory;
 
 try {
-	configFactory = require( './config' );
+	configFactory = require( './config' ).default;
 } catch ( ex ) {
 	configFactory = {};
 }
@@ -27,17 +27,13 @@ const env = isClientSide && (
 		? 'production'
 		: 'development';
 
-console.log( 'environment: %j', env );
-
 const config = configFactory[ env ] || {};
 
 if ( isClientSide ) {
 	const clientId = config.oauth.client_id;
-	console.log( 'clientId: %o', clientId );
 
 	qryString = qs.parse( document.location.search.replace( /^\?/, '' ) );
 	reqHandler = qryString.handler || 'wpcom-proxy-request';
-	console.log( `reqHandler: %o`, reqHandler );
 
 	if (
 		'wpcom-xhr-request' === reqHandler ||
@@ -73,7 +69,6 @@ function wpcom() {
 		reqHandler = qryString.handler || 'wpcom-proxy-request';
 
 		if ( 'wpcom-proxy-request' === reqHandler ) {
-			console.log( 'PROXY request handler' );
 			let proxy = require( 'wpcom-proxy-request' );
 			_wpcom = wpcomFactory( proxy );
 			_wpcom.request( {