diff --git a/mockns1/testcase.go b/mockns1/testcase.go
index d6c3d56..06ef323 100644
--- a/mockns1/testcase.go
+++ b/mockns1/testcase.go
@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	"github.com/stretchr/testify/assert"
+	api "gopkg.in/ns1/ns1-go.v2/rest"
 )
 
 type testCase struct {
@@ -29,6 +30,7 @@ func (s *Service) AddTestCase(
 	method, uri string, returnStatus int,
 	requestHeaders, responseHeaders http.Header,
 	requestBody, responseBody interface{},
+	params ...api.Param,
 ) error {
 	s.stopTimer()
 	defer s.startTimer()
@@ -36,6 +38,15 @@ func (s *Service) AddTestCase(
 	if !strings.HasPrefix(uri, "/v1/") {
 		uri = "/v1/" + uri
 	}
+
+	if len(params) > 0 {
+		uri = fmt.Sprintf("%s?%s=%s", uri, params[0].Key, params[0].Value)
+
+		for _, p := range params[1:] {
+			uri = fmt.Sprintf("%s&%s=%s", uri, p.Key, p.Value)
+		}
+	}
+
 	uri = strings.Replace(uri, "//", "/", -1)
 
 	tc := &testCase{
diff --git a/rest/client.go b/rest/client.go
index e8846f2..d047142 100644
--- a/rest/client.go
+++ b/rest/client.go
@@ -187,10 +187,22 @@ func SetDDIAPI() func(*Client) {
 	return func(c *Client) { c.DDI = true }
 }
 
+// Param is a container struct which holds a `Key` and `Value` field corresponding to the values of a URL parameter. 
+type Param struct {
+	Key, Value string
+}
+
 // Do satisfies the Doer interface. resp will be nil if a non-HTTP error
 // occurs, otherwise it is available for inspection when the error reflects a
-// non-2XX response.
-func (c Client) Do(req *http.Request, v interface{}) (*http.Response, error) {
+// non-2XX response. It accepts a variadic number of optional URL parameters to
+// supply to the request. URL parameters are of type `rest.Param`.
+func (c Client) Do(req *http.Request, v interface{}, params ...Param) (*http.Response, error) {
+	q := req.URL.Query()
+	for _, p := range params {
+		q.Set(p.Key, p.Value)
+	}
+	req.URL.RawQuery = q.Encode()
+
 	resp, err := c.httpClient.Do(req)
 	if err != nil {
 		return nil, err
@@ -229,9 +241,11 @@ type NextFunc func(v *interface{}, uri string) (*http.Response, error)
 // DoWithPagination Does, and follows Link headers for pagination. The returned
 // Response is from the last URI visited - either the last page, or one that
 // responded with a non-2XX status. If a non-HTTP error occurs, resp will be
-// nil.
-func (c Client) DoWithPagination(req *http.Request, v interface{}, f NextFunc) (*http.Response, error) {
-	resp, err := c.Do(req, v)
+// nil. It accepts a variadic number of optional URL parameters to supply to
+// the underlying `.Do()` method request(s). URL parameters are of type
+// `rest.Param`.
+func (c Client) DoWithPagination(req *http.Request, v interface{}, f NextFunc, params ...Param) (*http.Response, error) {
+	resp, err := c.Do(req, v, params...)
 	if err != nil {
 		return resp, err
 	}