diff --git a/_site/testhelper/http_responses.go b/_site/testhelper/http_responses.go
new file mode 100644
index 0000000..481a833
--- /dev/null
+++ b/_site/testhelper/http_responses.go
@@ -0,0 +1,113 @@
+package testhelper
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"reflect"
+	"testing"
+)
+
+var (
+	// Mux is a multiplexer that can be used to register handlers.
+	Mux *http.ServeMux
+
+	// Server is an in-memory HTTP server for testing.
+	Server *httptest.Server
+)
+
+// SetupHTTP prepares the Mux and Server.
+func SetupHTTP() {
+	Mux = http.NewServeMux()
+	Server = httptest.NewServer(Mux)
+}
+
+// TeardownHTTP releases HTTP-related resources.
+func TeardownHTTP() {
+	Server.Close()
+}
+
+// Endpoint returns a fake endpoint that will actually target the Mux.
+func Endpoint() string {
+	return Server.URL + "/"
+}
+
+// TestFormValues ensures that all the URL parameters given to the http.Request are the same as values.
+func TestFormValues(t *testing.T, r *http.Request, values map[string]string) {
+	want := url.Values{}
+	for k, v := range values {
+		want.Add(k, v)
+	}
+
+	r.ParseForm()
+	if !reflect.DeepEqual(want, r.Form) {
+		t.Errorf("Request parameters = %v, want %v", r.Form, want)
+	}
+}
+
+// TestMethod checks that the Request has the expected method (e.g. GET, POST).
+func TestMethod(t *testing.T, r *http.Request, expected string) {
+	if expected != r.Method {
+		t.Errorf("Request method = %v, expected %v", r.Method, expected)
+	}
+}
+
+// TestHeader checks that the header on the http.Request matches the expected value.
+func TestHeader(t *testing.T, r *http.Request, header string, expected string) {
+	if actual := r.Header.Get(header); expected != actual {
+		t.Errorf("Header %s = %s, expected %s", header, actual, expected)
+	}
+}
+
+// TestBody verifies that the request body matches an expected body.
+func TestBody(t *testing.T, r *http.Request, expected string) {
+	b, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		t.Errorf("Unable to read body: %v", err)
+	}
+	str := string(b)
+	if expected != str {
+		t.Errorf("Body = %s, expected %s", str, expected)
+	}
+}
+
+// TestJSONRequest verifies that the JSON payload of a request matches an expected structure, without asserting things about
+// whitespace or ordering.
+func TestJSONRequest(t *testing.T, r *http.Request, expected string) {
+	b, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		t.Errorf("Unable to read request body: %v", err)
+	}
+
+	var expectedJSON interface{}
+	err = json.Unmarshal([]byte(expected), &expectedJSON)
+	if err != nil {
+		t.Errorf("Unable to parse expected value as JSON: %v", err)
+	}
+
+	var actualJSON interface{}
+	err = json.Unmarshal(b, &actualJSON)
+	if err != nil {
+		t.Errorf("Unable to parse request body as JSON: %v", err)
+	}
+
+	if !reflect.DeepEqual(expectedJSON, actualJSON) {
+		prettyExpected, err := json.MarshalIndent(expectedJSON, "", "  ")
+		if err != nil {
+			t.Logf("Unable to pretty-print expected JSON: %v\n%s", err, expected)
+		} else {
+			t.Logf("Expected JSON:\n%s", prettyExpected)
+		}
+
+		prettyActual, err := json.MarshalIndent(actualJSON, "", "  ")
+		if err != nil {
+			t.Logf("Unable to pretty-print actual JSON: %v\n%s", err, b)
+		} else {
+			t.Logf("Actual JSON:\n%s", prettyActual)
+		}
+
+		t.Errorf("Response body did not contain the correct JSON.")
+	}
+}