diff --git a/handler_test.go b/handler_test.go
new file mode 100644
index 0000000..42aa66f
--- /dev/null
+++ b/handler_test.go
@@ -0,0 +1,85 @@
+package main
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestEchoHandler_ValidJWT(t *testing.T) {
+	header := base64.RawURLEncoding.EncodeToString([]byte(`{"alg":"HS256","typ":"JWT"}`))
+	payload := base64.RawURLEncoding.EncodeToString([]byte(`{"sub":"1234567890","name":"John Doe","iat":1516239022}`))
+	signature := "dummy"
+
+	jwt := header + "." + payload + "." + signature
+
+	req := httptest.NewRequest(http.MethodGet, "/echo", nil)
+	req.Header.Set("Authorization", "Bearer "+jwt)
+
+	w := httptest.NewRecorder()
+	echoHandler(w, req)
+
+	res := w.Result()
+	defer res.Body.Close()
+
+	if res.StatusCode != http.StatusOK {
+		t.Errorf("Expected status OK, got %v", res.Status)
+	}
+
+	var respMap map[string]any
+	if err := json.NewDecoder(res.Body).Decode(&respMap); err != nil {
+		t.Fatalf("Failed to decode response: %v", err)
+	}
+
+	authzInfo, ok := respMap["Authorization"].(map[string]any)
+	if !ok {
+		t.Fatalf("Authorization is missing or not a map")
+	}
+
+	jwtInfo, ok := authzInfo["jwt"].(map[string]any)
+	if !ok {
+		t.Fatalf("jwt is missing in Authorization info")
+	}
+
+	if jwtInfo["header"] == nil || jwtInfo["payload"] == nil {
+		t.Errorf("Expected header and payload in jwt info, got %v", jwtInfo)
+	}
+}
+
+func TestEchoHandler_InvalidJSONJWT(t *testing.T) {
+	header := base64.RawURLEncoding.EncodeToString([]byte(`{"alg":"HS256","typ":"JWT"}`))
+	payload := base64.RawURLEncoding.EncodeToString([]byte(`{invalid_json}`))
+	signature := "dummy"
+
+	jwt := header + "." + payload + "." + signature
+
+	req := httptest.NewRequest(http.MethodGet, "/echo", nil)
+	req.Header.Set("Authorization", "Bearer "+jwt)
+
+	w := httptest.NewRecorder()
+	echoHandler(w, req)
+
+	res := w.Result()
+	defer res.Body.Close()
+
+	if res.StatusCode != http.StatusOK {
+		t.Errorf("Expected status OK, got %v", res.Status)
+	}
+
+	var respMap map[string]any
+	if err := json.NewDecoder(res.Body).Decode(&respMap); err != nil {
+		t.Fatalf("Failed to decode response: %v", err)
+	}
+
+	authzInfo, ok := respMap["Authorization"].(map[string]any)
+	if !ok {
+		t.Fatalf("Authorization is missing or not a map")
+	}
+
+	_, ok = authzInfo["jwt"]
+	if ok {
+		t.Errorf("Expected jwt to be missing due to invalid JSON payload")
+	}
+}