diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..a2a3452
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,35 @@
+name: CI
+
+on:
+  push:
+    branches: [develop]
+  pull_request:
+    branches: [develop]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.25"
+
+      - name: Check formatting
+        run: |
+          fmt_out="$(gofmt -l .)"
+          if [ -n "$fmt_out" ]; then
+            echo "The following files are not gofmt'd:"
+            echo "$fmt_out"
+            exit 1
+          fi
+
+      - name: Vet
+        run: go vet ./...
+
+      - name: Test
+        run: go test ./... -race -cover
+
+      - name: Build
+        run: go build ./...
diff --git a/.github/workflows/docker-publish.yml b/.github/workflows/docker-publish.yml
new file mode 100644
index 0000000..2e6b236
--- /dev/null
+++ b/.github/workflows/docker-publish.yml
@@ -0,0 +1,31 @@
+name: Build and Publish Docker Image
+
+on:
+  push:
+    branches: [develop]
+
+permissions:
+  contents: read
+  packages: write
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Log in to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          push: true
+          tags: |
+            ghcr.io/${{ github.repository }}:latest
+            ghcr.io/${{ github.repository }}:${{ github.sha }}
diff --git a/internal/handlers/health_test.go b/internal/handlers/health_test.go
new file mode 100644
index 0000000..419016c
--- /dev/null
+++ b/internal/handlers/health_test.go
@@ -0,0 +1,23 @@
+package handlers
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestHealthHandler(t *testing.T) {
+	req := httptest.NewRequest(http.MethodGet, "/health", nil)
+	rec := httptest.NewRecorder()
+
+	HealthHandler(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("expected status %d, got %d", http.StatusOK, rec.Code)
+	}
+
+	want := `{"status":"ok"}` + "\n"
+	if got := rec.Body.String(); got != want {
+		t.Errorf("body = %q, want %q", got, want)
+	}
+}
diff --git a/internal/handlers/hello_test.go b/internal/handlers/hello_test.go
new file mode 100644
index 0000000..11a0931
--- /dev/null
+++ b/internal/handlers/hello_test.go
@@ -0,0 +1,41 @@
+package handlers
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"go-demo/internal/service"
+)
+
+func TestHelloHandler(t *testing.T) {
+	h := NewHelloHandler(service.NewHelloService())
+
+	req := httptest.NewRequest(http.MethodGet, "/hello?name=Test", nil)
+	rec := httptest.NewRecorder()
+
+	h.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("expected status %d, got %d", http.StatusOK, rec.Code)
+	}
+
+	want := `{"message":"Hello, Test!"}` + "\n"
+	if got := rec.Body.String(); got != want {
+		t.Errorf("body = %q, want %q", got, want)
+	}
+}
+
+func TestHelloHandlerDefaultName(t *testing.T) {
+	h := NewHelloHandler(service.NewHelloService())
+
+	req := httptest.NewRequest(http.MethodGet, "/hello", nil)
+	rec := httptest.NewRecorder()
+
+	h.ServeHTTP(rec, req)
+
+	want := `{"message":"Hello, World!"}` + "\n"
+	if got := rec.Body.String(); got != want {
+		t.Errorf("body = %q, want %q", got, want)
+	}
+}
diff --git a/internal/service/hello_test.go b/internal/service/hello_test.go
new file mode 100644
index 0000000..f285bae
--- /dev/null
+++ b/internal/service/hello_test.go
@@ -0,0 +1,20 @@
+package service
+
+import "testing"
+
+func TestGreet(t *testing.T) {
+	tests := []struct {
+		name string
+		want string
+	}{
+		{name: "", want: "Hello, World!"},
+		{name: "Go", want: "Hello, Go!"},
+	}
+
+	s := NewHelloService()
+	for _, tt := range tests {
+		if got := s.Greet(tt.name); got != tt.want {
+			t.Errorf("Greet(%q) = %q, want %q", tt.name, got, tt.want)
+		}
+	}
+}