diff --git a/pkg/project/config.go b/pkg/project/config.go
index 108b72d6..f53ccffd 100644
--- a/pkg/project/config.go
+++ b/pkg/project/config.go
@@ -40,7 +40,7 @@ func WriteConfig(filename string, config *ProjectConfig) error {
 
 	switch ext {
 	case ".json":
-		data, err = json.Marshal(config)
+		data, err = json.MarshalIndent(config, "", "  ")
 		if err != nil {
 			return err
 		}
diff --git a/pkg/project/config_test.go b/pkg/project/config_test.go
new file mode 100644
index 00000000..a5a888b3
--- /dev/null
+++ b/pkg/project/config_test.go
@@ -0,0 +1,40 @@
+package project
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestWriteAndReadConfigJSON(t *testing.T) {
+	dir := t.TempDir()
+	filename := filepath.Join(dir, "depot.json")
+
+	cfg := &ProjectConfig{ID: "proj_12345"}
+	err := WriteConfig(filename, cfg)
+	if err != nil {
+		t.Fatalf("WriteConfig failed: %v", err)
+	}
+
+	content, err := os.ReadFile(filename)
+	if err != nil {
+		t.Fatalf("ReadFile failed: %v", err)
+	}
+
+	// Verify JSON output is indented with 2 spaces for human readability
+	if !strings.Contains(string(content), "  \"id\": \"proj_12345\"") {
+		t.Errorf("expected indented JSON output, got:\n%s", string(content))
+	}
+
+	readCfg, path, err := ReadConfig(dir)
+	if err != nil {
+		t.Fatalf("ReadConfig failed: %v", err)
+	}
+	if path != filename {
+		t.Errorf("expected path %s, got %s", filename, path)
+	}
+	if readCfg.ID != cfg.ID {
+		t.Errorf("expected ID %s, got %s", cfg.ID, readCfg.ID)
+	}
+}