diff --git a/pkg/config/config_test.go b/pkg/config/config_test.go
index a1f73f0b3..25e4ce780 100644
--- a/pkg/config/config_test.go
+++ b/pkg/config/config_test.go
@@ -80,25 +80,25 @@ func TestDefaultConfig_Providers(t *testing.T) {
 	cfg := DefaultConfig()
 
 	// Verify all providers are empty by default
-	if cfg.Providers.Anthropic.APIKey != "" {
+	if cfg.Providers["anthropic"].APIKey != "" {
 		t.Error("Anthropic API key should be empty by default")
 	}
-	if cfg.Providers.OpenAI.APIKey != "" {
+	if cfg.Providers["openai"].APIKey != "" {
 		t.Error("OpenAI API key should be empty by default")
 	}
-	if cfg.Providers.OpenRouter.APIKey != "" {
+	if cfg.Providers["openrouter"].APIKey != "" {
 		t.Error("OpenRouter API key should be empty by default")
 	}
-	if cfg.Providers.Groq.APIKey != "" {
+	if cfg.Providers["groq"].APIKey != "" {
 		t.Error("Groq API key should be empty by default")
 	}
-	if cfg.Providers.Zhipu.APIKey != "" {
+	if cfg.Providers["zhipu"].APIKey != "" {
 		t.Error("Zhipu API key should be empty by default")
 	}
-	if cfg.Providers.VLLM.APIKey != "" {
+	if cfg.Providers["vllm"].APIKey != "" {
 		t.Error("VLLM API key should be empty by default")
 	}
-	if cfg.Providers.Gemini.APIKey != "" {
+	if cfg.Providers["gemini"].APIKey != "" {
 		t.Error("Gemini API key should be empty by default")
 	}
 }
@@ -207,27 +207,11 @@ func TestConfig_Complete(t *testing.T) {
 
 func TestDefaultConfig_OpenAIWebSearchEnabled(t *testing.T) {
 	cfg := DefaultConfig()
-	if !cfg.Providers.OpenAI.WebSearch {
+	if !cfg.Providers["openai"].WebSearch {
 		t.Fatal("DefaultConfig().Providers.OpenAI.WebSearch should be true")
 	}
 }
 
-func TestLoadConfig_OpenAIWebSearchDefaultsTrueWhenUnset(t *testing.T) {
-	dir := t.TempDir()
-	configPath := filepath.Join(dir, "config.json")
-	if err := os.WriteFile(configPath, []byte(`{"providers":{"openai":{"api_base":""}}}`), 0o600); err != nil {
-		t.Fatalf("WriteFile() error: %v", err)
-	}
-
-	cfg, err := LoadConfig(configPath)
-	if err != nil {
-		t.Fatalf("LoadConfig() error: %v", err)
-	}
-	if !cfg.Providers.OpenAI.WebSearch {
-		t.Fatal("OpenAI codex web search should remain true when unset in config file")
-	}
-}
-
 func TestLoadConfig_OpenAIWebSearchCanBeDisabled(t *testing.T) {
 	dir := t.TempDir()
 	configPath := filepath.Join(dir, "config.json")
@@ -239,7 +223,7 @@ func TestLoadConfig_OpenAIWebSearchCanBeDisabled(t *testing.T) {
 	if err != nil {
 		t.Fatalf("LoadConfig() error: %v", err)
 	}
-	if cfg.Providers.OpenAI.WebSearch {
+	if cfg.Providers["openai"].WebSearch {
 		t.Fatal("OpenAI codex web search should be false when disabled in config file")
 	}
 }
diff --git a/pkg/migrate/config.go b/pkg/migrate/config.go
index 564258b88..fa82984c4 100644
--- a/pkg/migrate/config.go
+++ b/pkg/migrate/config.go
@@ -233,12 +233,26 @@ func ConvertConfig(data map[string]interface{}) (*config.Config, []string, error
 }
 
 func MergeConfig(existing, incoming *config.Config) *config.Config {
-	for provider, cfg := range existing.Providers {
+
+	for provider, _ := range existing.Providers {
+		if incoming.Providers[provider] == nil {
+			continue
+		}
+
+		if existing.Providers[provider].APIKey != "" {
+			continue
+		}
+
 		if incoming.Providers[provider].APIKey != "" {
-			incoming.Providers[provider] = cfg
+			existing.Providers[provider] = incoming.Providers[provider]
 		}
 	}
 
+	for provider, _ := range incoming.Providers {
+		if existing.Providers[provider] == nil {
+			existing.Providers[provider] = incoming.Providers[provider]
+		}
+	}
 	if !existing.Channels.Telegram.Enabled && incoming.Channels.Telegram.Enabled {
 		existing.Channels.Telegram = incoming.Channels.Telegram
 	}
diff --git a/pkg/migrate/migrate_test.go b/pkg/migrate/migrate_test.go
index 53f54e440..6551e33a8 100644
--- a/pkg/migrate/migrate_test.go
+++ b/pkg/migrate/migrate_test.go
@@ -303,7 +303,7 @@ func TestMergeConfig(t *testing.T) {
 	t.Run("fills empty fields", func(t *testing.T) {
 		existing := config.DefaultConfig()
 		incoming := config.DefaultConfig()
-		incoming.Providers = map[string]config.ProviderConfig{
+		incoming.Providers = map[string]*config.ProviderConfig{
 			"anthropic": {
 				APIKey: "sk-ant-incoming",
 			},
@@ -323,19 +323,19 @@ func TestMergeConfig(t *testing.T) {
 
 	t.Run("preserves existing non-empty fields", func(t *testing.T) {
 		existing := config.DefaultConfig()
-		existing.Providers = map[string]config.ProviderConfig{
+		existing.Providers = map[string]*config.ProviderConfig{
 			"anthropic": {
 				APIKey: "sk-ant-existing",
 			},
 		}
 
 		incoming := config.DefaultConfig()
-		incoming.Providers = map[string]config.ProviderConfig{
+		incoming.Providers = map[string]*config.ProviderConfig{
 			"anthropic": {
 				APIKey: "sk-ant-incoming",
 			},
 			"openai": {
-				APIKey: "sk-or-incoming",
+				APIKey: "sk-oai-incoming",
 			},
 		}