diff --git a/README.fr.md b/README.fr.md
index d09276c27..f59807739 100644
--- a/README.fr.md
+++ b/README.fr.md
@@ -226,7 +226,7 @@ picoclaw onboard
   ],
   "agents": {
     "defaults": {
-      "model": "gpt4"
+      "model_name": "gpt4"
     }
   },
   "channels": {
diff --git a/README.ja.md b/README.ja.md
index 67eccddc2..5a7bb8542 100644
--- a/README.ja.md
+++ b/README.ja.md
@@ -188,7 +188,7 @@ picoclaw onboard
   ],
   "agents": {
     "defaults": {
-      "model": "gpt4"
+      "model_name": "gpt4"
     }
   },
   "channels": {
diff --git a/README.md b/README.md
index 778530db5..2b770f215 100644
--- a/README.md
+++ b/README.md
@@ -222,7 +222,7 @@ picoclaw onboard
   "agents": {
     "defaults": {
       "workspace": "~/.picoclaw/workspace",
-      "model": "gpt4",
+      "model_name": "gpt4",
       "max_tokens": 8192,
       "temperature": 0.7,
       "max_tool_iterations": 20
diff --git a/README.pt-br.md b/README.pt-br.md
index 8d87333bc..0115b7f89 100644
--- a/README.pt-br.md
+++ b/README.pt-br.md
@@ -227,7 +227,7 @@ picoclaw onboard
   ],
   "agents": {
     "defaults": {
-      "model": "gpt4"
+      "model_name": "gpt4"
     }
   },
   "tools": {
diff --git a/README.vi.md b/README.vi.md
index 1be58d9f6..015bc264e 100644
--- a/README.vi.md
+++ b/README.vi.md
@@ -207,7 +207,7 @@ picoclaw onboard
   ],
   "agents": {
     "defaults": {
-      "model": "gpt4"
+      "model_name": "gpt4"
     }
   },
   "channels": {
diff --git a/README.zh.md b/README.zh.md
index 74760b3b1..4f4bde46a 100644
--- a/README.zh.md
+++ b/README.zh.md
@@ -224,7 +224,7 @@ picoclaw onboard
   "agents": {
     "defaults": {
       "workspace": "~/.picoclaw/workspace",
-      "model": "gpt4",
+      "model_name": "gpt4",
       "max_tokens": 8192,
       "temperature": 0.7,
       "max_tool_iterations": 20
diff --git a/cmd/picoclaw/cmd_agent.go b/cmd/picoclaw/cmd_agent.go
index 8658c9d32..98ea51103 100644
--- a/cmd/picoclaw/cmd_agent.go
+++ b/cmd/picoclaw/cmd_agent.go
@@ -56,7 +56,7 @@ func agentCmd() {
 	}
 
 	if modelOverride != "" {
-		cfg.Agents.Defaults.Model = modelOverride
+		cfg.Agents.Defaults.ModelName = modelOverride
 	}
 
 	provider, modelID, err := providers.CreateProvider(cfg)
@@ -66,7 +66,7 @@ func agentCmd() {
 	}
 	// Use the resolved model ID from provider creation
 	if modelID != "" {
-		cfg.Agents.Defaults.Model = modelID
+		cfg.Agents.Defaults.ModelName = modelID
 	}
 
 	msgBus := bus.NewMessageBus()
diff --git a/cmd/picoclaw/cmd_auth.go b/cmd/picoclaw/cmd_auth.go
index 729c56177..55eb3cec3 100644
--- a/cmd/picoclaw/cmd_auth.go
+++ b/cmd/picoclaw/cmd_auth.go
@@ -144,7 +144,7 @@ func authLoginOpenAI(useDeviceCode bool) {
 		}
 
 		// Update default model to use OpenAI
-		appCfg.Agents.Defaults.Model = "gpt-5.2"
+		appCfg.Agents.Defaults.ModelName = "gpt-5.2"
 
 		if err := config.SaveConfig(getConfigPath(), appCfg); err != nil {
 			fmt.Printf("Warning: could not update config: %v\n", err)
@@ -218,7 +218,7 @@ func authLoginGoogleAntigravity() {
 		}
 
 		// Update default model
-		appCfg.Agents.Defaults.Model = "gemini-flash"
+		appCfg.Agents.Defaults.ModelName = "gemini-flash"
 
 		if err := config.SaveConfig(getConfigPath(), appCfg); err != nil {
 			fmt.Printf("Warning: could not update config: %v\n", err)
@@ -292,7 +292,7 @@ func authLoginPasteToken(provider string) {
 				})
 			}
 			// Update default model
-			appCfg.Agents.Defaults.Model = "claude-sonnet-4.6"
+			appCfg.Agents.Defaults.ModelName = "claude-sonnet-4.6"
 		case "openai":
 			appCfg.Providers.OpenAI.AuthMethod = "token"
 			// Update ModelList
@@ -312,7 +312,7 @@ func authLoginPasteToken(provider string) {
 				})
 			}
 			// Update default model
-			appCfg.Agents.Defaults.Model = "gpt-5.2"
+			appCfg.Agents.Defaults.ModelName = "gpt-5.2"
 		}
 		if err := config.SaveConfig(getConfigPath(), appCfg); err != nil {
 			fmt.Printf("Warning: could not update config: %v\n", err)
@@ -320,7 +320,7 @@ func authLoginPasteToken(provider string) {
 	}
 
 	fmt.Printf("Token saved for %s!\n", provider)
-	fmt.Printf("Default model set to: %s\n", appCfg.Agents.Defaults.Model)
+	fmt.Printf("Default model set to: %s\n", appCfg.Agents.Defaults.GetModelName())
 }
 
 func authLogoutCmd() {
diff --git a/cmd/picoclaw/cmd_gateway.go b/cmd/picoclaw/cmd_gateway.go
index 28ef76ad3..cf7f3563a 100644
--- a/cmd/picoclaw/cmd_gateway.go
+++ b/cmd/picoclaw/cmd_gateway.go
@@ -52,7 +52,7 @@ func gatewayCmd() {
 	}
 	// Use the resolved model ID from provider creation
 	if modelID != "" {
-		cfg.Agents.Defaults.Model = modelID
+		cfg.Agents.Defaults.ModelName = modelID
 	}
 
 	msgBus := bus.NewMessageBus()
diff --git a/cmd/picoclaw/cmd_status.go b/cmd/picoclaw/cmd_status.go
index 07296784e..6a117bd17 100644
--- a/cmd/picoclaw/cmd_status.go
+++ b/cmd/picoclaw/cmd_status.go
@@ -41,7 +41,7 @@ func statusCmd() {
 	}
 
 	if _, err := os.Stat(configPath); err == nil {
-		fmt.Printf("Model: %s\n", cfg.Agents.Defaults.Model)
+		fmt.Printf("Model: %s\n", cfg.Agents.Defaults.GetModelName())
 
 		hasOpenRouter := cfg.Providers.OpenRouter.APIKey != ""
 		hasAnthropic := cfg.Providers.Anthropic.APIKey != ""
diff --git a/config/config.example.json b/config/config.example.json
index 555509732..e8c6b3d3f 100644
--- a/config/config.example.json
+++ b/config/config.example.json
@@ -3,7 +3,7 @@
     "defaults": {
       "workspace": "~/.picoclaw/workspace",
       "restrict_to_workspace": true,
-      "model": "gpt4",
+      "model_name": "gpt4",
       "max_tokens": 8192,
       "temperature": 0.7,
       "max_tool_iterations": 20
diff --git a/pkg/agent/instance.go b/pkg/agent/instance.go
index dfbef9fbc..c6a54c7d2 100644
--- a/pkg/agent/instance.go
+++ b/pkg/agent/instance.go
@@ -133,7 +133,7 @@ func resolveAgentModel(agentCfg *config.AgentConfig, defaults *config.AgentDefau
 	if agentCfg != nil && agentCfg.Model != nil && strings.TrimSpace(agentCfg.Model.Primary) != "" {
 		return strings.TrimSpace(agentCfg.Model.Primary)
 	}
-	return defaults.Model
+	return defaults.GetModelName()
 }
 
 // resolveAgentFallbacks resolves the fallback models for an agent.
diff --git a/pkg/channels/telegram_commands.go b/pkg/channels/telegram_commands.go
index a084b641b..f28434f46 100644
--- a/pkg/channels/telegram_commands.go
+++ b/pkg/channels/telegram_commands.go
@@ -81,7 +81,7 @@ func (c *cmd) Show(ctx context.Context, message telego.Message) error {
 	switch args {
 	case "model":
 		response = fmt.Sprintf("Current Model: %s (Provider: %s)",
-			c.config.Agents.Defaults.Model,
+			c.config.Agents.Defaults.GetModelName(),
 			c.config.Agents.Defaults.Provider)
 	case "channel":
 		response = "Current Channel: telegram"
@@ -120,7 +120,7 @@ func (c *cmd) List(ctx context.Context, message telego.Message) error {
 			provider = "configured default"
 		}
 		response = fmt.Sprintf("Configured Model: %s\nProvider: %s\n\nTo change models, update config.yaml",
-			c.config.Agents.Defaults.Model, provider)
+			c.config.Agents.Defaults.GetModelName(), provider)
 
 	case "channels":
 		var enabled []string
diff --git a/pkg/config/config.go b/pkg/config/config.go
index 2595398c7..33e7d30e7 100644
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -170,7 +170,8 @@ type AgentDefaults struct {
 	Workspace           string   `json:"workspace"                       env:"PICOCLAW_AGENTS_DEFAULTS_WORKSPACE"`
 	RestrictToWorkspace bool     `json:"restrict_to_workspace"           env:"PICOCLAW_AGENTS_DEFAULTS_RESTRICT_TO_WORKSPACE"`
 	Provider            string   `json:"provider"                        env:"PICOCLAW_AGENTS_DEFAULTS_PROVIDER"`
-	Model               string   `json:"model"                           env:"PICOCLAW_AGENTS_DEFAULTS_MODEL"`
+	ModelName           string   `json:"model_name,omitempty"            env:"PICOCLAW_AGENTS_DEFAULTS_MODEL_NAME"`
+	Model               string   `json:"model,omitempty"                 env:"PICOCLAW_AGENTS_DEFAULTS_MODEL"` // Deprecated: use model_name instead
 	ModelFallbacks      []string `json:"model_fallbacks,omitempty"`
 	ImageModel          string   `json:"image_model,omitempty"           env:"PICOCLAW_AGENTS_DEFAULTS_IMAGE_MODEL"`
 	ImageModelFallbacks []string `json:"image_model_fallbacks,omitempty"`
@@ -179,6 +180,15 @@ type AgentDefaults struct {
 	MaxToolIterations   int      `json:"max_tool_iterations"             env:"PICOCLAW_AGENTS_DEFAULTS_MAX_TOOL_ITERATIONS"`
 }
 
+// GetModelName returns the effective model name for the agent defaults.
+// It prefers the new "model_name" field but falls back to "model" for backward compatibility.
+func (d *AgentDefaults) GetModelName() string {
+	if d.ModelName != "" {
+		return d.ModelName
+	}
+	return d.Model
+}
+
 type ChannelsConfig struct {
 	WhatsApp WhatsAppConfig `json:"whatsapp"`
 	Telegram TelegramConfig `json:"telegram"`
diff --git a/pkg/config/migration.go b/pkg/config/migration.go
index 30eaa7474..70e1de438 100644
--- a/pkg/config/migration.go
+++ b/pkg/config/migration.go
@@ -41,7 +41,7 @@ func ConvertProvidersToModelList(cfg *Config) []ModelConfig {
 
 	// Get user's configured provider and model
 	userProvider := strings.ToLower(cfg.Agents.Defaults.Provider)
-	userModel := cfg.Agents.Defaults.Model
+	userModel := cfg.Agents.Defaults.GetModelName()
 
 	p := cfg.Providers
 
diff --git a/pkg/config/model_config_test.go b/pkg/config/model_config_test.go
index 3c411dc0f..99eea2782 100644
--- a/pkg/config/model_config_test.go
+++ b/pkg/config/model_config_test.go
@@ -6,6 +6,7 @@
 package config
 
 import (
+	"encoding/json"
 	"strings"
 	"sync"
 	"testing"
@@ -114,6 +115,137 @@ func TestGetModelConfig_Concurrent(t *testing.T) {
 	}
 }
 
+func TestAgentDefaults_GetModelName_BackwardCompat(t *testing.T) {
+	tests := []struct {
+		name     string
+		defaults AgentDefaults
+		wantName string
+	}{
+		{
+			name:     "new model_name field only",
+			defaults: AgentDefaults{ModelName: "new-model"},
+			wantName: "new-model",
+		},
+		{
+			name:     "old model field only",
+			defaults: AgentDefaults{Model: "legacy-model"},
+			wantName: "legacy-model",
+		},
+		{
+			name:     "both fields - model_name takes precedence",
+			defaults: AgentDefaults{ModelName: "new-model", Model: "old-model"},
+			wantName: "new-model",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := tt.defaults.GetModelName(); got != tt.wantName {
+				t.Errorf("GetModelName() = %q, want %q", got, tt.wantName)
+			}
+		})
+	}
+}
+
+func TestAgentDefaults_JSON_BackwardCompat(t *testing.T) {
+	tests := []struct {
+		name     string
+		json     string
+		wantName string
+	}{
+		{
+			name:     "new model_name field",
+			json:     `{"model_name": "gpt4"}`,
+			wantName: "gpt4",
+		},
+		{
+			name:     "old model field",
+			json:     `{"model": "gpt4"}`,
+			wantName: "gpt4",
+		},
+		{
+			name:     "both fields - model_name wins",
+			json:     `{"model_name": "new", "model": "old"}`,
+			wantName: "new",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var defaults AgentDefaults
+			if err := json.Unmarshal([]byte(tt.json), &defaults); err != nil {
+				t.Fatalf("Unmarshal error: %v", err)
+			}
+			if got := defaults.GetModelName(); got != tt.wantName {
+				t.Errorf("GetModelName() = %q, want %q", got, tt.wantName)
+			}
+		})
+	}
+}
+
+func TestFullConfig_JSON_BackwardCompat(t *testing.T) {
+	// Test complete config with both old and new formats
+	oldFormat := `{
+		"agents": {
+			"defaults": {
+				"workspace": "~/.picoclaw/workspace",
+				"model": "gpt4",
+				"max_tokens": 4096
+			}
+		},
+		"model_list": [
+			{
+				"model_name": "gpt4",
+				"model": "openai/gpt-4o",
+				"api_key": "test-key"
+			}
+		]
+	}`
+
+	newFormat := `{
+		"agents": {
+			"defaults": {
+				"workspace": "~/.picoclaw/workspace",
+				"model_name": "gpt4",
+				"max_tokens": 4096
+			}
+		},
+		"model_list": [
+			{
+				"model_name": "gpt4",
+				"model": "openai/gpt-4o",
+				"api_key": "test-key"
+			}
+		]
+	}`
+
+	for name, jsonStr := range map[string]string{
+		"old format (model)":      oldFormat,
+		"new format (model_name)": newFormat,
+	} {
+		t.Run(name, func(t *testing.T) {
+			cfg := &Config{}
+			if err := json.Unmarshal([]byte(jsonStr), cfg); err != nil {
+				t.Fatalf("Unmarshal error: %v", err)
+			}
+
+			// Check that GetModelName returns correct value
+			if got := cfg.Agents.Defaults.GetModelName(); got != "gpt4" {
+				t.Errorf("GetModelName() = %q, want %q", got, "gpt4")
+			}
+
+			// Check that GetModelConfig works
+			modelCfg, err := cfg.GetModelConfig("gpt4")
+			if err != nil {
+				t.Fatalf("GetModelConfig error: %v", err)
+			}
+			if modelCfg.Model != "openai/gpt-4o" {
+				t.Errorf("Model = %q, want %q", modelCfg.Model, "openai/gpt-4o")
+			}
+		})
+	}
+}
+
 func TestModelConfig_Validate(t *testing.T) {
 	tests := []struct {
 		name    string
diff --git a/pkg/migrate/config.go b/pkg/migrate/config.go
index 24ce33e94..869b39827 100644
--- a/pkg/migrate/config.go
+++ b/pkg/migrate/config.go
@@ -73,7 +73,10 @@ func ConvertConfig(data map[string]any) (*config.Config, []string, error) {
 
 	if agents, ok := getMap(data, "agents"); ok {
 		if defaults, ok := getMap(agents, "defaults"); ok {
-			if v, ok := getString(defaults, "model"); ok {
+			// Prefer model_name, fallback to model for backward compatibility
+			if v, ok := getString(defaults, "model_name"); ok {
+				cfg.Agents.Defaults.ModelName = v
+			} else if v, ok := getString(defaults, "model"); ok {
 				cfg.Agents.Defaults.Model = v
 			}
 			if v, ok := getFloat(defaults, "max_tokens"); ok {
diff --git a/pkg/providers/factory.go b/pkg/providers/factory.go
index cda4753ea..11af14da4 100644
--- a/pkg/providers/factory.go
+++ b/pkg/providers/factory.go
@@ -36,7 +36,7 @@ type providerSelection struct {
 }
 
 func resolveProviderSelection(cfg *config.Config) (providerSelection, error) {
-	model := cfg.Agents.Defaults.Model
+	model := cfg.Agents.Defaults.GetModelName()
 	providerName := strings.ToLower(cfg.Agents.Defaults.Provider)
 	lowerModel := strings.ToLower(model)
 
diff --git a/pkg/providers/legacy_provider.go b/pkg/providers/legacy_provider.go
index eb13cec65..23f137538 100644
--- a/pkg/providers/legacy_provider.go
+++ b/pkg/providers/legacy_provider.go
@@ -16,7 +16,7 @@ import (
 // The old providers config is automatically converted to model_list during config loading.
 // Returns the provider, the model ID to use, and any error.
 func CreateProvider(cfg *config.Config) (LLMProvider, string, error) {
-	model := cfg.Agents.Defaults.Model
+	model := cfg.Agents.Defaults.GetModelName()
 
 	// Ensure model_list is populated (should be done by LoadConfig, but handle edge cases)
 	if len(cfg.ModelList) == 0 && cfg.HasProvidersConfig() {