fix: remove unnecessary lock mechanism and upgrade Claude 3 to Claude 4

- Remove sync.RWMutex and rrCounters from Config struct
- Simplify GetModelConfig to use global atomic counter for load balancing
- Remove unnecessary locks from HasProvidersConfig, SaveConfig, etc.
- Add buildModelWithProtocol helper to handle models with existing prefix
- Fix TestCreateProviderReturnsHTTPProviderForOpenRouter to use model_list
- Upgrade all Claude 3 references to Claude 4 across documentation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.fr.md

@@ -838,8 +838,8 @@ Cette conception permet également le **support multi-agent** avec une sélectio
       "api_key": "sk-your-openai-key"
     },
     {
-      "model_name": "claude-3-sonnet",
-      "model": "anthropic/claude-3-5-sonnet-20241022",
+      "model_name": "claude-sonnet-4",
+      "model": "anthropic/claude-sonnet-4-20250514",
       "api_key": "sk-ant-your-key"
     },
     {

README.ja.md

@@ -774,8 +774,8 @@ HEARTBEAT_OK 応答         ユーザーが直接結果を受け取る
       "api_key": "sk-your-openai-key"
     },
     {
-      "model_name": "claude-3-sonnet",
-      "model": "anthropic/claude-3-5-sonnet-20241022",
+      "model_name": "claude-sonnet-4",
+      "model": "anthropic/claude-sonnet-4-20250514",
       "api_key": "sk-ant-your-key"
     },
     {

README.md

@@ -222,8 +222,8 @@ picoclaw onboard
       "api_key": "your-api-key"
     },
     {
-      "model_name": "claude3",
-      "model": "anthropic/claude-3-sonnet",
+      "model_name": "claude-sonnet-4",
+      "model": "anthropic/claude-sonnet-4",
       "api_key": "your-anthropic-key"
     }
   ],
@@ -733,8 +733,8 @@ This design also enables **multi-agent support** with flexible provider selectio
       "api_key": "sk-your-openai-key"
     },
     {
-      "model_name": "claude-3-sonnet",
-      "model": "anthropic/claude-3-5-sonnet-20241022",
+      "model_name": "claude-sonnet-4",
+      "model": "anthropic/claude-sonnet-4-20250514",
       "api_key": "sk-ant-your-key"
     },
     {

README.pt-br.md

@@ -839,8 +839,8 @@ Este design também possibilita o **suporte multi-agent** com seleção flexíve
       "api_key": "sk-your-openai-key"
     },
     {
-      "model_name": "claude-3-sonnet",
-      "model": "anthropic/claude-3-5-sonnet-20241022",
+      "model_name": "claude-sonnet-4",
+      "model": "anthropic/claude-sonnet-4-20250514",
       "api_key": "sk-ant-your-key"
     },
     {

README.vi.md

@@ -816,8 +816,8 @@ Thiết kế này cũng cho phép **hỗ trợ đa tác nhân** với lựa ch
       "api_key": "sk-your-openai-key"
     },
     {
-      "model_name": "claude-3-sonnet",
-      "model": "anthropic/claude-3-5-sonnet-20241022",
+      "model_name": "claude-sonnet-4",
+      "model": "anthropic/claude-sonnet-4-20250514",
       "api_key": "sk-ant-your-key"
     },
     {

README.zh.md

@@ -231,8 +231,8 @@ picoclaw onboard
       "api_key": "your-api-key"
     },
     {
-      "model_name": "claude3",
-      "model": "anthropic/claude-3-sonnet",
+      "model_name": "claude-sonnet-4",
+      "model": "anthropic/claude-sonnet-4",
       "api_key": "your-anthropic-key"
     }
   ],
@@ -610,8 +610,8 @@ Agent 读取 HEARTBEAT.md
       "api_key": "sk-your-openai-key"
     },
     {
-      "model_name": "claude-3-sonnet",
-      "model": "anthropic/claude-3-5-sonnet-20241022",
+      "model_name": "claude-sonnet-4",
+      "model": "anthropic/claude-sonnet-4-20250514",
       "api_key": "sk-ant-your-key"
     },
     {

config/config.example.json

@@ -17,8 +17,8 @@
       "api_base": "https://api.openai.com/v1"
     },
     {
-      "model_name": "claude3",
-      "model": "anthropic/claude-3-sonnet",
+      "model_name": "claude-sonnet-4",
+      "model": "anthropic/claude-sonnet-4",
       "api_key": "sk-ant-your-key",
       "api_base": "https://api.anthropic.com/v1"
     },

docs/design/provider-refactoring.md

@@ -66,7 +66,7 @@ Problem: Agent needs to know both `provider` and `model`, adding complexity.
 Inspired by [LiteLLM](https://docs.litellm.ai/docs/proxy/configs) design:
 
 1. **Model-centric**: Users care about models, not providers
-2. **Protocol prefix**: Use `protocol/model_name` format, e.g., `openai/gpt-5.2`, `anthropic/claude-3-sonnet`
+2. **Protocol prefix**: Use `protocol/model_name` format, e.g., `openai/gpt-5.2`, `anthropic/claude-sonnet-4`
 3. **Configuration-driven**: Adding new Providers only requires config changes, no code changes
 
 ### 2.2 New Configuration Structure
@@ -86,8 +86,8 @@ Inspired by [LiteLLM](https://docs.litellm.ai/docs/proxy/configs) design:
       "api_key": "sk-xxx"
     },
     {
-      "model_name": "claude-3-sonnet",
-      "model": "anthropic/claude-3-5-sonnet-20241022",
+      "model_name": "claude-sonnet-4",
+      "model": "anthropic/claude-sonnet-4-20250514",
       "api_key": "sk-xxx"
     },
     {
@@ -184,7 +184,7 @@ Identify protocol via prefix in `model` field:
       "system_prompt": "You are a coding assistant..."
     },
     "translator": {
-      "model": "claude-3-sonnet"
+      "model": "claude-sonnet-4"
     }
   }
 }

docs/migration/model-list-migration.md

@@ -58,8 +58,8 @@ The new `model_list` configuration offers several advantages:
       "api_base": "https://api.openai.com/v1"
     },
     {
-      "model_name": "claude3",
-      "model": "anthropic/claude-3-sonnet",
+      "model_name": "claude-sonnet-4",
+      "model": "anthropic/claude-sonnet-4",
       "api_key": "sk-ant-your-key"
     },
     {
@@ -83,12 +83,12 @@ The `model` field uses a protocol prefix format: `[protocol/]model-identifier`
 | Prefix | Description | Example |
 |--------|-------------|---------|
 | `openai/` | OpenAI API (default) | `openai/gpt-5.2` |
-| `anthropic/` | Anthropic API | `anthropic/claude-3-opus` |
+| `anthropic/` | Anthropic API | `anthropic/claude-opus-4` |
 | `antigravity/` | Google via Antigravity OAuth | `antigravity/gemini-2.0-flash` |
-| `claude-cli/` | Claude CLI (local) | `claude-cli/claude-3-sonnet` |
+| `claude-cli/` | Claude CLI (local) | `claude-cli/claude-sonnet-4` |
 | `codex-cli/` | Codex CLI (local) | `codex-cli/codex-4` |
 | `github-copilot/` | GitHub Copilot | `github-copilot/gpt-4o` |
-| `openrouter/` | OpenRouter | `openrouter/anthropic/claude-3` |
+| `openrouter/` | OpenRouter | `openrouter/anthropic/claude-sonnet-4` |
 | `groq/` | Groq API | `groq/llama-3.1-70b` |
 | `deepseek/` | DeepSeek API | `deepseek/deepseek-chat` |
 | `cerebras/` | Cerebras API | `cerebras/llama-3.3-70b` |

pkg/config/config.go

@@ -5,12 +5,14 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
-	"sync"
 	"sync/atomic"
 
 	"github.com/caarlos0/env/v11"
 )
 
+// rrCounter is a global counter for round-robin load balancing across models.
+var rrCounter atomic.Uint64
+
 // FlexibleStringSlice is a []string that also accepts JSON numbers,
 // so allow_from can contain both "123" and 123.
 type FlexibleStringSlice []string
@@ -45,18 +47,16 @@ func (f *FlexibleStringSlice) UnmarshalJSON(data []byte) error {
 }
 
 type Config struct {
-	Agents     AgentsConfig    `json:"agents"`
-	Bindings   []AgentBinding  `json:"bindings,omitempty"`
-	Session    SessionConfig   `json:"session,omitempty"`
-	Channels   ChannelsConfig  `json:"channels"`
-	Providers  ProvidersConfig `json:"providers,omitempty"`
-	ModelList  []ModelConfig   `json:"model_list"` // New model-centric provider configuration
-	Gateway    GatewayConfig   `json:"gateway"`
-	Tools      ToolsConfig     `json:"tools"`
-	Heartbeat  HeartbeatConfig `json:"heartbeat"`
-	Devices    DevicesConfig   `json:"devices"`
-	mu         sync.RWMutex
-	rrCounters map[string]*atomic.Uint64 // Round-robin counters for load balancing
+	Agents    AgentsConfig    `json:"agents"`
+	Bindings  []AgentBinding  `json:"bindings,omitempty"`
+	Session   SessionConfig   `json:"session,omitempty"`
+	Channels  ChannelsConfig  `json:"channels"`
+	Providers ProvidersConfig `json:"providers,omitempty"`
+	ModelList []ModelConfig   `json:"model_list"` // New model-centric provider configuration
+	Gateway   GatewayConfig   `json:"gateway"`
+	Tools     ToolsConfig     `json:"tools"`
+	Heartbeat HeartbeatConfig `json:"heartbeat"`
+	Devices   DevicesConfig   `json:"devices"`
 }
 
 // MarshalJSON implements custom JSON marshaling for Config
@@ -350,7 +350,7 @@ type OpenAIProviderConfig struct {
 type ModelConfig struct {
 	// Required fields
 	ModelName string `json:"model_name"` // User-facing alias for the model
-	Model     string `json:"model"`      // Protocol/model-identifier (e.g., "openai/gpt-4o", "anthropic/claude-3")
+	Model     string `json:"model"`      // Protocol/model-identifier (e.g., "openai/gpt-4o", "anthropic/claude-sonnet-4")
 
 	// HTTP-based providers
 	APIBase string `json:"api_base,omitempty"` // API endpoint URL
@@ -454,9 +454,6 @@ func LoadConfig(path string) (*Config, error) {
 }
 
 func SaveConfig(path string, cfg *Config) error {
-	cfg.mu.RLock()
-	defer cfg.mu.RUnlock()
-
 	data, err := json.MarshalIndent(cfg, "", "  ")
 	if err != nil {
 		return err
@@ -471,14 +468,10 @@ func SaveConfig(path string, cfg *Config) error {
 }
 
 func (c *Config) WorkspacePath() string {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
 	return expandHome(c.Agents.Defaults.Workspace)
 }
 
 func (c *Config) GetAPIKey() string {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
 	if c.Providers.OpenRouter.APIKey != "" {
 		return c.Providers.OpenRouter.APIKey
 	}
@@ -510,8 +503,6 @@ func (c *Config) GetAPIKey() string {
 }
 
 func (c *Config) GetAPIBase() string {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
 	if c.Providers.OpenRouter.APIKey != "" {
 		if c.Providers.OpenRouter.APIBase != "" {
 			return c.Providers.OpenRouter.APIBase
@@ -544,54 +535,22 @@ func expandHome(path string) string {
 // GetModelConfig returns the ModelConfig for the given model name.
 // If multiple configs exist with the same model_name, it uses round-robin
 // selection for load balancing. Returns an error if the model is not found.
-// Uses double-check locking for optimal read performance.
 func (c *Config) GetModelConfig(modelName string) (*ModelConfig, error) {
-	// First pass: use read lock to find matches
-	c.mu.RLock()
-	matches := c.findMatchesLocked(modelName)
+	matches := c.findMatches(modelName)
 	if len(matches) == 0 {
-		c.mu.RUnlock()
 		return nil, fmt.Errorf("model %q not found in model_list or providers", modelName)
 	}
 	if len(matches) == 1 {
-		c.mu.RUnlock()
 		return &matches[0], nil
 	}
 
-	// Multiple configs - check if counter exists
-	counter, ok := c.rrCounters[modelName]
-	c.mu.RUnlock()
-
-	// Double-check locking: only acquire write lock if counter needs initialization
-	if !ok {
-		c.mu.Lock()
-		// Re-check after acquiring write lock
-		if c.rrCounters == nil {
-			c.rrCounters = make(map[string]*atomic.Uint64)
-		}
-		if c.rrCounters[modelName] == nil {
-			c.rrCounters[modelName] = &atomic.Uint64{}
-		}
-		counter = c.rrCounters[modelName]
-		c.mu.Unlock()
-	}
-
-	// Re-fetch matches to ensure consistency (ModelList could have changed)
-	c.mu.RLock()
-	matches = c.findMatchesLocked(modelName)
-	c.mu.RUnlock()
-
-	if len(matches) == 0 {
-		return nil, fmt.Errorf("model %q not found in model_list or providers", modelName)
-	}
-
-	idx := counter.Add(1) % uint64(len(matches))
+	// Multiple configs - use round-robin for load balancing
+	idx := rrCounter.Add(1) % uint64(len(matches))
 	return &matches[idx], nil
 }
 
-// findMatchesLocked finds all ModelConfig entries with the given model_name.
-// Must be called with c.mu locked (read or write).
-func (c *Config) findMatchesLocked(modelName string) []ModelConfig {
+// findMatches finds all ModelConfig entries with the given model_name.
+func (c *Config) findMatches(modelName string) []ModelConfig {
 	var matches []ModelConfig
 	for i := range c.ModelList {
 		if c.ModelList[i].ModelName == modelName {
@@ -603,9 +562,6 @@ func (c *Config) findMatchesLocked(modelName string) []ModelConfig {
 
 // HasProvidersConfig checks if any provider in the old providers config has configuration.
 func (c *Config) HasProvidersConfig() bool {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-
 	v := c.Providers
 	return v.Anthropic.APIKey != "" || v.Anthropic.APIBase != "" ||
 		v.OpenAI.APIKey != "" || v.OpenAI.APIBase != "" ||

pkg/config/defaults.go

@@ -160,6 +160,12 @@ func DefaultConfig() *Config {
 			},
 
 			// OpenRouter (100+ models) - https://openrouter.ai/keys
+			{
+				ModelName: "openrouter-auto",
+				Model:     "openrouter/auto",
+				APIBase:   "https://openrouter.ai/api/v1",
+				APIKey:    "",
+			},
 			{
 				ModelName: "openrouter-gpt-5.2",
 				Model:     "openrouter/openai/gpt-5.2",

pkg/config/migration.go

@@ -10,6 +10,17 @@ import (
 	"strings"
 )
 
+// buildModelWithProtocol constructs a model string with protocol prefix.
+// If the model already contains a "/" (indicating it has a protocol prefix), it is returned as-is.
+// Otherwise, the protocol prefix is added.
+func buildModelWithProtocol(protocol, model string) string {
+	if strings.Contains(model, "/") {
+		// Model already has a protocol prefix, return as-is
+		return model
+	}
+	return protocol + "/" + model
+}
+
 // providerMigrationConfig defines how to migrate a provider from old config to new format.
 type providerMigrationConfig struct {
 	// providerNames are the possible names used in agents.defaults.provider
@@ -67,7 +78,7 @@ func ConvertProvidersToModelList(cfg *Config) []ModelConfig {
 				}
 				return ModelConfig{
 					ModelName:  "anthropic",
-					Model:      "anthropic/claude-3-sonnet",
+					Model:      "anthropic/claude-sonnet-4",
 					APIKey:     p.Anthropic.APIKey,
 					APIBase:    p.Anthropic.APIBase,
 					Proxy:      p.Anthropic.Proxy,
@@ -325,13 +336,13 @@ func ConvertProvidersToModelList(cfg *Config) []ModelConfig {
 		// Check if this is the user's configured provider
 		if slices.Contains(m.providerNames, userProvider) && userModel != "" {
 			// Use the user's configured model instead of default
-			mc.Model = m.protocol + "/" + userModel
+			mc.Model = buildModelWithProtocol(m.protocol, userModel)
 		} else if userProvider == "" && userModel != "" && !legacyModelNameApplied {
 			// Legacy config: no explicit provider field but model is specified
 			// Use userModel as ModelName for the FIRST provider so GetModelConfig(model) can find it
 			// This maintains backward compatibility with old configs that relied on implicit provider selection
 			mc.ModelName = userModel
-			mc.Model = m.protocol + "/" + userModel
+			mc.Model = buildModelWithProtocol(m.protocol, userModel)
 			legacyModelNameApplied = true
 		}
 

pkg/config/migration_test.go

@@ -58,8 +58,8 @@ func TestConvertProvidersToModelList_Anthropic(t *testing.T) {
 	if result[0].ModelName != "anthropic" {
 		t.Errorf("ModelName = %q, want %q", result[0].ModelName, "anthropic")
 	}
-	if result[0].Model != "anthropic/claude-3-sonnet" {
-		t.Errorf("Model = %q, want %q", result[0].Model, "anthropic/claude-3-sonnet")
+	if result[0].Model != "anthropic/claude-sonnet-4" {
+		t.Errorf("Model = %q, want %q", result[0].Model, "anthropic/claude-sonnet-4")
 	}
 }
 
@@ -239,7 +239,7 @@ func TestConvertProvidersToModelList_PreservesUserModel_Anthropic(t *testing.T)
 		Agents: AgentsConfig{
 			Defaults: AgentDefaults{
 				Provider: "claude", // alternative name
-				Model:    "claude-3-opus-20240229",
+				Model:    "claude-opus-4-20250514",
 			},
 		},
 		Providers: ProvidersConfig{
@@ -253,8 +253,8 @@ func TestConvertProvidersToModelList_PreservesUserModel_Anthropic(t *testing.T)
 		t.Fatalf("len(result) = %d, want 1", len(result))
 	}
 
-	if result[0].Model != "anthropic/claude-3-opus-20240229" {
-		t.Errorf("Model = %q, want %q", result[0].Model, "anthropic/claude-3-opus-20240229")
+	if result[0].Model != "anthropic/claude-opus-4-20250514" {
+		t.Errorf("Model = %q, want %q", result[0].Model, "anthropic/claude-opus-4-20250514")
 	}
 }
 
@@ -495,3 +495,57 @@ func TestConvertProvidersToModelList_NoProviderField_NoModel(t *testing.T) {
 		t.Errorf("ModelName = %q, want %q", result[0].ModelName, "zhipu")
 	}
 }
+
+// Tests for buildModelWithProtocol helper function
+
+func TestBuildModelWithProtocol_NoPrefix(t *testing.T) {
+	result := buildModelWithProtocol("openai", "gpt-5.2")
+	if result != "openai/gpt-5.2" {
+		t.Errorf("buildModelWithProtocol(openai, gpt-5.2) = %q, want %q", result, "openai/gpt-5.2")
+	}
+}
+
+func TestBuildModelWithProtocol_AlreadyHasPrefix(t *testing.T) {
+	result := buildModelWithProtocol("openrouter", "openrouter/auto")
+	if result != "openrouter/auto" {
+		t.Errorf("buildModelWithProtocol(openrouter, openrouter/auto) = %q, want %q", result, "openrouter/auto")
+	}
+}
+
+func TestBuildModelWithProtocol_DifferentPrefix(t *testing.T) {
+	result := buildModelWithProtocol("anthropic", "openrouter/claude-sonnet-4")
+	if result != "openrouter/claude-sonnet-4" {
+		t.Errorf("buildModelWithProtocol(anthropic, openrouter/claude-sonnet-4) = %q, want %q", result, "openrouter/claude-sonnet-4")
+	}
+}
+
+// Test for legacy config with protocol prefix in model name
+func TestConvertProvidersToModelList_LegacyModelWithProtocolPrefix(t *testing.T) {
+	cfg := &Config{
+		Agents: AgentsConfig{
+			Defaults: AgentDefaults{
+				Provider: "",                // No explicit provider
+				Model:    "openrouter/auto", // Model already has protocol prefix
+			},
+		},
+		Providers: ProvidersConfig{
+			OpenRouter: ProviderConfig{APIKey: "sk-or-test"},
+		},
+	}
+
+	result := ConvertProvidersToModelList(cfg)
+
+	if len(result) < 1 {
+		t.Fatalf("len(result) = %d, want at least 1", len(result))
+	}
+
+	// First provider should use userModel as ModelName for backward compatibility
+	if result[0].ModelName != "openrouter/auto" {
+		t.Errorf("ModelName = %q, want %q", result[0].ModelName, "openrouter/auto")
+	}
+
+	// Model should NOT have duplicated prefix
+	if result[0].Model != "openrouter/auto" {
+		t.Errorf("Model = %q, want %q (should not duplicate prefix)", result[0].Model, "openrouter/auto")
+	}
+}

pkg/providers/factory_test.go

@@ -196,8 +196,15 @@ func TestResolveProviderSelection(t *testing.T) {
 
 func TestCreateProviderReturnsHTTPProviderForOpenRouter(t *testing.T) {
 	cfg := config.DefaultConfig()
-	cfg.Agents.Defaults.Model = "openrouter/auto"
-	cfg.Providers.OpenRouter.APIKey = "sk-or-test"
+	cfg.Agents.Defaults.Model = "test-openrouter"
+	cfg.ModelList = []config.ModelConfig{
+		{
+			ModelName: "test-openrouter",
+			Model:     "openrouter/auto",
+			APIKey:    "sk-or-test",
+			APIBase:   "https://openrouter.ai/api/v1",
+		},
+	}
 
 	provider, _, err := CreateProvider(cfg)
 	if err != nil {