diff --git a/pkg/agent/loop.go b/pkg/agent/loop.go
index 269f415c0..ef6d58775 100644
--- a/pkg/agent/loop.go
+++ b/pkg/agent/loop.go
@@ -49,6 +49,7 @@ type AgentLoop struct {
 	transcriber    voice.Transcriber
 	cmdRegistry    *commands.Registry
 	version        string
+	wg             sync.WaitGroup
 }
 
 // processOptions configures how a message is processed
@@ -430,6 +431,10 @@ func (al *AgentLoop) Stop() {
 	al.running.Store(false)
 }
 
+func (al *AgentLoop) Wait() {
+	al.wg.Wait()
+}
+
 func (al *AgentLoop) RegisterTool(tool tools.Tool) {
 	for _, agentID := range al.registry.ListAgentIDs() {
 		if agent, ok := al.registry.GetAgent(agentID); ok {
@@ -1122,12 +1127,16 @@ func (al *AgentLoop) runLLMIteration(
 			return "", iteration, fmt.Errorf("LLM call failed after retries: %w", err)
 		}
 
-		go al.handleReasoning(
-			ctx,
-			response.Reasoning,
-			opts.Channel,
-			al.targetReasoningChannelID(opts.Channel),
-		)
+		al.wg.Add(1)
+		go func() {
+			defer al.wg.Done()
+			al.handleReasoning(
+				ctx,
+				response.Reasoning,
+				opts.Channel,
+				al.targetReasoningChannelID(opts.Channel),
+			)
+		}()
 
 		logger.DebugCF("agent", "LLM response",
 			map[string]any{
@@ -1402,7 +1411,9 @@ func (al *AgentLoop) maybeSummarize(agent *AgentInstance, sessionKey, channel, c
 	if len(newHistory) > agent.SummarizeMessageThreshold || tokenEstimate > threshold {
 		summarizeKey := agent.ID + ":" + sessionKey
 		if _, loading := al.summarizing.LoadOrStore(summarizeKey, true); !loading {
+			al.wg.Add(1)
 			go func() {
+				defer al.wg.Done()
 				defer al.summarizing.Delete(summarizeKey)
 				logger.Debug("Memory threshold reached. Optimizing conversation history...")
 				al.summarizeSession(agent, sessionKey)
diff --git a/pkg/channels/split.go b/pkg/channels/split.go
index bb26c6d8f..fb7120562 100644
--- a/pkg/channels/split.go
+++ b/pkg/channels/split.go
@@ -42,7 +42,11 @@ func SplitMessage(content string, maxLen int) []string {
 		end := start + effectiveLimit
 
 		// Find natural split point within the effective limit
-		msgEnd := findLastNewlineInRange(runes, start, end, 200)
+		// Try double-newline (\n\n) first for semantic paragraph splitting.
+		msgEnd := findLastDoubleNewlineInRange(runes, start, end, 300)
+		if msgEnd <= start {
+			msgEnd = findLastNewlineInRange(runes, start, end, 200)
+		}
 		if msgEnd <= start {
 			msgEnd = findLastSpaceInRange(runes, start, end, 100)
 		}
@@ -206,3 +210,16 @@ func findLastSpaceInRange(runes []rune, start, end, searchWindow int) int {
 	}
 	return start - 1
 }
+
+// findLastDoubleNewlineInRange finds the last \n\n within the last searchWindow runes
+// of the range runes[start:end]. Returns the absolute index of the second newline or start-1.
+func findLastDoubleNewlineInRange(runes []rune, start, end, searchWindow int) int {
+	searchStart := max(end-searchWindow, start)
+	for i := end - 1; i > searchStart; i-- {
+		if runes[i] == '\n' && runes[i-1] == '\n' {
+			return i
+		}
+	}
+	return start - 1
+}
+
diff --git a/pkg/providers/builtin_resolvers.go b/pkg/providers/builtin_resolvers.go
new file mode 100644
index 000000000..7386af7da
--- /dev/null
+++ b/pkg/providers/builtin_resolvers.go
@@ -0,0 +1,344 @@
+package providers
+
+import (
+	"strings"
+	"github.com/sipeed/picoclaw/pkg/config"
+)
+
+func init() {
+	RegisterProvider("groq", groqResolver)
+	RegisterProvider("openai", openaiResolver)
+	RegisterProvider("gpt", openaiResolver)
+	RegisterProvider("anthropic", anthropicResolver)
+	RegisterProvider("claude", anthropicResolver)
+	RegisterProvider("openrouter", openrouterResolver)
+	RegisterProvider("litellm", litellmResolver)
+	RegisterProvider("zhipu", zhipuResolver)
+	RegisterProvider("glm", zhipuResolver)
+	RegisterProvider("gemini", geminiResolver)
+	RegisterProvider("google", geminiResolver)
+	RegisterProvider("vllm", vllmResolver)
+	RegisterProvider("shengsuanyun", shengsuanyunResolver)
+	RegisterProvider("nvidia", nvidiaResolver)
+	RegisterProvider("vivgrid", vivgridResolver)
+	RegisterProvider("deepseek", deepseekResolver)
+	RegisterProvider("avian", avianResolver)
+	RegisterProvider("mistral", mistralResolver)
+	RegisterProvider("minimax", minimaxResolver)
+	RegisterProvider("claude-cli", claudeCLIResolver)
+	RegisterProvider("claude-code", claudeCLIResolver)
+	RegisterProvider("claudecode", claudeCLIResolver)
+	RegisterProvider("codex-cli", codexCLIResolver)
+	RegisterProvider("codex-code", codexCLIResolver)
+	RegisterProvider("github_copilot", copilotResolver)
+	RegisterProvider("copilot", copilotResolver)
+}
+
+func groqResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	if cfg.Providers.Groq.APIKey != "" {
+		sel := providerSelection{
+			providerType: providerTypeHTTPCompat,
+			model:        model,
+			apiKey:       cfg.Providers.Groq.APIKey,
+			apiBase:      cfg.Providers.Groq.APIBase,
+			proxy:        cfg.Providers.Groq.Proxy,
+		}
+		if sel.apiBase == "" {
+			sel.apiBase = "https://api.groq.com/openai/v1"
+		}
+		return sel, true, nil
+	}
+	return providerSelection{}, false, nil
+}
+
+func openaiResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	if cfg.Providers.OpenAI.APIKey != "" || cfg.Providers.OpenAI.AuthMethod != "" {
+		sel := providerSelection{
+			providerType:    providerTypeHTTPCompat,
+			model:           model,
+			enableWebSearch: cfg.Providers.OpenAI.WebSearch,
+		}
+		if cfg.Providers.OpenAI.AuthMethod == "codex-cli" {
+			sel.providerType = providerTypeCodexCLIToken
+			return sel, true, nil
+		}
+		if cfg.Providers.OpenAI.AuthMethod == "oauth" || cfg.Providers.OpenAI.AuthMethod == "token" {
+			sel.providerType = providerTypeCodexAuth
+			return sel, true, nil
+		}
+		sel.apiKey = cfg.Providers.OpenAI.APIKey
+		sel.apiBase = cfg.Providers.OpenAI.APIBase
+		sel.proxy = cfg.Providers.OpenAI.Proxy
+		if sel.apiBase == "" {
+			sel.apiBase = "https://api.openai.com/v1"
+		}
+		return sel, true, nil
+	}
+	return providerSelection{}, false, nil
+}
+
+func anthropicResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	if cfg.Providers.Anthropic.APIKey != "" || cfg.Providers.Anthropic.AuthMethod != "" {
+		sel := providerSelection{
+			providerType: providerTypeHTTPCompat,
+			model:        model,
+		}
+		if cfg.Providers.Anthropic.AuthMethod == "oauth" || cfg.Providers.Anthropic.AuthMethod == "token" {
+			sel.apiBase = cfg.Providers.Anthropic.APIBase
+			if sel.apiBase == "" {
+				sel.apiBase = defaultAnthropicAPIBase
+			}
+			sel.providerType = providerTypeClaudeAuth
+			return sel, true, nil
+		}
+		sel.apiKey = cfg.Providers.Anthropic.APIKey
+		sel.apiBase = cfg.Providers.Anthropic.APIBase
+		sel.proxy = cfg.Providers.Anthropic.Proxy
+		if sel.apiBase == "" {
+			sel.apiBase = defaultAnthropicAPIBase
+		}
+		return sel, true, nil
+	}
+	return providerSelection{}, false, nil
+}
+
+func openrouterResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	if cfg.Providers.OpenRouter.APIKey != "" {
+		sel := providerSelection{
+			providerType: providerTypeHTTPCompat,
+			model:        model,
+			apiKey:       cfg.Providers.OpenRouter.APIKey,
+			proxy:        cfg.Providers.OpenRouter.Proxy,
+			apiBase:      cfg.Providers.OpenRouter.APIBase,
+		}
+		if sel.apiBase == "" {
+			sel.apiBase = "https://openrouter.ai/api/v1"
+		}
+		return sel, true, nil
+	}
+	return providerSelection{}, false, nil
+}
+
+func litellmResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	if cfg.Providers.LiteLLM.APIKey != "" || cfg.Providers.LiteLLM.APIBase != "" {
+		sel := providerSelection{
+			providerType: providerTypeHTTPCompat,
+			model:        model,
+			apiKey:       cfg.Providers.LiteLLM.APIKey,
+			apiBase:      cfg.Providers.LiteLLM.APIBase,
+			proxy:        cfg.Providers.LiteLLM.Proxy,
+		}
+		if sel.apiBase == "" {
+			sel.apiBase = "http://localhost:4000/v1"
+		}
+		return sel, true, nil
+	}
+	return providerSelection{}, false, nil
+}
+
+func zhipuResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	if cfg.Providers.Zhipu.APIKey != "" {
+		sel := providerSelection{
+			providerType: providerTypeHTTPCompat,
+			model:        model,
+			apiKey:       cfg.Providers.Zhipu.APIKey,
+			apiBase:      cfg.Providers.Zhipu.APIBase,
+			proxy:        cfg.Providers.Zhipu.Proxy,
+		}
+		if sel.apiBase == "" {
+			sel.apiBase = "https://open.bigmodel.cn/api/paas/v4"
+		}
+		return sel, true, nil
+	}
+	return providerSelection{}, false, nil
+}
+
+func geminiResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	if cfg.Providers.Gemini.APIKey != "" {
+		sel := providerSelection{
+			providerType: providerTypeHTTPCompat,
+			model:        model,
+			apiKey:       cfg.Providers.Gemini.APIKey,
+			apiBase:      cfg.Providers.Gemini.APIBase,
+			proxy:        cfg.Providers.Gemini.Proxy,
+		}
+		if sel.apiBase == "" {
+			sel.apiBase = "https://generativelanguage.googleapis.com/v1beta"
+		}
+		return sel, true, nil
+	}
+	return providerSelection{}, false, nil
+}
+
+func vllmResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	if cfg.Providers.VLLM.APIBase != "" {
+		return providerSelection{
+			providerType: providerTypeHTTPCompat,
+			model:        model,
+			apiKey:       cfg.Providers.VLLM.APIKey,
+			apiBase:      cfg.Providers.VLLM.APIBase,
+			proxy:        cfg.Providers.VLLM.Proxy,
+		}, true, nil
+	}
+	return providerSelection{}, false, nil
+}
+
+func shengsuanyunResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	if cfg.Providers.ShengSuanYun.APIKey != "" {
+		sel := providerSelection{
+			providerType: providerTypeHTTPCompat,
+			model:        model,
+			apiKey:       cfg.Providers.ShengSuanYun.APIKey,
+			apiBase:      cfg.Providers.ShengSuanYun.APIBase,
+			proxy:        cfg.Providers.ShengSuanYun.Proxy,
+		}
+		if sel.apiBase == "" {
+			sel.apiBase = "https://router.shengsuanyun.com/api/v1"
+		}
+		return sel, true, nil
+	}
+	return providerSelection{}, false, nil
+}
+
+func nvidiaResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	if cfg.Providers.Nvidia.APIKey != "" {
+		sel := providerSelection{
+			providerType: providerTypeHTTPCompat,
+			model:        model,
+			apiKey:       cfg.Providers.Nvidia.APIKey,
+			apiBase:      cfg.Providers.Nvidia.APIBase,
+			proxy:        cfg.Providers.Nvidia.Proxy,
+		}
+		if sel.apiBase == "" {
+			sel.apiBase = "https://integrate.api.nvidia.com/v1"
+		}
+		return sel, true, nil
+	}
+	return providerSelection{}, false, nil
+}
+
+func vivgridResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	if cfg.Providers.Vivgrid.APIKey != "" {
+		sel := providerSelection{
+			providerType: providerTypeHTTPCompat,
+			model:        model,
+			apiKey:       cfg.Providers.Vivgrid.APIKey,
+			apiBase:      cfg.Providers.Vivgrid.APIBase,
+			proxy:        cfg.Providers.Vivgrid.Proxy,
+		}
+		if sel.apiBase == "" {
+			sel.apiBase = "https://api.vivgrid.com/v1"
+		}
+		return sel, true, nil
+	}
+	return providerSelection{}, false, nil
+}
+
+func claudeCLIResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	workspace := cfg.WorkspacePath()
+	if workspace == "" {
+		workspace = "."
+	}
+	return providerSelection{
+		providerType: providerTypeClaudeCLI,
+		model:        model,
+		workspace:    workspace,
+	}, true, nil
+}
+
+func codexCLIResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	workspace := cfg.WorkspacePath()
+	if workspace == "" {
+		workspace = "."
+	}
+	return providerSelection{
+		providerType: providerTypeCodexCLI,
+		model:        model,
+		workspace:    workspace,
+	}, true, nil
+}
+
+func deepseekResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	if cfg.Providers.DeepSeek.APIKey != "" {
+		sel := providerSelection{
+			providerType: providerTypeHTTPCompat,
+			model:        model,
+			apiKey:       cfg.Providers.DeepSeek.APIKey,
+			apiBase:      cfg.Providers.DeepSeek.APIBase,
+			proxy:        cfg.Providers.DeepSeek.Proxy,
+		}
+		if sel.apiBase == "" {
+			sel.apiBase = "https://api.deepseek.com/v1"
+		}
+		if model != "deepseek-chat" && model != "deepseek-reasoner" {
+			sel.model = "deepseek-chat"
+		}
+		return sel, true, nil
+	}
+	return providerSelection{}, false, nil
+}
+
+func avianResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	if cfg.Providers.Avian.APIKey != "" {
+		sel := providerSelection{
+			providerType: providerTypeHTTPCompat,
+			model:        model,
+			apiKey:       cfg.Providers.Avian.APIKey,
+			apiBase:      cfg.Providers.Avian.APIBase,
+			proxy:        cfg.Providers.Avian.Proxy,
+		}
+		if sel.apiBase == "" {
+			sel.apiBase = "https://api.avian.io/v1"
+		}
+		return sel, true, nil
+	}
+	return providerSelection{}, false, nil
+}
+
+func mistralResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	if cfg.Providers.Mistral.APIKey != "" {
+		sel := providerSelection{
+			providerType: providerTypeHTTPCompat,
+			model:        model,
+			apiKey:       cfg.Providers.Mistral.APIKey,
+			apiBase:      cfg.Providers.Mistral.APIBase,
+			proxy:        cfg.Providers.Mistral.Proxy,
+		}
+		if sel.apiBase == "" {
+			sel.apiBase = "https://api.mistral.ai/v1"
+		}
+		return sel, true, nil
+	}
+	return providerSelection{}, false, nil
+}
+
+func minimaxResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	if cfg.Providers.Minimax.APIKey != "" {
+		sel := providerSelection{
+			providerType: providerTypeHTTPCompat,
+			model:        model,
+			apiKey:       cfg.Providers.Minimax.APIKey,
+			apiBase:      cfg.Providers.Minimax.APIBase,
+			proxy:        cfg.Providers.Minimax.Proxy,
+		}
+		if sel.apiBase == "" {
+			sel.apiBase = "https://api.minimaxi.com/v1"
+		}
+		return sel, true, nil
+	}
+	return providerSelection{}, false, nil
+}
+
+func copilotResolver(cfg *config.Config, name, model string) (providerSelection, bool, error) {
+	sel := providerSelection{
+		providerType: providerTypeGitHubCopilot,
+		model:        model,
+		connectMode:  cfg.Providers.GitHubCopilot.ConnectMode,
+	}
+	if cfg.Providers.GitHubCopilot.APIBase != "" {
+		sel.apiBase = cfg.Providers.GitHubCopilot.APIBase
+	} else {
+		sel.apiBase = "localhost:4321"
+	}
+	return sel, true, nil
+}
diff --git a/pkg/providers/factory.go b/pkg/providers/factory.go
index d952c8cb0..f783f031f 100644
--- a/pkg/providers/factory.go
+++ b/pkg/providers/factory.go
@@ -47,185 +47,14 @@ func resolveProviderSelection(cfg *config.Config) (providerSelection, error) {
 
 	// First, prefer explicit provider configuration.
 	if providerName != "" {
-		switch providerName {
-		case "groq":
-			if cfg.Providers.Groq.APIKey != "" {
-				sel.apiKey = cfg.Providers.Groq.APIKey
-				sel.apiBase = cfg.Providers.Groq.APIBase
-				sel.proxy = cfg.Providers.Groq.Proxy
-				if sel.apiBase == "" {
-					sel.apiBase = "https://api.groq.com/openai/v1"
-				}
+		if resolver, ok := registry[providerName]; ok {
+			s, resolved, err := resolver(cfg, providerName, model)
+			if err != nil {
+				return providerSelection{}, err
 			}
-		case "openai", "gpt":
-			if cfg.Providers.OpenAI.APIKey != "" || cfg.Providers.OpenAI.AuthMethod != "" {
-				sel.enableWebSearch = cfg.Providers.OpenAI.WebSearch
-				if cfg.Providers.OpenAI.AuthMethod == "codex-cli" {
-					sel.providerType = providerTypeCodexCLIToken
-					return sel, nil
-				}
-				if cfg.Providers.OpenAI.AuthMethod == "oauth" || cfg.Providers.OpenAI.AuthMethod == "token" {
-					sel.providerType = providerTypeCodexAuth
-					return sel, nil
-				}
-				sel.apiKey = cfg.Providers.OpenAI.APIKey
-				sel.apiBase = cfg.Providers.OpenAI.APIBase
-				sel.proxy = cfg.Providers.OpenAI.Proxy
-				if sel.apiBase == "" {
-					sel.apiBase = "https://api.openai.com/v1"
-				}
+			if resolved {
+				return s, nil
 			}
-		case "anthropic", "claude":
-			if cfg.Providers.Anthropic.APIKey != "" || cfg.Providers.Anthropic.AuthMethod != "" {
-				if cfg.Providers.Anthropic.AuthMethod == "oauth" || cfg.Providers.Anthropic.AuthMethod == "token" {
-					sel.apiBase = cfg.Providers.Anthropic.APIBase
-					if sel.apiBase == "" {
-						sel.apiBase = defaultAnthropicAPIBase
-					}
-					sel.providerType = providerTypeClaudeAuth
-					return sel, nil
-				}
-				sel.apiKey = cfg.Providers.Anthropic.APIKey
-				sel.apiBase = cfg.Providers.Anthropic.APIBase
-				sel.proxy = cfg.Providers.Anthropic.Proxy
-				if sel.apiBase == "" {
-					sel.apiBase = defaultAnthropicAPIBase
-				}
-			}
-		case "openrouter":
-			if cfg.Providers.OpenRouter.APIKey != "" {
-				sel.apiKey = cfg.Providers.OpenRouter.APIKey
-				sel.proxy = cfg.Providers.OpenRouter.Proxy
-				if cfg.Providers.OpenRouter.APIBase != "" {
-					sel.apiBase = cfg.Providers.OpenRouter.APIBase
-				} else {
-					sel.apiBase = "https://openrouter.ai/api/v1"
-				}
-			}
-		case "litellm":
-			if cfg.Providers.LiteLLM.APIKey != "" || cfg.Providers.LiteLLM.APIBase != "" {
-				sel.apiKey = cfg.Providers.LiteLLM.APIKey
-				sel.apiBase = cfg.Providers.LiteLLM.APIBase
-				sel.proxy = cfg.Providers.LiteLLM.Proxy
-				if sel.apiBase == "" {
-					sel.apiBase = "http://localhost:4000/v1"
-				}
-			}
-		case "zhipu", "glm":
-			if cfg.Providers.Zhipu.APIKey != "" {
-				sel.apiKey = cfg.Providers.Zhipu.APIKey
-				sel.apiBase = cfg.Providers.Zhipu.APIBase
-				sel.proxy = cfg.Providers.Zhipu.Proxy
-				if sel.apiBase == "" {
-					sel.apiBase = "https://open.bigmodel.cn/api/paas/v4"
-				}
-			}
-		case "gemini", "google":
-			if cfg.Providers.Gemini.APIKey != "" {
-				sel.apiKey = cfg.Providers.Gemini.APIKey
-				sel.apiBase = cfg.Providers.Gemini.APIBase
-				sel.proxy = cfg.Providers.Gemini.Proxy
-				if sel.apiBase == "" {
-					sel.apiBase = "https://generativelanguage.googleapis.com/v1beta"
-				}
-			}
-		case "vllm":
-			if cfg.Providers.VLLM.APIBase != "" {
-				sel.apiKey = cfg.Providers.VLLM.APIKey
-				sel.apiBase = cfg.Providers.VLLM.APIBase
-				sel.proxy = cfg.Providers.VLLM.Proxy
-			}
-		case "shengsuanyun":
-			if cfg.Providers.ShengSuanYun.APIKey != "" {
-				sel.apiKey = cfg.Providers.ShengSuanYun.APIKey
-				sel.apiBase = cfg.Providers.ShengSuanYun.APIBase
-				sel.proxy = cfg.Providers.ShengSuanYun.Proxy
-				if sel.apiBase == "" {
-					sel.apiBase = "https://router.shengsuanyun.com/api/v1"
-				}
-			}
-		case "nvidia":
-			if cfg.Providers.Nvidia.APIKey != "" {
-				sel.apiKey = cfg.Providers.Nvidia.APIKey
-				sel.apiBase = cfg.Providers.Nvidia.APIBase
-				sel.proxy = cfg.Providers.Nvidia.Proxy
-				if sel.apiBase == "" {
-					sel.apiBase = "https://integrate.api.nvidia.com/v1"
-				}
-			}
-		case "vivgrid":
-			if cfg.Providers.Vivgrid.APIKey != "" {
-				sel.apiKey = cfg.Providers.Vivgrid.APIKey
-				sel.apiBase = cfg.Providers.Vivgrid.APIBase
-				sel.proxy = cfg.Providers.Vivgrid.Proxy
-				if sel.apiBase == "" {
-					sel.apiBase = "https://api.vivgrid.com/v1"
-				}
-			}
-		case "claude-cli", "claude-code", "claudecode":
-			workspace := cfg.WorkspacePath()
-			if workspace == "" {
-				workspace = "."
-			}
-			sel.providerType = providerTypeClaudeCLI
-			sel.workspace = workspace
-			return sel, nil
-		case "codex-cli", "codex-code":
-			workspace := cfg.WorkspacePath()
-			if workspace == "" {
-				workspace = "."
-			}
-			sel.providerType = providerTypeCodexCLI
-			sel.workspace = workspace
-			return sel, nil
-		case "deepseek":
-			if cfg.Providers.DeepSeek.APIKey != "" {
-				sel.apiKey = cfg.Providers.DeepSeek.APIKey
-				sel.apiBase = cfg.Providers.DeepSeek.APIBase
-				sel.proxy = cfg.Providers.DeepSeek.Proxy
-				if sel.apiBase == "" {
-					sel.apiBase = "https://api.deepseek.com/v1"
-				}
-				if model != "deepseek-chat" && model != "deepseek-reasoner" {
-					sel.model = "deepseek-chat"
-				}
-			}
-		case "avian":
-			if cfg.Providers.Avian.APIKey != "" {
-				sel.apiKey = cfg.Providers.Avian.APIKey
-				sel.apiBase = cfg.Providers.Avian.APIBase
-				sel.proxy = cfg.Providers.Avian.Proxy
-				if sel.apiBase == "" {
-					sel.apiBase = "https://api.avian.io/v1"
-				}
-			}
-		case "mistral":
-			if cfg.Providers.Mistral.APIKey != "" {
-				sel.apiKey = cfg.Providers.Mistral.APIKey
-				sel.apiBase = cfg.Providers.Mistral.APIBase
-				sel.proxy = cfg.Providers.Mistral.Proxy
-				if sel.apiBase == "" {
-					sel.apiBase = "https://api.mistral.ai/v1"
-				}
-			}
-		case "minimax":
-			if cfg.Providers.Minimax.APIKey != "" {
-				sel.apiKey = cfg.Providers.Minimax.APIKey
-				sel.apiBase = cfg.Providers.Minimax.APIBase
-				sel.proxy = cfg.Providers.Minimax.Proxy
-				if sel.apiBase == "" {
-					sel.apiBase = "https://api.minimaxi.com/v1"
-				}
-			}
-		case "github_copilot", "copilot":
-			sel.providerType = providerTypeGitHubCopilot
-			if cfg.Providers.GitHubCopilot.APIBase != "" {
-				sel.apiBase = cfg.Providers.GitHubCopilot.APIBase
-			} else {
-				sel.apiBase = "localhost:4321"
-			}
-			sel.connectMode = cfg.Providers.GitHubCopilot.ConnectMode
-			return sel, nil
 		}
 	}
 
diff --git a/pkg/providers/registry.go b/pkg/providers/registry.go
new file mode 100644
index 000000000..98b1af17f
--- /dev/null
+++ b/pkg/providers/registry.go
@@ -0,0 +1,22 @@
+package providers
+
+import (
+	"github.com/sipeed/picoclaw/pkg/config"
+)
+
+// ProviderResolver is a function that attempts to resolve a provider and its configuration.
+// It returns the selection, a boolean indicating if it was successfully resolved, and any error.
+type ProviderResolver func(cfg *config.Config, providerName string, model string) (providerSelection, bool, error)
+
+var (
+	registry = make(map[string]ProviderResolver)
+)
+
+// RegisterProvider registers a new provider resolver.
+func RegisterProvider(name string, resolver ProviderResolver) {
+	registry[name] = resolver
+}
+
+func init() {
+	// Built-in providers will register themselves here or via init() in their respective files.
+}
diff --git a/pkg/session/manager.go b/pkg/session/manager.go
index baf0cb9e7..52d4a5df6 100644
--- a/pkg/session/manager.go
+++ b/pkg/session/manager.go
@@ -233,6 +233,8 @@ func (sm *SessionManager) Save(key string) error {
 	}
 
 	sessionPath := filepath.Join(sm.storage, filename+".json")
+	bakPath := sessionPath + ".bak"
+
 	tmpFile, err := os.CreateTemp(sm.storage, "session-*.tmp")
 	if err != nil {
 		return err
@@ -262,7 +264,13 @@ func (sm *SessionManager) Save(key string) error {
 		return err
 	}
 
+	// If primary exists, rename it to .bak before applying the new version.
+	if _, err := os.Stat(sessionPath); err == nil {
+		_ = os.Rename(sessionPath, bakPath)
+	}
+
 	if err := os.Rename(tmpPath, sessionPath); err != nil {
+		_ = os.Rename(bakPath, sessionPath)
 		return err
 	}
 	cleanup = false
@@ -285,6 +293,8 @@ func (sm *SessionManager) loadSessions() error {
 		}
 
 		sessionPath := filepath.Join(sm.storage, file.Name())
+		bakPath := sessionPath + ".bak"
+
 		data, err := os.ReadFile(sessionPath)
 		if err != nil {
 			continue
@@ -292,6 +302,13 @@ func (sm *SessionManager) loadSessions() error {
 
 		var session Session
 		if err := json.Unmarshal(data, &session); err != nil {
+			// Try to recover from backup
+			if bakData, bakErr := os.ReadFile(bakPath); bakErr == nil {
+				if err := json.Unmarshal(bakData, &session); err == nil {
+					sm.sessions[session.Key] = &session
+					continue
+				}
+			}
 			continue
 		}