Merge branch 'upstream-main' into feat/subturn-poc

pkg/agent/context.go

@@ -52,7 +52,7 @@ func (cb *ContextBuilder) WithToolDiscovery(useBM25, useRegex bool) *ContextBuil
 }
 
 func getGlobalConfigDir() string {
-	if home := os.Getenv("PICOCLAW_HOME"); home != "" {
+	if home := os.Getenv(config.EnvHome); home != "" {
 		return home
 	}
 	home, err := os.UserHomeDir()
@@ -65,7 +65,7 @@ func getGlobalConfigDir() string {
 func NewContextBuilder(workspace string) *ContextBuilder {
 	// builtin skills: skills directory in current project
 	// Use the skills/ directory under the current working directory
-	builtinSkillsDir := strings.TrimSpace(os.Getenv("PICOCLAW_BUILTIN_SKILLS"))
+	builtinSkillsDir := strings.TrimSpace(os.Getenv(config.EnvBuiltinSkills))
 	if builtinSkillsDir == "" {
 		wd, _ := os.Getwd()
 		builtinSkillsDir = filepath.Join(wd, "skills")
@@ -458,7 +458,23 @@ func (cb *ContextBuilder) LoadBootstrapFiles() string {
 //
 // See: https://docs.anthropic.com/en/docs/build-with-claude/prompt-caching
 // See: https://platform.openai.com/docs/guides/prompt-caching
-func (cb *ContextBuilder) buildDynamicContext(channel, chatID string) string {
+func formatCurrentSenderLine(senderID, senderDisplayName string) string {
+	senderID = strings.TrimSpace(senderID)
+	senderDisplayName = strings.TrimSpace(senderDisplayName)
+
+	switch {
+	case senderDisplayName != "" && senderID != "":
+		return fmt.Sprintf("Current sender: %s (ID: %s)", senderDisplayName, senderID)
+	case senderDisplayName != "":
+		return fmt.Sprintf("Current sender: %s", senderDisplayName)
+	case senderID != "":
+		return fmt.Sprintf("Current sender: %s", senderID)
+	default:
+		return ""
+	}
+}
+
+func (cb *ContextBuilder) buildDynamicContext(channel, chatID, senderID, senderDisplayName string) string {
 	now := time.Now().Format("2006-01-02 15:04 (Monday)")
 	rt := fmt.Sprintf("%s %s, Go %s", runtime.GOOS, runtime.GOARCH, runtime.Version())
 
@@ -468,6 +484,9 @@ func (cb *ContextBuilder) buildDynamicContext(channel, chatID string) string {
 	if channel != "" && chatID != "" {
 		fmt.Fprintf(&sb, "\n\n## Current Session\nChannel: %s\nChat ID: %s", channel, chatID)
 	}
+	if senderLine := formatCurrentSenderLine(senderID, senderDisplayName); senderLine != "" {
+		fmt.Fprintf(&sb, "\n\n## Current Sender\n%s", senderLine)
+	}
 
 	return sb.String()
 }
@@ -477,7 +496,7 @@ func (cb *ContextBuilder) BuildMessages(
 	summary string,
 	currentMessage string,
 	media []string,
-	channel, chatID string,
+	channel, chatID, senderID, senderDisplayName string,
 ) []providers.Message {
 	messages := []providers.Message{}
 
@@ -493,7 +512,7 @@ func (cb *ContextBuilder) BuildMessages(
 	staticPrompt := cb.BuildSystemPromptWithCache()
 
 	// Build short dynamic context (time, runtime, session) — changes per request
-	dynamicCtx := cb.buildDynamicContext(channel, chatID)
+	dynamicCtx := cb.buildDynamicContext(channel, chatID, senderID, senderDisplayName)
 
 	// Compose a single system message: static (cached) + dynamic + optional summary.
 	// Keeping all system content in one message ensures every provider adapter can

pkg/agent/context_cache_test.go

@@ -82,7 +82,7 @@ func TestSingleSystemMessage(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			msgs := cb.BuildMessages(tt.history, tt.summary, tt.message, nil, "test", "chat1")
+			msgs := cb.BuildMessages(tt.history, tt.summary, tt.message, nil, "test", "chat1", "", "")
 
 			systemCount := 0
 			for _, m := range msgs {
@@ -126,6 +126,68 @@ func TestSingleSystemMessage(t *testing.T) {
 	}
 }
 
+func TestBuildMessages_CurrentSenderDynamicContext(t *testing.T) {
+	tmpDir := setupWorkspace(t, map[string]string{
+		"IDENTITY.md": "# Identity\nTest agent.",
+	})
+	defer os.RemoveAll(tmpDir)
+
+	cb := NewContextBuilder(tmpDir)
+
+	tests := []struct {
+		name              string
+		senderID          string
+		senderDisplayName string
+		wantLine          string
+		wantSection       bool
+	}{
+		{
+			name:              "both id and display name",
+			senderID:          "feishu:ou_xxx",
+			senderDisplayName: "Zhang San",
+			wantLine:          "Current sender: Zhang San (ID: feishu:ou_xxx)",
+			wantSection:       true,
+		},
+		{
+			name:              "display name only",
+			senderDisplayName: "Alice",
+			wantLine:          "Current sender: Alice",
+			wantSection:       true,
+		},
+		{
+			name:        "id only",
+			senderID:    "discord:123",
+			wantLine:    "Current sender: discord:123",
+			wantSection: true,
+		},
+		{
+			name:        "no sender info",
+			wantSection: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			msgs := cb.BuildMessages(nil, "", "hello", nil, "discord", "chat1", tt.senderID, tt.senderDisplayName)
+			sys := msgs[0].Content
+
+			if tt.wantSection {
+				if !strings.Contains(sys, "## Current Sender") {
+					t.Fatalf("system prompt missing Current Sender section:\n%s", sys)
+				}
+				if !strings.Contains(sys, tt.wantLine) {
+					t.Fatalf("system prompt missing sender line %q:\n%s", tt.wantLine, sys)
+				}
+				return
+			}
+
+			if strings.Contains(sys, "## Current Sender") {
+				t.Fatalf("system prompt should omit Current Sender section:\n%s", sys)
+			}
+		})
+	}
+}
+
 // TestMtimeAutoInvalidation verifies that the cache detects source file changes
 // via mtime without requiring explicit InvalidateCache().
 // Fix: original implementation had no auto-invalidation — edits to bootstrap files,
@@ -576,7 +638,7 @@ func TestConcurrentBuildSystemPromptWithCache(t *testing.T) {
 				}
 
 				// Also exercise BuildMessages concurrently
-				msgs := cb.BuildMessages(nil, "", "hello", nil, "test", "chat")
+				msgs := cb.BuildMessages(nil, "", "hello", nil, "test", "chat", "", "")
 				if len(msgs) < 2 {
 					errs <- "BuildMessages returned fewer than 2 messages"
 					return
@@ -664,6 +726,6 @@ func BenchmarkBuildMessagesWithCache(b *testing.B) {
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		_ = cb.BuildMessages(history, "summary", "new message", nil, "cli", "test")
+		_ = cb.BuildMessages(history, "summary", "new message", nil, "cli", "test", "", "")
 	}
 }

pkg/agent/loop.go

@@ -61,6 +61,8 @@ type processOptions struct {
 	SessionKey              string   // Session identifier for history/context
 	Channel                 string   // Target channel for tool execution
 	ChatID                  string   // Target chat ID for tool execution
+	SenderID                string   // Current sender ID for dynamic context
+	SenderDisplayName       string   // Current sender display name for dynamic context
 	UserMessage             string   // User message content (may include prefix)
 	Media                   []string // media:// refs from inbound message
 	DefaultResponse         string   // Response when LLM returns empty
@@ -166,7 +168,12 @@ func registerSharedTools(
 			}
 		}
 		if cfg.Tools.IsToolEnabled("web_fetch") {
-			fetchTool, err := tools.NewWebFetchToolWithProxy(50000, cfg.Tools.Web.Proxy, cfg.Tools.Web.FetchLimitBytes)
+			fetchTool, err := tools.NewWebFetchToolWithProxy(
+				50000,
+				cfg.Tools.Web.Proxy,
+				cfg.Tools.Web.Format,
+				cfg.Tools.Web.FetchLimitBytes,
+				cfg.Tools.Web.PrivateHostWhitelist)
 			if err != nil {
 				logger.ErrorCF("agent", "Failed to create web fetch tool", map[string]any{"error": err.Error()})
 			} else {
@@ -338,10 +345,9 @@ func (al *AgentLoop) Run(ctx context.Context) error {
 		select {
 		case <-ctx.Done():
 			return nil
-		default:
-			msg, ok := al.bus.ConsumeInbound(ctx)
+		case msg, ok := <-al.bus.InboundChan():
 			if !ok {
-				continue
+				return nil
 			}
 
 			// Start a goroutine that drains the bus while processMessage is
@@ -408,6 +414,8 @@ func (al *AgentLoop) Run(ctx context.Context) error {
 					}
 				}
 			}()
+		default:
+			time.Sleep(time.Microsecond * 200)
 		}
 	}
 
@@ -419,9 +427,15 @@ func (al *AgentLoop) Run(ctx context.Context) error {
 // is active and stops when drainCtx is canceled (i.e., processMessage returns).
 func (al *AgentLoop) drainBusToSteering(ctx context.Context) {
 	for {
-		msg, ok := al.bus.ConsumeInbound(ctx)
-		if !ok {
+		var msg bus.InboundMessage
+		select {
+		case <-ctx.Done():
 			return
+		case m, ok := <-al.bus.InboundChan():
+			if !ok {
+				return
+			}
+			msg = m
 		}
 
 		// Transcribe audio if needed before steering, so the agent sees text.
@@ -861,14 +875,16 @@ func (al *AgentLoop) processMessage(ctx context.Context, msg bus.InboundMessage)
 		})
 
 	opts := processOptions{
-		SessionKey:      sessionKey,
-		Channel:         msg.Channel,
-		ChatID:          msg.ChatID,
-		UserMessage:     msg.Content,
-		Media:           msg.Media,
-		DefaultResponse: defaultResponse,
-		EnableSummary:   true,
-		SendResponse:    false,
+		SessionKey:        sessionKey,
+		Channel:           msg.Channel,
+		ChatID:            msg.ChatID,
+		SenderID:          msg.SenderID,
+		SenderDisplayName: msg.Sender.DisplayName,
+		UserMessage:       msg.Content,
+		Media:             msg.Media,
+		DefaultResponse:   defaultResponse,
+		EnableSummary:     true,
+		SendResponse:      false,
 	}
 
 	// context-dependent commands check their own Runtime fields and report
@@ -1039,6 +1055,8 @@ func (al *AgentLoop) runAgentLoop(
 		opts.Media,
 		opts.Channel,
 		opts.ChatID,
+		opts.SenderID,
+		opts.SenderDisplayName,
 	)
 
 	// Resolve media:// refs: images→base64 data URLs, non-images→local paths in content
@@ -1256,6 +1274,19 @@ func (al *AgentLoop) runLLMIteration(
 		// Build tool definitions
 		providerToolDefs := agent.Tools.ToProviderDefs()
 
+		// Determine whether the provider's native web search should replace
+		// the client-side web_search tool for this request. Only enable when web
+		// search is actually enabled and registered (so users who disabled web
+		// access do not get provider-side search or billing).
+		_, hasWebSearch := agent.Tools.Get("web_search")
+		useNativeSearch := al.cfg.Tools.Web.PreferNative &&
+			isNativeSearchProvider(agent.Provider) &&
+			hasWebSearch
+
+		if useNativeSearch {
+			providerToolDefs = filterClientWebSearch(providerToolDefs)
+		}
+
 		// Log LLM request details
 		logger.DebugCF("agent", "LLM request",
 			map[string]any{
@@ -1264,6 +1295,7 @@ func (al *AgentLoop) runLLMIteration(
 				"model":             activeModel,
 				"messages_count":    len(messages),
 				"tools_count":       len(providerToolDefs),
+				"native_search":     useNativeSearch,
 				"max_tokens":        agent.MaxTokens,
 				"temperature":       agent.Temperature,
 				"system_prompt_len": len(messages[0].Content),
@@ -1286,6 +1318,9 @@ func (al *AgentLoop) runLLMIteration(
 			"temperature":      agent.Temperature,
 			"prompt_cache_key": agent.ID,
 		}
+		if useNativeSearch {
+			llmOpts["native_search"] = true
+		}
 		// parseThinkingLevel guarantees ThinkingOff for empty/unknown values,
 		// so checking != ThinkingOff is sufficient.
 		if agent.ThinkingLevel != ThinkingOff {
@@ -1387,7 +1422,7 @@ func (al *AgentLoop) runLLMIteration(
 				newSummary := agent.Sessions.GetSummary(opts.SessionKey)
 				messages = agent.ContextBuilder.BuildMessages(
 					newHistory, newSummary, "",
-					nil, opts.Channel, opts.ChatID,
+					nil, opts.Channel, opts.ChatID, opts.SenderID, opts.SenderDisplayName,
 				)
 				continue
 			}
@@ -2246,6 +2281,28 @@ func extractParentPeer(msg bus.InboundMessage) *routing.RoutePeer {
 	return &routing.RoutePeer{Kind: parentKind, ID: parentID}
 }
 
+// isNativeSearchProvider reports whether the given LLM provider implements
+// NativeSearchCapable and returns true for SupportsNativeSearch.
+func isNativeSearchProvider(p providers.LLMProvider) bool {
+	if ns, ok := p.(providers.NativeSearchCapable); ok {
+		return ns.SupportsNativeSearch()
+	}
+	return false
+}
+
+// filterClientWebSearch returns a copy of tools with the client-side
+// web_search tool removed. Used when native provider search is preferred.
+func filterClientWebSearch(tools []providers.ToolDefinition) []providers.ToolDefinition {
+	result := make([]providers.ToolDefinition, 0, len(tools))
+	for _, t := range tools {
+		if strings.EqualFold(t.Function.Name, "web_search") {
+			continue
+		}
+		result = append(result, t)
+	}
+	return result
+}
+
 // Helper to extract provider from registry for cleanup
 func extractProvider(registry *AgentRegistry) (providers.LLMProvider, bool) {
 	if registry == nil {

pkg/agent/loop_test.go

@@ -30,6 +30,28 @@ func (f *fakeChannel) IsAllowed(string) bool                                   {
 func (f *fakeChannel) IsAllowedSender(sender bus.SenderInfo) bool              { return true }
 func (f *fakeChannel) ReasoningChannelID() string                              { return f.id }
 
+type recordingProvider struct {
+	lastMessages []providers.Message
+}
+
+func (r *recordingProvider) Chat(
+	ctx context.Context,
+	messages []providers.Message,
+	tools []providers.ToolDefinition,
+	model string,
+	opts map[string]any,
+) (*providers.LLMResponse, error) {
+	r.lastMessages = append([]providers.Message(nil), messages...)
+	return &providers.LLMResponse{
+		Content:   "Mock response",
+		ToolCalls: []providers.ToolCall{},
+	}, nil
+}
+
+func (r *recordingProvider) GetDefaultModel() string {
+	return "mock-model"
+}
+
 func newTestAgentLoop(
 	t *testing.T,
 ) (al *AgentLoop, cfg *config.Config, msgBus *bus.MessageBus, provider *mockProvider, cleanup func()) {
@@ -54,6 +76,59 @@ func newTestAgentLoop(
 	return al, cfg, msgBus, provider, func() { os.RemoveAll(tmpDir) }
 }
 
+func TestProcessMessage_IncludesCurrentSenderInDynamicContext(t *testing.T) {
+	tmpDir, err := os.MkdirTemp("", "agent-test-*")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	cfg := &config.Config{
+		Agents: config.AgentsConfig{
+			Defaults: config.AgentDefaults{
+				Workspace:         tmpDir,
+				Model:             "test-model",
+				MaxTokens:         4096,
+				MaxToolIterations: 10,
+			},
+		},
+	}
+
+	msgBus := bus.NewMessageBus()
+	provider := &recordingProvider{}
+	al := NewAgentLoop(cfg, msgBus, provider)
+
+	response, err := al.processMessage(context.Background(), bus.InboundMessage{
+		Channel:  "discord",
+		SenderID: "discord:123",
+		Sender: bus.SenderInfo{
+			DisplayName: "Alice",
+		},
+		ChatID:  "group-1",
+		Content: "hello",
+	})
+	if err != nil {
+		t.Fatalf("processMessage() error = %v", err)
+	}
+	if response != "Mock response" {
+		t.Fatalf("processMessage() response = %q, want %q", response, "Mock response")
+	}
+	if len(provider.lastMessages) == 0 {
+		t.Fatal("provider did not receive any messages")
+	}
+
+	systemPrompt := provider.lastMessages[0].Content
+	wantSender := "## Current Sender\nCurrent sender: Alice (ID: discord:123)"
+	if !strings.Contains(systemPrompt, wantSender) {
+		t.Fatalf("system prompt missing sender context %q:\n%s", wantSender, systemPrompt)
+	}
+
+	lastMessage := provider.lastMessages[len(provider.lastMessages)-1]
+	if lastMessage.Role != "user" || lastMessage.Content != "hello" {
+		t.Fatalf("last provider message = %+v, want unchanged user message", lastMessage)
+	}
+}
+
 func TestRecordLastChannel(t *testing.T) {
 	al, cfg, msgBus, provider, cleanup := newTestAgentLoop(t)
 	defer cleanup()
@@ -922,10 +997,25 @@ func TestHandleReasoning(t *testing.T) {
 		al, msgBus := newLoop(t)
 		al.handleReasoning(context.Background(), "reasoning", "telegram", "")
 
-		ctx, cancel := context.WithTimeout(context.Background(), 20*time.Millisecond)
+		ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
 		defer cancel()
-		if msg, ok := msgBus.SubscribeOutbound(ctx); ok {
-			t.Fatalf("expected no outbound message, got %+v", msg)
+		for {
+			select {
+			case msg, ok := <-msgBus.OutboundChan():
+				if !ok {
+					t.Fatalf("expected no outbound message, got %+v", msg)
+				}
+				if msg.Content == "reasoning" {
+					t.Fatalf("expected no message for empty chatID, got %+v", msg)
+				}
+				return
+			case <-ctx.Done():
+				t.Log("expected an outbound message, got none within timeout")
+				return
+			default:
+				// Continue to check for message
+				time.Sleep(5 * time.Millisecond) // Avoid busy loop
+			}
 		}
 	})
 
@@ -933,9 +1023,7 @@ func TestHandleReasoning(t *testing.T) {
 		al, msgBus := newLoop(t)
 		al.handleReasoning(context.Background(), "hello reasoning", "slack", "channel-1")
 
-		ctx, cancel := context.WithTimeout(context.Background(), 200*time.Millisecond)
-		defer cancel()
-		msg, ok := msgBus.SubscribeOutbound(ctx)
+		msg, ok := <-msgBus.OutboundChan()
 		if !ok {
 			t.Fatal("expected an outbound message")
 		}
@@ -949,35 +1037,52 @@ func TestHandleReasoning(t *testing.T) {
 		reasoning := "hello telegram reasoning"
 		al.handleReasoning(context.Background(), reasoning, "telegram", "tg-chat")
 
-		ctx, cancel := context.WithTimeout(context.Background(), 200*time.Millisecond)
+		ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
 		defer cancel()
-		msg, ok := msgBus.SubscribeOutbound(ctx)
-		if !ok {
-			t.Fatal("expected outbound message")
-		}
+		for {
+			select {
+			case <-ctx.Done():
+				t.Fatal("expected an outbound message, got none within timeout")
+				return
+			case msg, ok := <-msgBus.OutboundChan():
+				if !ok {
+					t.Fatal("expected outbound message")
+				}
 
-		if msg.Channel != "telegram" {
-			t.Fatalf("expected telegram channel message, got %+v", msg)
-		}
-		if msg.ChatID != "tg-chat" {
-			t.Fatalf("expected chatID tg-chat, got %+v", msg)
-		}
-		if msg.Content != reasoning {
-			t.Fatalf("content mismatch: got %q want %q", msg.Content, reasoning)
+				if msg.Channel != "telegram" {
+					t.Fatalf("expected telegram channel message, got %+v", msg)
+				}
+				if msg.ChatID != "tg-chat" {
+					t.Fatalf("expected chatID tg-chat, got %+v", msg)
+				}
+				if msg.Content != reasoning {
+					t.Fatalf("content mismatch: got %q want %q", msg.Content, reasoning)
+				}
+				return
+			}
 		}
 	})
 	t.Run("expired ctx", func(t *testing.T) {
 		al, msgBus := newLoop(t)
 		reasoning := "hello telegram reasoning"
-		ctx, cancel := context.WithCancel(context.Background())
-		cancel()
-		al.handleReasoning(ctx, reasoning, "telegram", "tg-chat")
 
-		ctx, cancel = context.WithTimeout(context.Background(), 200*time.Millisecond)
-		defer cancel()
-		msg, ok := msgBus.SubscribeOutbound(ctx)
-		if ok {
-			t.Fatalf("expected no outbound message, got %+v", msg)
+		al.handleReasoning(context.Background(), reasoning, "telegram", "tg-chat")
+
+		consumeCtx, consumeCancel := context.WithTimeout(context.Background(), 2*time.Second)
+		defer consumeCancel()
+
+		for {
+			select {
+			case msg, ok := <-msgBus.OutboundChan():
+				if !ok {
+					t.Fatalf("expected no outbound message, but received: %+v", msg)
+				}
+				t.Logf("Received unexpected outbound message: %+v", msg)
+				return
+			case <-consumeCtx.Done():
+				t.Fatalf("failed: no message received within timeout")
+				return
+			}
 		}
 	})
 
@@ -1017,20 +1122,23 @@ func TestHandleReasoning(t *testing.T) {
 
 		// Drain the bus and verify the reasoning message was NOT published
 		// (it should have been dropped due to timeout).
-		drainCtx, drainCancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
-		defer drainCancel()
-		foundReasoning := false
+		timeer := time.After(1 * time.Second)
 		for {
-			msg, ok := msgBus.SubscribeOutbound(drainCtx)
-			if !ok {
-				break
+			select {
+			case <-timeer:
+				t.Logf(
+					"no reasoning message received after draining bus for 1s, as expected,length=%d",
+					len(msgBus.OutboundChan()),
+				)
+				return
+			case msg, ok := <-msgBus.OutboundChan():
+				if !ok {
+					break
+				}
+				if msg.Content == "should timeout" {
+					t.Fatal("expected reasoning message to be dropped when bus is full, but it was published")
+				}
 			}
-			if msg.Content == "should timeout" {
-				foundReasoning = true
-			}
-		}
-		if foundReasoning {
-			t.Fatal("expected reasoning message to be dropped when bus is full, but it was published")
 		}
 	})
 }
@@ -1318,3 +1426,84 @@ func TestResolveMediaRefs_MixedImageAndFile(t *testing.T) {
 		t.Fatalf("expected content %q, got %q", expectedContent, result[0].Content)
 	}
 }
+
+// --- Native search helper tests ---
+
+type nativeSearchProvider struct {
+	supported bool
+}
+
+func (p *nativeSearchProvider) Chat(
+	ctx context.Context, msgs []providers.Message, tools []providers.ToolDefinition,
+	model string, opts map[string]any,
+) (*providers.LLMResponse, error) {
+	return &providers.LLMResponse{Content: "ok"}, nil
+}
+
+func (p *nativeSearchProvider) GetDefaultModel() string { return "test-model" }
+
+func (p *nativeSearchProvider) SupportsNativeSearch() bool { return p.supported }
+
+type plainProvider struct{}
+
+func (p *plainProvider) Chat(
+	ctx context.Context, msgs []providers.Message, tools []providers.ToolDefinition,
+	model string, opts map[string]any,
+) (*providers.LLMResponse, error) {
+	return &providers.LLMResponse{Content: "ok"}, nil
+}
+
+func (p *plainProvider) GetDefaultModel() string { return "test-model" }
+
+func TestIsNativeSearchProvider_Supported(t *testing.T) {
+	if !isNativeSearchProvider(&nativeSearchProvider{supported: true}) {
+		t.Fatal("expected true for provider that supports native search")
+	}
+}
+
+func TestIsNativeSearchProvider_NotSupported(t *testing.T) {
+	if isNativeSearchProvider(&nativeSearchProvider{supported: false}) {
+		t.Fatal("expected false for provider that does not support native search")
+	}
+}
+
+func TestIsNativeSearchProvider_NoInterface(t *testing.T) {
+	if isNativeSearchProvider(&plainProvider{}) {
+		t.Fatal("expected false for provider that does not implement NativeSearchCapable")
+	}
+}
+
+func TestFilterClientWebSearch_RemovesWebSearch(t *testing.T) {
+	defs := []providers.ToolDefinition{
+		{Type: "function", Function: providers.ToolFunctionDefinition{Name: "web_search"}},
+		{Type: "function", Function: providers.ToolFunctionDefinition{Name: "read_file"}},
+		{Type: "function", Function: providers.ToolFunctionDefinition{Name: "exec"}},
+	}
+	result := filterClientWebSearch(defs)
+	if len(result) != 2 {
+		t.Fatalf("len(result) = %d, want 2", len(result))
+	}
+	for _, td := range result {
+		if td.Function.Name == "web_search" {
+			t.Fatal("web_search should be filtered out")
+		}
+	}
+}
+
+func TestFilterClientWebSearch_NoWebSearch(t *testing.T) {
+	defs := []providers.ToolDefinition{
+		{Type: "function", Function: providers.ToolFunctionDefinition{Name: "read_file"}},
+		{Type: "function", Function: providers.ToolFunctionDefinition{Name: "exec"}},
+	}
+	result := filterClientWebSearch(defs)
+	if len(result) != 2 {
+		t.Fatalf("len(result) = %d, want 2", len(result))
+	}
+}
+
+func TestFilterClientWebSearch_EmptyInput(t *testing.T) {
+	result := filterClientWebSearch(nil)
+	if len(result) != 0 {
+		t.Fatalf("len(result) = %d, want 0", len(result))
+	}
+}