Add projects

backend/examples/plugin/claude-web-search-router/go/fallback.go

@@ -0,0 +1,107 @@
+package main
+
+import (
+	"strings"
+
+	"github.com/router-for-me/CLIProxyAPI/v7/sdk/pluginapi"
+)
+
+// defaultWebSearchFallbackChain is the ordered backend try list when route=fallback.
+func defaultWebSearchFallbackChain() []routeBackend {
+	return []routeBackend{
+		backendAntigravityGoogle,
+		backendCodexWebSearch,
+		backendXAIWebSearch,
+		backendTavily,
+	}
+}
+
+func isFallbackRoute(route string) bool {
+	r := strings.ToLower(strings.TrimSpace(route))
+	return r == "" || r == string(backendFallback)
+}
+
+// tryRouteBackend returns a handled ModelRouteResponse and true when this backend can serve the request.
+func tryRouteBackend(backend routeBackend, cfg pluginConfig, req pluginapi.ModelRouteRequest) (pluginapi.ModelRouteResponse, bool) {
+	switch backend {
+	case backendTavily:
+		client := newTavilyClient(cfg.TavilyAPIKeys)
+		if !client.available() {
+			return pluginapi.ModelRouteResponse{Handled: false, Reason: "tavily_unavailable"}, false
+		}
+		return pluginapi.ModelRouteResponse{
+			Handled:    true,
+			TargetKind: pluginapi.ModelRouteTargetSelf,
+			Reason:     "claude_code_web_search_tavily",
+		}, true
+	case backendAntigravityGoogle:
+		if !hasProvider(req.AvailableProviders, "antigravity") {
+			return pluginapi.ModelRouteResponse{Handled: false, Reason: "antigravity_unavailable"}, false
+		}
+		targetModel := resolveAntigravityWebSearchTargetModel(cfg.AntigravityModel, req.RequestedModel)
+		if targetModel == "" {
+			return pluginapi.ModelRouteResponse{Handled: false, Reason: "antigravity_web_search_model_unresolved"}, false
+		}
+		return pluginapi.ModelRouteResponse{
+			Handled:     true,
+			TargetKind:  pluginapi.ModelRouteTargetProvider,
+			Target:      "antigravity",
+			TargetModel: targetModel,
+			Reason:      "claude_code_web_search_antigravity_google",
+		}, true
+	case backendCodexWebSearch:
+		if !hasProvider(req.AvailableProviders, "codex") {
+			return pluginapi.ModelRouteResponse{Handled: false, Reason: "codex_unavailable"}, false
+		}
+		targetModel := resolveCodexWebSearchTargetModel(cfg.CodexModel)
+		return pluginapi.ModelRouteResponse{
+			Handled:     true,
+			TargetKind:  pluginapi.ModelRouteTargetProvider,
+			Target:      "codex",
+			TargetModel: targetModel,
+			Reason:      "claude_code_web_search_codex",
+		}, true
+	case backendXAIWebSearch:
+		if !hasProvider(req.AvailableProviders, "xai") {
+			return pluginapi.ModelRouteResponse{Handled: false, Reason: "xai_unavailable"}, false
+		}
+		targetModel := resolveXAIWebSearchTargetModel(cfg.XAIModel)
+		return pluginapi.ModelRouteResponse{
+			Handled:     true,
+			TargetKind:  pluginapi.ModelRouteTargetProvider,
+			Target:      "xai",
+			TargetModel: targetModel,
+			Reason:      "claude_code_web_search_xai",
+		}, true
+	case backendDefaultProvider:
+		provider := cfg.DefaultProvider
+		if provider == "" || !hasProvider(req.AvailableProviders, provider) {
+			return pluginapi.ModelRouteResponse{Handled: false, Reason: "default_provider_unavailable"}, false
+		}
+		return pluginapi.ModelRouteResponse{
+			Handled:     true,
+			TargetKind:  pluginapi.ModelRouteTargetProvider,
+			Target:      provider,
+			TargetModel: cfg.DefaultProviderModel,
+			Reason:      "claude_code_web_search_default_provider",
+		}, true
+	default:
+		return pluginapi.ModelRouteResponse{Handled: false}, false
+	}
+}
+
+func routeWithFallback(cfg pluginConfig, req pluginapi.ModelRouteRequest) pluginapi.ModelRouteResponse {
+	return routeWithExecutionOrchestration(cfg, req, string(backendFallback))
+}
+
+func routeWithExecutionOrchestration(cfg pluginConfig, req pluginapi.ModelRouteRequest, route string) pluginapi.ModelRouteResponse {
+	plans := executionPlansForRoute(cfg, req, route)
+	if len(plans) == 0 {
+		return pluginapi.ModelRouteResponse{Handled: false, Reason: "web_search_fallback_exhausted"}
+	}
+	return pluginapi.ModelRouteResponse{
+		Handled:    true,
+		TargetKind: pluginapi.ModelRouteTargetSelf,
+		Reason:     "claude_code_web_search_orchestrated",
+	}
+}