fix: improve server and client error extraction to eliminate HTTP 200 generic message

frontend/lib/api.ts

@@ -18,6 +18,15 @@ function generateRequestId(): string {
   return `REQ_${Math.random().toString(36).substring(2, 8).toUpperCase()}`;
 }
 
+function extractErrorMessage(json: any, fallback: string): string {
+  if (!json) return fallback;
+  if (typeof json.error === "string") return json.error;
+  if (json.error?.message) return json.error.message;
+  if (json.error?.details) return json.error.details;
+  if (json.message) return json.message;
+  return fallback;
+}
+
 /**
  * Health check probe via /api/health
  */
@@ -28,12 +37,15 @@ export async function checkBackendHealth(): Promise<BackendHealthStatus> {
     const res = await fetch("/api/health", { cache: "no-store" });
     const latency = Math.round(performance.now() - start);
     if (res.ok) {
-      return {
-        status: "CONNECTED",
-        endpoint: "/api/health (Vercel Server Proxy)",
-        last_sync_at: new Date().toISOString(),
-        roundtrip_latency_ms: latency,
-      };
+      const json = await res.json();
+      if (json.success) {
+        return {
+          status: "CONNECTED",
+          endpoint: "/api/health (Vercel Server Proxy)",
+          last_sync_at: new Date().toISOString(),
+          roundtrip_latency_ms: latency,
+        };
+      }
     }
   } catch (err: any) {
     console.warn("Health check error via /api/health:", err);
@@ -68,7 +80,7 @@ export async function analyzeTransaction(
   const json = await res.json();
 
   if (!res.ok || !json.success || !json.data) {
-    throw new Error(json?.error?.message || `Transaction analysis failed with HTTP ${res.status}`);
+    throw new Error(extractErrorMessage(json, `Transaction analysis failed with HTTP ${res.status}`));
   }
 
   const parsed: AnalyzeTransactionResponse = json.data;
@@ -104,7 +116,7 @@ export async function runScenarioReplay(
   const json = await res.json();
 
   if (!res.ok || !json.success || !json.data) {
-    throw new Error(json?.error?.message || `Scenario replay failed with HTTP ${res.status}`);
+    throw new Error(extractErrorMessage(json, `Scenario replay failed with HTTP ${res.status}`));
   }
 
   const parsed: ScenarioReplayResult = json.data;
@@ -137,7 +149,7 @@ export async function queryMerchantState(merchantId: string): Promise<MerchantSt
   const json = await res.json();
 
   if (!res.ok || !json.success || !json.data) {
-    throw new Error(json?.error?.message || `Merchant query failed with HTTP ${res.status}`);
+    throw new Error(extractErrorMessage(json, `Merchant query failed with HTTP ${res.status}`));
   }
 
   const parsed: MerchantStateQueryResponse = json.data;
@@ -164,7 +176,7 @@ export async function explainEvidencePayload(evidenceJson: string): Promise<any>
 
   const json = await res.json();
   if (!res.ok || !json.success) {
-    throw new Error(json?.error?.message || `Explanation failed with HTTP ${res.status}`);
+    throw new Error(extractErrorMessage(json, `Explanation failed with HTTP ${res.status}`));
   }
 
   return json.data;
@@ -186,7 +198,7 @@ export async function resetDemoState(): Promise<{ status: string; message: strin
   const json = await res.json();
 
   if (!res.ok || !json.success || !json.data) {
-    throw new Error(json?.error?.message || `Reset demo state failed with HTTP ${res.status}`);
+    throw new Error(extractErrorMessage(json, `Reset demo state failed with HTTP ${res.status}`));
   }
 
   const parsed = json.data;

frontend/lib/server/razorshield.ts

@@ -86,9 +86,20 @@ async function callGradioApi<T = any>(apiName: string, data: any[]): Promise<T>
 export async function healthCheck(): Promise<ApiResponse<{ status: string; service: string; model: string; slm_loaded: boolean; policy_mode: string }>> {
   try {
     const start = performance.now();
-    await callGradioApi("analyze_merchant", ["M_HEALTH_CHECK"]);
+    const res = await callGradioApi("analyze_merchant", ["M_HEALTH_CHECK"]);
     const latency = Math.round(performance.now() - start);
 
+    if ((res as any)?.error) {
+      return {
+        success: false,
+        error: {
+          code: "BACKEND_ERROR",
+          message: (res as any).error,
+          details: (res as any).details || (res as any).error,
+        },
+      };
+    }
+
     return {
       success: true,
       data: {
@@ -141,6 +152,17 @@ export async function analyzeTransaction(
       policyMode,
     ]);
 
+    if ((parsed as any)?.error) {
+      return {
+        success: false,
+        error: {
+          code: "BACKEND_ERROR",
+          message: (parsed as any).error,
+          details: (parsed as any).details || (parsed as any).error,
+        },
+      };
+    }
+
     return {
       success: true,
       data: parsed,
@@ -151,7 +173,7 @@ export async function analyzeTransaction(
       success: false,
       error: {
         code: "TRANSACTION_ANALYSIS_FAILED",
-        message: "Failed to evaluate transaction through backend risk engine.",
+        message: err.message || "Failed to evaluate transaction through backend risk engine.",
         details: err.message,
       },
     };
@@ -166,6 +188,18 @@ export async function analyzeMerchant(
 ): Promise<ApiResponse<MerchantStateQueryResponse>> {
   try {
     const parsed = await callGradioApi<MerchantStateQueryResponse>("analyze_merchant", [merchantId]);
+
+    if ((parsed as any)?.error) {
+      return {
+        success: false,
+        error: {
+          code: "BACKEND_ERROR",
+          message: (parsed as any).error,
+          details: (parsed as any).details || (parsed as any).error,
+        },
+      };
+    }
+
     return {
       success: true,
       data: parsed,
@@ -176,7 +210,7 @@ export async function analyzeMerchant(
       success: false,
       error: {
         code: "MERCHANT_QUERY_FAILED",
-        message: "Failed to query merchant incident state from backend.",
+        message: err.message || "Failed to query merchant incident state from backend.",
         details: err.message,
       },
     };
@@ -192,6 +226,18 @@ export async function runScenario(
 ): Promise<ApiResponse<ScenarioReplayResult>> {
   try {
     const parsed = await callGradioApi<ScenarioReplayResult>("run_scenario", [scenarioName, policyMode]);
+
+    if ((parsed as any)?.error) {
+      return {
+        success: false,
+        error: {
+          code: "BACKEND_ERROR",
+          message: (parsed as any).error,
+          details: (parsed as any).details || (parsed as any).error,
+        },
+      };
+    }
+
     return {
       success: true,
       data: parsed,
@@ -202,7 +248,7 @@ export async function runScenario(
       success: false,
       error: {
         code: "SCENARIO_REPLAY_FAILED",
-        message: "Failed to execute scenario replay through backend.",
+        message: err.message || "Failed to execute scenario replay through backend.",
         details: err.message,
       },
     };
@@ -217,6 +263,18 @@ export async function explainEvidence(
 ): Promise<ApiResponse<any>> {
   try {
     const parsed = await callGradioApi("explain_evidence", [evidenceJson]);
+
+    if ((parsed as any)?.error) {
+      return {
+        success: false,
+        error: {
+          code: "BACKEND_ERROR",
+          message: (parsed as any).error,
+          details: (parsed as any).details || (parsed as any).error,
+        },
+      };
+    }
+
     return {
       success: true,
       data: parsed,
@@ -227,7 +285,7 @@ export async function explainEvidence(
       success: false,
       error: {
         code: "EXPLANATION_GENERATION_FAILED",
-        message: "Failed to generate explanation for evidence.",
+        message: err.message || "Failed to generate explanation for evidence.",
         details: err.message,
       },
     };
@@ -240,6 +298,18 @@ export async function explainEvidence(
 export async function resetDemoState(): Promise<ApiResponse<{ status: string; message: string }>> {
   try {
     const parsed = await callGradioApi<{ status: string; message: string }>("reset_demo_state", []);
+
+    if ((parsed as any)?.error) {
+      return {
+        success: false,
+        error: {
+          code: "BACKEND_ERROR",
+          message: (parsed as any).error,
+          details: (parsed as any).details || (parsed as any).error,
+        },
+      };
+    }
+
     return {
       success: true,
       data: parsed,
@@ -250,7 +320,7 @@ export async function resetDemoState(): Promise<ApiResponse<{ status: string; me
       success: false,
       error: {
         code: "RESET_FAILED",
-        message: "Failed to reset demo state on backend.",
+        message: err.message || "Failed to reset demo state on backend.",
         details: err.message,
       },
     };