Fix public answer search when anonymous limiter is unavailable

src/app/api/answer/route.ts

@@ -21,6 +21,7 @@ import {
 } from "@/lib/source-governance";
 import { parseJsonBody } from "@/lib/validation/body";
 import { createAdminClient } from "@/lib/supabase/admin";
+import { nonProductionSupabaseDemoFallbackReason } from "@/lib/supabase/errors";
 import * as serverAuth from "@/lib/supabase/auth";
 import type { RagAnswer } from "@/lib/types";
 
@@ -35,6 +36,8 @@ const answerSchema = z.object({
   skipCache: z.boolean().optional().default(false),
 });
 
+type AnswerRequestBody = z.infer<typeof answerSchema>;
+
 function answerDegradedModeSignal(answer?: Pick<RagAnswer, "degradedMode" | "answerQualityTier" | "fallbackReason">) {
   if (answer?.degradedMode) return answer.degradedMode;
   const active = answer?.answerQualityTier === "source_only";
@@ -44,26 +47,33 @@ function answerDegradedModeSignal(answer?: Pick<RagAnswer, "degradedMode" | "ans
   };
 }
 
+function buildDemoAnswerPayload(body: AnswerRequestBody, fallbackReason?: string) {
+  const answer = demoAnswer(body.query, body.documentId, body.documentIds);
+  const answerFocusQuery = queryForClinicalMode(body.query, body.queryMode);
+  const smartApiPlan = buildSmartRagApiPlan({
+    query: answerFocusQuery,
+    queryClass: queryClassForClinicalMode(body.queryMode) ?? classifyRagQuery(answerFocusQuery).queryClass,
+    results: answer.sources,
+    routeMode: answer.routingMode,
+    retrievalStrategy: "hybrid",
+  });
+  return {
+    ...answer,
+    responseMode: smartApiPlan.displayMode,
+    smartApiPlan,
+    demoMode: true,
+    degradedMode: fallbackReason ? { active: true, reason: fallbackReason } : answerDegradedModeSignal(answer),
+    ...(fallbackReason ? { fallbackMode: "non_production_demo", fallbackReason } : {}),
+  };
+}
+
 export async function POST(request: Request) {
+  let body: AnswerRequestBody | null = null;
   try {
-    const body = await parseJsonBody(request, answerSchema, "Invalid answer request.");
+    const answerBody = await parseJsonBody(request, answerSchema, "Invalid answer request.");
+    body = answerBody;
     if (isDemoMode()) {
-      const answer = demoAnswer(body.query, body.documentId, body.documentIds);
-      const answerFocusQuery = queryForClinicalMode(body.query, body.queryMode);
-      const smartApiPlan = buildSmartRagApiPlan({
-        query: answerFocusQuery,
-        queryClass: queryClassForClinicalMode(body.queryMode) ?? classifyRagQuery(answerFocusQuery).queryClass,
-        results: answer.sources,
-        routeMode: answer.routingMode,
-        retrievalStrategy: "hybrid",
-      });
-      return NextResponse.json({
-        ...answer,
-        responseMode: smartApiPlan.displayMode,
-        smartApiPlan,
-        demoMode: true,
-        degradedMode: answerDegradedModeSignal(answer),
-      });
+      return NextResponse.json(buildDemoAnswerPayload(answerBody));
     }
 
     const supabase = createAdminClient();
@@ -84,8 +94,8 @@ export async function POST(request: Request) {
       supabase,
       ownerId: access.ownerId,
       publicOnly,
-      documentIds: body.documentIds ?? (body.documentId ? [body.documentId] : undefined),
-      filters: body.filters,
+      documentIds: answerBody.documentIds ?? (answerBody.documentId ? [answerBody.documentId] : undefined),
+      filters: answerBody.filters,
     });
     if (scope.documentIds?.length === 0) {
       return NextResponse.json({
@@ -96,22 +106,26 @@ export async function POST(request: Request) {
         citations: [],
         sources: [],
         degradedMode: answerDegradedModeSignal(),
-        scope: { ...scope, queryMode: body.queryMode },
+        scope: { ...scope, queryMode: answerBody.queryMode },
         sourceGovernanceWarnings: sourceGovernanceWarnings({ results: [] }),
       });
     }
 
-    const singleDocumentScope = Boolean(body.documentId && !body.documentIds?.length && scope.activeFilterCount === 0);
+    const singleDocumentScope = Boolean(
+      answerBody.documentId && !answerBody.documentIds?.length && scope.activeFilterCount === 0,
+    );
     const answer = await answerQuestionWithScope({
-      query: body.query,
-      documentId: singleDocumentScope ? body.documentId : undefined,
+      query: answerBody.query,
+      documentId: singleDocumentScope ? answerBody.documentId : undefined,
       documentIds: singleDocumentScope
         ? undefined
-        : (scope.documentIds ?? body.documentIds ?? (body.documentId ? [body.documentId] : undefined)),
+        : (scope.documentIds ??
+          answerBody.documentIds ??
+          (answerBody.documentId ? [answerBody.documentId] : undefined)),
       ownerId: access.ownerId,
       allowGlobalSearch: !access.ownerId,
-      queryMode: body.queryMode,
-      skipCache: body.skipCache,
+      queryMode: answerBody.queryMode,
+      skipCache: answerBody.skipCache,
       signal: request.signal,
     });
     const warnings = sourceGovernanceWarnings({
@@ -132,15 +146,15 @@ export async function POST(request: Request) {
         citations: [],
         sources: [],
         degradedMode: answerDegradedModeSignal(answer),
-        scope: { ...scope, queryMode: body.queryMode },
+        scope: { ...scope, queryMode: answerBody.queryMode },
         sourceGovernanceWarnings: warnings,
       });
     }
 
     return NextResponse.json({
       ...answer,
       degradedMode: answerDegradedModeSignal(answer),
-      scope: { ...scope, queryMode: body.queryMode },
+      scope: { ...scope, queryMode: answerBody.queryMode },
       sourceGovernanceWarnings: warnings,
     });
   } catch (error) {
@@ -154,6 +168,13 @@ export async function POST(request: Request) {
       return jsonError(error, error.status);
     }
     if (error instanceof Error) {
+      const fallbackBody = body;
+      const fallbackReason = fallbackBody ? nonProductionSupabaseDemoFallbackReason(error) : null;
+      if (fallbackBody && fallbackReason) {
+        return NextResponse.json(buildDemoAnswerPayload(fallbackBody, fallbackReason), {
+          headers: { "X-Clinical-KB-Fallback": fallbackReason },
+        });
+      }
       return jsonError(
         new PublicApiError("Answer generation failed. Retry with a narrower question.", 500, { code: error.name }),
         500,

src/app/api/search/route.ts

@@ -31,6 +31,7 @@ import {
   queryTextForStorage,
 } from "@/lib/query-privacy";
 import { safeErrorLogDetails } from "@/lib/privacy";
+import { nonProductionSupabaseDemoFallbackReason } from "@/lib/supabase/errors";
 import type { ChunkImage, ClinicalSourceMetadata, SearchResult } from "@/lib/types";
 
 export const runtime = "nodejs";
@@ -311,6 +312,43 @@ function searchDegradedModeSignal(telemetry?: { embedding_skip_reason?: string |
   };
 }
 
+function buildDemoSearchPayload(body: SearchRequestBody, fallbackReason?: string) {
+  const searchFocusQuery = queryForClinicalMode(body.query, body.queryMode);
+  const queryClass = queryClassForClinicalMode(body.queryMode) ?? classifyRagQuery(searchFocusQuery).queryClass;
+  const results = annotateSearchResults(
+    searchFocusQuery,
+    demoSearch(body.query, body.topK ?? 8, body.documentId, body.documentIds),
+  );
+  const relevance = buildEvidenceRelevance(searchFocusQuery, results);
+  const documentMatches = isSourceLibrarySearchMode(body.mode)
+    ? annotateDocumentMatches(searchFocusQuery, buildDocumentMatchesFromResults(results, body.documentLimit), results)
+    : [];
+  const cachedVisualEvidence = buildVisualEvidence(results);
+  return {
+    results: compactSearchResults(searchFocusQuery, results),
+    facets: buildSearchFacets(results),
+    visualEvidence: cachedVisualEvidence,
+    relevance,
+    smartPanel: {
+      ...buildSmartPanel(searchFocusQuery, results, { relevance, visualEvidence: cachedVisualEvidence }),
+      relevance,
+    },
+    smartApiPlan: buildSmartRagApiPlan({
+      query: searchFocusQuery,
+      queryClass,
+      results,
+      retrievalStrategy: "hybrid",
+      routeMode: isSourceLibrarySearchMode(body.mode) ? undefined : "fast",
+      preferredResponseMode: isSourceLibrarySearchMode(body.mode) ? "document_lookup" : undefined,
+    }),
+    relatedDocuments: [],
+    documentMatches,
+    demoMode: true,
+    degradedMode: fallbackReason ? { active: true, reason: fallbackReason } : searchDegradedModeSignal(),
+    ...(fallbackReason ? { fallbackMode: "non_production_demo", fallbackReason } : {}),
+  };
+}
+
 function facetCounts(values: Array<string | null | undefined>, limit = 12) {
   const counts = new Map<string, number>();
   for (const raw of values) {
@@ -845,47 +883,13 @@ function extractSqlState(error: unknown) {
 export async function POST(request: Request) {
   let supabase: ReturnType<typeof createAdminClient> | null = null;
   let ownerId: string | null = null;
+  let body: SearchRequestBody | null = null;
 
   try {
-    const body = await parseJsonBody(request, searchSchema, "Invalid search request.");
+    const searchBody = await parseJsonBody(request, searchSchema, "Invalid search request.");
+    body = searchBody;
     if (isDemoMode()) {
-      const searchFocusQuery = queryForClinicalMode(body.query, body.queryMode);
-      const queryClass = queryClassForClinicalMode(body.queryMode) ?? classifyRagQuery(searchFocusQuery).queryClass;
-      const results = annotateSearchResults(
-        searchFocusQuery,
-        demoSearch(body.query, body.topK ?? 8, body.documentId, body.documentIds),
-      );
-      const relevance = buildEvidenceRelevance(searchFocusQuery, results);
-      const documentMatches = isSourceLibrarySearchMode(body.mode)
-        ? annotateDocumentMatches(
-            searchFocusQuery,
-            buildDocumentMatchesFromResults(results, body.documentLimit),
-            results,
-          )
-        : [];
-      const cachedVisualEvidence = buildVisualEvidence(results);
-      return NextResponse.json({
-        results: compactSearchResults(searchFocusQuery, results),
-        facets: buildSearchFacets(results),
-        visualEvidence: cachedVisualEvidence,
-        relevance,
-        smartPanel: {
-          ...buildSmartPanel(searchFocusQuery, results, { relevance, visualEvidence: cachedVisualEvidence }),
-          relevance,
-        },
-        smartApiPlan: buildSmartRagApiPlan({
-          query: searchFocusQuery,
-          queryClass,
-          results,
-          retrievalStrategy: "hybrid",
-          routeMode: isSourceLibrarySearchMode(body.mode) ? undefined : "fast",
-          preferredResponseMode: isSourceLibrarySearchMode(body.mode) ? "document_lookup" : undefined,
-        }),
-        relatedDocuments: [],
-        documentMatches,
-        demoMode: true,
-        degradedMode: searchDegradedModeSignal(),
-      });
+      return NextResponse.json(buildDemoSearchPayload(searchBody));
     }
 
     supabase = createAdminClient();
@@ -906,9 +910,9 @@ export async function POST(request: Request) {
       );
     }
 
-    const key = scopedSearchKey(body, ownerId, publicOnly);
+    const key = scopedSearchKey(searchBody, ownerId, publicOnly);
     const { payload, coalesced } = await coalesceScopedSearch(key, () =>
-      buildScopedSearchPayload(body, supabase!, ownerId, publicOnly),
+      buildScopedSearchPayload(searchBody, supabase!, ownerId, publicOnly),
     );
     return NextResponse.json({
       ...payload,
@@ -929,6 +933,13 @@ export async function POST(request: Request) {
     }
     if (error instanceof Error && error.message.trim()) {
       const code = classifySearchFailure(error);
+      const fallbackBody = body;
+      const fallbackReason = fallbackBody ? nonProductionSupabaseDemoFallbackReason(error) : null;
+      if (fallbackBody && fallbackReason) {
+        return NextResponse.json(buildDemoSearchPayload(fallbackBody, fallbackReason), {
+          headers: { "X-Clinical-KB-Fallback": fallbackReason },
+        });
+      }
       const failurePayload = {
         results: [],
         telemetry: {

src/lib/api-rate-limit.ts

@@ -9,6 +9,14 @@ export function allowRateLimitInMemoryFallbackOnUnavailable() {
   return isLocalNoAuthMode() || process.env.NODE_ENV === "production";
 }
 
+function allowAnonymousRateLimitFallback(bucket: ApiRateLimitBucket, allowInMemoryFallbackOnUnavailable?: boolean) {
+  if (allowInMemoryFallbackOnUnavailable) return true;
+
+  // Anonymous public read/search paths must stay reachable if the durable limiter
+  // migration is temporarily unavailable; the per-instance limiter still applies.
+  return bucket === "answer" || bucket === "search" || bucket === "document_read" || bucket === "registry";
+}
+
 export type ApiRateLimitBucket =
   | "answer"
   | "search"
@@ -159,7 +167,7 @@ export async function consumeSubjectApiRateLimit(args: {
   });
 
   if (error) {
-    if (args.allowInMemoryFallbackOnUnavailable) {
+    if (allowAnonymousRateLimitFallback(args.bucket, args.allowInMemoryFallbackOnUnavailable)) {
       console.warn("Durable anonymous API rate limit check unavailable; using local in-memory fallback.", {
         bucket: args.bucket,
         code: error.code,
@@ -177,7 +185,7 @@ export async function consumeSubjectApiRateLimit(args: {
 
   const row = parseRateLimitRow(data);
   if (!row || typeof row.limited !== "boolean") {
-    if (args.allowInMemoryFallbackOnUnavailable) {
+    if (allowAnonymousRateLimitFallback(args.bucket, args.allowInMemoryFallbackOnUnavailable)) {
       return consumeInMemoryApiRateLimit({
         ownerId: args.subject.subjectKey,
         bucket: args.bucket,

src/lib/supabase/errors.ts

@@ -0,0 +1,18 @@
+function errorMessage(error: unknown) {
+  if (error instanceof Error) return error.message;
+  if (typeof error === "string") return error;
+  if (error && typeof error === "object" && "message" in error) {
+    return String((error as { message?: unknown }).message ?? "");
+  }
+  return String(error ?? "");
+}
+
+export function isSupabaseApiKeyConfigurationError(error: unknown) {
+  return /\b(?:unregistered|invalid)\s+api\s+key\b/i.test(errorMessage(error));
+}
+
+export function nonProductionSupabaseDemoFallbackReason(error: unknown) {
+  if (process.env.NODE_ENV === "production") return null;
+  if (!isSupabaseApiKeyConfigurationError(error)) return null;
+  return "supabase_api_key_configuration_unavailable";
+}