diff --git a/src/plugins/contracts/registry.retry.test.ts b/src/plugins/contracts/registry.retry.test.ts
index d6cd3dd000f0..298be48bbb26 100644
--- a/src/plugins/contracts/registry.retry.test.ts
+++ b/src/plugins/contracts/registry.retry.test.ts
@@ -35,6 +35,30 @@ function createMockRuntimeRegistry(params: {
   };
 }
 
+function createMockContractSnapshot(pluginId: string, providerIds: string[]) {
+  return {
+    pluginId,
+    cliBackendIds: [],
+    providerIds,
+    providerEnvVars: {},
+    embeddingProviderIds: [],
+    speechProviderIds: [],
+    realtimeTranscriptionProviderIds: [],
+    realtimeVoiceProviderIds: [],
+    mediaUnderstandingProviderIds: [],
+    transcriptSourceProviderIds: [],
+    documentExtractorIds: [],
+    imageGenerationProviderIds: [],
+    videoGenerationProviderIds: [],
+    musicGenerationProviderIds: [],
+    webContentExtractorIds: [],
+    webFetchProviderIds: [],
+    webSearchProviderIds: [],
+    migrationProviderIds: [],
+    toolNames: [],
+  };
+}
+
 afterEach(() => {
   vi.resetModules();
   vi.restoreAllMocks();
@@ -259,6 +283,68 @@ describe("plugin contract registry scoped retries", () => {
     expect(loadBundledCapabilityRuntimeRegistry).not.toHaveBeenCalled();
   });
 
+  it("ignores poisoned provider metadata while resolving provider aliases", async () => {
+    const poisonedProvider = Object.defineProperties(
+      {
+        label: "Poisoned",
+        docsPath: "/providers/poisoned",
+        auth: [],
+      },
+      {
+        id: {
+          enumerable: true,
+          get() {
+            throw new Error("provider contract alias metadata exploded");
+          },
+        },
+        aliases: {
+          enumerable: true,
+          get() {
+            throw new Error("provider contract aliases exploded");
+          },
+        },
+        hookAliases: {
+          enumerable: true,
+          get() {
+            throw new Error("provider contract hook aliases exploded");
+          },
+        },
+      },
+    ) as ProviderPlugin;
+    const healthyProvider = {
+      id: "healthy-provider",
+      label: "Healthy",
+      docsPath: "/providers/healthy",
+      aliases: ["healthy-alias"],
+      auth: [],
+    } as ProviderPlugin;
+    const resolveBundledExplicitProviderContractsFromPublicArtifacts = vi.fn(
+      ({ onlyPluginIds }: { onlyPluginIds: readonly string[] }) =>
+        onlyPluginIds[0] === "poisoned"
+          ? [{ pluginId: "poisoned", provider: poisonedProvider }]
+          : [{ pluginId: "healthy", provider: healthyProvider }],
+    );
+
+    vi.doMock("./inventory/bundled-capability-metadata.js", () => ({
+      BUNDLED_PLUGIN_CONTRACT_SNAPSHOTS: [
+        createMockContractSnapshot("poisoned", ["poisoned"]),
+        createMockContractSnapshot("healthy", ["healthy-provider"]),
+      ],
+    }));
+    vi.doMock("../bundled-capability-runtime.js", () => ({
+      loadBundledCapabilityRuntimeRegistry: vi.fn(() => {
+        throw new Error("provider public artifacts should be enough");
+      }),
+    }));
+    vi.doMock("../provider-contract-public-artifacts.js", () => ({
+      resolveBundledExplicitProviderContractsFromPublicArtifacts,
+    }));
+
+    const { resolveProviderContractPluginIdsForProviderAlias } = await import("./registry.js");
+
+    expect(resolveProviderContractPluginIdsForProviderAlias("healthy-alias")).toEqual(["healthy"]);
+  });
+
   it("uses web search public artifacts before falling back to the bundled runtime registry", async () => {
     const loadBundledCapabilityRuntimeRegistry = vi.fn(() => {
       throw new Error(
diff --git a/src/plugins/contracts/registry.ts b/src/plugins/contracts/registry.ts
index f8f0a9626f55..3ab5b0eddeb2 100644
--- a/src/plugins/contracts/registry.ts
+++ b/src/plugins/contracts/registry.ts
@@ -391,11 +391,7 @@ function loadProviderContractRegistry(): ProviderContractEntry[] {
 }
 
 function loadUniqueProviderContractProviders(): ProviderPlugin[] {
-  return [
-    ...new Map(
-      loadProviderContractRegistry().map((entry) => [entry.provider.id, entry.provider]),
-    ).values(),
-  ];
+  return uniqueProviderContractProvidersFromEntries(loadProviderContractRegistry());
 }
 
 function loadProviderContractPluginIds(): string[] {
@@ -666,14 +662,49 @@ export const providerContractCompatPluginIds: string[] = createLazyArrayView(
   loadProviderContractCompatPluginIds,
 );
 
+function readProviderContractId(provider: ProviderPlugin): string | undefined {
+  try {
+    return typeof provider.id === "string" ? provider.id : undefined;
+  } catch {
+    return undefined;
+  }
+}
+
+function readProviderContractAliases(
+  provider: ProviderPlugin,
+  key: "aliases" | "hookAliases",
+): string[] {
+  try {
+    const aliases = provider[key];
+    return Array.isArray(aliases)
+      ? aliases.filter((alias): alias is string => typeof alias === "string")
+      : [];
+  } catch {
+    return [];
+  }
+}
+
+function uniqueProviderContractProvidersFromEntries(
+  entries: readonly ProviderContractEntry[],
+): ProviderPlugin[] {
+  const providers = new Map<string, ProviderPlugin>();
+  for (const entry of entries) {
+    const providerId = readProviderContractId(entry.provider);
+    if (providerId) {
+      providers.set(providerId, entry.provider);
+    }
+  }
+  return [...providers.values()];
+}
+
 export function requireProviderContractProvider(providerId: string): ProviderPlugin {
   const pluginIds = resolveBundledProviderContractPluginIdsByProviderId().get(providerId) ?? [];
   const entries = loadProviderContractEntriesForPluginIds(pluginIds);
-  const provider = entries.find((entry) => entry.provider.id === providerId)?.provider;
+  const provider = entries.find(
+    (entry) => readProviderContractId(entry.provider) === providerId,
+  )?.provider;
   if (!provider) {
-    const pluginScopedProviders = [
-      ...new Map(entries.map((entry) => [entry.provider.id, entry.provider])).values(),
-    ];
+    const pluginScopedProviders = uniqueProviderContractProvidersFromEntries(entries);
     if (pluginIds.length === 1 && pluginScopedProviders.length === 1) {
       return pluginScopedProviders[0];
     }
@@ -705,10 +736,10 @@ export function resolveProviderContractPluginIdsForProviderAlias(
     loadProviderContractEntriesForPluginIds(resolveBundledProviderContractPluginIds())
       .filter((entry) => {
         const providerIds = [
-          entry.provider.id,
-          ...(entry.provider.aliases ?? []),
-          ...(entry.provider.hookAliases ?? []),
-        ];
+          readProviderContractId(entry.provider),
+          ...readProviderContractAliases(entry.provider, "aliases"),
+          ...readProviderContractAliases(entry.provider, "hookAliases"),
+        ].filter((candidate): candidate is string => typeof candidate === "string");
         return providerIds.some(
           (candidate) => normalizeProviderId(candidate) === normalizedProvider,
         );
@@ -722,13 +753,11 @@ export function resolveProviderContractProvidersForPluginIds(
   pluginIds: readonly string[],
 ): ProviderPlugin[] {
   const allowed = new Set(pluginIds);
-  return [
-    ...new Map(
-      loadProviderContractEntriesForPluginIds([...allowed])
-        .filter((entry) => allowed.has(entry.pluginId))
-        .map((entry) => [entry.provider.id, entry.provider]),
-    ).values(),
-  ];
+  return uniqueProviderContractProvidersFromEntries(
+    loadProviderContractEntriesForPluginIds([...allowed]).filter((entry) =>
+      allowed.has(entry.pluginId),
+    ),
+  );
 }
 
 export const webSearchProviderContractRegistry: WebSearchProviderContractEntry[] =