[WRONG BRANCH] fix(config): validate provider modelInputModalities maps as string-array records

src/config.ts

@@ -746,6 +746,20 @@ export function booleanRecordConfigError(value: unknown, field: string): string
   return null;
 }
 
+export function stringArrayRecordConfigError(value: unknown, field: string): string | null {
+  if (value === undefined) return null;
+  if (!value || typeof value !== "object" || Array.isArray(value)) return `${field} must be a plain object`;
+  const prototype = Object.getPrototypeOf(value);
+  if (prototype !== Object.prototype && prototype !== null) return `${field} must be a plain object with own properties`;
+  for (const [key, entry] of Object.entries(value)) {
+    if (!key.trim()) return `${field} keys must be nonblank model ids`;
+    if (!Array.isArray(entry) || entry.some(item => typeof item !== "string")) {
+      return `${field}.${key} must be an array of strings`;
+    }
+  }
+  return null;
+}
+
 const REASONING_SUMMARY_DELIVERY_SET = new Set<string>(REASONING_SUMMARY_DELIVERY_VALUES);
 
 export function reasoningSummaryDeliveryRecordConfigError(
@@ -1274,6 +1288,17 @@ const configSchema = z.object({
         message: reasoningSummariesError,
       });
     }
+    const inputModalitiesError = stringArrayRecordConfigError(
+      (provider as { modelInputModalities?: unknown }).modelInputModalities,
+      "modelInputModalities",
+    );
+    if (inputModalitiesError) {
+      ctx.addIssue({
+        code: "custom",
+        path: ["providers", name, "modelInputModalities"],
+        message: inputModalitiesError,
+      });
+    }
     const reasoningSummaryDeliveryError = reasoningSummaryDeliveryRecordConfigError(
       (provider as { modelReasoningSummaryDelivery?: unknown }).modelReasoningSummaryDelivery,
       (provider as { modelSupportsReasoningSummaries?: unknown }).modelSupportsReasoningSummaries,

src/server/auth-cors.ts

@@ -12,6 +12,7 @@ import {
   providerHeadersConfigError,
   reasoningSummaryDeliveryRecordConfigError,
   retryOn429PolicyConfigError,
+  stringArrayRecordConfigError,
 } from "../config";
 import { providerDestinationConfigError } from "../lib/destination-policy";
 import { redactSecretString } from "../lib/redact";
@@ -477,6 +478,8 @@ export function providerManagementConfigError(name: unknown, provider: unknown):
   if (maxInputError) return `provider ${name} ${maxInputError}`;
   const reasoningSummariesError = booleanRecordConfigError(raw.modelSupportsReasoningSummaries, "modelSupportsReasoningSummaries");
   if (reasoningSummariesError) return `provider ${name} ${reasoningSummariesError}`;
+  const inputModalitiesError = stringArrayRecordConfigError(raw.modelInputModalities, "modelInputModalities");
+  if (inputModalitiesError) return `provider ${name} ${inputModalitiesError}`;
   const reasoningSummaryDeliveryError = reasoningSummaryDeliveryRecordConfigError(
     raw.modelReasoningSummaryDelivery,
     raw.modelSupportsReasoningSummaries,

tests/config.test.ts

@@ -1405,6 +1405,18 @@ describe("opencodex config defaults", () => {
     expect(readConfigDiagnostics().error).toContain("providers.custom.modelMaxInputTokens");
   });
 
+  test("disk config rejects malformed modelInputModalities", () => {
+    writeConfig({
+      port: 10100,
+      providers: {
+        custom: { adapter: "openai-chat", baseUrl: "https://example.test/v1", modelInputModalities: { model: null } },
+      },
+      defaultProvider: "custom",
+    });
+    expect(readConfigDiagnostics().source).toBe("fallback");
+    expect(readConfigDiagnostics().error).toContain("providers.custom.modelInputModalities");
+  });
+
   test("disk config preserves valid OpenRouter routing and rejects invalid destinations", () => {
     writeConfig({
       port: 10100,

tests/management-provider-validation.test.ts

@@ -411,6 +411,18 @@ describe("provider management validation", () => {
       }
       expect(loadConfig().providers["custom-max-input"].modelMaxInputTokens).toEqual({ model: 1000 });
 
+      for (const invalid of [null, [], { model: null }, { model: "text" }, { model: ["text", null] }]) {
+        const rejected = await fetch(new URL("/api/providers", server.url), {
+          method: "POST",
+          headers: { "content-type": "application/json" },
+          body: JSON.stringify({
+            name: "xai",
+            provider: { adapter: "openai-chat", baseUrl: "https://api.x.ai/v1", modelInputModalities: invalid },
+          }),
+        });
+        expect(rejected.status).toBe(400);
+      }
+
       const acceptedSummaryCapability = await fetch(new URL("/api/providers", server.url), {
         method: "POST",
         headers: { "content-type": "application/json" },