diff --git a/extensions/openai/realtime-provider-shared.ts b/extensions/openai/realtime-provider-shared.ts
index cf202924cba..168f5ce0063 100644
--- a/extensions/openai/realtime-provider-shared.ts
+++ b/extensions/openai/realtime-provider-shared.ts
@@ -78,6 +78,7 @@ type OpenAIRealtimeSecretRequest = {
   url: string;
   body: unknown;
   errorMessage: string;
+  authRejectedMessage?: string;
   missingValueMessage: string;
 };
 
@@ -117,7 +118,14 @@ async function createOpenAIRealtimeSecret(
   const payload = await (async () => {
     try {
       if (!response.ok) {
-        throw await createProviderHttpError(response, params.errorMessage);
+        const error = await createProviderHttpError(response, params.errorMessage);
+        // Provider details can echo a masked credential while hiding which
+        // OpenClaw auth source won. Keep the status metadata, but give callers
+        // a bounded remediation for an explicitly configured key.
+        if (response.status === 401 && params.authRejectedMessage) {
+          error.message = params.authRejectedMessage;
+        }
+        throw error;
       }
       return await readProviderJsonResponse<unknown>(response, "openai.realtime-session");
     } finally {
@@ -147,6 +155,7 @@ export async function createOpenAIRealtimeClientSecret(params: {
   authToken: string;
   auditContext: string;
   session: Record<string, unknown>;
+  authRejectedMessage?: string;
 }): Promise<OpenAIRealtimeClientSecretResult> {
   const url = `${OPENAI_REALTIME_API_BASE_URL}/realtime/client_secrets`;
   return createOpenAIRealtimeSecret({
diff --git a/extensions/openai/realtime-voice-provider.test.ts b/extensions/openai/realtime-voice-provider.test.ts
index 0cc9cba4a30..bd84218edd4 100644
--- a/extensions/openai/realtime-voice-provider.test.ts
+++ b/extensions/openai/realtime-voice-provider.test.ts
@@ -568,6 +568,60 @@ describe("buildOpenAIRealtimeVoiceProvider", () => {
     expect((session as { offerHeaders?: Record<string, string> }).offerHeaders).toBeUndefined();
   });
 
+  it.each(["configured", "profile", "environment"] as const)(
+    "explains how auth precedence affects a rejected %s API key",
+    async (source) => {
+      if (source === "profile") {
+        resolveProviderAuthProfileApiKeyMock.mockResolvedValueOnce("sk-profile"); // pragma: allowlist secret
+      } else if (source === "environment") {
+        vi.stubEnv("OPENAI_API_KEY", "sk-env"); // pragma: allowlist secret
+      }
+      fetchWithSsrFGuardMock.mockResolvedValueOnce({
+        response: createJsonResponse(
+          { error: { message: "Incorrect API key provided: sk-proj-***" } },
+          { status: 401 },
+        ),
+        release: vi.fn(async () => undefined),
+      });
+      const provider = buildOpenAIRealtimeVoiceProvider();
+      if (!provider.createBrowserSession) {
+        throw new Error("expected OpenAI realtime provider to support browser sessions");
+      }
+
+      await expect(
+        provider.createBrowserSession({
+          providerConfig:
+            source === "configured"
+              ? { apiKey: "sk-stale" } // pragma: allowlist secret
+              : {},
+        }),
+      ).rejects.toThrow(
+        "OpenAI Realtime rejected the selected API key. Update or remove the active OpenAI API-key source; Codex OAuth is used only when no API-key source is configured",
+      );
+    },
+  );
+
+  it("preserves the provider detail when Codex OAuth is rejected", async () => {
+    resolveProviderAuthProfileApiKeyMock
+      .mockResolvedValueOnce(undefined)
+      .mockResolvedValueOnce("oauth-token"); // pragma: allowlist secret
+    fetchWithSsrFGuardMock.mockResolvedValueOnce({
+      response: createJsonResponse(
+        { error: { message: "OAuth token expired" } },
+        { status: 401 },
+      ),
+      release: vi.fn(async () => undefined),
+    });
+    const provider = buildOpenAIRealtimeVoiceProvider();
+    if (!provider.createBrowserSession) {
+      throw new Error("expected OpenAI realtime provider to support browser sessions");
+    }
+
+    await expect(provider.createBrowserSession({ providerConfig: {} })).rejects.toThrow(
+      "OAuth token expired",
+    );
+  });
+
   it("omits unsupported OpenAI tool names from browser sessions", async () => {
     fetchWithSsrFGuardMock.mockResolvedValueOnce({
       response: createJsonResponse({ client_secret: { value: "client-secret-123" } }),
diff --git a/extensions/openai/realtime-voice-provider.ts b/extensions/openai/realtime-voice-provider.ts
index d84cef4fa57..3cace79fcc2 100644
--- a/extensions/openai/realtime-voice-provider.ts
+++ b/extensions/openai/realtime-voice-provider.ts
@@ -247,10 +247,15 @@ function asUnitInterval(value: unknown): number | undefined {
 type OpenAIRealtimeApiKeyResolution =
   | { status: "available"; value: string }
   | { status: "missing" };
+type OpenAIRealtimePlatformAuthResolution =
+  | { status: "available"; value: string; source: "api-key" | "oauth" }
+  | { status: "missing" };
 
 const OPENAI_REALTIME_PLATFORM_AUTH_REQUIRED =
   "OpenAI Realtime voice requires an OpenAI API key or Codex OAuth sign-in";
 const OPENAI_REALTIME_API_KEY_REQUIRED = "OpenAI Realtime voice requires an API key";
+const OPENAI_REALTIME_CONFIGURED_API_KEY_REJECTED =
+  "OpenAI Realtime rejected the selected API key. Update or remove the active OpenAI API-key source; Codex OAuth is used only when no API-key source is configured";
 const OPENAI_REALTIME_PLATFORM_AUTH_PROFILE_TYPES = ["api_key", "oauth"] as const;
 const KEYCHAIN_SECRET_REF_RE = /^keychain:([^:]+):([^:]+)$/;
 const KEYCHAIN_LOOKUP_TIMEOUT_MS = 5000;
@@ -380,13 +385,15 @@ function normalizeOpenAIRealtimeTools(
 async function resolveOpenAIRealtimePlatformAuth(params: {
   configuredApiKey: string | undefined;
   cfg: RealtimeVoiceBrowserSessionCreateRequest["cfg"] | undefined;
-}): Promise<OpenAIRealtimeApiKeyResolution> {
+}): Promise<OpenAIRealtimePlatformAuthResolution> {
   const configured = resolveOpenAIRealtimeSecretInput(params.configuredApiKey);
   if (
     configured.status === "available" ||
     hasOpenAIRealtimeConfiguredApiKeyInput(params.configuredApiKey)
   ) {
-    return configured;
+    return configured.status === "available"
+      ? { ...configured, source: "api-key" }
+      : configured;
   }
 
   const profileApiKey = await resolveProviderAuthProfileApiKey({
@@ -395,7 +402,7 @@ async function resolveOpenAIRealtimePlatformAuth(params: {
     profileTypes: ["api_key"],
   });
   if (profileApiKey) {
-    return { status: "available", value: profileApiKey };
+    return { status: "available", value: profileApiKey, source: "api-key" };
   }
   const hasConfiguredApiKeyProfile = isProviderAuthProfileConfigured({
     provider: "openai",
@@ -405,7 +412,7 @@ async function resolveOpenAIRealtimePlatformAuth(params: {
 
   const envApiKey = resolveOpenAIRealtimeEnvApiKey();
   if (envApiKey.status === "available") {
-    return envApiKey;
+    return { ...envApiKey, source: "api-key" };
   }
   if (hasConfiguredApiKeyProfile || hasOpenAIRealtimeApiKeyInput(undefined)) {
     return { status: "missing" };
@@ -418,19 +425,19 @@ async function resolveOpenAIRealtimePlatformAuth(params: {
     includeExternalCliAuth: true,
   });
   if (oauthToken) {
-    return { status: "available", value: oauthToken };
+    return { status: "available", value: oauthToken, source: "oauth" };
   }
 
   return { status: "missing" };
 }
 
-async function requireOpenAIRealtimePlatformAuthToken(params: {
+async function requireOpenAIRealtimePlatformAuth(params: {
   configuredApiKey: string | undefined;
   cfg: RealtimeVoiceBrowserSessionCreateRequest["cfg"] | undefined;
-}): Promise<string> {
+}): Promise<Extract<OpenAIRealtimePlatformAuthResolution, { status: "available" }>> {
   const resolved = await resolveOpenAIRealtimePlatformAuth(params);
   if (resolved.status === "available") {
-    return resolved.value;
+    return resolved;
   }
   throw new Error(OPENAI_REALTIME_PLATFORM_AUTH_REQUIRED);
 }
@@ -815,11 +822,11 @@ class OpenAIRealtimeVoiceBridge implements RealtimeVoiceBridge {
     url: string;
     headers: Record<string, string>;
   }> {
-    const authToken = await requireOpenAIRealtimePlatformAuthToken({
+    const auth = await requireOpenAIRealtimePlatformAuth({
       configuredApiKey: this.config.apiKey,
       cfg: this.config.cfg,
     });
-    return this.resolveApiKeyConnectionParams(authToken, model);
+    return this.resolveApiKeyConnectionParams(auth.value, model);
   }
 
   private resolveApiKeyConnectionParams(
@@ -1465,7 +1472,7 @@ async function createOpenAIRealtimeBrowserSession(
   }
 
   const model = req.model ?? config.model ?? OPENAI_REALTIME_DEFAULT_MODEL;
-  const authToken = await requireOpenAIRealtimePlatformAuthToken({
+  const auth = await requireOpenAIRealtimePlatformAuth({
     configuredApiKey: config.apiKey,
     cfg: req.cfg,
   });
@@ -1507,9 +1514,12 @@ async function createOpenAIRealtimeBrowserSession(
   }
 
   const clientSecret = await createOpenAIRealtimeClientSecret({
-    authToken,
+    authToken: auth.value,
     auditContext: "openai-realtime-browser-session",
     session,
+    ...(auth.source === "api-key"
+      ? { authRejectedMessage: OPENAI_REALTIME_CONFIGURED_API_KEY_REJECTED }
+      : {}),
   });
   const offerHeaders = resolveOpenAIRealtimeBrowserOfferHeaders();
   return {