Verify each finding against the current code and only fix it if needed.

In `@components/VercelChat/ToolComponents.tsx` around lines 346 - 349, The code
unconditionally JSON.parse's dynamic-tool output into result, which throws for
empty/non-JSON redirect outputs; change the logic so parsing is guarded: either
defer JSON.parse until after you inspect the tool branch (e.g., check for
redirect tool type/name) or wrap the parse of (output as
CallToolResult).content[0].text in a safe path that verifies content exists and
is valid JSON (or try/catch) before assigning to result; adjust the logic around
the variables type, output, CallToolResult and the redirect handling so lines
handling redirect (around the current branching at/after where result is used)
never see an unguarded JSON.parse (also apply same guard to the code at the
other occurrence noted).

Verify each finding against the current code and only fix it if needed.

In `@hooks/useVercelChat.ts` around lines 189 - 196, The pending redirect handling
inside onToolCall currently only completes if refetchCredits() resolves, so a
rejected refetch can leave pendingRedirectPathRef.current set and prevent
navigation; update onToolCall to always perform the redirect navigation and
reset pendingRedirectPathRef.current regardless of refetchCredits() outcome by
moving the redirect nav/cleanup into a finally block or by catching errors from
refetchCredits() and then executing the redirect and clearing
pendingRedirectPathRef; refer to onToolCall, pendingRedirectPathRef, and
refetchCredits() in the change.

Verify each finding against the current code and only fix it if needed.

In `@lib/api/getClientApiBaseUrl.ts` around lines 11 - 18, The current
getClientApiBaseUrl logic allows any ?api= absolute URL which can redirect
production traffic; change it to only accept overrides if the origin is trusted
or when running in a non-production/dev mode. Specifically, update the code
around apiParam (in getClientApiBaseUrl) to: 1) parse apiParam and validate its
origin against a hardcoded allowlist of trusted origins or check a runtime
feature flag/ENV (e.g., NODE_ENV !== 'production' or an ALLOW_API_OVERRIDE flag)
before returning it; 2) if validation fails, fall back to defaultApiBaseUrl; and
3) keep the trimming of trailing slashes but do not accept raw hostnames/paths
without explicit allowlist/flag; also ensure any persistent use in
providers/ApiOverrideSync.tsx and hooks/useChatTransport.ts respects the same
validation function to avoid leaking requests to untrusted origins.

Check if this issue is valid — if so, understand the root cause and fix it. At hooks/useVercelChat.ts, line 64:

<comment>This behavior change (tool-triggered redirect via `onToolCall`/`onFinish`) ships without a regression test, which Rule 3 explicitly flags for bug-fix/behavior-change PRs.</comment>

<file context>
@@ -61,6 +61,7 @@ export function useVercelChat({
   const { refetchCredits } = usePaymentProvider();
   const { transport, getHeaders } = useChatTransport();
   const { authenticated } = usePrivy();
+  const pendingRedirectPathRef = useRef<string | null>(null);
 
   // Load artist files for mentions (from Supabase)
</file context>

Check if this issue is valid — if so, understand the root cause and fix it. At hooks/useVercelChat.ts, line 189:

<comment>This adds more behavior to an already far-over-limit hook file instead of splitting responsibilities; Rule 1 requires files to stay under 100 LOC.</comment>

<file context>
@@ -181,12 +182,27 @@ export function useVercelChat({
         console.error("An error occurred, please try again!", e);
         toast.error("An error occurred, please try again!");
       },
+      onToolCall: async ({ toolCall }) => {
+        if ("toolName" in toolCall && toolCall.toolName === "redirect") {
+          const path = (toolCall.input as { path?: string } | undefined)?.path;
</file context>

Check if this issue is valid — if so, understand the root cause and fix it. At lib/api/getClientApiBaseUrl.ts, line 17:

<comment>Validate or restrict the `api` query param before using it as the API base URL. As written, any link can set `?api=...` to an arbitrary origin, which can redirect client API requests to an untrusted host and potentially leak auth headers or user data.</comment>

<file context>
@@ -8,6 +8,15 @@ export function getClientApiBaseUrl(): string {
+      }
+
+      if (apiParam) {
+        return new URL(apiParam).toString().replace(/\/+$/, "");
+      }
+
</file context>

Check if this issue is valid — if so, understand the root cause and fix it. At components/VercelChat/ToolComponents.tsx, line 346:

<comment>Handle the `redirect` case before parsing dynamic-tool output, or parse defensively. `JSON.parse` here can throw on empty/non-JSON output and crash rendering before the redirect branch runs.</comment>

<file context>
@@ -335,10 +343,10 @@ export function getToolCallComponent(part: ToolUIPart) {
-  const result = isMcp
-    ? JSON.parse((output as CallToolResult).content[0].text)
-    : output;
+  const result =
+    type === "dynamic-tool"
+      ? JSON.parse((output as CallToolResult).content[0].text)
</file context>

Check if this issue is valid — if so, understand the root cause and fix it. At hooks/useVercelChat.ts, line 204:

<comment>`history.replaceState` only changes the address bar, so the redirect tool won’t navigate to the new route and the chat will keep using the old `id`. Use a real navigation call (e.g., `window.location.replace` or the Next router) so the redirect actually takes effect.</comment>

<file context>
@@ -181,12 +182,27 @@ export function useVercelChat({
+        if (pendingRedirectPathRef.current) {
+          const redirectPath = pendingRedirectPathRef.current;
+          pendingRedirectPathRef.current = null;
+          window.history.replaceState({}, "", redirectPath);
+        }
       },
</file context>

Check if this issue is valid — if so, understand the root cause and fix it. At hooks/useChatTransport.ts, line 16:

<comment>API base URL is frozen at render time, so request-time API override changes are not reliably applied to send/reconnect requests.</comment>

<file context>
@@ -5,27 +5,17 @@ import { usePrivy } from "@privy-io/react-auth";
-        headers: request.headers,
-        credentials: request.credentials,
-      }),
+      api: `${baseUrl}/api/chat`,
     });
-  }, []);
</file context>