fix(ui): bound WebSocket turn rendering and remove quadratic scans

ui/litellm-dashboard/src/components/view_logs/LogDetailsDrawer/PrettyMessagesView.integration.test.tsx

@@ -1,9 +1,30 @@
 import React from "react";
-import { render, screen } from "@testing-library/react";
+import { fireEvent, render, screen } from "@testing-library/react";
 import { describe, it, expect } from "vitest";
 import { PrettyMessagesView } from "./PrettyMessagesView";
 
 describe("PrettyMessagesView", () => {
+  it("bounds rendered WebSocket turns and lets operators navigate all pages", () => {
+    const response = Array.from({ length: 101 }, (_, index) => ({
+      type: "response.completed",
+      response: { id: `resp_${index}`, output: [] },
+    }));
+    render(<PrettyMessagesView request={{}} response={response} />);
+    expect(screen.getAllByRole("region", { name: /^Turn / })).toHaveLength(50);
+    expect(screen.getByText("Turns 1–50 of 101")).toBeInTheDocument();
+    expect(screen.getByRole("button", { name: "Previous turns" })).toBeDisabled();
+    fireEvent.click(screen.getByRole("button", { name: "Next turns" }));
+    expect(screen.queryByText("Turn 1 · Completed")).not.toBeInTheDocument();
+    expect(screen.getByText("Turn 51 · Completed")).toBeInTheDocument();
+    expect(screen.getAllByRole("region", { name: /^Turn / })).toHaveLength(50);
+    fireEvent.click(screen.getByRole("button", { name: "Next turns" }));
+    expect(screen.getByText("Turns 101–101 of 101")).toBeInTheDocument();
+    expect(screen.getAllByRole("region", { name: /^Turn / })).toHaveLength(1);
+    expect(screen.getByRole("button", { name: "Next turns" })).toBeDisabled();
+    fireEvent.click(screen.getByRole("button", { name: "Previous turns" }));
+    expect(screen.getByText("Turn 51 · Completed")).toBeInTheDocument();
+  });
+
   it.each([false, true])("renders separate WebSocket turns (wrapped: %s)", (wrapped) => {
     const events = [
       { type: "response.created", response: { id: "resp_1", output: [] } },

ui/litellm-dashboard/src/components/view_logs/LogDetailsDrawer/ResponsesWebSocketPrettyView.tsx

@@ -3,6 +3,9 @@ import { toast } from "@/lib/toast";
 import { ResponsesWebSocketTurn } from "./prettyMessagesTypes";
 import { SectionHeader } from "./SectionHeader";
 import { SimpleMessageBlock } from "./SimpleMessageBlock";
+import { Button } from "@/components/ui/button";
+
+const TURNS_PER_PAGE = 50;
 
 interface ResponsesWebSocketPrettyViewProps {
   turns: readonly ResponsesWebSocketTurn[];
@@ -16,6 +19,11 @@ export function ResponsesWebSocketPrettyView({
   outputCost,
 }: ResponsesWebSocketPrettyViewProps) {
   const [isCollapsed, setIsCollapsed] = useState(false);
+  const [page, setPage] = useState(0);
+  const lastPage = Math.max(0, Math.ceil(turns.length / TURNS_PER_PAGE) - 1);
+  const currentPage = Math.min(page, lastPage);
+  const start = currentPage * TURNS_PER_PAGE;
+  const end = Math.min(start + TURNS_PER_PAGE, turns.length);
   const copyOutput = async () => {
     await navigator.clipboard.writeText(JSON.stringify(turns, null, 2));
     toast.success("Output copied");
@@ -32,14 +40,14 @@ export function ResponsesWebSocketPrettyView({
       />
       {!isCollapsed && (
         <div className="divide-y divide-border">
-          {turns.map((turn, index) => (
+          {turns.slice(start, end).map((turn, index) => (
             <section
-              key={`${turn.id}-${index}`}
+              key={`${turn.id}-${start + index}`}
               className="px-4 py-3"
-              aria-label={`Turn ${index + 1} · ${turn.status}`}
+              aria-label={`Turn ${start + index + 1} · ${turn.status}`}
             >
               <h4 className="mb-2 text-sm font-medium">
-                Turn {index + 1} · {turn.status}
+                Turn {start + index + 1} · {turn.status}
               </h4>
               {turn.id && <div className="mb-2 break-all text-xs text-muted-foreground">{turn.id}</div>}
               {turn.detail && <p className="mb-2 whitespace-pre-wrap text-sm">{turn.detail}</p>}
@@ -54,6 +62,24 @@ export function ResponsesWebSocketPrettyView({
               )}
             </section>
           ))}
+          {turns.length > TURNS_PER_PAGE && (
+            <nav aria-label="Response turns" className="flex items-center justify-between gap-2 px-4 py-3">
+              <Button variant="outline" size="sm" disabled={currentPage === 0} onClick={() => setPage(currentPage - 1)}>
+                Previous turns
+              </Button>
+              <span className="text-sm" aria-live="polite">
+                Turns {start + 1}–{end} of {turns.length}
+              </span>
+              <Button
+                variant="outline"
+                size="sm"
+                disabled={currentPage === lastPage}
+                onClick={() => setPage(currentPage + 1)}
+              >
+                Next turns
+              </Button>
+            </nav>
+          )}
         </div>
       )}
     </div>

ui/litellm-dashboard/src/components/view_logs/LogDetailsDrawer/prettyMessagesUtils.test.ts

@@ -2,6 +2,23 @@ import { describe, expect, it } from "vitest";
 import { parseResponsesWebSocketTurns } from "./prettyMessagesUtils";
 
 describe("parseResponsesWebSocketTurns", () => {
+  it("reads event types a bounded number of times for a large session", () => {
+    const reads = { count: 0 };
+    const events = Array.from({ length: 2000 }, (_, index) =>
+      ["response.created", "response.completed", "response.completed"].map((type) => ({
+        get type() {
+          reads.count += 1;
+          return type;
+        },
+        response: { id: `resp_${index}`, output: [] },
+      })),
+    ).flat();
+    const turns = parseResponsesWebSocketTurns(events);
+    expect(turns).toHaveLength(2000);
+    expect(turns?.[1999].id).toBe("resp_1999");
+    expect(reads.count).toBeLessThan(events.length * 20);
+  });
+
   it.each([
     null,
     {},

ui/litellm-dashboard/src/components/view_logs/LogDetailsDrawer/prettyMessagesUtils.ts

@@ -71,16 +71,17 @@ export const parseResponsesWebSocketTurns = (response: unknown): ResponsesWebSoc
     "response.incomplete": "Incomplete",
     "response.failed": "Failed",
   };
-  return events.flatMap((event, index): ResponsesWebSocketTurn[] => {
+  const terminalIds = new Set(
+    events.flatMap((event) =>
+      terminalTypes.includes(asString(event.type)) && isRecord(event.response) ? [asString(event.response.id)] : [],
+    ),
+  );
+  const seenTerminalIds = new Set<string>();
+  return events.flatMap((event): ResponsesWebSocketTurn[] => {
     const body = isRecord(event.response) ? event.response : {};
     const id = asString(body.id);
     if (event.type === "response.created") {
-      const hasTerminal = events.some(
-        (other) =>
-          terminalTypes.includes(asString(other.type)) &&
-          isRecord(other.response) &&
-          asString(other.response.id) === id,
-      );
+      const hasTerminal = terminalIds.has(id);
       return hasTerminal ? [] : [{ id, status: "No terminal event recorded", message: null, detail: "" }];
     }
     if (event.type === "error") {
@@ -88,16 +89,8 @@ export const parseResponsesWebSocketTurns = (response: unknown): ResponsesWebSoc
       return [{ id: "", status: "Error", message: null, detail: asString(error.message) || asString(error.code) }];
     }
     if (!terminalTypes.includes(asString(event.type))) return [];
-    if (
-      id &&
-      events
-        .slice(0, index)
-        .some(
-          (other) =>
-            terminalTypes.includes(asString(other.type)) && isRecord(other.response) && other.response.id === id,
-        )
-    )
-      return [];
+    if (id && seenTerminalIds.has(id)) return [];
+    if (id) seenTerminalIds.add(id);
     const error = isRecord(body.error) ? body.error : {};
     const incomplete = isRecord(body.incomplete_details) ? body.incomplete_details : {};
     return [