diff --git a/services/hackbot-ui/app/api/runs/[runId]/retrigger/route.ts b/services/hackbot-ui/app/api/runs/[runId]/retrigger/route.ts
new file mode 100644
index 0000000000..f5cb3dee9b
--- /dev/null
+++ b/services/hackbot-ui/app/api/runs/[runId]/retrigger/route.ts
@@ -0,0 +1,37 @@
+import { NextResponse } from "next/server";
+
+import { createRun, getRun, HackbotError } from "@/lib/hackbot";
+import { getAuthedEmail } from "@/lib/session";
+import { isFailed } from "@/lib/types";
+
+export const dynamic = "force-dynamic";
+
+// POST /api/runs/:runId/retrigger: start a new run with the same inputs as a
+// failed one. Inputs are read server-side, so the browser only sends a run id.
+// Like POST /api/runs, the new run is attributed to the signed-in user rather
+// than to the original run's requester.
+export async function POST(
+  _req: Request,
+  { params }: { params: Promise<{ runId: string }> }
+) {
+  const email = await getAuthedEmail();
+  if (!email) {
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
+  }
+
+  const { runId } = await params;
+  try {
+    const doc = await getRun(runId);
+    if (!isFailed(doc.status)) {
+      return NextResponse.json(
+        { error: `Only failed runs can be re-run (this one is ${doc.status})` },
+        { status: 409 }
+      );
+    }
+    const run = await createRun(doc.agent, doc.inputs, email);
+    return NextResponse.json(run, { status: 201 });
+  } catch (err) {
+    const status = err instanceof HackbotError ? err.status : 500;
+    return NextResponse.json({ error: (err as Error).message }, { status });
+  }
+}
diff --git a/services/hackbot-ui/app/runs/[runId]/page.tsx b/services/hackbot-ui/app/runs/[runId]/page.tsx
index 3fe6e24205..244da0dbd5 100644
--- a/services/hackbot-ui/app/runs/[runId]/page.tsx
+++ b/services/hackbot-ui/app/runs/[runId]/page.tsx
@@ -6,5 +6,6 @@ export default async function RunPage({
   params: Promise<{ runId: string }>;
 }) {
   const { runId } = await params;
-  return <RunDetail runId={runId} />;
+
+  return <RunDetail key={runId} runId={runId} />;
 }
diff --git a/services/hackbot-ui/components/RecentRuns.tsx b/services/hackbot-ui/components/RecentRuns.tsx
index 4df33174d3..476dbed643 100644
--- a/services/hackbot-ui/components/RecentRuns.tsx
+++ b/services/hackbot-ui/components/RecentRuns.tsx
@@ -6,7 +6,7 @@ import { Fragment, useCallback, useEffect, useState } from "react";
 
 import { AGENT_NAMES } from "@/lib/agents";
 import { useSession } from "@/lib/auth-client";
-import { isTerminal, type RunDoc, type RunStatus } from "@/lib/types";
+import { isFailed, isTerminal, type RunDoc, type RunStatus } from "@/lib/types";
 import { StatusBadge } from "./StatusBadge";
 
 // Poll the status of any non-terminal, currently-loaded runs so the dashboard
@@ -61,7 +61,7 @@ function toRow(d: RunDoc): RunRow {
 }
 
 function hasErrorDetail(r: RunRow): boolean {
-  return (r.status === "failed" || r.status === "timed_out") && !!r.error;
+  return isFailed(r.status) && !!r.error;
 }
 
 // Compact requester cell: the email's local part (full email on hover). Runs
diff --git a/services/hackbot-ui/components/RunDetail.tsx b/services/hackbot-ui/components/RunDetail.tsx
index 3c846f6407..30bd9f509f 100644
--- a/services/hackbot-ui/components/RunDetail.tsx
+++ b/services/hackbot-ui/components/RunDetail.tsx
@@ -1,10 +1,17 @@
 "use client";
 
 import Link from "next/link";
+import { useRouter } from "next/navigation";
 import { useCallback, useEffect, useRef, useState } from "react";
 
 import { updateRunStatus } from "@/lib/store";
-import { isTerminal, type RunAction, type RunDoc } from "@/lib/types";
+import {
+  isFailed,
+  isTerminal,
+  type RunAction,
+  type RunDoc,
+  type RunRef,
+} from "@/lib/types";
 import { FindingsView } from "./FindingsView";
 import { Markdown } from "./Markdown";
 import { StatusBadge } from "./StatusBadge";
@@ -46,12 +53,15 @@ function extractLog(run: RunDoc): string | null {
 }
 
 export function RunDetail({ runId }: { runId: string }) {
+  const router = useRouter();
   const [run, setRun] = useState<RunDoc | null>(null);
   const [error, setError] = useState<string | null>(null);
   const [polling, setPolling] = useState(true);
   const [actions, setActions] = useState<RunAction[] | null>(null);
   const [applying, setApplying] = useState(false);
   const [applyError, setApplyError] = useState<string | null>(null);
+  const [retriggering, setRetriggering] = useState(false);
+  const [retriggerError, setRetriggerError] = useState<string | null>(null);
   const timer = useRef<ReturnType<typeof setTimeout> | null>(null);
 
   const fetchRun = useCallback(async () => {
@@ -124,6 +134,24 @@ export function RunDetail({ runId }: { runId: string }) {
     }
   }, [runId]);
 
+  const retrigger = useCallback(async () => {
+    setRetriggering(true);
+    setRetriggerError(null);
+    try {
+      const res = await fetch(`/api/runs/${runId}/retrigger`, {
+        method: "POST",
+      });
+      const body = await res.json();
+      if (!res.ok)
+        throw new Error(body?.error ?? `Request failed (${res.status})`);
+      // Left disabled through the navigation; the remount clears it.
+      router.push(`/runs/${(body as RunRef).run_id}`);
+    } catch (err) {
+      setRetriggerError((err as Error).message);
+      setRetriggering(false);
+    }
+  }, [runId, router]);
+
   if (!run && error) {
     return <div className="error-banner">{error}</div>;
   }
@@ -159,12 +187,27 @@ export function RunDetail({ runId }: { runId: string }) {
             </span>
           )}
         </div>
-        <Link href="/" className="muted">
-          ← all runs
-        </Link>
+        <div style={{ display: "flex", alignItems: "center", gap: 12 }}>
+          {isFailed(run.status) && (
+            <button
+              type="button"
+              className="secondary"
+              onClick={retrigger}
+              disabled={retriggering}
+            >
+              {retriggering ? "Re-running…" : "Re-run with same inputs"}
+            </button>
+          )}
+          <Link href="/" className="muted">
+            ← all runs
+          </Link>
+        </div>
       </div>
 
       {error && <div className="error-banner">Refresh error: {error}</div>}
+      {retriggerError && (
+        <div className="error-banner">Re-run failed: {retriggerError}</div>
+      )}
 
       <div className="panel">
         <h2>Run</h2>
diff --git a/services/hackbot-ui/lib/types.ts b/services/hackbot-ui/lib/types.ts
index 1fc07ab664..1f586f116e 100644
--- a/services/hackbot-ui/lib/types.ts
+++ b/services/hackbot-ui/lib/types.ts
@@ -17,6 +17,10 @@ export function isTerminal(status: RunStatus): boolean {
   return TERMINAL_STATUSES.includes(status);
 }
 
+export function isFailed(status: RunStatus): boolean {
+  return status === "failed" || status === "timed_out";
+}
+
 export interface AgentDescriptor {
   name: string;
   description: string;