diff --git a/frontend/src/App.css b/frontend/src/App.css
index 720eea7..ba54afb 100644
--- a/frontend/src/App.css
+++ b/frontend/src/App.css
@@ -2977,3 +2977,106 @@ a.app-footer__repo:hover {
   max-height: 300px;
   overflow-y: auto;
 }
+
+/* ── Debug Payload Viewer ───────────────────────────────────────────────── */
+
+.debug-viewer {
+  margin-top: 0.375rem;
+  border: 1px solid var(--color-border);
+  border-radius: 4px;
+  background: var(--color-bg-surface);
+  overflow: hidden;
+}
+
+.debug-viewer__header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 0.375rem 0.625rem;
+  border-bottom: 1px solid var(--color-border);
+}
+
+.debug-viewer__label {
+  font-size: 0.7rem;
+  font-weight: 600;
+  color: var(--color-accent);
+  text-transform: uppercase;
+  letter-spacing: 0.03em;
+}
+
+.debug-viewer__export {
+  background: none;
+  border: 1px solid var(--color-border);
+  border-radius: 3px;
+  color: var(--color-text-secondary);
+  font-size: 0.7rem;
+  cursor: pointer;
+  padding: 0.125rem 0.5rem;
+  font-family: inherit;
+  transition: color 0.15s, border-color 0.15s;
+}
+
+.debug-viewer__export:hover {
+  color: var(--color-accent);
+  border-color: var(--color-accent);
+}
+
+.debug-viewer__section {
+  border-top: 1px solid var(--color-border);
+}
+
+.debug-viewer__section:first-of-type {
+  border-top: none;
+}
+
+.debug-viewer__section-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 0.25rem 0.625rem;
+}
+
+.debug-viewer__section-toggle {
+  background: none;
+  border: none;
+  color: var(--color-text-primary);
+  font-size: 0.75rem;
+  cursor: pointer;
+  padding: 0;
+  font-family: inherit;
+}
+
+.debug-viewer__section-toggle:hover {
+  color: var(--color-accent);
+}
+
+.debug-viewer__copy {
+  background: none;
+  border: none;
+  color: var(--color-text-secondary);
+  font-size: 0.675rem;
+  cursor: pointer;
+  padding: 0.125rem 0.375rem;
+  font-family: inherit;
+  border-radius: 3px;
+  transition: color 0.15s, background 0.15s;
+}
+
+.debug-viewer__copy:hover {
+  color: var(--color-accent);
+  background: var(--color-accent-subtle);
+}
+
+.debug-viewer__content {
+  margin: 0;
+  padding: 0.5rem 0.75rem;
+  background: var(--color-bg-transcript);
+  color: var(--color-text-secondary);
+  font-size: 0.75rem;
+  line-height: 1.5;
+  overflow-x: auto;
+  max-height: 400px;
+  overflow-y: auto;
+  white-space: pre-wrap;
+  word-break: break-word;
+}
diff --git a/frontend/src/api/public-client.ts b/frontend/src/api/public-client.ts
index 650da87..4f6817b 100644
--- a/frontend/src/api/public-client.ts
+++ b/frontend/src/api/public-client.ts
@@ -389,6 +389,9 @@ export interface PipelineEvent {
   model: string | null;
   duration_ms: number | null;
   payload: Record<string, unknown> | null;
+  system_prompt_text: string | null;
+  user_prompt_text: string | null;
+  response_text: string | null;
   created_at: string | null;
 }
 
diff --git a/frontend/src/pages/AdminPipeline.tsx b/frontend/src/pages/AdminPipeline.tsx
index f903ba0..2a1ac72 100644
--- a/frontend/src/pages/AdminPipeline.tsx
+++ b/frontend/src/pages/AdminPipeline.tsx
@@ -95,6 +95,105 @@ function JsonViewer({ data }: { data: Record<string, unknown> | null }) {
   );
 }
 
+// ── Debug Payload Viewer ─────────────────────────────────────────────────────
+
+interface DebugSection {
+  label: string;
+  content: string;
+}
+
+function DebugPayloadViewer({ event }: { event: PipelineEvent }) {
+  const sections: DebugSection[] = [];
+  if (event.system_prompt_text) sections.push({ label: "System Prompt", content: event.system_prompt_text });
+  if (event.user_prompt_text) sections.push({ label: "User Prompt", content: event.user_prompt_text });
+  if (event.response_text) sections.push({ label: "Response", content: event.response_text });
+
+  const [openSections, setOpenSections] = useState<Record<string, boolean>>({});
+  const [copiedKey, setCopiedKey] = useState<string | null>(null);
+
+  if (sections.length === 0) return null;
+
+  const toggleSection = (label: string) => {
+    setOpenSections((prev) => ({ ...prev, [label]: !prev[label] }));
+  };
+
+  const copyToClipboard = async (label: string, text: string) => {
+    try {
+      await navigator.clipboard.writeText(text);
+      setCopiedKey(label);
+      setTimeout(() => setCopiedKey(null), 1500);
+    } catch {
+      // Fallback for non-HTTPS contexts
+      const ta = document.createElement("textarea");
+      ta.value = text;
+      ta.style.position = "fixed";
+      ta.style.opacity = "0";
+      document.body.appendChild(ta);
+      ta.select();
+      document.execCommand("copy");
+      document.body.removeChild(ta);
+      setCopiedKey(label);
+      setTimeout(() => setCopiedKey(null), 1500);
+    }
+  };
+
+  const exportAsJson = () => {
+    const data: Record<string, string | null> = {
+      event_id: event.id,
+      stage: event.stage,
+      event_type: event.event_type,
+      model: event.model,
+      system_prompt_text: event.system_prompt_text,
+      user_prompt_text: event.user_prompt_text,
+      response_text: event.response_text,
+    };
+    const blob = new Blob([JSON.stringify(data, null, 2)], { type: "application/json" });
+    const url = URL.createObjectURL(blob);
+    const a = document.createElement("a");
+    a.href = url;
+    a.download = `debug-${event.stage}-${event.id.slice(0, 8)}.json`;
+    a.click();
+    URL.revokeObjectURL(url);
+  };
+
+  return (
+    <div className="debug-viewer">
+      <div className="debug-viewer__header">
+        <span className="debug-viewer__label">LLM Debug</span>
+        <button className="debug-viewer__export" onClick={exportAsJson} title="Export debug payload as JSON">
+          ↓ JSON
+        </button>
+      </div>
+      {sections.map((sec) => {
+        const isOpen = !!openSections[sec.label];
+        return (
+          <div key={sec.label} className="debug-viewer__section">
+            <div className="debug-viewer__section-header">
+              <button
+                className="debug-viewer__section-toggle"
+                onClick={() => toggleSection(sec.label)}
+                aria-expanded={isOpen}
+              >
+                {isOpen ? "▾" : "▸"} {sec.label}
+              </button>
+              <button
+                className="debug-viewer__copy"
+                onClick={() => void copyToClipboard(sec.label, sec.content)}
+                title={`Copy ${sec.label}`}
+              >
+                {copiedKey === sec.label ? "✓ Copied" : "Copy"}
+              </button>
+            </div>
+            {isOpen && (
+              <pre className="debug-viewer__content">{sec.content}</pre>
+            )}
+          </div>
+        );
+      })}
+    </div>
+  );
+}
+
 // ── Event Log ────────────────────────────────────────────────────────────────
 
 function EventLog({ videoId }: { videoId: string }) {
@@ -177,6 +276,7 @@ function EventLog({ videoId }: { videoId: string }) {
               <span className="pipeline-event__time">{formatDate(evt.created_at)}</span>
             </div>
             <JsonViewer data={evt.payload} />
+            <DebugPayloadViewer event={evt} />
           </div>
         ))}
       </div>