diff --git a/src/handlers/debugHandlers.ts b/src/handlers/debugHandlers.ts
index 4df0f73..9ca6f6b 100644
--- a/src/handlers/debugHandlers.ts
+++ b/src/handlers/debugHandlers.ts
@@ -3,7 +3,7 @@ import { logger } from "firebase-functions";
 import { runDailyArchive } from "../scheduled/dailyArchive";
 import { forceSyncDay } from "../services/gameSyncService";
 import { runChatToolsSheet, renderSheetMarkdown } from "../services/chatToolsSheetService";
-import { runChatProbe, runChatProbeBatch, renderProbeMarkdown } from "../services/chatProbeService";
+import { runChatProbe, runChatProbeBatch, runChatProbeConversation, renderProbeMarkdown } from "../services/chatProbeService";
 import { sendError } from "../middleware/errors";
 import { daysAgoKst, parseDateString } from "../types/dateString";
 
@@ -89,16 +89,44 @@ export const debug = onRequest({ timeoutSeconds: 300 }, async (req, res) => {
         (typeof req.query.uid === "string" && req.query.uid) ||
         (typeof req.body?.uid === "string" && req.body.uid) ||
         "";
-      const q =
-        (typeof req.query.q === "string" && req.query.q) ||
-        (typeof req.body?.q === "string" && req.body.q) ||
-        "";
-      if (!uid || !q) {
-        res.status(400).json({ error: "uid and q are required (e.g. ?uid=<UID>&q=<문장>)" });
+      // uid 누락만 400(설정 오류). content는 어떤 값이든 4xx를 내지 않는다 —
+      // garak RestGenerator가 4xx를 치명적 에러로 보고 런 전체를 중단하기 때문.
+      if (!uid) {
+        res.status(400).json({ error: "uid is required (e.g. ?uid=<UID>&q=<문장>)" });
         return;
       }
       const model = typeof req.query.model === "string" ? req.query.model : undefined;
       const style = typeof req.query.style === "string" ? req.query.style : undefined;
+
+      // 멀티턴: body.messages([{role,content}...])가 오면 전체 대화를 그대로 리플레이.
+      const rawMessages = req.body?.messages;
+      if (Array.isArray(rawMessages)) {
+        const messages = rawMessages
+          .filter((m): m is { role: unknown; content: unknown } => !!m && typeof m === "object")
+          .map((m) => ({
+            role: m.role === "assistant" ? "assistant" as const : "user" as const,
+            content: typeof m.content === "string" ? m.content : String(m.content ?? ""),
+          }));
+        logger.info(
+          `debug.chatProbe[turns=${messages.length}] (uid=${uid}, model=${model ?? "default"})`,
+        );
+        const result = await runChatProbeConversation(uid, messages, model, style);
+        res.status(200).json(result);
+        return;
+      }
+
+      // 단발: q. 빈 문자열도 200으로 안전 반환(모델 미호출).
+      const q =
+        (typeof req.query.q === "string" && req.query.q) ||
+        (typeof req.body?.q === "string" && req.body.q) ||
+        "";
+      if (!q) {
+        res.status(200).json({
+          message: "", reply: "", finishReason: "empty", toolCalls: [],
+          elapsedMs: 0, inputTokens: 0, outputTokens: 0, cachedTokens: 0,
+        });
+        return;
+      }
       logger.info(
         `debug.chatProbe triggered (uid=${uid}, model=${model ?? "default"}, style=${style ?? "default"})`,
       );
diff --git a/src/services/chatProbeService.ts b/src/services/chatProbeService.ts
index f1a223e..8038f5a 100644
--- a/src/services/chatProbeService.ts
+++ b/src/services/chatProbeService.ts
@@ -10,6 +10,7 @@ import {
   callProviderWithBudget,
   getChatProvider,
   type ChatProvider,
+  type ChatProviderMessage,
   type ChatTool,
 } from "./chatProviderService";
 import { HttpError } from "../middleware/errors";
@@ -151,18 +152,32 @@ function instrument(tools: ChatTool[], trace: ProbeToolCall[]): ChatTool[] {
 }
 
 async function runOne(env: ProbeEnv, q: string, expect?: string): Promise<ProbeResult> {
+  return runMessages(env, [{ role: "user", content: q }], q, expect);
+}
+
+/**
+ * 임의의 대화(messages 배열)를 모델+도구 루프로 1회 실행한다. 멀티턴 프로브용 —
+ * 상태는 호출자(garak)가 전체 대화를 매번 실어 보내고 서버는 그대로 리플레이한다(stateless).
+ * `label`은 결과의 message 필드(보통 마지막 user 발화)로 표시용.
+ */
+async function runMessages(
+  env: ProbeEnv,
+  messages: ChatProviderMessage[],
+  label: string,
+  expect?: string,
+): Promise<ProbeResult> {
   const started = Date.now();
   const trace: ProbeToolCall[] = [];
   const tools = instrument(buildChatTools(env.toolCtx), trace);
   try {
     const result = await callProviderWithBudget(env.provider, {
       system: env.system,
-      messages: [{ role: "user", content: q }],
+      messages,
       config: env.config.provider,
       tools,
     });
     return {
-      message: q,
+      message: label,
       expect,
       reply: result.reply,
       finishReason: result.finishReason,
@@ -175,7 +190,7 @@ async function runOne(env: ProbeEnv, q: string, expect?: string): Promise<ProbeR
   } catch (err) {
     const error = err instanceof Error ? `${err.name}: ${err.message}` : String(err);
     return {
-      message: q,
+      message: label,
       expect,
       reply: "",
       finishReason: "error",
@@ -200,6 +215,28 @@ export async function runChatProbe(
   return runOne(env, message);
 }
 
+/**
+ * 멀티턴 프로브 — 호출자가 전체 대화(messages)를 보내면 그대로 모델+도구 루프에 흘린다.
+ * garak의 대화형 probe(atkgen·tap 등)를 stateless로 받기 위함. 마지막 메시지는 user여야
+ * 의미가 있다(provider 제약). 빈 배열이면 빈 응답을 즉시 돌려 비용을 쓰지 않는다.
+ */
+export async function runChatProbeConversation(
+  uid: string,
+  messages: ChatProviderMessage[],
+  modelOverride?: string,
+  styleOverride?: string,
+): Promise<ProbeResult> {
+  const label = [...messages].reverse().find((m) => m.role === "user")?.content ?? "";
+  if (messages.length === 0) {
+    return {
+      message: label, reply: "", finishReason: "empty", toolCalls: [],
+      elapsedMs: 0, inputTokens: 0, outputTokens: 0, cachedTokens: 0,
+    };
+  }
+  const env = await buildProbeEnv(uid, modelOverride, styleOverride);
+  return runMessages(env, messages, label);
+}
+
 /** 자연어 문장 배치 프로브(순차). prompts 미지정 시 기본 세트. modelOverride로 테스트 모델 지정. */
 export async function runChatProbeBatch(
   uid: string,