diff --git a/src/bot/commands/ask.history.test.ts b/src/bot/commands/ask.history.test.ts
index 378fa0df..79834e6b 100644
--- a/src/bot/commands/ask.history.test.ts
+++ b/src/bot/commands/ask.history.test.ts
@@ -74,7 +74,10 @@ class FakeAgent {
     return agentRunMock(question, history);
   }
 }
-mock.module('../../services/ai/agent', () => ({ ExpenseBotAgent: FakeAgent }));
+mock.module('../../services/ai/agent', () => ({
+  ExpenseBotAgent: FakeAgent,
+  UNCLASSIFIED_FAILURE_MESSAGE: '❌ Ошибка при обработке вопроса. Попробуй еще раз.',
+}));
 mock.module('../../services/analytics/spending-analytics', () => ({
   spendingAnalytics: { getFinancialSnapshot: mock(() => ({})) },
 }));
diff --git a/src/bot/commands/ask.ts b/src/bot/commands/ask.ts
index f524a5a5..a62c0537 100644
--- a/src/bot/commands/ask.ts
+++ b/src/bot/commands/ask.ts
@@ -9,7 +9,7 @@ import { database } from '../../database';
 import type { Group, User } from '../../database/types';
 import { AgentError } from '../../errors';
 import { validateAdvice } from '../../services/ai/advice-validator';
-import { ExpenseBotAgent } from '../../services/ai/agent';
+import { ExpenseBotAgent, UNCLASSIFIED_FAILURE_MESSAGE } from '../../services/ai/agent';
 import { aiStreamRound, stripThinkingTags } from '../../services/ai/streaming';
 import { NO_ANSWER_MESSAGE } from '../../services/ai/telegram-stream';
 import type { AgentContext } from '../../services/ai/types';
@@ -265,9 +265,8 @@ async function handleAskWithAnthropic(
       return false;
     }
     logger.error({ err: error }, '[ASK] Anthropic agent error');
-    const failureMessage = '❌ Ошибка при обработке вопроса. Попробуй еще раз.';
-    await sendMessage(failureMessage);
-    persistAssistantReply(failureMessage);
+    await sendMessage(UNCLASSIFIED_FAILURE_MESSAGE);
+    persistAssistantReply(UNCLASSIFIED_FAILURE_MESSAGE);
     return false;
   }
 }
diff --git a/src/errors/service-errors.ts b/src/errors/service-errors.ts
index 9db9d004..2a541437 100644
--- a/src/errors/service-errors.ts
+++ b/src/errors/service-errors.ts
@@ -21,7 +21,11 @@ export class OAuthError extends AppError {}
 
 /** AI agent error — user-facing message already sent to Telegram, no further action needed */
 export class AgentError extends AppError {
-  constructor(public readonly userMessage: string) {
-    super(userMessage, 'AGENT_ERROR');
+  /** `cause` keeps the original error (e.g. an unclassified non-AI one) for the logs. */
+  constructor(
+    public readonly userMessage: string,
+    cause?: unknown,
+  ) {
+    super(userMessage, 'AGENT_ERROR', cause);
   }
 }
diff --git a/src/services/ai/agent.errors.test.ts b/src/services/ai/agent.errors.test.ts
index b10add19..054d3a1f 100644
--- a/src/services/ai/agent.errors.test.ts
+++ b/src/services/ai/agent.errors.test.ts
@@ -505,5 +505,28 @@ describe('ExpenseBotAgent', () => {
       expect(shown).toContain('Записываю расход: 5 EUR, Еда');
       expect(shown.endsWith('⏳ Слишком много запросов к AI. Подожди минуту.')).toBe(true);
     });
+
+    it('a write tool, then an unclassified non-AI error: the work log stays, failure under it', async () => {
+      mockIsRetryableError.mockReturnValue(false);
+      mockClassifyAiError.mockReturnValue(null);
+      const bug = new TypeError('bug after the write');
+      mockToolCallRound('add_expense', '{"amount":5,"currency":"EUR","category":"Еда"}');
+      mockAiStreamRound.mockRejectedValueOnce(bug);
+
+      const { AgentError } = await import('../../errors');
+      let thrown: unknown;
+      await agent.run('запиши 5 евро еда', [], mockBot as unknown as Bot).catch((e) => {
+        thrown = e;
+      });
+
+      // The caller must not send a second, duplicate failure message: the agent already
+      // rendered it under the preserved work log.
+      expect(thrown).toBeInstanceOf(AgentError);
+      expect(mockBot.api.deleteMessage).not.toHaveBeenCalled();
+      const edits = mockBot.api.editMessageText.mock.calls as unknown as Array<[{ text: string }]>;
+      const shown = edits.at(-1)?.[0].text ?? '';
+      expect(shown).toContain('Записываю расход: 5 EUR, Еда');
+      expect(shown).toContain('Ошибка при обработке вопроса');
+    });
   });
 });
diff --git a/src/services/ai/agent.ts b/src/services/ai/agent.ts
index 49a5d92f..db80bfe0 100644
--- a/src/services/ai/agent.ts
+++ b/src/services/ai/agent.ts
@@ -60,6 +60,9 @@ import type { AgentContext, ToolCallResult, ToolResult } from './types';
 
 const logger = createLogger('agent');
 
+/** Failure text for a non-AI error mid-run; ask.ts shows the same one when it owns the reply. */
+export const UNCLASSIFIED_FAILURE_MESSAGE = '❌ Ошибка при обработке вопроса. Попробуй еще раз.';
+
 /** Singleton debug logger — writes full AI conversations to logs/chats/ when enabled */
 export const aiDebugLogger = new AiDebugLogger(env.AI_DEBUG_LOGS, 'logs');
 
@@ -360,9 +363,21 @@ export class ExpenseBotAgent {
     debugCtx?.flush();
     this.recordTrajectory('error', classification?.kind ?? 'unclassified');
     if (!classification) {
-      // Not a recognizable AI/network/timeout failure — propagate so the caller
-      // (and logs) see the real, unrelated error instead of a masked generic one.
+      // Not a recognizable AI/network/timeout failure — a bug or an unrelated error.
       // (No admin AI-failure report here: it isn't an AI failure.)
+      if (this.writeToolRan) {
+        // A write tool already changed data: the work log is the user's only record of
+        // what was done, so keep it and show the failure under it (issue #182). The
+        // AgentError tells the caller the message is already on screen — no duplicate.
+        logger.error(
+          { err: error },
+          '[AGENT] non-AI error after write tools — keeping the work log, failure under it',
+        );
+        await writer.fail(UNCLASSIFIED_FAILURE_MESSAGE);
+        throw new AgentError(UNCLASSIFIED_FAILURE_MESSAGE, error);
+      }
+      // Nothing user-visible was done — propagate so the caller (and logs) see the
+      // real, unrelated error instead of a masked generic one.
       await writer.deleteSentMessage();
       throw error;
     }