diff --git a/apps/cli/src/ai/agent.test.ts b/apps/cli/src/ai/agent.test.ts
new file mode 100644
index 00000000..380c5b03
--- /dev/null
+++ b/apps/cli/src/ai/agent.test.ts
@@ -0,0 +1,80 @@
+import assert from 'node:assert/strict'
+import { mkdtempSync, rmSync } from 'node:fs'
+import { basename, dirname, join } from 'node:path'
+import { tmpdir } from 'node:os'
+import test from 'node:test'
+import { AIChatManager } from '../../../../packages/node-runtime/src/ai/chats'
+import type { AgentStreamChunk } from '@openchatlab/node-runtime'
+
+test('cancelling a session agent must not persist a compression summary', async (t) => {
+  let controller: AbortController
+  let compressionCalls = 0
+  let compressionSignal: AbortSignal | undefined
+  await t.mock.module('../../../../packages/node-runtime/src/ai/compression/adapter-factory', {
+    namedExports: {
+      createCompressionLlmAdapter: (options: { onCompressing?: () => void }) => ({
+        contextWindow: 1000,
+        compress: async (_prompt: string, _maxTokens: number, signal?: AbortSignal) => {
+          options.onCompressing?.()
+          compressionCalls++
+          compressionSignal = signal
+          controller.abort()
+          return 'Summary returned after cancellation'
+        },
+      }),
+    },
+  })
+  const { runServerAgent } = await import('./agent')
+
+  for (const alreadyAborted of [true, false]) {
+    await t.test(alreadyAborted ? 'cancelled before compression' : 'cancelled during compression', async () => {
+      controller = new AbortController()
+      compressionCalls = 0
+      compressionSignal = undefined
+      const dir = mkdtempSync(join(tmpdir(), 'chatlab-session-cancel-'))
+      const nativeBinding = process.env.CHATLAB_TEST_SQLITE_NATIVE_BINDING
+      const manager = new AIChatManager(dir, nativeBinding ? { nativeBinding } : undefined)
+      try {
+        const chat = manager.createAIChat('session-1', 'Cancellation', 'general_cn')
+        for (let index = 0; index < 6; index++) {
+          const message = manager.addMessage(chat.id, index % 2 ? 'assistant' : 'user', 'history '.repeat(200))
+          manager.executeAiSQL(`UPDATE ai_message SET timestamp = ${1700000000 + index} WHERE id = '${message.id}'`)
+        }
+        const activeBefore = manager.getAIChat(chat.id)?.activeMessageId
+        const events: AgentStreamChunk[] = []
+        if (alreadyAborted) controller.abort()
+
+        await runServerAgent({
+          userMessage: 'Continue',
+          aiChatId: chat.id,
+          aiChatManager: manager,
+          llmConfig: { provider: 'openai-compatible', model: 'test-model', apiKey: 'test-placeholder' },
+          abortSignal: controller.signal,
+          onEvent: (event) => events.push(event),
+        })
+
+        assert.equal(manager.getLatestSummary(chat.id), null)
+        assert.equal(manager.getAIChat(chat.id)?.activeMessageId, activeBefore)
+        assert.equal(compressionCalls, alreadyAborted ? 0 : 1)
+        if (!alreadyAborted) assert.equal(compressionSignal, controller.signal)
+        assert.equal(
+          events.some((event) => event.type === 'compression_done'),
+          false
+        )
+        assert.deepEqual(
+          events
+            .filter((event) => event.type === 'status')
+            .map((event) => event.status?.phase)
+            .filter((phase) => phase === 'aborted' || phase === 'completed' || phase === 'error'),
+          ['aborted']
+        )
+        assert.equal(events.filter((event) => event.type === 'done').length, 1)
+      } finally {
+        manager.close()
+        assert.equal(dirname(dir), tmpdir())
+        assert.ok(basename(dir).startsWith('chatlab-session-cancel-'))
+        rmSync(dir, { recursive: true, force: true, maxRetries: 5, retryDelay: 50 })
+      }
+    })
+  }
+})
diff --git a/apps/cli/src/ai/agent.ts b/apps/cli/src/ai/agent.ts
index c713213c..8f17e200 100644
--- a/apps/cli/src/ai/agent.ts
+++ b/apps/cli/src/ai/agent.ts
@@ -133,7 +133,8 @@ export async function runServerAgent(options: RunAgentOptions): Promise<void> {
       systemPrompt,
       llmAdapter,
       aiChatManager,
-      aiLogger ?? undefined
+      aiLogger ?? undefined,
+      { signal: abortSignal }
     )
     if (compressionResult.compressed) {
       onEvent({
diff --git a/apps/desktop/main/ai/agent-stream-runner.ts b/apps/desktop/main/ai/agent-stream-runner.ts
index 7cf11424..e3838fd8 100644
--- a/apps/desktop/main/ai/agent-stream-runner.ts
+++ b/apps/desktop/main/ai/agent-stream-runner.ts
@@ -212,7 +212,8 @@ export function createElectronRunAgentStream(
             })
           }),
           getAIChatManager(),
-          compressionLogger
+          compressionLogger,
+          { signal: abortSignal }
         )
 
         if (compressionResult.compressed && compressionResult.summaryContent) {