diff --git a/app/llm.js b/app/llm.js
index bd63588..71f06cb 100644
--- a/app/llm.js
+++ b/app/llm.js
@@ -1,7 +1,7 @@
 import axios from 'axios';
 import { getLLMConfig, getOpenCodeHttpsAgent } from './config.js';
 import { recordUsage } from './usage.js';
-import { line, error } from './log.js';
+import { line } from './log.js';
 
 /**
  * 將模型識別字串解析為 OpenCode API 所需的 provider 與 model 識別碼。
@@ -49,6 +49,23 @@ function extractOpenCodeContent(data) {
     .join('');
 }
 
+function summarizeErrorResponse(data) {
+  if (data == null) return '';
+  if (typeof data === 'string') return data.slice(0, 500);
+  try {
+    return JSON.stringify(data).slice(0, 500);
+  } catch {
+    return String(data).slice(0, 500);
+  }
+}
+
+function formatOpenCodeError(e) {
+  const status = e.response?.status;
+  const response = summarizeErrorResponse(e.response?.data);
+  const statusText = status ? `HTTP ${status}` : e.message;
+  return response ? `${statusText}: ${response}` : statusText;
+}
+
 /**
  * 對 OpenCode server 執行一次完整對話：建立 session 後送出訊息並回傳結果。
  *
@@ -91,8 +108,8 @@ async function chatOpenCode(baseURL, model, systemPrompt, userContent, headers)
  * 對 OpenCode server 送出一次對話請求並回傳模型純文字回應。
  *
  * 從設定取得 provider/baseURL/model；未設定 provider 時拋錯。成功時記錄
- * usage 並回傳內容。OpenCode 呼叫失敗時會記錄錯誤並以 `process.exit(1)`
- * 終止整個行程（不會回傳）。
+ * usage 並回傳內容。OpenCode 呼叫失敗時會記錄錯誤並向外拋出，讓呼叫端
+ * 決定是否降級、略過單一角色或終止整體流程。
  *
  * @param {string} systemPrompt - 系統提示詞。
  * @param {string} userContent - 使用者輸入內容。
@@ -112,10 +129,10 @@ export async function chat(systemPrompt, userContent) {
     recordUsage(data);
     return content;
   } catch (e) {
-    line(`[LLM] OpenCode 呼叫失敗: ${e.message}`);
+    const message = formatOpenCodeError(e);
+    line(`[LLM] OpenCode 呼叫失敗: ${message}`);
+    throw new Error(message);
   }
-  error('[LLM] OpenCode 呼叫失敗，終止流程');
-  process.exit(1);
 }
 
 /**
diff --git a/app/main.js b/app/main.js
index ec3974e..ca1b967 100644
--- a/app/main.js
+++ b/app/main.js
@@ -122,10 +122,18 @@ async function main() {
   }
   const analyses = await Promise.allSettled(roles.map(role => analyzeWithRole(role, diff)));
   const newFindings = [];
+  let fulfilledAnalyses = 0;
   for (let i = 0; i < analyses.length; i++) {
-    if (analyses[i].status === 'fulfilled') newFindings.push(...analyses[i].value);
+    if (analyses[i].status === 'fulfilled') {
+      fulfilledAnalyses += 1;
+      newFindings.push(...analyses[i].value);
+    }
     else warn(`[${roles[i].name}] 分析失敗（跳過）: ${analyses[i].reason?.message}`);
   }
+  if (fulfilledAnalyses === 0) {
+    result(false, '所有角色分析皆失敗，終止流程以避免誤判為審查通過');
+    process.exit(1);
+  }
   // 對只有檔名、缺行號的問題，反問原角色補上行號（最多重試數次），確保後續能行內標註
   await resolveMissingLineNumbers(newFindings, diff);
   output(`新 findings ${newFindings.length} 筆（${formatFindingsStatsLine(newFindings)}）`);
diff --git a/app/test/llm.test.js b/app/test/llm.test.js
index b99dd94..a23122f 100644
--- a/app/test/llm.test.js
+++ b/app/test/llm.test.js
@@ -85,14 +85,18 @@ describe('chat - OpenCode', async () => {
     assert.equal(result, 'hello world');
   });
 
-  it('calls process.exit(1) when OpenCode fails', async () => {
+  it('throws an error when OpenCode fails instead of exiting the process', async () => {
     process.env.OPENCODE_BASE_URL = 'http://opencode.local:4096';
-    mock.method(axios, 'post', async () => { throw new Error('fail'); });
-    const exitMock = mock.method(process, 'exit', () => { throw new Error('exit:1'); });
+    mock.method(axios, 'post', async () => {
+      const err = new Error('Request failed with status code 500');
+      err.response = { status: 500, data: { error: 'provider overloaded' } };
+      throw err;
+    });
+    const exitMock = mock.method(process, 'exit', () => { throw new Error('exit should not be called'); });
 
-    await assert.rejects(() => chat('sys', 'user'), /exit:1/);
+    await assert.rejects(() => chat('sys', 'user'), /HTTP 500.*provider overloaded/);
 
-    assert.equal(exitMock.mock.calls[0].arguments[0], 1);
+    assert.equal(exitMock.mock.calls.length, 0);
   });
 });