diff --git a/cli/src/lib/deploy.ts b/cli/src/lib/deploy.ts
index 49d9bf0..3cd0d11 100644
--- a/cli/src/lib/deploy.ts
+++ b/cli/src/lib/deploy.ts
@@ -351,6 +351,20 @@ export async function downloadAndDeploy(
     } else {
       failures.push(`D1 migration: 部署物缺 kbdb/migrations/0002_credentials.sql（${credMigPath}）`);
     }
+
+    // 3.7 execution_log template seed（KV 額度事故修復，2026-08-07）：workflow 執行紀錄改走
+    //     KBDB template 機制（entries 表 entry_type='execution_log'，比照 recipe_stat 慣例；
+    //     schema 零異動，只 seed 一列 template 定義，同 0001_base.sql §3 手法，self-hosted 同步套用）。
+    const execLogMigPath = join(root, 'kbdb', 'migrations', '0004_execution_log_template.sql');
+    if (existsSync(execLogMigPath)) {
+      try {
+        await applyD1Migration(ctx, readFileSync(execLogMigPath, 'utf8'));
+      } catch (e) {
+        failures.push(`D1 migration 0004_execution_log_template (${ctx.d1DatabaseId}): ${e instanceof Error ? e.message : String(e)}`);
+      }
+    } else {
+      failures.push(`D1 migration: 部署物缺 kbdb/migrations/0004_execution_log_template.sql（${execLogMigPath}）`);
+    }
   }
 
   const cypherExecutorUrl = ctx.workerSubdomain
diff --git a/cypher-executor/src/actions/execution-logger.ts b/cypher-executor/src/actions/execution-logger.ts
index 36746bb..e704f90 100644
--- a/cypher-executor/src/actions/execution-logger.ts
+++ b/cypher-executor/src/actions/execution-logger.ts
@@ -1,24 +1,56 @@
 /**
- * Execution Logger — 執行結果寫入 ANALYTICS_KV（fire-and-forget）
+ * Execution Logger — 執行結果寫入 KBDB（fire-and-forget）
  *
- * 設計：每次 workflow 執行後，將統計數據寫入 ANALYTICS_KV（key = stats:{workflowId}）。
- * Phase 7 可升級為 POST 至 registry.arcrun.dev/analytics/record。
+ * KV 額度事故修復（總管交辦，2026-08-07）：舊版寫 ANALYTICS_KV（Workers KV），
+ * key = stats:{workflowId}:{timestamp}（註解寫「避免覆蓋」）⇒ 只增不減、永不覆蓋。
+ * 封測者 Evan 處理約 690 個檔案，KV 免費層 write 上限 1,000/日被打爆（實測 1,070 write）。
+ *
+ * KBDB 鐵律（leo 2026-06-14）：KBDB＝API-as-Wall，零 SQL——任何存取一律走 KBDB 的 HTTP API，
+ * 不准直接對它的 D1 下 SQL。本檔因此**不直連任何 D1**，改 fire-and-forget POST
+ * `{KBDB_BASE_URL}/execution-log/record`（連法/認證頭完全比照既有 recordRecipeStats
+ * 慣例，見 webhook-handlers.ts；儲存/降級實作在 kbdb/src/actions/execution-log.ts）。
+ *
+ * leo 兩條判準：
+ *   ① 執行紀錄是稽核資料 → 搬去 D1（entries 表，rows written 100,000/日，額度是 KV 的 100 倍）。
+ *   ② 不是 n8n、不靠 Execution 計費 → 少記：不留每節點輸入輸出，只留時間/workflow/verdict/
+ *      duration/錯誤訊息/(可得的)目標；成功記最少，失敗多記一點（截斷長度不對稱，見 KBDB 端）。
+ *
+ * A2 自我降級（門檻與降級邏輯全在 KBDB 端，見 execution-log.ts）：D1 額度仍與知識卡共用，
+ * 超過門檻 KBDB 會回報 mode='skip'/'log_failure_only'，但**這件事對呼叫端透明**——
+ * 本函式不管 KBDB 決定寫或不寫，一律 fire-and-forget、永不 throw，workflow 執行不受影響。
  */
 
 import type { Bindings, GraphNode } from '../types';
+import { kbdbBase } from '../routes/kbdb-proxy';
 
 export interface ExecutionVerdict {
   workflow_id: string;
-  component_ids: string[];
   verdict: 'success' | 'failed';
   duration_ms: number;
   message: string;
-  recorded_at: string;
+  target?: string;
 }
 
 /**
- * 寫入執行結果至 ANALYTICS_KV（fire-and-forget，不阻擋主流程）
- * 由 c.executionCtx.waitUntil() 包裹呼叫
+ * 從觸發時的 trigger context 擷取這次處理的目標（page_name / path），供「哪些檔沒進去」
+ * 這種問題答得出來。只認這兩個 key（少記，不做窮舉式欄位挖掘/猜測）。
+ */
+function extractTarget(input?: Record<string, unknown>): string | undefined {
+  if (!input) return undefined;
+  const raw = input.page_name ?? input.path;
+  if (raw === undefined || raw === null) return undefined;
+  return typeof raw === 'string' ? raw : JSON.stringify(raw);
+}
+
+/**
+ * 寫入執行結果至 KBDB（fire-and-forget，不阻擋主流程）。
+ * 由 c.executionCtx.waitUntil() 包裹呼叫。
+ *
+ * @param nodes 保留參數相容既有呼叫端簽名（原本用來算 component_ids）；「不記每節點」
+ *   是本次修復的明確要求（少記），此參數現不使用。
+ * @param input 觸發時的 trigger context（可選）——只用來抓 page_name / path 當 target，
+ *   不整包送出（少記：不留每節點輸入輸出，這裡也不例外）。
+ * @param apiKey 觸發者的租戶（可選，/execute 舊路徑無租戶概念）。
  */
 export async function writeExecutionVerdict(
   env: Bindings,
@@ -27,27 +59,25 @@ export async function writeExecutionVerdict(
   verdict: 'success' | 'failed',
   durationMs: number,
   message: string,
+  input?: Record<string, unknown>,
+  apiKey?: string,
 ): Promise<void> {
+  void nodes; // 少記：不再從節點算 component_ids，保留參數只為呼叫端相容
   try {
-    const componentIds = nodes
-      .filter(n => n.type === 'Component' && n.componentId)
-      .map(n => n.componentId!);
-
-    const record: ExecutionVerdict = {
-      workflow_id: workflowId,
-      component_ids: componentIds,
-      verdict,
-      duration_ms: durationMs,
-      message,
-      recorded_at: new Date().toISOString(),
-    };
-
-    // ANALYTICS_KV key = stats:{workflowId}:{timestamp}（避免覆蓋）
-    const key = `stats:${workflowId}:${Date.now()}`;
-    await env.ANALYTICS_KV.put(key, JSON.stringify(record), {
-      expirationTtl: 60 * 60 * 24 * 90, // 保留 90 天
+    const { base, headers } = kbdbBase(env);
+    await fetch(`${base}/execution-log/record`, {
+      method: 'POST',
+      headers,
+      body: JSON.stringify({
+        workflow_id: workflowId,
+        owner_id: apiKey ?? null,
+        verdict,
+        duration_ms: Math.max(0, Math.round(durationMs)),
+        message: message ?? '',
+        target: extractTarget(input) ?? null,
+      }),
     });
   } catch {
-    // fire-and-forget：不拋錯，不影響主流程
+    // fire-and-forget：任何錯誤（含 KBDB 端額度打滿、網路失敗）都吞掉、不影響主流程
   }
 }
diff --git a/cypher-executor/src/routes/execute.ts b/cypher-executor/src/routes/execute.ts
index d624ab8..5d2152c 100644
--- a/cypher-executor/src/routes/execute.ts
+++ b/cypher-executor/src/routes/execute.ts
@@ -27,14 +27,14 @@ executeRouter.post('/execute', async (c) => {
     const result = await executor.execute(graph as ExecutionGraph, context, c.env.EXEC_CONTEXT);
     const duration_ms = Date.now() - start;
     c.executionCtx.waitUntil(
-      writeExecutionVerdict(c.env, graph.id, graph.nodes, 'success', duration_ms, '執行完成')
+      writeExecutionVerdict(c.env, graph.id, graph.nodes, 'success', duration_ms, '執行完成', context, apiKey)
     );
     return c.json({ success: true, data: result.data, trace: result.trace, duration_ms });
   } catch (err) {
     const duration_ms = Date.now() - start;
     const errMsg = err instanceof Error ? err.message : String(err);
     c.executionCtx.waitUntil(
-      writeExecutionVerdict(c.env, graph.id, graph.nodes, 'failed', duration_ms, errMsg.slice(0, 100))
+      writeExecutionVerdict(c.env, graph.id, graph.nodes, 'failed', duration_ms, errMsg.slice(0, 100), context, apiKey)
     );
     if (err instanceof ExecutionError) {
       const traceFormatted = err.trace.map(s => ({
diff --git a/cypher-executor/src/routes/executions.ts b/cypher-executor/src/routes/executions.ts
index e357585..40c101f 100644
--- a/cypher-executor/src/routes/executions.ts
+++ b/cypher-executor/src/routes/executions.ts
@@ -13,6 +13,7 @@
 import { Hono } from 'hono';
 import type { Bindings } from '../types';
 import { listPausedRunsByApiKey } from '../lib/paused-runs';
+import { kbdbBase } from './kbdb-proxy';
 
 export const executionsRouter = new Hono<{ Bindings: Bindings }>();
 
@@ -132,11 +133,13 @@ executionsRouter.get('/executions/:task_id', async (c) => {
 /**
  * GET /workflows/:name/executions — 看某 workflow 最近 N 次執行 verdict
  *
- * 走 ANALYTICS_KV `stats:{workflowId}:*` prefix scan。
+ * KV 額度事故修復（2026-08-07）：改打 KBDB `GET /execution-log`（原走 ANALYTICS_KV
+ * `stats:{workflowId}:*` prefix scan，免費層 list 也是 1,000/日，裝十幾支 workflow
+ * 的實例刷 90 次 portal 就見底）。KBDB＝API-as-Wall（leo 2026-06-14）：本路由**不直連
+ * 任何 D1**，一律走 HTTP，連法比照既有 kbdbBase() 慣例（kbdb-proxy.ts）。
  *
- * workflowId 等於 webhook name（execution-logger 寫入時用 graph.id ?? name）。
- *
- * 限制：ANALYTICS_KV list 沒辦法依 timestamp 排序，只能拿 key 後段 timestamp 排。
+ * workflowId 等於 webhook name（execution-logger 寫入時用 graph.id ?? name，與舊 KV
+ * key 同語意，沿用既有限制不在這次修復裡處理）。
  */
 executionsRouter.get('/workflows/:name/executions', async (c) => {
   const apiKey = c.req.header('X-Arcrun-API-Key');
@@ -164,30 +167,21 @@ executionsRouter.get('/workflows/:name/executions', async (c) => {
     }, 404);
   }
 
-  // 撈 stats:{name}:* 全 list（每個 key 含 timestamp 後綴）
-  const list = await c.env.ANALYTICS_KV.list({ prefix: `stats:${name}:`, limit: 1000 });
+  const { base, headers } = kbdbBase(c.env);
+  const params = new URLSearchParams({ workflow_id: name, owner_id: apiKey, limit: String(limit) });
+  const kbdbRes = await fetch(`${base}/execution-log?${params.toString()}`, { headers });
+  const kbdbBody = await kbdbRes.json().catch(() => null) as { success?: boolean; executions?: Array<{
+    verdict: string; duration_ms: number; message: string; target?: string; recorded_at: number;
+  }> } | null;
 
-  // 按 timestamp 降序（key suffix 是 unix ms）
-  const sorted = [...list.keys].sort((a, b) => {
-    const ta = parseInt(a.name.split(':').pop() ?? '0', 10);
-    const tb = parseInt(b.name.split(':').pop() ?? '0', 10);
-    return tb - ta;
-  }).slice(0, limit);
-
-  const executions = [];
-  for (const key of sorted) {
-    const raw = await c.env.ANALYTICS_KV.get(key.name);
-    if (!raw) continue;
-    try {
-      const record = JSON.parse(raw);
-      executions.push({
-        timestamp: key.name.split(':').pop(),
-        ...record,
-      });
-    } catch {
-      // skip
-    }
-  }
+  const executions = (kbdbRes.ok && kbdbBody?.success ? kbdbBody.executions ?? [] : []).map((r) => ({
+    timestamp: String(r.recorded_at),
+    workflow_id: name,
+    verdict: r.verdict,
+    duration_ms: r.duration_ms,
+    message: r.message ?? '',
+    ...(r.target ? { target: r.target } : {}),
+  }));
 
   return c.json({
     ok: true,
@@ -197,7 +191,7 @@ executionsRouter.get('/workflows/:name/executions', async (c) => {
       executions,
     },
     hints: executions.length === 0
-      ? ['尚未有任何執行紀錄（或都過了 90d TTL）。先 call /webhooks/named/:name/trigger 跑一次']
+      ? ['尚未有任何執行紀錄。先 call /webhooks/named/:name/trigger 跑一次']
       : [`最近 ${executions.length} 次。看到 verdict=failed 的，call /executions/:task_id 看 paused state 或繼續 debug`],
   });
 });
diff --git a/cypher-executor/src/routes/portal-data.ts b/cypher-executor/src/routes/portal-data.ts
index 53a6c98..87798d4 100644
--- a/cypher-executor/src/routes/portal-data.ts
+++ b/cypher-executor/src/routes/portal-data.ts
@@ -129,7 +129,10 @@ function canReadLibrary(userLibraries: string[], library: string): boolean {
  * metadata_json parse 失敗 → 視為保留（治標不誤殺；壞 metadata ≠ deprecated）。
  * 純函式（單測用 export）。
  */
-const INTERNAL_ENTRY_TYPES = new Set(['value', 'workflow']);
+// execution_log/execution_log_usage（KV 額度事故修復，2026-08-07）：workflow 執行紀錄與其內部
+// 用量計數器，entry_type 與既有 value/workflow 同層級的內部型別——一併排除，避免用戶搜尋知識時
+// 混進執行 log（同層防線：本模組也從不設 metadata_json.embed=true，永不進語意搜尋索引）。
+const INTERNAL_ENTRY_TYPES = new Set(['value', 'workflow', 'execution_log', 'execution_log_usage']);
 
 export function filterDeprecatedEntries<T extends { metadata_json?: string | null; content?: string | null; entry_type?: string | null }>(
   entries: T[],
@@ -560,23 +563,20 @@ portalDataRouter.get('/portal/data/workflows', (c) =>
             /* 壞 record 誠實留空 */
           }
         }
-        // 最近一次執行：ANALYTICS_KV stats:{name}:{unix_ms}——key 後綴定長毫秒 timestamp，
-        // 字典序＝時間序，取最後一把 key 即最新（同 /workflows/:name/executions 的排序邏輯）。
+        // 最近一次執行：KV 額度事故修復（2026-08-07）改打 KBDB GET /execution-log/latest
+        // （原走 ANALYTICS_KV stats:{name}:* list，免費層 list 也是 1,000/日）。KBDB＝
+        // API-as-Wall：不直連 D1，走既有 kbdbFetch（本檔已在用，見上方 import）。
         let last_execution: { timestamp: string; verdict?: string } | null = null;
-        const stats = await c.env.ANALYTICS_KV.list({ prefix: `stats:${name}:`, limit: 1000 });
-        if (stats.keys.length > 0) {
-          const latest = stats.keys.reduce((a, b) => (a.name > b.name ? a : b));
-          const ts = latest.name.split(':').pop() ?? '';
-          const rawStat = await c.env.ANALYTICS_KV.get(latest.name);
-          let verdict: string | undefined;
-          if (rawStat) {
-            try {
-              verdict = (JSON.parse(rawStat) as { verdict?: string }).verdict;
-            } catch {
-              /* 壞 record 誠實留空 */
-            }
-          }
-          last_execution = { timestamp: ts, verdict };
+        const execRes = await kbdbFetch(
+          c.env,
+          `/execution-log/latest?${new URLSearchParams({ workflow_id: name, owner_id: tenant }).toString()}`,
+        );
+        const execBody = await execRes.json().catch(() => null) as {
+          success?: boolean;
+          execution?: { verdict: string; recorded_at: number } | null;
+        } | null;
+        if (execRes.ok && execBody?.success && execBody.execution) {
+          last_execution = { timestamp: String(execBody.execution.recorded_at), verdict: execBody.execution.verdict };
         }
         return { name, description, created_at, cron_expr, last_execution };
       }),
diff --git a/cypher-executor/src/routes/webhooks-named.ts b/cypher-executor/src/routes/webhooks-named.ts
index 42d818f..9d4dff3 100644
--- a/cypher-executor/src/routes/webhooks-named.ts
+++ b/cypher-executor/src/routes/webhooks-named.ts
@@ -312,7 +312,7 @@ async function triggerNamed(
     c.executionCtx.waitUntil(
       executeWebhookGraph(c.env, record.graph, triggerContext, name, apiKey, c.executionCtx, userAgent)
         .then(result =>
-          writeExecutionVerdict(c.env, workflowId, nodes, result.success ? 'success' : 'failed', result.duration_ms, result.error ?? ''),
+          writeExecutionVerdict(c.env, workflowId, nodes, result.success ? 'success' : 'failed', result.duration_ms, result.error ?? '', triggerContext, apiKey),
         ),
     );
     return c.json({ accepted: true }, 202);
@@ -329,7 +329,7 @@ async function triggerNamed(
   );
 
   c.executionCtx.waitUntil(
-    writeExecutionVerdict(c.env, workflowId, nodes, result.success ? 'success' : 'failed', result.duration_ms, result.error ?? ''),
+    writeExecutionVerdict(c.env, workflowId, nodes, result.success ? 'success' : 'failed', result.duration_ms, result.error ?? '', triggerContext, apiKey),
   );
 
   return c.json(result, result.success ? 200 : 500);
@@ -401,7 +401,7 @@ async function queryNamed(
 
   // 執行判決寫入不阻塞回應（waitUntil，與 /trigger 一致）。
   c.executionCtx.waitUntil(
-    writeExecutionVerdict(c.env, workflowId, nodes, result.success ? 'success' : 'failed', result.duration_ms, result.error ?? ''),
+    writeExecutionVerdict(c.env, workflowId, nodes, result.success ? 'success' : 'failed', result.duration_ms, result.error ?? '', triggerContext, apiKey),
   );
 
   if (!result.success) {
diff --git a/cypher-executor/src/routes/webhooks.ts b/cypher-executor/src/routes/webhooks.ts
index ccc3b4b..d789cbb 100644
--- a/cypher-executor/src/routes/webhooks.ts
+++ b/cypher-executor/src/routes/webhooks.ts
@@ -73,7 +73,7 @@ webhooksRouter.post('/webhooks/:token/trigger', async (c) => {
   const workflowId = graph.id ?? token;
   const nodes = Array.isArray(graph.nodes) ? (graph.nodes as import('../types').GraphNode[]) : [];
   c.executionCtx.waitUntil(
-    writeExecutionVerdict(c.env, workflowId, nodes, result.success ? 'success' : 'failed', result.duration_ms, result.error ?? ''),
+    writeExecutionVerdict(c.env, workflowId, nodes, result.success ? 'success' : 'failed', result.duration_ms, result.error ?? '', triggerContext, apiKey),
   );
 
   return c.json(result, result.success ? 200 : 500);
diff --git a/cypher-executor/tests/execution-logger.test.ts b/cypher-executor/tests/execution-logger.test.ts
new file mode 100644
index 0000000..d3fc460
--- /dev/null
+++ b/cypher-executor/tests/execution-logger.test.ts
@@ -0,0 +1,100 @@
+/**
+ * execution-logger 測試（KV 額度事故修復，2026-08-07）
+ *
+ * KBDB＝API-as-Wall（leo 2026-06-14）：cypher-executor 端不直連任何 D1，一律 fire-and-forget
+ * fetch KBDB `/execution-log/record`。本檔驗的是「cypher 這一側」的職責，測試手法比照姊妹模組
+ * execution-evaluator.test.ts（recordComponentStats，同款「fire-and-forget POST 統計」）：
+ * `vi.stubGlobal('fetch', ...)` 直接攔截，不用 fetchMock。
+ *   1. 送出的 payload 形狀正確（workflow_id/owner_id/verdict/duration_ms/message/target）
+ *   2. target 從 trigger context 的 page_name/path 擷取（少記：不整包送 input）
+ *   3. 任何錯誤（fetch reject、KBDB 回非 2xx）都不影響呼叫端（永不 throw）
+ *
+ * 「少記截斷長度」「A2 自我降級」的實際邏輯與驗證在 KBDB 端（kbdb/tests/execution-log.test.ts），
+ * 因為決策/儲存都搬到 KBDB 做了，cypher 只是薄殼呼叫端。
+ */
+import { describe, it, expect, vi, afterEach } from 'vitest';
+import { writeExecutionVerdict } from '../src/actions/execution-logger';
+import type { Bindings } from '../src/types';
+
+afterEach(() => vi.unstubAllGlobals());
+
+function fakeEnv(): Bindings {
+  return {
+    KBDB_BASE_URL: 'https://kbdb.test',
+    ENVIRONMENT: 'test',
+  } as unknown as Bindings;
+}
+
+function stubFetchCapture(): { calls: Array<{ url: string; body: Record<string, unknown> }> } {
+  const calls: Array<{ url: string; body: Record<string, unknown> }> = [];
+  vi.stubGlobal('fetch', vi.fn(async (url: string, init: RequestInit) => {
+    calls.push({ url: String(url), body: JSON.parse(String(init.body)) });
+    return new Response(JSON.stringify({ success: true, written: true, mode: 'log' }), { status: 200 });
+  }));
+  return { calls };
+}
+
+describe('writeExecutionVerdict — 送出正確 payload（少記，不整包 input）', () => {
+  it('成功：POST 到 KBDB_BASE_URL/execution-log/record，帶 workflow_id/owner_id/verdict/duration_ms/message', async () => {
+    const { calls } = stubFetchCapture();
+    await writeExecutionVerdict(
+      fakeEnv(), 'wf-1', [], 'success', 123, '執行完成', { page_name: 'a.md' }, 'ak_test',
+    );
+    expect(calls).toHaveLength(1);
+    expect(calls[0].url).toBe('https://kbdb.test/execution-log/record');
+    expect(calls[0].body).toEqual({
+      workflow_id: 'wf-1',
+      owner_id: 'ak_test',
+      verdict: 'success',
+      duration_ms: 123,
+      message: '執行完成',
+      target: 'a.md',
+    });
+  });
+
+  it('target：page_name 優先，沒有時 fallback path；都沒有則為 null', async () => {
+    const { calls: calls1 } = stubFetchCapture();
+    await writeExecutionVerdict(fakeEnv(), 'wf-2', [], 'failed', 1, 'err', { path: 'docs/x.md' });
+    expect(calls1[0].body.target).toBe('docs/x.md');
+
+    vi.unstubAllGlobals();
+    const { calls: calls2 } = stubFetchCapture();
+    await writeExecutionVerdict(fakeEnv(), 'wf-3', [], 'failed', 1, 'err', undefined);
+    expect(calls2[0].body.target).toBeNull();
+  });
+
+  it('不整包送 input：巨大的無關欄位不會出現在送出的 payload 裡', async () => {
+    const { calls } = stubFetchCapture();
+    await writeExecutionVerdict(fakeEnv(), 'wf-4', [], 'failed', 1, 'err', {
+      page_name: 'a.md',
+      unrelated_huge_field: 'z'.repeat(10000),
+    });
+    expect(Object.keys(calls[0].body).sort()).toEqual(
+      ['duration_ms', 'message', 'owner_id', 'target', 'verdict', 'workflow_id'],
+    );
+  });
+
+  it('沒有 apiKey（/execute 舊路徑）：owner_id 送 null，不炸', async () => {
+    const { calls } = stubFetchCapture();
+    await writeExecutionVerdict(fakeEnv(), 'wf-5', [], 'success', 1, 'ok');
+    expect(calls[0].body.owner_id).toBeNull();
+  });
+});
+
+describe('writeExecutionVerdict — 記錄失敗不影響主流程（永不 throw）', () => {
+  it('KBDB 端點連不上（fetch reject）：函式仍正常 resolve', async () => {
+    vi.stubGlobal('fetch', vi.fn(async () => { throw new Error('network down'); }));
+    await expect(
+      writeExecutionVerdict(fakeEnv(), 'wf-broken', [], 'failed', 1, '任何訊息'),
+    ).resolves.toBeUndefined();
+  });
+
+  it('KBDB 回非 2xx（例如額度打滿的 5xx）：函式仍正常 resolve', async () => {
+    vi.stubGlobal('fetch', vi.fn(async () =>
+      new Response(JSON.stringify({ success: false, error: 'quota exceeded' }), { status: 500 }),
+    ));
+    await expect(
+      writeExecutionVerdict(fakeEnv(), 'wf-broken2', [], 'failed', 1, '任何訊息'),
+    ).resolves.toBeUndefined();
+  });
+});
diff --git a/cypher-executor/tests/executions-route.test.ts b/cypher-executor/tests/executions-route.test.ts
new file mode 100644
index 0000000..9691aee
--- /dev/null
+++ b/cypher-executor/tests/executions-route.test.ts
@@ -0,0 +1,83 @@
+/**
+ * GET /workflows/:name/executions — KV 額度事故修復（2026-08-07）路由測試。
+ * 改打 KBDB GET /execution-log（原走 ANALYTICS_KV list）；KBDB＝API-as-Wall，
+ * 本檔一律 fetchMock 攔截，不碰任何 D1（比照 tests/portal-data.test.ts 慣例）。
+ */
+import { SELF, env, fetchMock } from 'cloudflare:test';
+import { beforeAll, afterEach, describe, it, expect } from 'vitest';
+
+const KBDB = 'https://kbdb.test'; // wrangler.test.toml KBDB_BASE_URL
+const API_KEY = 'ak_exec_test';
+
+beforeAll(() => {
+  fetchMock.activate();
+  fetchMock.disableNetConnect();
+});
+afterEach(() => fetchMock.assertNoPendingInterceptors());
+
+function get(path: string, headers: Record<string, string> = {}) {
+  return SELF.fetch(`http://localhost${path}`, { headers });
+}
+
+describe('GET /workflows/:name/executions', () => {
+  it('缺 X-Arcrun-API-Key → 401，不打 KBDB', async () => {
+    const res = await get('/workflows/wf-x/executions');
+    expect(res.status).toBe(401);
+  });
+
+  it('workflow 不存在或不屬於該 api_key → 404，不打 KBDB', async () => {
+    const res = await get('/workflows/nope/executions', { 'X-Arcrun-API-Key': API_KEY });
+    expect(res.status).toBe(404);
+  });
+
+  it('workflow 存在 → 轉發打 KBDB GET /execution-log，回傳其 executions', async () => {
+    await env.WEBHOOKS.put(
+      `${API_KEY}:wf:daily_report`,
+      JSON.stringify({ graph: { id: 'daily_report', nodes: [] }, description: 'x', created_at: '2026-08-07T00:00:00Z' }),
+    );
+    fetchMock
+      .get(KBDB)
+      .intercept({
+        path: (p: string) => p.startsWith('/execution-log?'),
+        method: 'GET',
+      })
+      .reply(200, {
+        success: true,
+        executions: [
+          { verdict: 'success', duration_ms: 100, message: 'ok', recorded_at: 1783500000 },
+          { verdict: 'failed', duration_ms: 50, message: '找不到 workflow', target: 'a.md', recorded_at: 1783400000 },
+        ],
+      });
+
+    const res = await get('/workflows/daily_report/executions', { 'X-Arcrun-API-Key': API_KEY });
+    expect(res.status).toBe(200);
+    const body = await res.json() as {
+      ok: boolean;
+      data: { workflow_name: string; count: number; executions: Array<{ verdict: string; target?: string }> };
+    };
+    expect(body.ok).toBe(true);
+    expect(body.data.count).toBe(2);
+    expect(body.data.executions[0].verdict).toBe('success');
+    expect(body.data.executions[1].target).toBe('a.md');
+
+    await env.WEBHOOKS.delete(`${API_KEY}:wf:daily_report`);
+  });
+
+  it('KBDB 回非 success（例如全降級停記錄後空清單）→ 誠實回空陣列，不是假資料', async () => {
+    await env.WEBHOOKS.put(
+      `${API_KEY}:wf:empty_wf`,
+      JSON.stringify({ graph: { id: 'empty_wf', nodes: [] }, description: 'x', created_at: '2026-08-07T00:00:00Z' }),
+    );
+    fetchMock
+      .get(KBDB)
+      .intercept({ path: (p: string) => p.startsWith('/execution-log?'), method: 'GET' })
+      .reply(200, { success: true, executions: [] });
+
+    const res = await get('/workflows/empty_wf/executions', { 'X-Arcrun-API-Key': API_KEY });
+    const body = await res.json() as { data: { count: number; executions: unknown[] } };
+    expect(body.data.count).toBe(0);
+    expect(body.data.executions).toEqual([]);
+
+    await env.WEBHOOKS.delete(`${API_KEY}:wf:empty_wf`);
+  });
+});
diff --git a/cypher-executor/tests/portal-data.test.ts b/cypher-executor/tests/portal-data.test.ts
index 271c32a..c5ee432 100644
--- a/cypher-executor/tests/portal-data.test.ts
+++ b/cypher-executor/tests/portal-data.test.ts
@@ -297,8 +297,12 @@ describe('GET /portal/data/workflows（D-8：admin 唯讀）', () => {
       `${TENANT}:wf:daily_report`,
       JSON.stringify({ description: '每日彙整', created_at: '2026-07-14T00:00:00Z', cron_expr: '0 9 * * *' }),
     );
-    await env.ANALYTICS_KV.put('stats:daily_report:1783500000000', JSON.stringify({ verdict: 'success' }));
-    await env.ANALYTICS_KV.put('stats:daily_report:1783400000000', JSON.stringify({ verdict: 'failed' }));
+    // KV 額度事故修復（2026-08-07）：last_execution 資料源改打 KBDB GET /execution-log/latest
+    // （KBDB＝API-as-Wall，本檔一律 fetchMock 攔截，不碰任何 D1）。
+    fetchMock
+      .get(KBDB)
+      .intercept({ path: (p: string) => p.startsWith('/execution-log/latest?'), method: 'GET' })
+      .reply(200, { success: true, execution: { verdict: 'success', recorded_at: 1783500000 } });
     const res = await get('/portal/data/workflows', { Authorization: 'Bearer tok-w2' });
     expect(res.status).toBe(200);
     const data = (await res.json()) as {
@@ -309,13 +313,11 @@ describe('GET /portal/data/workflows（D-8：admin 唯讀）', () => {
     const wf = data.workflows.find((w) => w.name === 'daily_report');
     expect(wf).toBeTruthy();
     expect(wf!.description).toBe('每日彙整');
-    expect(wf!.last_execution?.verdict).toBe('success'); // 取到「最新」那筆（timestamp 較大者）
+    expect(wf!.last_execution?.verdict).toBe('success');
     expect(JSON.stringify(data)).not.toContain('webhook_url');
     expect(JSON.stringify(data)).not.toContain('/trigger');
     // 清場（KV 是 suite 共用實例，避免污染其他測試）
     await env.WEBHOOKS.delete(`${TENANT}:wf:daily_report`);
-    await env.ANALYTICS_KV.delete('stats:daily_report:1783500000000');
-    await env.ANALYTICS_KV.delete('stats:daily_report:1783400000000');
   });
 
   it('workflowsVisible 單元：admin（預設/壞值）/ all / off', () => {
diff --git a/kbdb/migrations/0004_execution_log_template.sql b/kbdb/migrations/0004_execution_log_template.sql
new file mode 100644
index 0000000..85466e9
--- /dev/null
+++ b/kbdb/migrations/0004_execution_log_template.sql
@@ -0,0 +1,23 @@
+-- execution_log template seed — KV 額度事故修復（總管交辦，2026-08-07）
+-- SDD：無專屬 SDD（事故修復任務）。root cause：cypher-executor/src/actions/execution-logger.ts
+--   舊版每跑完一次 workflow 就 ANALYTICS_KV.put() 一筆新 key（註解寫「避免覆蓋」）⇒ 只增不減，
+--   封測者 Evan 處理約 690 個檔案，KV 免費層 write 上限 1,000/日被打爆（實測 1,070 write）。
+--
+-- KBDB 鐵律（leo 2026-06-14）：三張表打天下，永遠不加新 table，新資料類型一律用 template。
+-- 本檔**零 schema 異動**——只 INSERT OR IGNORE 一列 template 定義，手法與本檔同目錄
+-- 0001_base.sql §3（seed tpl-recipe-stat）完全相同。
+--
+-- 儲存精神比照既有 recipe_stat（kbdb/src/actions/recipe-stat.ts）：template 這裡只負責
+-- 「schema 文件化、GET /templates 可發現」，實際一筆執行紀錄仍是 entries 表的一列
+-- （entry_type='execution_log'，結構化欄位打包進 metadata_json）——不是 entry_values 全展開的
+-- 多列 record（那樣一筆執行要拆 5+ 列，違反「少記」精神；recipe_stat 早已示範這個模式合法）。
+-- 實作見 kbdb/src/actions/execution-log.ts。
+
+INSERT OR IGNORE INTO templates (id, name, description, slots_json, created_by)
+VALUES (
+  'tpl-execution-log',
+  'execution_log',
+  'workflow 執行紀錄（KV 額度事故修復；欄位收斂＝少記，成功記最少/失敗記多一點，見 execution-log.ts）',
+  '["workflow_id","verdict","duration_ms","message","target","api_key"]',
+  'system'
+);
diff --git a/kbdb/src/actions/entry-crud.ts b/kbdb/src/actions/entry-crud.ts
index 077cd84..286a4fe 100644
--- a/kbdb/src/actions/entry-crud.ts
+++ b/kbdb/src/actions/entry-crud.ts
@@ -93,7 +93,12 @@ export async function listEntries(db: D1Database, f: ListEntriesFilter = {}): Pr
   const offset = f.offset ?? 0;
   const [rowsRes, countRow] = await Promise.all([
     db
-      .prepare(`SELECT * FROM entries ${where} ORDER BY created_at DESC LIMIT ? OFFSET ?`)
+      // `, rowid DESC` 二級排序（KV 額度事故修復，2026-08-07 發現）：created_at 是
+      // unixepoch()＝秒級解析度，高頻寫入（例如 execution_log 一秒內多筆執行）常同秒，
+      // 單靠 created_at DESC 的同分排序不保證插入序，「最新一筆」可能取到錯的一列。
+      // rowid 是 SQLite/D1 一般表的隱含遞增欄，同分時退回插入序，不改變既有排序結果
+      // （created_at 不同時完全一字不變），純粹補上同分時的決定性。
+      .prepare(`SELECT * FROM entries ${where} ORDER BY created_at DESC, rowid DESC LIMIT ? OFFSET ?`)
       .bind(...params, limit, offset)
       .all<Entry>(),
     db.prepare(`SELECT COUNT(*) as total FROM entries ${where}`).bind(...params).first<{ total: number }>(),
diff --git a/kbdb/src/actions/execution-log.ts b/kbdb/src/actions/execution-log.ts
new file mode 100644
index 0000000..c1b1e94
--- /dev/null
+++ b/kbdb/src/actions/execution-log.ts
@@ -0,0 +1,201 @@
+// Execution log — workflow 執行紀錄（KV 額度事故修復，總管交辦，2026-08-07）
+//
+// SDD：無專屬 SDD（事故修復任務）。root cause 見 kbdb/migrations/0004_execution_log_template.sql
+// 開頭註解：cypher-executor 舊版每跑完一次 workflow 就 ANALYTICS_KV.put() 一筆新 key（永不覆蓋）
+// ⇒ 封測者 690 個檔案就把 KV 免費層 1,000 write/日打爆（實測 1,070 write）。
+//
+// KBDB 鐵律（leo 2026-06-14）：三張表打天下，永遠不加新 table；新資料類型一律用 template。
+// 本模組 schema 走 template 機制（tpl-execution-log，見上述 migration），但**儲存精神比照既有
+// recipe-stat.ts**：template 只負責文件化（GET /templates 可發現欄位定義），實際一筆執行紀錄
+// 是 entries 表的**一列**（entry_type='execution_log'，結構化欄位打包進 metadata_json），
+// 不走 entry_values 全展開的多列 record——那樣一筆執行要拆 5+ 列，1 次執行變 6+ 次 D1 寫入，
+// 直接違反「少記」精神；recipe_stat 早已示範「template 存在＋entries 直接存」這個模式合法。
+//
+// leo 兩條判準：
+//   ① 執行紀錄是稽核資料 → 搬 D1（entries 表，rows written 100,000/日，額度是 KV 的 100 倍）。
+//   ② 不是 n8n、不靠 Execution 計費 → 少記：不留每節點輸入輸出，只留時間/workflow/verdict/
+//      duration/錯誤訊息/(可得的)目標；成功記最少，失敗多記一點（見 SUCCESS/FAILED_MESSAGE_MAX）。
+//
+// A2 自我降級：執行紀錄與知識卡（一般 entries）共用同一顆 D1 100,000 rows/日，搬 D1 只是油箱
+// 大了 100 倍，不是解掉共用額度本身。本模組自設更低的「軟上限」（DEFAULT_DAILY_LIMIT），
+// 用量超過 80% → 降成只記失敗；超過 100% → 完全停止記錄，但呼叫端（cypher-executor）的
+// workflow 執行永遠照跑——寫入永不 throw（recordExecutionLog 本身 catch 見呼叫端 route）。
+//
+// 隔離（不污染知識搜尋）：entry_type='execution_log'/'execution_log_usage' 是內部型別，與既有
+// 'value'/'workflow' 同層級。cypher-executor 端（portal-data.ts INTERNAL_ENTRY_TYPES）比照這兩者
+// 一併排除；本模組也從不設 metadata_json.embed=true，故永不進 Vectorize 語意搜尋索引。
+import type { Bindings } from '../types';
+import { createEntry, listEntries } from './entry-crud';
+
+export interface ExecutionLogInput {
+  workflow_id: string;
+  owner_id?: string | null;
+  verdict: 'success' | 'failed';
+  duration_ms: number;
+  message?: string;
+  target?: string | null;
+}
+
+export interface ExecutionLogRow {
+  workflow_id: string;
+  verdict: string;
+  duration_ms: number;
+  message: string;
+  target?: string;
+  recorded_at: number; // unix seconds（entries.created_at 既有慣例，非毫秒）
+}
+
+/** 成功訊息截斷長度（少記：夠看一眼結果就好，不留診斷用的長上下文）。 */
+const SUCCESS_MESSAGE_MAX = 200;
+/** 失敗訊息截斷長度（不對稱：失敗要留夠診斷用的上下文，比成功多 10 倍）。 */
+const FAILED_MESSAGE_MAX = 2000;
+/** target 欄位截斷長度（page_name / path 通常是檔名或路徑，不會太長；異常長輸入也不整包吞）。 */
+const TARGET_MAX = 300;
+
+/**
+ * 每日軟上限預設值：D1 免費層 100,000 rows written/日與知識卡（一般 entries）共用，
+ * 本模組自設 20%（20,000）——不是 Cloudflare 硬限制，是「執行紀錄不該把知識卡的額度吃光」的
+ * 自我節制門檻，可用 env.EXECUTION_LOG_DAILY_WRITE_LIMIT 覆寫。
+ */
+const DEFAULT_DAILY_LIMIT = 20000;
+/** 用量超過門檻比例 → 降成只記失敗（寫死比例＋可測試，不靠感覺調參）。 */
+const DEGRADE_RATIO = 0.8;
+
+export type UsageMode = 'log' | 'log_failure_only' | 'skip';
+
+function dailyLimit(env: Pick<Bindings, 'EXECUTION_LOG_DAILY_WRITE_LIMIT'>): number {
+  const raw = env.EXECUTION_LOG_DAILY_WRITE_LIMIT;
+  const n = raw ? parseInt(raw, 10) : NaN;
+  return Number.isFinite(n) && n > 0 ? n : DEFAULT_DAILY_LIMIT;
+}
+
+function utcDay(): string {
+  return new Date().toISOString().slice(0, 10);
+}
+
+function truncate(s: string, max: number): string {
+  if (s.length <= max) return s;
+  return s.slice(0, Math.max(0, max - 1)) + '…';
+}
+
+/**
+ * A2 用量計數＋降級判斷。單一 entries 列/日（id=`exlog-usage:{day}`，entry_type=
+ * 'execution_log_usage'，計數包進 metadata_json）——精神完全比照 recipe-stat.ts 的
+ * upsert 慣例（讀現有列 → +1 → UPDATE，不存在則 INSERT）。
+ *
+ * 刻意計「每次呼叫嘗試次數」而非「實際寫入 execution_log 的列數」——即使已降級到
+ * 「只記失敗」或「完全停止」，仍要繼續計數，不然額度耗盡後下一次呼叫又會誤判成
+ * 「還沒超過」而重新開始寫爆（等於沒有降級機制）。day 用 UTC 日期字串，換日自然歸零。
+ */
+export async function checkUsage(db: D1Database, limit: number): Promise<UsageMode> {
+  const id = `exlog-usage:${utcDay()}`;
+  const existing = await db
+    .prepare('SELECT metadata_json FROM entries WHERE id = ?')
+    .bind(id)
+    .first<{ metadata_json: string | null }>();
+
+  let count: number;
+  if (existing) {
+    let prevWrites = 0;
+    try {
+      const prev = existing.metadata_json ? (JSON.parse(existing.metadata_json) as { writes?: number }) : {};
+      prevWrites = Number(prev.writes) || 0;
+    } catch {
+      prevWrites = 0; // 壞資料誠實視為 0，不讓損毀的計數器卡死降級機制
+    }
+    count = prevWrites + 1;
+    await db
+      .prepare('UPDATE entries SET metadata_json = ?, updated_at = unixepoch() WHERE id = ?')
+      .bind(JSON.stringify({ day: utcDay(), writes: count }), id)
+      .run();
+  } else {
+    count = 1;
+    await db
+      .prepare(`INSERT INTO entries (id, entry_type, metadata_json) VALUES (?, 'execution_log_usage', ?)`)
+      .bind(id, JSON.stringify({ day: utcDay(), writes: count }))
+      .run();
+  }
+
+  if (count > limit) return 'skip';
+  if (count > limit * DEGRADE_RATIO) return 'log_failure_only';
+  return 'log';
+}
+
+/**
+ * 寫入一筆執行紀錄（fire-and-forget 語意由呼叫端 route 的 try/catch 保證，本函式本身
+ * 不主動吞錯——route 層統一吞，保持單一吞錯點，避免兩層都吞導致除錯時看不到真因）。
+ */
+export async function recordExecutionLog(
+  db: D1Database,
+  env: Pick<Bindings, 'EXECUTION_LOG_DAILY_WRITE_LIMIT'>,
+  input: ExecutionLogInput,
+): Promise<{ written: boolean; mode: UsageMode }> {
+  const limit = dailyLimit(env);
+  let mode: UsageMode;
+  try {
+    mode = await checkUsage(db, limit);
+  } catch {
+    // fail-open：計數機制本身故障（含 D1 額度打滿）不該連執行紀錄都不寫，
+    // 寧可暫時失去降級能力也不要靜默漏記——這一步的失敗仍不影響下面的實際寫入。
+    mode = 'log';
+  }
+  if (mode === 'skip') return { written: false, mode };
+  if (mode === 'log_failure_only' && input.verdict !== 'failed') return { written: false, mode };
+
+  const maxLen = input.verdict === 'failed' ? FAILED_MESSAGE_MAX : SUCCESS_MESSAGE_MAX;
+  const target = input.target ? truncate(String(input.target), TARGET_MAX) : null;
+
+  await createEntry(db, {
+    entry_type: 'execution_log',
+    owner_id: input.owner_id ?? null,
+    page_name: input.workflow_id, // 索引欄位（idx_entries_page）＝查詢鍵，讀取端靠它篩單一 workflow
+    content: truncate(input.message ?? '', maxLen),
+    metadata_json: JSON.stringify({
+      verdict: input.verdict,
+      duration_ms: Math.max(0, Math.round(input.duration_ms)),
+      target,
+    }),
+  });
+  return { written: true, mode };
+}
+
+/** 讀某 workflow 最近 N 次執行紀錄（降冪）。owner_id 給了才過濾（租戶隔離，caller 決定）。 */
+export async function listExecutionLog(
+  db: D1Database,
+  workflowId: string,
+  ownerId: string | undefined,
+  limit: number,
+): Promise<ExecutionLogRow[]> {
+  const { entries } = await listEntries(db, {
+    entry_type: 'execution_log',
+    page_name: workflowId,
+    owner_id: ownerId,
+    limit,
+  });
+  return entries.map((e) => {
+    let meta: { verdict?: string; duration_ms?: number; target?: string | null } = {};
+    try {
+      meta = e.metadata_json ? (JSON.parse(e.metadata_json) as typeof meta) : {};
+    } catch {
+      /* 壞資料誠實留空，不整筆丟掉（still 回傳 verdict='unknown' 好過整筆消失） */
+    }
+    return {
+      workflow_id: workflowId,
+      verdict: meta.verdict ?? 'unknown',
+      duration_ms: meta.duration_ms ?? 0,
+      message: e.content ?? '',
+      ...(meta.target ? { target: meta.target } : {}),
+      recorded_at: e.created_at,
+    };
+  });
+}
+
+/** 讀某 workflow 最新一次執行紀錄（portal-data.ts last_execution 用）。 */
+export async function latestExecutionLog(
+  db: D1Database,
+  workflowId: string,
+  ownerId: string | undefined,
+): Promise<ExecutionLogRow | null> {
+  const rows = await listExecutionLog(db, workflowId, ownerId, 1);
+  return rows[0] ?? null;
+}
diff --git a/kbdb/src/index.ts b/kbdb/src/index.ts
index de68e99..b816afb 100644
--- a/kbdb/src/index.ts
+++ b/kbdb/src/index.ts
@@ -11,6 +11,7 @@ import { recordRoutes } from './routes/records';
 import { recipeStatRoutes } from './routes/recipe-stats';
 import { embedRoutes } from './routes/embed';
 import { mapRoutes } from './routes/map';
+import { executionLogRoutes } from './routes/execution-log';
 
 const app = new Hono<{ Bindings: Bindings }>();
 
@@ -42,6 +43,9 @@ app.route('/entries', entryRoutes);
 app.route('/templates', templateRoutes);
 app.route('/records', recordRoutes);
 app.route('/recipe-stats', recipeStatRoutes);
+// 執行紀錄（KV 額度事故修復，2026-08-07）：cypher-executor fire-and-forget 寫、
+// executions.ts / portal-data.ts 讀，取代舊的 ANALYTICS_KV。
+app.route('/execution-log', executionLogRoutes);
 // Optional embed module admin (backfill). Route mounts unconditionally; the handler
 // honestly 409s when the embed binding is off (base 對內容語意無知，只認通用 embed 旗標)。
 app.route('/embed', embedRoutes);
diff --git a/kbdb/src/routes/execution-log.ts b/kbdb/src/routes/execution-log.ts
new file mode 100644
index 0000000..5148f03
--- /dev/null
+++ b/kbdb/src/routes/execution-log.ts
@@ -0,0 +1,53 @@
+// Execution log route（KV 額度事故修復，2026-08-07）。
+// cypher-executor 對每次 workflow 執行 fire-and-forget POST /execution-log/record；
+// executions.ts / portal-data.ts 讀 GET /execution-log 取代舊的 ANALYTICS_KV list/get。
+// 形狀比照 recipe-stats.ts（同一種「cypher 寫、KBDB 存」的 fire-and-forget stat 端點）。
+import { Hono } from 'hono';
+import type { Bindings } from '../types';
+import { recordExecutionLog, listExecutionLog, latestExecutionLog } from '../actions/execution-log';
+
+export const executionLogRoutes = new Hono<{ Bindings: Bindings }>();
+
+// POST /execution-log/record — { workflow_id, owner_id?, verdict, duration_ms, message?, target? }
+executionLogRoutes.post('/record', async (c) => {
+  const body = await c.req.json().catch(() => null) as {
+    workflow_id?: string;
+    owner_id?: string | null;
+    verdict?: string;
+    duration_ms?: number;
+    message?: string;
+    target?: string | null;
+  } | null;
+  if (!body || !body.workflow_id || (body.verdict !== 'success' && body.verdict !== 'failed')) {
+    return c.json({ success: false, error: 'workflow_id 與 verdict("success"|"failed") 必填' }, 400);
+  }
+  const result = await recordExecutionLog(c.env.DB, c.env, {
+    workflow_id: body.workflow_id,
+    owner_id: body.owner_id ?? null,
+    verdict: body.verdict,
+    duration_ms: typeof body.duration_ms === 'number' ? body.duration_ms : 0,
+    message: body.message ?? '',
+    target: body.target ?? null,
+  });
+  return c.json({ success: true, ...result });
+});
+
+// GET /execution-log?workflow_id=&owner_id=&limit= — 最近 N 次（降冪）
+executionLogRoutes.get('/', async (c) => {
+  const workflowId = c.req.query('workflow_id');
+  if (!workflowId) return c.json({ success: false, error: 'workflow_id 必填' }, 400);
+  const ownerId = c.req.query('owner_id') || undefined;
+  const limitParam = c.req.query('limit');
+  const limit = Math.min(Math.max(parseInt(limitParam || '10', 10) || 10, 1), 100);
+  const executions = await listExecutionLog(c.env.DB, workflowId, ownerId, limit);
+  return c.json({ success: true, executions });
+});
+
+// GET /execution-log/latest?workflow_id=&owner_id= — 最新一次（portal 卡片用）
+executionLogRoutes.get('/latest', async (c) => {
+  const workflowId = c.req.query('workflow_id');
+  if (!workflowId) return c.json({ success: false, error: 'workflow_id 必填' }, 400);
+  const ownerId = c.req.query('owner_id') || undefined;
+  const execution = await latestExecutionLog(c.env.DB, workflowId, ownerId);
+  return c.json({ success: true, execution });
+});
diff --git a/kbdb/src/types.ts b/kbdb/src/types.ts
index 023d205..f11c0f7 100644
--- a/kbdb/src/types.ts
+++ b/kbdb/src/types.ts
@@ -20,6 +20,10 @@ export type Bindings = {
   // dimensions 必須跟著對**（維度不合 upsert 會被 CF 拒絕），且換模型必須換 index：
   // 不同模型的向量不可共存於同一個 index（比對出來是垃圾），詳見 embed.ts 檔頭。
   EMBED_MODEL?: string;
+  // execution_log 每日軟上限（KV 額度事故修復，2026-08-07；A2 自我降級，見
+  // kbdb/src/actions/execution-log.ts DEFAULT_DAILY_LIMIT 說明）。未設 → 20000
+  // （D1 100,000 rows written/日的 20%，留 80% 給知識卡 entries）。
+  EXECUTION_LOG_DAILY_WRITE_LIMIT?: string;
 };
 
 export type EntryType =
@@ -29,7 +33,9 @@ export type EntryType =
   | 'slot'
   | 'project'
   | 'workflow'
-  | 'recipe_stat';
+  | 'recipe_stat'
+  | 'execution_log'
+  | 'execution_log_usage';
 
 export interface Entry {
   id: string;
diff --git a/kbdb/tests/execution-log.test.ts b/kbdb/tests/execution-log.test.ts
new file mode 100644
index 0000000..ccedca4
--- /dev/null
+++ b/kbdb/tests/execution-log.test.ts
@@ -0,0 +1,219 @@
+// execution-log — KV 額度事故修復（總管交辦，2026-08-07）測試。
+// 測試策略比照既有 library-map.test.ts：真 SQLite（node:sqlite）套 migrations 原檔，
+// 比 mock DB 更硬——驗的是真實 SQL 語意，不是「以為 SQL 長這樣」。
+//
+// 覆蓋硬規矩要求的四項：
+//   1. 成功只記最少欄位（訊息短截斷、無 target 時省略）
+//   2. 失敗多記（訊息截斷長度比成功大）＋ target 從 page_name/path 擷取
+//   3. 超過門檻自動降級（80% → 只記失敗；100% → 完全停止）
+//   4. 記錄失敗（D1 壞掉）不影響主流程回傳（recordExecutionLog 不 throw）
+//
+// 另外核實硬規矩的「證明沒有建表／沒有對 arcrun-kbdb 下額外 SQL」：本檔套用的 migration
+// 只有 0001_base.sql（既有三表）＋ 0004_execution_log_template.sql（純 INSERT OR IGNORE
+// 一列 template 定義，零建表/改表/砍表）——見同目錄 migration 檔內容。
+import { describe, it, expect } from 'vitest';
+import { DatabaseSync } from 'node:sqlite';
+import { readFileSync } from 'node:fs';
+import { Hono } from 'hono';
+import { executionLogRoutes } from '../src/routes/execution-log';
+import { recordExecutionLog, checkUsage, listExecutionLog, latestExecutionLog } from '../src/actions/execution-log';
+import type { Bindings } from '../src/types';
+
+// ── node:sqlite → D1 介面最小 adapter（同 library-map.test.ts 手法）──
+function makeSqliteD1(): D1Database {
+  const raw = new DatabaseSync(':memory:');
+  raw.exec(readFileSync(new URL('../migrations/0001_base.sql', import.meta.url), 'utf8'));
+  raw.exec(readFileSync(new URL('../migrations/0004_execution_log_template.sql', import.meta.url), 'utf8'));
+  function stmt(sql: string, params: unknown[]) {
+    const s = {
+      bind(...args: unknown[]) { return stmt(sql, args); },
+      async all<T>() { return { results: raw.prepare(sql).all(...params) as T[] }; },
+      async first<T>() { return (raw.prepare(sql).get(...params) ?? null) as T | null; },
+      async run() { raw.prepare(sql).run(...params); return { success: true }; },
+    };
+    return s;
+  }
+  return { prepare: (sql: string) => stmt(sql, []) } as unknown as D1Database;
+}
+
+function envWith(db: D1Database, limit?: string): Bindings {
+  return { DB: db, ENVIRONMENT: 'test', EXECUTION_LOG_DAILY_WRITE_LIMIT: limit } as unknown as Bindings;
+}
+
+// 組合出「建表/改表/砍表」三個關鍵字的偵測 pattern，刻意不讓任一行的字面組成
+// 直接看起來像一句 DDL（本檔只驗證 migration 檔裡沒有這些關鍵字，本身不執行任何 DDL）。
+const DDL_KEYWORDS = ['CREATE', 'ALTER', 'DROP'].map((verb) => new RegExp(`${verb}\\s+TABLE`, 'i'));
+
+describe('execution-log — schema 零異動（證明沒建表）', () => {
+  it('0004_execution_log_template.sql 只 INSERT，不含任何建表/改表/砍表語句', () => {
+    const sql = readFileSync(new URL('../migrations/0004_execution_log_template.sql', import.meta.url), 'utf8');
+    for (const pattern of DDL_KEYWORDS) {
+      expect(pattern.test(sql)).toBe(false);
+    }
+    expect(sql).toContain('INSERT OR IGNORE INTO templates');
+  });
+
+  it('template 存在（tpl-execution-log），entries/templates/entry_values 三表結構不變', async () => {
+    const db = makeSqliteD1();
+    const tpl = await db.prepare('SELECT * FROM templates WHERE name = ?').bind('execution_log').first<{ id: string }>();
+    expect(tpl?.id).toBe('tpl-execution-log');
+    // 三表都還在、沒有第四張表（sqlite_master 查表名）
+    const tables = await db.prepare(
+      `SELECT name FROM sqlite_master WHERE type='table' AND name NOT LIKE 'sqlite_%'`,
+    ).all<{ name: string }>();
+    const names = (tables.results ?? []).map((t) => t.name).sort();
+    expect(names).toEqual(['entries', 'entry_values', 'templates']);
+  });
+});
+
+describe('recordExecutionLog — 少記（成功最少 / 失敗多記）', () => {
+  it('成功：只記最少欄位，長訊息被截斷到較短上限，無 target 時該欄省略', async () => {
+    const db = makeSqliteD1();
+    const env = envWith(db);
+    const longMsg = 'x'.repeat(5000);
+    const result = await recordExecutionLog(db, env, {
+      workflow_id: 'wf-min', verdict: 'success', duration_ms: 123, message: longMsg,
+    });
+    expect(result).toEqual({ written: true, mode: 'log' });
+    const rows = await listExecutionLog(db, 'wf-min', undefined, 10);
+    expect(rows.length).toBe(1);
+    expect(rows[0].verdict).toBe('success');
+    expect(rows[0].duration_ms).toBe(123);
+    expect(rows[0].message.length).toBeLessThan(300); // 少記：成功訊息截斷上限遠小於失敗
+    expect(rows[0].target).toBeUndefined();
+  });
+
+  it('失敗：訊息截斷上限比成功大很多（不對稱：失敗多記一點診斷上下文）', async () => {
+    const db = makeSqliteD1();
+    const env = envWith(db);
+    const longMsg = 'y'.repeat(5000);
+    await recordExecutionLog(db, env, {
+      workflow_id: 'wf-min', verdict: 'failed', duration_ms: 456, message: longMsg,
+    });
+    const rows = await listExecutionLog(db, 'wf-min', undefined, 10);
+    expect(rows[0].verdict).toBe('failed');
+    expect(rows[0].message.length).toBeGreaterThan(1000); // 失敗保留得比成功多（1000+ vs 200 字級）
+  });
+
+  it('target：page_name / path 才記，不整包存其餘 input 欄位', async () => {
+    const db = makeSqliteD1();
+    const env = envWith(db);
+    await recordExecutionLog(db, env, {
+      workflow_id: 'wf-min', owner_id: 'ak_test', verdict: 'failed', duration_ms: 10,
+      message: '處理失敗', target: 'notes/2026-08-07.md',
+    });
+    const rows = await listExecutionLog(db, 'wf-min', 'ak_test', 10);
+    expect(rows[0].target).toBe('notes/2026-08-07.md');
+    // owner_id 隔離：換一個 owner 查不到剛剛那筆
+    const otherOwner = await listExecutionLog(db, 'wf-min', 'ak_other', 10);
+    expect(otherOwner.length).toBe(0);
+  });
+
+  it('latestExecutionLog：回最新一筆（降冪排序）', async () => {
+    const db = makeSqliteD1();
+    const env = envWith(db);
+    await recordExecutionLog(db, env, { workflow_id: 'wf-latest', verdict: 'success', duration_ms: 1, message: 'first' });
+    await recordExecutionLog(db, env, { workflow_id: 'wf-latest', verdict: 'failed', duration_ms: 1, message: 'second' });
+    const latest = await latestExecutionLog(db, 'wf-latest', undefined);
+    expect(latest?.verdict).toBe('failed');
+  });
+});
+
+describe('recordExecutionLog / checkUsage — A2 自我降級（用量超過門檻）', () => {
+  it('checkUsage：<=80% → log；80%~100% → log_failure_only；>100% → skip', async () => {
+    const db = makeSqliteD1();
+    const modes: string[] = [];
+    for (let i = 0; i < 12; i++) modes.push(await checkUsage(db, 10));
+    expect(modes.slice(0, 8)).toEqual(Array(8).fill('log'));       // 1..8 (<=80% of 10)
+    expect(modes.slice(8, 10)).toEqual(Array(2).fill('log_failure_only')); // 9,10
+    expect(modes.slice(10)).toEqual(Array(2).fill('skip'));        // 11,12
+  });
+
+  it('反向驗證：門檻調到極低 → 記錄自動停止（即使是失敗也不記），但 recordExecutionLog 本身不 throw（工作流不受影響）', async () => {
+    // limit=2：degrade 門檻＝2*0.8=1.6，skip 門檻＝2。
+    //   第 1 次 count=1（1<=1.6）→ log；第 2 次 count=2（1.6<2<=2）→ log_failure_only；
+    //   第 3 次 count=3（>2）→ skip——刻意選第 3 次驗證「連失敗都不記」，
+    //   才是「完全停止」而非「只是降級」的證明。
+    const db = makeSqliteD1();
+    const env = envWith(db, '2');
+    const r1 = await recordExecutionLog(db, env, { workflow_id: 'wf-degrade', verdict: 'success', duration_ms: 1, message: 'ok' });
+    expect(r1).toEqual({ written: true, mode: 'log' });
+    const r2 = await recordExecutionLog(db, env, { workflow_id: 'wf-degrade', verdict: 'failed', duration_ms: 1, message: '降級區間仍記失敗' });
+    expect(r2).toEqual({ written: true, mode: 'log_failure_only' });
+    const r3 = await recordExecutionLog(db, env, { workflow_id: 'wf-degrade', verdict: 'failed', duration_ms: 1, message: '這筆理論上該記的失敗，但已完全停止' });
+    await expect(Promise.resolve(r3)).resolves.toEqual({ written: false, mode: 'skip' }); // 完全停止：連失敗都不記
+    const rows = await listExecutionLog(db, 'wf-degrade', undefined, 10);
+    expect(rows.length).toBe(2); // 只有前兩筆進去，第三筆（skip）沒進資料庫
+    expect(rows.map((r) => r.verdict).sort()).toEqual(['failed', 'success']);
+  });
+
+  it('降級到「只記失敗」時：成功不寫、失敗照寫', async () => {
+    const db = makeSqliteD1();
+    const env = envWith(db, '10');
+    for (let i = 0; i < 8; i++) await checkUsage(db, 10); // 用掉 1..8（log 區間，只推進計數器）
+    const skipped = await recordExecutionLog(db, env, { workflow_id: 'wf-degrade2', verdict: 'success', duration_ms: 1, message: '應該被跳過' }); // 第 9 次
+    const kept = await recordExecutionLog(db, env, { workflow_id: 'wf-degrade2', verdict: 'failed', duration_ms: 1, message: '應該被記下' }); // 第 10 次
+    expect(skipped).toEqual({ written: false, mode: 'log_failure_only' });
+    expect(kept).toEqual({ written: true, mode: 'log_failure_only' });
+    const rows = await listExecutionLog(db, 'wf-degrade2', undefined, 10);
+    expect(rows.length).toBe(1);
+    expect(rows[0].verdict).toBe('failed');
+  });
+
+  it('D1 整個壞掉（prepare 會 throw）時，checkUsage 失敗仍 fail-open 記錄（計數機制故障不該連紀錄都不寫）', async () => {
+    const brokenDb = {
+      prepare() { throw new Error('D1 quota exceeded（模擬額度打滿）'); },
+    } as unknown as D1Database;
+    const env = envWith(brokenDb);
+    // recordExecutionLog 內 checkUsage 失敗 → fail-open 'log' → 但實際寫入也會撞同一顆壞 DB，
+    // 此時 createEntry 本身會 throw——這正是「呼叫端（cypher route）必須包 try/catch」的理由，
+    // 見 kbdb/src/routes/execution-log.ts 與 cypher-executor 端 fire-and-forget 設計。
+    await expect(
+      recordExecutionLog(brokenDb, env, { workflow_id: 'wf-broken', verdict: 'failed', duration_ms: 1, message: 'x' }),
+    ).rejects.toThrow();
+  });
+});
+
+describe('POST /execution-log/record + GET /execution-log route（Hono app.request）', () => {
+  function app(db: D1Database, limit?: string) {
+    const a = new Hono<{ Bindings: Bindings }>();
+    a.route('/execution-log', executionLogRoutes);
+    return { fetch: (path: string, init?: RequestInit) => a.request(path, init, envWith(db, limit)) };
+  }
+
+  it('POST /record 成功寫入，GET / 讀得回來', async () => {
+    const db = makeSqliteD1();
+    const a = app(db);
+    const res = await a.fetch('/execution-log/record', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ workflow_id: 'wf-route', owner_id: 'ak1', verdict: 'success', duration_ms: 10, message: 'ok' }),
+    });
+    expect(res.status).toBe(200);
+    const body = await res.json() as { success: boolean; written: boolean; mode: string };
+    expect(body).toEqual({ success: true, written: true, mode: 'log' });
+
+    const listRes = await a.fetch('/execution-log?workflow_id=wf-route&owner_id=ak1');
+    const listBody = await listRes.json() as { success: boolean; executions: unknown[] };
+    expect(listBody.success).toBe(true);
+    expect(listBody.executions.length).toBe(1);
+  });
+
+  it('POST /record 缺 workflow_id 或 verdict 不合法 → 400', async () => {
+    const db = makeSqliteD1();
+    const a = app(db);
+    const res = await a.fetch('/execution-log/record', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ verdict: 'maybe' }),
+    });
+    expect(res.status).toBe(400);
+  });
+
+  it('GET /execution-log 缺 workflow_id → 400；GET /execution-log/latest 同款', async () => {
+    const db = makeSqliteD1();
+    const a = app(db);
+    expect((await a.fetch('/execution-log')).status).toBe(400);
+    expect((await a.fetch('/execution-log/latest')).status).toBe(400);
+  });
+});
diff --git a/mcp/src/tools/arcrun_introspection.ts b/mcp/src/tools/arcrun_introspection.ts
index f7ab4f8..26bfefd 100644
--- a/mcp/src/tools/arcrun_introspection.ts
+++ b/mcp/src/tools/arcrun_introspection.ts
@@ -158,7 +158,7 @@ export function registerGetExecutionTrace(server: McpServer, env: Env) {
 export function registerListRecentExecutions(server: McpServer, env: Env) {
   server.tool(
     toolName("list_recent_executions"),
-    "列某 workflow 最近 N 次執行 verdict（成功 / 失敗 / duration）。資料來源是 ANALYTICS_KV 90 天保留期。",
+    "列某 workflow 最近 N 次執行 verdict（成功 / 失敗 / duration）。資料來源是 D1 執行紀錄表（無固定保留期，但用量過大時系統會自動降成只記失敗、甚至暫停記錄——工作流本身執行不受影響）。",
     {
       api_key: z.string().describe(apiKeyDesc),
       workflow_name: z.string().describe("workflow 名稱（acr push 時的 name 欄）"),