diff --git a/registry/examples/km-wiki-ingest/drainer/README.md b/registry/examples/km-wiki-ingest/drainer/README.md
index d7d6a33..f5273cc 100644
--- a/registry/examples/km-wiki-ingest/drainer/README.md
+++ b/registry/examples/km-wiki-ingest/drainer/README.md
@@ -57,10 +57,13 @@ printf '%s' "$GITEA_TOKEN" | npx wrangler secret put GITEA_TOKEN
 - Secret：若設，同步 `GITEA_WEBHOOK_SECRET` secret（本 Worker 驗 `X-Gitea-Signature` HMAC-SHA256）
 - Gitea 的 ping event → Worker 回 `{ok:true,pong:true}`（測連通）
 
-## config（wrangler.toml [vars]）
+## config
 
-`REPO=Leo/notes REF=main OWNER=leo CARDS_ROOT=system-dev/wiki/cards BATCH_SIZE=2`
-`CODE_WORKER_URL / KBDB_URL / GRAPH_URL / GRAPH_KEY`（皆 leo21c live 服務）。
+- **vars**：`REPO=Leo/notes REF=main OWNER=leo CARDS_ROOT=system-dev/wiki/cards GRAPH_KEY=leo BATCH_SIZE=2`
+- **Service Bindings（`[[services]]`）**：`SVC_CODE→arcrun-code`、`SVC_KBDB→arcrun-kbdb`、`SVC_GRAPH→kbdb-graph-plugin`。
+  ⚠️ 同帳號 worker-to-worker **必須走 Service Binding**（`env.SVC_X.fetch()`）——直接 `fetch("https://arcrun-*.leo21c.workers.dev")`
+  會撞 **CF 1042**（同帳號 worker 互打限制）。Gitea（`git.uncle6.me`，非 CF）才用 plain `fetch`。
+  註：`wrangler dev` 本地 miniflare **不強制** 1042，故本地測會假綠 → 一律對部署後真端點驗收。
 
 ## 規模備註（5,083 檔）
 
diff --git a/registry/examples/km-wiki-ingest/drainer/src/index.ts b/registry/examples/km-wiki-ingest/drainer/src/index.ts
index 1c0ba65..ef9d548 100644
--- a/registry/examples/km-wiki-ingest/drainer/src/index.ts
+++ b/registry/examples/km-wiki-ingest/drainer/src/index.ts
@@ -28,15 +28,21 @@ export interface Env {
   REF: string;             // main
   OWNER: string;           // leo（KBDB 租戶 owner_id）
   CARDS_ROOT: string;      // system-dev/wiki/cards
-  CODE_WORKER_URL: string; // https://arcrun-code.leo21c.workers.dev/
-  KBDB_URL: string;        // https://arcrun-kbdb.leo21c.workers.dev
-  GRAPH_URL: string;       // https://kbdb-graph-plugin.leo21c.workers.dev
+  // 同帳號 worker-to-worker 必須走 Service Binding（直接 fetch(*.leo21c.workers.dev) 會撞 CF 1042）。
+  SVC_CODE: Fetcher;       // → arcrun-code
+  SVC_KBDB: Fetcher;       // → arcrun-kbdb
+  SVC_GRAPH: Fetcher;      // → kbdb-graph-plugin
   GRAPH_KEY: string;       // leo
   BATCH_SIZE: string;      // "2"
   GITEA_TOKEN: string;         // secret：讀 repo
   GITEA_WEBHOOK_SECRET?: string; // secret（選填）：驗 webhook 簽章
 }
 
+// Service Binding fetch 輔助：host 是 placeholder（binding 直接路由到目標 worker），path/query/method/body 才重要。
+function svc(binding: Fetcher, path: string, init?: RequestInit): Promise<Response> {
+  return binding.fetch(new Request(`https://svc${path}`, init));
+}
+
 const CURSOR_TYPE = 'ingest_cursor';
 const cursorPageName = (env: Env) => `cursor:km_wiki_ingest_drain:${env.REPO}`;
 
@@ -73,7 +79,7 @@ async function giteaRaw(env: Env, relPath: string): Promise<string> {
 
 // ── card-processing 核心 ──────────────────────────────────────────────────────
 async function parseCard(env: Env, md: string, relPath: string): Promise<any> {
-  const r = await fetch(env.CODE_WORKER_URL, {
+  const r = await svc(env.SVC_CODE, '/', {
     method: 'POST',
     headers: { 'content-type': 'application/json' },
     body: JSON.stringify({
@@ -99,20 +105,20 @@ async function upsertEntry(env: Env, entry: any): Promise<{ action: string; id?:
   const pageName = entry.page_name;
   const metadata_json = JSON.stringify(entry.metadata);
   const newHash = entry.metadata.content_hash;
-  const lookup = await fetch(
-    `${env.KBDB_URL}/entries?page_name=${encodeURIComponent(pageName)}&owner_id=${encodeURIComponent(env.OWNER)}`,
+  const lookup = await svc(env.SVC_KBDB,
+    `/entries?page_name=${encodeURIComponent(pageName)}&owner_id=${encodeURIComponent(env.OWNER)}`,
   );
   const existing = ((await lookup.json()) as { entries?: any[] }).entries?.[0];
   if (existing) {
     if (metaHash(existing) === newHash) return { action: 'skip', id: existing.id };
-    const r = await fetch(`${env.KBDB_URL}/entries/${existing.id}`, {
+    const r = await svc(env.SVC_KBDB, `/entries/${existing.id}`, {
       method: 'PATCH',
       headers: { 'content-type': 'application/json' },
       body: JSON.stringify({ content: entry.content, tags_json: JSON.stringify(entry.tags || []), metadata_json }),
     });
     return { action: 'patch', id: existing.id, ...(r.ok ? {} : { action: 'patch-failed' }) };
   }
-  const r = await fetch(`${env.KBDB_URL}/entries`, {
+  const r = await svc(env.SVC_KBDB, `/entries`, {
     method: 'POST',
     headers: { 'content-type': 'application/json' },
     body: JSON.stringify({
@@ -134,7 +140,7 @@ async function postEnvelopes(env: Env, envelopes: any[]): Promise<any[]> {
   for (const envp of envelopes) {
     // envelopes 已由 code 節點剝除 _-鍵；此處再保險剝一次。
     const clean = Object.fromEntries(Object.entries(envp).filter(([k]) => !k.startsWith('_')));
-    const r = await fetch(`${env.GRAPH_URL}/triplets/ingest?owner_id=${encodeURIComponent(env.OWNER)}`, {
+    const r = await svc(env.SVC_GRAPH, `/triplets/ingest?owner_id=${encodeURIComponent(env.OWNER)}`, {
       method: 'POST',
       headers: { 'content-type': 'application/json', 'X-Arcrun-API-Key': env.GRAPH_KEY },
       body: JSON.stringify(clean),
@@ -168,8 +174,8 @@ async function processCard(env: Env, relPath: string): Promise<any> {
 interface CursorState { last_path: string; cycle: number; processed_total: number; updated_at: number; }
 
 async function getCursor(env: Env): Promise<{ id?: string; state: CursorState }> {
-  const r = await fetch(
-    `${env.KBDB_URL}/entries?page_name=${encodeURIComponent(cursorPageName(env))}&owner_id=${encodeURIComponent(env.OWNER)}`,
+  const r = await svc(env.SVC_KBDB,
+    `/entries?page_name=${encodeURIComponent(cursorPageName(env))}&owner_id=${encodeURIComponent(env.OWNER)}`,
   );
   const e = ((await r.json()) as { entries?: any[] }).entries?.[0];
   if (e) {
@@ -182,11 +188,11 @@ async function getCursor(env: Env): Promise<{ id?: string; state: CursorState }>
 async function setCursor(env: Env, cur: { id?: string; state: CursorState }): Promise<void> {
   const content = JSON.stringify(cur.state);
   if (cur.id) {
-    await fetch(`${env.KBDB_URL}/entries/${cur.id}`, {
+    await svc(env.SVC_KBDB, `/entries/${cur.id}`, {
       method: 'PATCH', headers: { 'content-type': 'application/json' }, body: JSON.stringify({ content }),
     });
   } else {
-    await fetch(`${env.KBDB_URL}/entries`, {
+    await svc(env.SVC_KBDB, `/entries`, {
       method: 'POST', headers: { 'content-type': 'application/json' },
       body: JSON.stringify({ entry_type: CURSOR_TYPE, page_name: cursorPageName(env), owner_id: env.OWNER, content,
         metadata_json: JSON.stringify({ kind: 'ingest_cursor', embed: false }) }),
diff --git a/registry/examples/km-wiki-ingest/drainer/wrangler.toml b/registry/examples/km-wiki-ingest/drainer/wrangler.toml
index 658b1e3..631eb2d 100644
--- a/registry/examples/km-wiki-ingest/drainer/wrangler.toml
+++ b/registry/examples/km-wiki-ingest/drainer/wrangler.toml
@@ -3,20 +3,27 @@ main = "src/index.ts"
 compatibility_date = "2025-02-19"
 workers_dev = true
 
-# ⚠️ 維持「非-auto」：預設不註冊 cron trigger（不自走排程、不無人值守亂寫）。
-# drain 以 POST /drain 手動觸發（與 scheduled handler 同核心）。
-# 要開自走 Phase 0 backfill：leo 過閘後，取消下面兩行註解再 deploy（scheduled handler 已在 code）。
+# ⚠️ 維持「非-auto」：預設不註冊 cron trigger（不自走排程）。drain 走 POST /drain（與 scheduled 同核心）。
+# 要開自走 Phase 0 backfill：leo 過閘後取消下面兩行註解再 deploy（scheduled handler 已在 code）。
 # [triggers]
 # crons = ["*/5 * * * *"]
 
+# ── Service Bindings（同帳號 worker-to-worker 正解；直接 fetch(*.leo21c.workers.dev) 會撞 CF 1042）──
+[[services]]
+binding = "SVC_CODE"
+service = "arcrun-code"
+[[services]]
+binding = "SVC_KBDB"
+service = "arcrun-kbdb"
+[[services]]
+binding = "SVC_GRAPH"
+service = "kbdb-graph-plugin"
+
 [vars]
 REPO = "Leo/notes"
 REF = "main"
 OWNER = "leo"
 CARDS_ROOT = "system-dev/wiki/cards"
-CODE_WORKER_URL = "https://arcrun-code.leo21c.workers.dev/"
-KBDB_URL = "https://arcrun-kbdb.leo21c.workers.dev"
-GRAPH_URL = "https://kbdb-graph-plugin.leo21c.workers.dev"
 GRAPH_KEY = "leo"
 BATCH_SIZE = "2"
 # secret（wrangler secret put）：GITEA_TOKEN（必），GITEA_WEBHOOK_SECRET（選）