diff --git a/node/secret_tripwire.mjs b/node/secret_tripwire.mjs
index cdfd6b8..1295044 100644
--- a/node/secret_tripwire.mjs
+++ b/node/secret_tripwire.mjs
@@ -66,7 +66,9 @@ export async function ensureTripwire({ fetchManifest } = {}) {
   if (!fetchManifest) return new SecretTripwire(vendored);
   try {
     const fresh = await fetchManifest();
-    if (fresh && Array.isArray(fresh.rules)) return new SecretTripwire(fresh);
+    if (fresh && Array.isArray(fresh.rules) && fresh.rules.length > 0) {
+      return new SecretTripwire(fresh);
+    }
   } catch {
     // offline fallback — vendored baseline
   }
diff --git a/node/test/secret_tripwire.test.mjs b/node/test/secret_tripwire.test.mjs
index 9308992..dc56e24 100644
--- a/node/test/secret_tripwire.test.mjs
+++ b/node/test/secret_tripwire.test.mjs
@@ -1,5 +1,5 @@
 import { describe, it, expect } from "vitest";
-import { SecretTripwire, loadVendoredManifest } from "../secret_tripwire.mjs";
+import { SecretTripwire, ensureTripwire, loadVendoredManifest } from "../secret_tripwire.mjs";
 import { VeriSwarmClient } from "../veriswarm_client.mjs";
 
 const GH = "ghp_" + "A".repeat(36);
@@ -30,6 +30,14 @@ describe("node SecretTripwire", () => {
     expect(m.version).toMatch(/^sha256:/);
     expect(m.rules.some((r) => r.name === "github_pat")).toBe(true);
   });
+
+  it("falls back to vendored rules when fetched manifest is empty", async () => {
+    const tw = await ensureTripwire({
+      fetchManifest: async () => ({ version: "sha256:empty", rules: [] }),
+    });
+    expect(tw.scan(GH).length).toBeGreaterThan(0);
+    expect(tw.version).toMatch(/^sha256:/);
+  });
 });
 
 describe("guardOutboundText", () => {
@@ -58,4 +66,17 @@ describe("guardOutboundText", () => {
     const gh = "ghp_" + "A".repeat(36);
     expect(await c.guardOutboundText(gh)).toBe(gh);
   });
+
+  it("redacts when tokenize omits tokenized_text after reporting tokens", async () => {
+    const c = new VeriSwarmClient({
+      baseUrl: "https://example.invalid",
+      apiKey: "k",
+      secretsDetection: true,
+    });
+    c.getSecretRules = async () => MANIFEST;
+    c.tokenizePii = async () => ({ tokens_created: 1 });
+
+    const out = await c.guardOutboundText(GH);
+    expect(out).toBe("[VS:GITHUB_TOKEN:offline]");
+  });
 });
diff --git a/node/veriswarm_client.mjs b/node/veriswarm_client.mjs
index cfd5892..8459829 100644
--- a/node/veriswarm_client.mjs
+++ b/node/veriswarm_client.mjs
@@ -171,7 +171,7 @@ export class VeriSwarmClient {
     if (this._tripwire.scan(text).length === 0) return text;
     try {
       const result = await this.tokenizePii({ text, agentId, sessionId });
-      let guarded = result?.tokens_created > 0 ? result.tokenized_text : text;
+      let guarded = result?.tokens_created > 0 ? result.tokenized_text || text : text;
       // Belt-and-suspenders: if the API left any known-prefix span intact
       // (the PII tokenizer is not a secret detector), redact it locally.
       if (this._tripwire.scan(guarded).length > 0) {
diff --git a/openclaw-plugin/src/index.ts b/openclaw-plugin/src/index.ts
index 4e44747..7041743 100644
--- a/openclaw-plugin/src/index.ts
+++ b/openclaw-plugin/src/index.ts
@@ -86,6 +86,108 @@ function piiSessionKey(toolName: string, conversationId?: string | null): string
   return `${conv}:${toolName}`;
 }
 
+type SecretGuardMode = "online" | "offline";
+
+interface SecretGuardOutcome {
+  value: unknown;
+  changed: boolean;
+  rules: Set<string>;
+  modes: Set<SecretGuardMode>;
+}
+
+function emptySecretGuardOutcome(value: unknown): SecretGuardOutcome {
+  return {
+    value,
+    changed: false,
+    rules: new Set<string>(),
+    modes: new Set<SecretGuardMode>(),
+  };
+}
+
+function mergeSecretGuardOutcome(
+  target: SecretGuardOutcome,
+  child: SecretGuardOutcome
+): void {
+  target.changed ||= child.changed;
+  for (const rule of child.rules) target.rules.add(rule);
+  for (const mode of child.modes) target.modes.add(mode);
+}
+
+async function guardSecretInput(
+  input: unknown,
+  state: PluginState,
+  toolName: string,
+  piiKey: string,
+  seen = new WeakSet<object>()
+): Promise<SecretGuardOutcome> {
+  if (!state.client || !state.tripwire) return emptySecretGuardOutcome(input);
+
+  if (typeof input === "string") {
+    const hits = state.tripwire.scan(input);
+    if (hits.length === 0) return emptySecretGuardOutcome(input);
+
+    try {
+      const result = await state.client.tokenizePii(input);
+      let guarded =
+        result.tokens_created > 0 ? result.tokenized_text || input : input;
+      if (result.tokens_created > 0 && result.session_id) {
+        state.piiSessions.set(piiKey, result.session_id);
+      }
+      // The PII tokenizer is not a secret detector; fail closed if a
+      // provider-prefix span remains, or if tokenized_text was omitted.
+      if (state.tripwire.scan(guarded).length > 0) {
+        guarded = state.tripwire.redactOffline(guarded);
+      }
+      return {
+        value: guarded,
+        changed: guarded !== input,
+        rules: new Set(hits.map((h) => h.ruleName)),
+        modes: new Set<SecretGuardMode>(["online"]),
+      };
+    } catch (e) {
+      console.warn(
+        `[VeriSwarm] Secret tripwire: API unreachable for tool=${toolName}; ` +
+          `applying offline redaction. Error: ${(e as Error)?.message ?? e}`
+      );
+      return {
+        value: state.tripwire.redactOffline(input),
+        changed: true,
+        rules: new Set(hits.map((h) => h.ruleName)),
+        modes: new Set<SecretGuardMode>(["offline"]),
+      };
+    }
+  }
+
+  if (Array.isArray(input)) {
+    if (seen.has(input)) return emptySecretGuardOutcome(input);
+    seen.add(input);
+    const next = [...input];
+    const outcome = emptySecretGuardOutcome(next);
+    for (let i = 0; i < input.length; i++) {
+      const child = await guardSecretInput(input[i], state, toolName, piiKey, seen);
+      if (child.changed) next[i] = child.value;
+      mergeSecretGuardOutcome(outcome, child);
+    }
+    return outcome.changed ? outcome : emptySecretGuardOutcome(input);
+  }
+
+  if (input && typeof input === "object") {
+    const record = input as Record<string, unknown>;
+    if (seen.has(record)) return emptySecretGuardOutcome(input);
+    seen.add(record);
+    const next: Record<string, unknown> = { ...record };
+    const outcome = emptySecretGuardOutcome(next);
+    for (const [key, value] of Object.entries(record)) {
+      const child = await guardSecretInput(value, state, toolName, piiKey, seen);
+      if (child.changed) next[key] = child.value;
+      mergeSecretGuardOutcome(outcome, child);
+    }
+    return outcome.changed ? outcome : emptySecretGuardOutcome(input);
+  }
+
+  return emptySecretGuardOutcome(input);
+}
+
 // ── Plugin State ────────────────────────────────────────────────────────
 
 interface PluginState {
@@ -333,45 +435,19 @@ export const pluginEntry: PluginEntry = {
       if (
         state.secretsDetection &&
         state.tripwire &&
-        event.input &&
-        typeof event.input === "string"
+        event.input !== undefined &&
+        event.input !== null
       ) {
-        const hits = state.tripwire.scan(event.input);
-        if (hits.length > 0) {
-          const convId = event.conversation_id || event.conversationId || event.session_id;
-          const key = piiSessionKey(toolName, convId);
-          try {
-            const result = await state.client.tokenizePii(event.input);
-            let guarded =
-              result.tokens_created > 0 ? result.tokenized_text : event.input;
-            if (result.tokens_created > 0) {
-              state.piiSessions.set(key, result.session_id);
-            }
-            // Belt-and-suspenders: if any known-prefix span survived the
-            // API's tokenization, redact it locally so no recognized
-            // secret leaves unprotected.
-            if (state.tripwire.scan(guarded).length > 0) {
-              guarded = state.tripwire.redactOffline(guarded);
-            }
-            await logEvent("secret.tripwire", {
-              tool_name: toolName,
-              rules: hits.map((h) => h.ruleName),
-              mode: "online",
-            });
-            return { input: guarded };
-          } catch (e) {
-            // Offline / API failure → fail closed with local redaction.
-            console.warn(
-              `[VeriSwarm] Secret tripwire: API unreachable for tool=${toolName}; ` +
-              `applying offline redaction. Error: ${(e as Error)?.message ?? e}`
-            );
-            await logEvent("secret.tripwire", {
-              tool_name: toolName,
-              rules: hits.map((h) => h.ruleName),
-              mode: "offline",
-            }).catch(() => {});
-            return { input: state.tripwire.redactOffline(event.input) };
-          }
+        const convId = event.conversation_id || event.conversationId || event.session_id;
+        const key = piiSessionKey(toolName, convId);
+        const guarded = await guardSecretInput(event.input, state, toolName, key);
+        if (guarded.changed) {
+          await logEvent("secret.tripwire", {
+            tool_name: toolName,
+            rules: Array.from(guarded.rules),
+            mode: guarded.modes.has("offline") ? "offline" : "online",
+          }).catch(() => {});
+          return { input: guarded.value };
         }
       }
 
diff --git a/openclaw-plugin/src/secret_tripwire.ts b/openclaw-plugin/src/secret_tripwire.ts
index 94bf383..726547a 100644
--- a/openclaw-plugin/src/secret_tripwire.ts
+++ b/openclaw-plugin/src/secret_tripwire.ts
@@ -93,7 +93,9 @@ export async function ensureTripwire(opts: EnsureOptions = {}): Promise<SecretTr
   if (!opts.fetchManifest) return new SecretTripwire(vendored);
   try {
     const fresh = await opts.fetchManifest();
-    if (fresh && Array.isArray(fresh.rules)) return new SecretTripwire(fresh);
+    if (fresh && Array.isArray(fresh.rules) && fresh.rules.length > 0) {
+      return new SecretTripwire(fresh);
+    }
   } catch {
     // fall through to vendored — offline baseline
   }
diff --git a/openclaw-plugin/test/secret_tripwire_hook.test.ts b/openclaw-plugin/test/secret_tripwire_hook.test.ts
index 4652092..2438571 100644
--- a/openclaw-plugin/test/secret_tripwire_hook.test.ts
+++ b/openclaw-plugin/test/secret_tripwire_hook.test.ts
@@ -56,6 +56,25 @@ describe("before_tool_call secret tripwire", () => {
     expect(res.input).not.toContain(GH_PAT);
   });
 
+  it("fails closed for secrets nested in structured tool input", async () => {
+    const { api, hooks } = makeApi();
+    pluginEntry.register(api as any, BASE_CONFIG);
+
+    const res = await hooks["before_tool_call"]({
+      name: "http_post",
+      input: {
+        url: "https://example.test",
+        headers: {
+          Authorization: `Bearer ${GH_PAT}`,
+        },
+      },
+    });
+
+    expect(res.input.headers.Authorization).toContain("[VS:");
+    expect(res.input.headers.Authorization).toContain(":offline]");
+    expect(JSON.stringify(res.input)).not.toContain(GH_PAT);
+  });
+
   it("passes clean input through untouched", async () => {
     const { api, hooks } = makeApi();
     pluginEntry.register(api as any, BASE_CONFIG);
diff --git a/openclaw-plugin/test/secret_tripwire_wiring.test.ts b/openclaw-plugin/test/secret_tripwire_wiring.test.ts
index 25c40b5..738cfe8 100644
--- a/openclaw-plugin/test/secret_tripwire_wiring.test.ts
+++ b/openclaw-plugin/test/secret_tripwire_wiring.test.ts
@@ -16,4 +16,11 @@ describe("vendored manifest loader", () => {
     });
     expect(tw.version).toMatch(/^sha256:/);
   });
+
+  it("ensureTripwire falls back to vendored copy when fetch returns no rules", async () => {
+    const tw = await ensureTripwire({
+      fetchManifest: async () => ({ version: "sha256:empty", rules: [] }),
+    });
+    expect(tw.version).toMatch(/^sha256:/);
+  });
 });
diff --git a/python/src/veriswarm/secret_tripwire.py b/python/src/veriswarm/secret_tripwire.py
index 3445a21..5f2f0b1 100644
--- a/python/src/veriswarm/secret_tripwire.py
+++ b/python/src/veriswarm/secret_tripwire.py
@@ -78,7 +78,11 @@ def ensure_tripwire(
         return SecretTripwire(vendored)
     try:
         fresh = fetch_manifest()
-        if isinstance(fresh, dict) and isinstance(fresh.get("rules"), list):
+        if (
+            isinstance(fresh, dict)
+            and isinstance(fresh.get("rules"), list)
+            and len(fresh["rules"]) > 0
+        ):
             return SecretTripwire(fresh)
     except Exception:
         pass  # offline fallback to vendored
diff --git a/python/tests/test_secret_tripwire.py b/python/tests/test_secret_tripwire.py
index fa9a0bd..fafd1a7 100644
--- a/python/tests/test_secret_tripwire.py
+++ b/python/tests/test_secret_tripwire.py
@@ -1,6 +1,10 @@
 from __future__ import annotations
 
-from veriswarm.secret_tripwire import SecretTripwire, load_vendored_manifest
+from veriswarm.secret_tripwire import (
+    SecretTripwire,
+    ensure_tripwire,
+    load_vendored_manifest,
+)
 
 GH = "ghp_" + "A" * 36
 MANIFEST = {
@@ -50,3 +54,10 @@ def test_load_vendored_manifest():
     m = load_vendored_manifest()
     assert m["version"].startswith("sha256:")
     assert any(r["name"] == "github_pat" for r in m["rules"])
+
+
+def test_ensure_tripwire_falls_back_when_fetched_manifest_has_no_rules():
+    tw = ensure_tripwire(fetch_manifest=lambda: {"version": "sha256:empty", "rules": []})
+
+    assert tw.version.startswith("sha256:")
+    assert tw.scan(GH)