diff --git a/src/selfTest.ts b/src/selfTest.ts
index d7f653e..915048f 100644
--- a/src/selfTest.ts
+++ b/src/selfTest.ts
@@ -42,6 +42,7 @@ import {
 } from "./tools/napcatAutomation.types.js";
 import {
   loadNapcatAutomationPrompt,
+  type NapcatAutomationPromptName,
   napcatAutomationPromptNames,
 } from "./tools/napcatAutomation.prompts.js";
 import {
@@ -99,6 +100,17 @@ export async function runSelfTest(): Promise<void> {
       throw new Error(`NapCat prompt safety contract missing: ${promptName}`);
     }
   }
+  let traversalPromptRejected = false;
+  try {
+    loadNapcatAutomationPrompt("../../README" as NapcatAutomationPromptName);
+  } catch (error) {
+    traversalPromptRejected = String(error).includes(
+      "Unsupported NapCat automation prompt",
+    );
+  }
+  if (!traversalPromptRejected) {
+    throw new Error("NapCat prompt traversal self-check failed");
+  }
 
   const reviewClassifier = {
     localizedSecretLabelAllowed: isBenignCredentialReviewValue("密钥"),
diff --git a/src/tools/napcatAutomation.prompts.ts b/src/tools/napcatAutomation.prompts.ts
index d6b1179..2438b0f 100644
--- a/src/tools/napcatAutomation.prompts.ts
+++ b/src/tools/napcatAutomation.prompts.ts
@@ -17,14 +17,48 @@ const promptsRoot = path.resolve(
   'prompts',
   'napcat',
 );
+const promptsRootBoundary = promptsRoot.endsWith(path.sep)
+  ? promptsRoot
+  : `${promptsRoot}${path.sep}`;
+const napcatAutomationPromptNameSet = new Set<string>(
+  napcatAutomationPromptNames,
+);
+const napcatAutomationPromptFileNames = {
+  'upstream-audit': 'upstream-audit.md',
+  'sync-candidate-review': 'sync-candidate-review.md',
+  'runtime-release-readiness': 'runtime-release-readiness.md',
+  'remote-dev-handoff': 'remote-dev-handoff.md',
+} satisfies Record<NapcatAutomationPromptName, string>;
+
+/**
+ * Parses an external prompt name into the source-controlled NapCat prompt enum.
+ * @param value - Raw prompt name from CLI, JSON, MCP input, or a typed caller; only exact entries in `napcatAutomationPromptNames` are accepted.
+ * @returns A stable prompt name that can be mapped to a fixed file under `prompts/napcat`.
+ */
+export function parseNapcatAutomationPromptName(
+  value: string,
+): NapcatAutomationPromptName {
+  if (napcatAutomationPromptNameSet.has(value)) {
+    return value as NapcatAutomationPromptName;
+  }
+  throw new Error(`Unsupported NapCat automation prompt: ${value}`);
+}
 
 /**
  * Loads a source-controlled NapCat automation prompt by stable prompt name.
- * @param name - Prompt identifier from `napcatAutomationPromptNames`; because it is an enum value rather than a user-supplied path, callers cannot escape `prompts/napcat`.
+ * @param name - Prompt identifier from `napcatAutomationPromptNames`; runtime callers may still pass untyped external strings, so the loader re-validates and resolves only fixed filenames.
  * @returns UTF-8 prompt text used by Codex CLI automation.
  */
 export function loadNapcatAutomationPrompt(
   name: NapcatAutomationPromptName,
 ): string {
-  return readFileSync(path.join(promptsRoot, `${name}.md`), 'utf8');
+  const promptName = parseNapcatAutomationPromptName(String(name));
+  const promptPath = path.resolve(
+    promptsRoot,
+    napcatAutomationPromptFileNames[promptName],
+  );
+  if (!promptPath.startsWith(promptsRootBoundary)) {
+    throw new Error(`NapCat automation prompt escaped prompt root: ${name}`);
+  }
+  return readFileSync(promptPath, 'utf8');
 }