diff --git a/packages/core/src/loop/boringstack/reachability.ts b/packages/core/src/loop/boringstack/reachability.ts
index bc756d65..bd8ef809 100644
--- a/packages/core/src/loop/boringstack/reachability.ts
+++ b/packages/core/src/loop/boringstack/reachability.ts
@@ -56,10 +56,7 @@ export function checkFeatureReachable(
   }
 
   // 2. API registration: the resource must be mounted in the API route table.
-  if (
-    inputs.apiRoutes !== null &&
-    !inputs.apiRoutes.includes(`${camel}Routes`)
-  ) {
+  if (inputs.apiRoutes !== null && !registersRoutes(inputs.apiRoutes, camel)) {
     problems.push(
       `API route missing: ${camel}Routes is not registered in ` +
         `config/routes/routes.ts — the endpoints would be unreachable.`
@@ -80,6 +77,29 @@ export function checkFeatureReachable(
   return { ok: problems.length === 0, problems };
 }
 
+/**
+ * True when `apiRoutes` mounts `<camel>Routes` as a WHOLE identifier, not merely as a
+ * substring of a longer name. A bare `.includes("countRoutes")` matches an unrelated
+ * slice's `accountRoutes` (`account` ⊃ `count`), so a `count` feature whose own
+ * `countRoutes` is genuinely absent would be reported reachable — a false green in the
+ * one check meant to catch unregistered (hollow) features. The `\p{ID_Continue}`
+ * lookarounds (the canonical Unicode "identifier continue" set — same idiom as
+ * `fieldIsMentioned`) reject a match glued to an adjacent identifier char on either
+ * side, while still matching every real mount idiom (`count: countRoutes`,
+ * `.use(countRoutes)`, `[countRoutes]`), whose delimiter before the name is not an
+ * identifier char. `$` is added to the class because it is a JS IdentifierPart that
+ * `\p{ID_Continue}` omits — so `$countRoutes` is a distinct identifier, not a match.
+ * (`_`, ZWJ, and ZWNJ are already in `\p{ID_Continue}`, verified at runtime.)
+ */
+function registersRoutes(apiRoutes: string, camel: string): boolean {
+  const boundary = "[\\p{ID_Continue}$]";
+  const ident = `${camel}Routes`.replace(/[.*+?^${}()|[\]\\]/gu, "\\$&");
+
+  return new RegExp(`(?<!${boundary})${ident}(?!${boundary})`, "u").test(
+    apiRoutes
+  );
+}
+
 /** True when a locale JSON string has non-empty `features.<lower>.title` + `.empty`. */
 function localeHasFeatureKeys(jsonSrc: string, lower: string): boolean {
   let data: unknown;
diff --git a/packages/core/tests/boringstack-reachability.test.ts b/packages/core/tests/boringstack-reachability.test.ts
index b3479ff6..fa3747c8 100644
--- a/packages/core/tests/boringstack-reachability.test.ts
+++ b/packages/core/tests/boringstack-reachability.test.ts
@@ -46,6 +46,61 @@ describe("checkFeatureReachable", () => {
     expect(r.problems.join("\n")).toMatch(/API route missing/u);
   });
 
+  test("a substring-only API match is NOT accepted (no false green off a sibling slice)", () => {
+    // `count`'s own `countRoutes` is absent, but a prior slice registered
+    // `accountRoutes` — which CONTAINS "countRoutes". A bare `.includes` would wrongly
+    // pass `count` as reachable; the whole-identifier check must still flag it.
+    const r = checkFeatureReachable("Count", {
+      uiRoutes:
+        'const CountPage = lazy(() => import("@/features/count/components/CountPage/CountPage"));',
+      apiRoutes: "export const routes = {\n  account: accountRoutes,\n};",
+      localeJsons: [
+        JSON.stringify({
+          features: { count: { title: "Counts", empty: "None." } },
+        }),
+      ],
+    });
+
+    expect(r.ok).toBe(false);
+    expect(r.problems.join("\n")).toMatch(/API route missing/u);
+  });
+
+  test("a `$`-prefixed sibling identifier is NOT accepted (JS `$` is an identifier char)", () => {
+    // `$` is a valid JS IdentifierPart that `\p{ID_Continue}` omits, so `$countRoutes`
+    // is a DISTINCT identifier — it must not satisfy `count`'s reachability.
+    const r = checkFeatureReachable("Count", {
+      uiRoutes:
+        'const CountPage = lazy(() => import("@/features/count/components/CountPage/CountPage"));',
+      apiRoutes: "export const routes = {\n  meta: $countRoutes,\n};",
+      localeJsons: [
+        JSON.stringify({
+          features: { count: { title: "Counts", empty: "None." } },
+        }),
+      ],
+    });
+
+    expect(r.ok).toBe(false);
+    expect(r.problems.join("\n")).toMatch(/API route missing/u);
+  });
+
+  test("a whole-identifier API match is accepted even next to a superstring sibling", () => {
+    // Both `count` and `account` are registered: `count` must be seen as reachable
+    // (its own whole-word `countRoutes` is present), not masked by `accountRoutes`.
+    const r = checkFeatureReachable("Count", {
+      uiRoutes:
+        'const CountPage = lazy(() => import("@/features/count/components/CountPage/CountPage"));',
+      apiRoutes:
+        "export const routes = {\n  account: accountRoutes,\n  count: countRoutes,\n};",
+      localeJsons: [
+        JSON.stringify({
+          features: { count: { title: "Counts", empty: "None." } },
+        }),
+      ],
+    });
+
+    expect(r.ok).toBe(true);
+  });
+
   test("flags missing i18n keys (page would show raw keys)", () => {
     const r = checkFeatureReachable("Bookmark", {
       ...wiredInputs(),