diff --git a/apps/api/src/index.ts b/apps/api/src/index.ts
index fb791a1..2a2bb41 100644
--- a/apps/api/src/index.ts
+++ b/apps/api/src/index.ts
@@ -1,3 +1,5 @@
+import { fileURLToPath } from 'node:url'
+import { realpathSync } from 'node:fs'
 import { serve } from '@hono/node-server'
 import { serveStatic } from '@hono/node-server/serve-static'
 import { Hono } from 'hono'
@@ -75,8 +77,28 @@ startOutboxWorker()
 app.use('/*', serveStatic({ root: './public' }))
 app.get('*', serveStatic({ path: './public/index.html' }))
 
+/**
+ * True only when this module is the process entrypoint (run directly), not when it
+ * is imported (e.g. by route tests that import `app`).
+ *
+ * WR-05: the previous basename-tail comparison
+ *   import.meta.url.endsWith(process.argv[1].replace(/^.*\//, ''))
+ * was fragile — a symlinked entrypoint or a differently-located file sharing the same
+ * basename could make it mis-fire (start the server during an unrelated import, or fail
+ * to start it in production). Compare fully-resolved real paths instead. realpathSync
+ * resolves symlinks on argv[1]; fileURLToPath turns the module URL into a real path.
+ */
+function isMainModule(): boolean {
+  if (!process.argv[1]) return false
+  try {
+    return fileURLToPath(import.meta.url) === realpathSync(process.argv[1])
+  } catch {
+    return false
+  }
+}
+
 // Only start the HTTP server when this module is run directly (not imported in tests)
-if (process.argv[1] && import.meta.url.endsWith(process.argv[1].replace(/^.*\//, ''))) {
+if (isMainModule()) {
   serve({ fetch: app.fetch, port: 3000 }, (info) => {
     console.log(`FamilySync API running on http://localhost:${info.port}`)
   })