diff --git a/workflow-engine/src/main/java/dev/openan/workflow/engine/client/AgentAuthManager.java b/workflow-engine/src/main/java/dev/openan/workflow/engine/client/AgentAuthManager.java
index 65368909..ee66267c 100644
--- a/workflow-engine/src/main/java/dev/openan/workflow/engine/client/AgentAuthManager.java
+++ b/workflow-engine/src/main/java/dev/openan/workflow/engine/client/AgentAuthManager.java
@@ -75,15 +75,33 @@ private static Map<String, Map<String, Map<String, Object>>> loadFromFile(String
         if (path == null) {
             return new HashMap<>();
         }
-        File file = new File(path);
-        if (!file.exists()) {
-            return new HashMap<>();
-        }
         try {
-            Map<String, Map<String, Map<String, Object>>> loaded =
-                    mapper.readValue(
-                            file,
-                            new TypeReference<Map<String, Map<String, Map<String, Object>>>>() {});
+            Map<String, Map<String, Map<String, Object>>> loaded;
+            if (path.startsWith("classpath:")) {
+                String resource = path.substring("classpath:".length());
+                java.io.InputStream is =
+                        AgentAuthManager.class.getClassLoader().getResourceAsStream(resource);
+                if (is == null) {
+                    log.warn("[Auth] Classpath resource not found: {}", resource);
+                    return new HashMap<>();
+                }
+                loaded =
+                        mapper.readValue(
+                                is,
+                                new TypeReference<
+                                        Map<String, Map<String, Map<String, Object>>>>() {});
+            } else {
+                File file = new File(path);
+                if (!file.exists()) {
+                    log.warn("[Auth] Credentials file not found: {}", path);
+                    return new HashMap<>();
+                }
+                loaded =
+                        mapper.readValue(
+                                file,
+                                new TypeReference<
+                                        Map<String, Map<String, Map<String, Object>>>>() {});
+            }
             log.info("[Auth] Loaded credentials for {} agent(s) from {}", loaded.size(), path);
             return loaded;
         } catch (Exception e) {
diff --git a/workflow-engine/src/test/java/dev/openan/workflow/engine/client/AgentAuthManagerTest.java b/workflow-engine/src/test/java/dev/openan/workflow/engine/client/AgentAuthManagerTest.java
index 8f7aba7b..44aae2d6 100644
--- a/workflow-engine/src/test/java/dev/openan/workflow/engine/client/AgentAuthManagerTest.java
+++ b/workflow-engine/src/test/java/dev/openan/workflow/engine/client/AgentAuthManagerTest.java
@@ -31,6 +31,19 @@ void loadsCredentialsFromClasspathLocation() throws Exception {
                 config.get("bearerAuth").get("login_url"));
     }
 
+    @Test
+    void loadsCredentialsFromClasspathPrefix() {
+        AgentAuthManager manager =
+                new AgentAuthManager("classpath:test-agent-credentials.json");
+
+        var config = manager.getConfig("Test Agent");
+
+        assertNotNull(config);
+        assertEquals(
+                "https://auth.example.test/token",
+                config.get("bearerAuth").get("login_url"));
+    }
+
     @Test
     void missingFileDoesNotCreateCredentials() {
         AgentAuthManager manager =
@@ -38,4 +51,12 @@ void missingFileDoesNotCreateCredentials() {
 
         assertNull(manager.getConfig("Test Agent"));
     }
+
+    @Test
+    void missingClasspathResourceDoesNotCreateCredentials() {
+        AgentAuthManager manager =
+                new AgentAuthManager("classpath:nonexistent-credentials.json");
+
+        assertNull(manager.getConfig("Test Agent"));
+    }
 }