diff --git a/backend-java/src/test/java/com/nanri/aiimage/metrics/FileJobMetricsTest.java b/backend-java/src/test/java/com/nanri/aiimage/metrics/FileJobMetricsTest.java
new file mode 100644
index 00000000..6d113541
--- /dev/null
+++ b/backend-java/src/test/java/com/nanri/aiimage/metrics/FileJobMetricsTest.java
@@ -0,0 +1,82 @@
+package com.nanri.aiimage.metrics;
+
+import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
+import org.junit.jupiter.api.Test;
+
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * task-185：file-job.* 指标契约（spec 11 §1，TaskResultFileJobWorker 接线面）。
+ * pending/running/success/failed/retry 计数 + duration 耗时，分 moduleType/instanceId。
+ */
+class FileJobMetricsTest {
+
+    private final SimpleMeterRegistry registry = new SimpleMeterRegistry();
+    private final TaskObservabilityMetrics metrics = new TaskObservabilityMetrics("server-110", registry);
+
+    private double count(String state, String moduleType) {
+        io.micrometer.core.instrument.Counter c = registry.find("aiimage.file-job." + state)
+                .tag("moduleType", moduleType).counter();
+        return c == null ? 0.0 : c.count();
+    }
+
+    @Test
+    void pendingCounted() {
+        metrics.fileJobState("similarasin", "pending");
+        assertEquals(1.0, count("pending", "similarasin"));
+    }
+
+    @Test
+    void runningCounted() {
+        metrics.fileJobState("similarasin", "running");
+        assertEquals(1.0, count("running", "similarasin"));
+    }
+
+    @Test
+    void successCounted() {
+        metrics.fileJobState("similarasin", "success");
+        assertEquals(1.0, count("success", "similarasin"));
+    }
+
+    @Test
+    void failedCounted() {
+        metrics.fileJobState("similarasin", "failed");
+        assertEquals(1.0, count("failed", "similarasin"));
+    }
+
+    @Test
+    void retryCounted() {
+        metrics.fileJobState("similarasin", "retry");
+        assertEquals(1.0, count("retry", "similarasin"));
+    }
+
+    @Test
+    void durationRecorded() {
+        metrics.fileJobDuration("similarasin", 2_000L);
+        assertEquals(1, registry.get("aiimage.file-job.duration").tag("moduleType", "similarasin").timer().count());
+        assertEquals(2_000.0,
+                registry.get("aiimage.file-job.duration").tag("moduleType", "similarasin").timer()
+                        .totalTime(TimeUnit.MILLISECONDS), 0.001);
+    }
+
+    @Test
+    void splitByModuleAndInstance() {
+        metrics.fileJobState("similarasin", "success");
+        metrics.fileJobState("publish", "success");
+        assertEquals(1.0, count("success", "similarasin"));
+        assertEquals(1.0, count("success", "publish"));
+        assertEquals("server-110",
+                registry.get("aiimage.file-job.success").counter().getId().getTag("instanceId"));
+    }
+
+    @Test
+    void fileJobNamesFrozen() {
+        metrics.fileJobState("similarasin", "success");
+        metrics.fileJobDuration("similarasin", 10L);
+        assertTrue(registry.getMeters().stream().anyMatch(m -> m.getId().getName().equals("aiimage.file-job.success")));
+        assertTrue(registry.getMeters().stream().anyMatch(m -> m.getId().getName().equals("aiimage.file-job.duration")));
+    }
+}