diff --git a/backend-java/src/test/java/com/nanri/aiimage/metrics/UploadMetricsTest.java b/backend-java/src/test/java/com/nanri/aiimage/metrics/UploadMetricsTest.java
new file mode 100644
index 00000000..05feb5d2
--- /dev/null
+++ b/backend-java/src/test/java/com/nanri/aiimage/metrics/UploadMetricsTest.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-186：上传耗时/大小/成功率指标契约（spec 11 §1，模块 file 上传接线面）。
+ * aiimage.upload.duration Timer + aiimage.upload.size summary + aiimage.upload.result(.success/failure)。
+ */
+class UploadMetricsTest {
+
+    private final SimpleMeterRegistry registry = new SimpleMeterRegistry();
+    private final TaskObservabilityMetrics metrics = new TaskObservabilityMetrics("server-110", registry);
+
+    @Test
+    void uploadDurationRecorded() {
+        metrics.upload("collectdata", 10_000L, 350L, true);
+        assertEquals(1, registry.get("aiimage.upload.duration").tag("moduleType", "collectdata").timer().count());
+        assertEquals(350.0, registry.get("aiimage.upload.duration").tag("moduleType", "collectdata").timer()
+                .totalTime(TimeUnit.MILLISECONDS), 0.001);
+    }
+
+    @Test
+    void uploadSizeRecorded() {
+        metrics.upload("collectdata", 1024L, 100L, true);
+        assertEquals(1024.0,
+                registry.get("aiimage.upload.size").tag("moduleType", "collectdata").summary().totalAmount(), 0.001);
+    }
+
+    @Test
+    void uploadSuccessResultCounted() {
+        metrics.upload("collectdata", 1L, 1L, true);
+        assertEquals(1.0, registry.get("aiimage.upload.result.success").tag("moduleType", "collectdata").counter().count());
+    }
+
+    @Test
+    void uploadFailureResultCounted() {
+        metrics.upload("collectdata", 1L, 1L, false);
+        assertEquals(1.0, registry.get("aiimage.upload.result.failure").tag("moduleType", "collectdata").counter().count());
+        assertEquals(0.0, registry.find("aiimage.upload.result.success").tag("moduleType", "collectdata").counter() == null
+                ? 0.0
+                : registry.find("aiimage.upload.result.success").tag("moduleType", "collectdata").counter().count());
+    }
+
+    @Test
+    void uploadSplitByModule() {
+        metrics.upload("similarasin", 10L, 10L, true);
+        metrics.upload("publish", 20L, 20L, true);
+        assertEquals(1, registry.get("aiimage.upload.duration").tag("moduleType", "similarasin").timer().count());
+        assertEquals(1, registry.get("aiimage.upload.duration").tag("moduleType", "publish").timer().count());
+    }
+
+    @Test
+    void largeUploadRecorded() {
+        metrics.upload("shopdatacrawl", 500_000_000L, 30_000L, true);
+        assertEquals(500_000_000.0,
+                registry.get("aiimage.upload.size").tag("moduleType", "shopdatacrawl").summary().totalAmount(), 0.001);
+    }
+
+    @Test
+    void uploadNamesFrozen() {
+        metrics.upload("similarasin", 1L, 1L, true);
+        assertTrue(registry.getMeters().stream()
+                .anyMatch(m -> m.getId().getName().equals("aiimage.upload.duration")));
+        assertTrue(registry.getMeters().stream()
+                .anyMatch(m -> m.getId().getName().equals("aiimage.upload.size")));
+        assertTrue(registry.getMeters().stream()
+                .anyMatch(m -> m.getId().getName().equals("aiimage.upload.result.success")));
+    }
+
+    @Test
+    void uploadNoMonitoringStackFallbackNoError() {
+        TaskObservabilityMetrics without = new TaskObservabilityMetrics("server-121", null);
+        without.upload("similarasin", 1L, 1L, true);
+        assertEquals("server-121", without.instanceId());
+    }
+}