diff --git a/judoscale-core/src/main/java/com/judoscale/core/Adapter.java b/judoscale-core/src/main/java/com/judoscale/core/Adapter.java
index fab766e..ed95964 100644
--- a/judoscale-core/src/main/java/com/judoscale/core/Adapter.java
+++ b/judoscale-core/src/main/java/com/judoscale/core/Adapter.java
@@ -11,14 +11,16 @@ public final class Adapter {
 
     private final String name;
     private final String version;
+    private final String runtimeVersion;
 
     /**
-     * Creates an Adapter with the specified name and version.
+     * Creates an Adapter with the specified name, version, and runtime version.
      *
      * @param name the adapter name (e.g., "judoscale-spring-boot", "judoscale-spring-boot-2"), must not be null
      * @param version the adapter version, must not be null
+     * @param runtimeVersion the runtime version (e.g., Spring Boot version), may be null
      */
-    public Adapter(String name, String version) {
+    public Adapter(String name, String version, String runtimeVersion) {
         if (name == null) {
             throw new IllegalArgumentException("Adapter name must not be null");
         }
@@ -27,6 +29,7 @@ public Adapter(String name, String version) {
         }
         this.name = name;
         this.version = version;
+        this.runtimeVersion = runtimeVersion;
     }
 
     /**
@@ -47,21 +50,31 @@ public String version() {
         return version;
     }
 
+    /**
+     * Returns the runtime version (e.g., Spring Boot version).
+     *
+     * @return the runtime version, or null if not set
+     */
+    public String runtimeVersion() {
+        return runtimeVersion;
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;
         if (o == null || getClass() != o.getClass()) return false;
         Adapter adapter = (Adapter) o;
-        return Objects.equals(name, adapter.name) && Objects.equals(version, adapter.version);
+        return Objects.equals(name, adapter.name) && Objects.equals(version, adapter.version)
+            && Objects.equals(runtimeVersion, adapter.runtimeVersion);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(name, version);
+        return Objects.hash(name, version, runtimeVersion);
     }
 
     @Override
     public String toString() {
-        return "Adapter{name='" + name + "', version='" + version + "'}";
+        return "Adapter{name='" + name + "', version='" + version + "', runtimeVersion='" + runtimeVersion + "'}";
     }
 }
diff --git a/judoscale-core/src/main/java/com/judoscale/core/ReportBuilder.java b/judoscale-core/src/main/java/com/judoscale/core/ReportBuilder.java
index 9dcf968..cae6a7c 100644
--- a/judoscale-core/src/main/java/com/judoscale/core/ReportBuilder.java
+++ b/judoscale-core/src/main/java/com/judoscale/core/ReportBuilder.java
@@ -57,6 +57,7 @@ public static String buildReportJson(List<Metric> metrics, Collection<Adapter> a
         for (Adapter adapter : adapters) {
             ObjectNode adapterNode = objectMapper.createObjectNode();
             adapterNode.put("adapter_version", adapter.version());
+            adapterNode.put("runtime_version", adapter.runtimeVersion());
             adaptersNode.set(adapter.name(), adapterNode);
         }
         root.set("adapters", adaptersNode);
diff --git a/judoscale-core/src/test/java/com/judoscale/core/AdapterTest.java b/judoscale-core/src/test/java/com/judoscale/core/AdapterTest.java
index 1d1082c..992b0b1 100644
--- a/judoscale-core/src/test/java/com/judoscale/core/AdapterTest.java
+++ b/judoscale-core/src/test/java/com/judoscale/core/AdapterTest.java
@@ -8,35 +8,47 @@
 class AdapterTest {
 
     @Test
-    void createsAdapterWithNameAndVersion() {
-        Adapter adapter = new Adapter("judoscale-spring-boot", "1.0.0");
+    void createsAdapterWithAllFields() {
+        Adapter adapter = new Adapter("judoscale-spring-boot", "1.0.0", "3.2.2");
 
         assertThat(adapter.name()).isEqualTo("judoscale-spring-boot");
         assertThat(adapter.version()).isEqualTo("1.0.0");
+        assertThat(adapter.runtimeVersion()).isEqualTo("3.2.2");
+    }
+
+    @Test
+    void allowsNullRuntimeVersion() {
+        Adapter adapter = new Adapter("judoscale-spring-boot", "1.0.0", null);
+
+        assertThat(adapter.runtimeVersion()).isNull();
     }
 
     @Test
     void throwsExceptionWhenNameIsNull() {
-        assertThatThrownBy(() -> new Adapter(null, "1.0.0"))
+        assertThatThrownBy(() -> new Adapter(null, "1.0.0", "3.2.2"))
             .isInstanceOf(IllegalArgumentException.class)
             .hasMessage("Adapter name must not be null");
     }
 
     @Test
     void throwsExceptionWhenVersionIsNull() {
-        assertThatThrownBy(() -> new Adapter("judoscale-spring-boot", null))
+        assertThatThrownBy(() -> new Adapter("judoscale-spring-boot", null, "3.2.2"))
             .isInstanceOf(IllegalArgumentException.class)
             .hasMessage("Adapter version must not be null");
     }
 
     @Test
     void equalsAndHashCodeWorkCorrectly() {
-        Adapter adapter1 = new Adapter("judoscale-spring-boot", "1.0.0");
-        Adapter adapter2 = new Adapter("judoscale-spring-boot", "1.0.0");
-        Adapter adapter3 = new Adapter("judoscale-spring-boot-2", "1.0.0");
+        Adapter adapter1 = new Adapter("judoscale-spring-boot", "1.0.0", "3.2.2");
+        Adapter adapter2 = new Adapter("judoscale-spring-boot", "1.0.0", "3.2.2");
+        Adapter adapter3 = new Adapter("judoscale-spring-boot-2", "1.0.0", "3.2.2");
+        Adapter adapter4 = new Adapter("judoscale-spring-boot", "1.0.0", "2.7.0");
+        Adapter adapter5 = new Adapter("judoscale-spring-boot", "1.0.0", null);
 
         assertThat(adapter1).isEqualTo(adapter2);
         assertThat(adapter1.hashCode()).isEqualTo(adapter2.hashCode());
         assertThat(adapter1).isNotEqualTo(adapter3);
+        assertThat(adapter1).isNotEqualTo(adapter4);
+        assertThat(adapter1).isNotEqualTo(adapter5);
     }
 }
diff --git a/judoscale-core/src/test/java/com/judoscale/core/ReportBuilderTest.java b/judoscale-core/src/test/java/com/judoscale/core/ReportBuilderTest.java
index 21e96f0..8b49e99 100644
--- a/judoscale-core/src/test/java/com/judoscale/core/ReportBuilderTest.java
+++ b/judoscale-core/src/test/java/com/judoscale/core/ReportBuilderTest.java
@@ -11,7 +11,7 @@
 
 class ReportBuilderTest {
 
-    private static final Adapter TEST_ADAPTER = new Adapter("judoscale-test", "1.0.0");
+    private static final Adapter TEST_ADAPTER = new Adapter("judoscale-test", "1.0.0", "3.2.1");
 
     @Test
     void buildReportJsonFormatsMetricsCorrectly() {
@@ -31,6 +31,7 @@ void buildReportJsonFormatsMetricsCorrectly() {
         assertThat(json).contains("\"adapters\":");
         assertThat(json).contains("\"judoscale-test\"");
         assertThat(json).contains("\"adapter_version\":\"1.0.0\"");
+        assertThat(json).contains("\"runtime_version\":\"3.2.1\"");
     }
 
     @Test
@@ -81,8 +82,8 @@ void buildReportJsonHandlesEmptyContainer() {
 
     @Test
     void buildReportJsonSupportsMultipleAdapters() {
-        Adapter springBootAdapter = new Adapter("judoscale-spring-boot", "1.0.0");
-        Adapter sidekiqAdapter = new Adapter("judoscale-sidekiq", "2.0.0");
+        Adapter springBootAdapter = new Adapter("judoscale-spring-boot", "1.0.0", "3.2.2");
+        Adapter sidekiqAdapter = new Adapter("judoscale-sidekiq", "2.0.0", null);
         List<Adapter> adapters = Arrays.asList(springBootAdapter, sidekiqAdapter);
 
         String json = ReportBuilder.buildReportJson(Collections.emptyList(), adapters, "web.1");
@@ -91,6 +92,8 @@ void buildReportJsonSupportsMultipleAdapters() {
         assertThat(json).contains("\"judoscale-sidekiq\"");
         assertThat(json).contains("\"adapter_version\":\"1.0.0\"");
         assertThat(json).contains("\"adapter_version\":\"2.0.0\"");
+        assertThat(json).contains("\"runtime_version\":\"3.2.2\"");
+        assertThat(json).contains("\"runtime_version\":null");
     }
 
     @Test
diff --git a/judoscale-spring-boot-2-starter/src/main/java/com/judoscale/spring/JudoscaleApiClient.java b/judoscale-spring-boot-2-starter/src/main/java/com/judoscale/spring/JudoscaleApiClient.java
index 929bdac..9bcc74e 100644
--- a/judoscale-spring-boot-2-starter/src/main/java/com/judoscale/spring/JudoscaleApiClient.java
+++ b/judoscale-spring-boot-2-starter/src/main/java/com/judoscale/spring/JudoscaleApiClient.java
@@ -5,6 +5,7 @@
 import com.judoscale.core.Metric;
 import com.judoscale.core.ReportBuilder;
 import org.apache.http.client.config.RequestConfig;
+import org.springframework.boot.SpringBootVersion;
 import org.apache.http.client.methods.CloseableHttpResponse;
 import org.apache.http.client.methods.HttpPost;
 import org.apache.http.entity.ContentType;
@@ -30,7 +31,8 @@ public class JudoscaleApiClient implements ApiClient, Closeable {
     private static final int MAX_RETRIES = 3;
     private static final Adapter ADAPTER = new Adapter(
         "judoscale-spring-boot-2",
-        ReportBuilder.loadAdapterVersion(JudoscaleApiClient.class)
+        ReportBuilder.loadAdapterVersion(JudoscaleApiClient.class),
+        SpringBootVersion.getVersion()
     );
 
     private final JudoscaleConfig config;
diff --git a/judoscale-spring-boot-starter/src/main/java/com/judoscale/spring/JudoscaleApiClient.java b/judoscale-spring-boot-starter/src/main/java/com/judoscale/spring/JudoscaleApiClient.java
index fd56cb1..d2069cc 100644
--- a/judoscale-spring-boot-starter/src/main/java/com/judoscale/spring/JudoscaleApiClient.java
+++ b/judoscale-spring-boot-starter/src/main/java/com/judoscale/spring/JudoscaleApiClient.java
@@ -6,6 +6,7 @@
 import com.judoscale.core.ReportBuilder;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.boot.SpringBootVersion;
 
 import java.io.IOException;
 import java.net.URI;
@@ -24,7 +25,8 @@ public class JudoscaleApiClient implements ApiClient {
     private static final int MAX_RETRIES = 3;
     private static final Adapter ADAPTER = new Adapter(
         "judoscale-spring-boot",
-        ReportBuilder.loadAdapterVersion(JudoscaleApiClient.class)
+        ReportBuilder.loadAdapterVersion(JudoscaleApiClient.class),
+        SpringBootVersion.getVersion()
     );
 
     private final JudoscaleConfig config;