diff --git a/OpacityCore/src/main/cpp/OpacityCore.cpp b/OpacityCore/src/main/cpp/OpacityCore.cpp
index e695d79..8a4a0e3 100644
--- a/OpacityCore/src/main/cpp/OpacityCore.cpp
+++ b/OpacityCore/src/main/cpp/OpacityCore.cpp
@@ -558,12 +558,29 @@ extern "C" JNIEXPORT jobject JNICALL
 Java_com_opacitylabs_opacitycore_OpacityCore_getNative(JNIEnv *env,
                                                        jobject thiz,
                                                        jstring name,
-                                                       jstring params) {
+                                                       jstring params,
+                                                       jstring traceparent,
+                                                       jstring tracestate) {
   char *res, *err;
   const char *name_str = env->GetStringUTFChars(name, nullptr);
   const char *params_str =
       params != nullptr ? env->GetStringUTFChars(params, nullptr) : nullptr;
-  int status = opacity_core::opacity_get(name_str, params_str, &res, &err);
+  // Optional W3C trace context. A null traceparent runs the plain
+  // `opacity_get` (standalone per-flow trace); a non-null one runs
+  // `opacity_get_with_context` to join the caller's trace.
+  const char *traceparent_str =
+      traceparent != nullptr ? env->GetStringUTFChars(traceparent, nullptr)
+                             : nullptr;
+  const char *tracestate_str =
+      tracestate != nullptr ? env->GetStringUTFChars(tracestate, nullptr)
+                            : nullptr;
+  int status;
+  if (traceparent_str != nullptr) {
+    status = opacity_core::opacity_get_with_context(
+        name_str, params_str, traceparent_str, tracestate_str, &res, &err);
+  } else {
+    status = opacity_core::opacity_get(name_str, params_str, &res, &err);
+  }
   return createOpacityResponse(env, status, res, err);
 }
 
diff --git a/OpacityCore/src/main/jni/include/sdk.h b/OpacityCore/src/main/jni/include/sdk.h
index 88820dc..4062793 100644
--- a/OpacityCore/src/main/jni/include/sdk.h
+++ b/OpacityCore/src/main/jni/include/sdk.h
@@ -178,6 +178,17 @@ int32_t opacity_init(const char *api_key_str,
 
 int32_t opacity_get(const char *name, const char *params, char **res_ptr, char **err_ptr);
 
+/**
+ * Like [`opacity_get`], but joins the caller's W3C trace: the flow's root span
+ * is parented to the supplied `traceparent`. `tracestate` is optional
+ */
+int32_t opacity_get_with_context(const char *name,
+                                 const char *params,
+                                 const char *traceparent,
+                                 const char *tracestate,
+                                 char **res_ptr,
+                                 char **err_ptr);
+
 void opacity_free_string(char *ptr);
 
 void emit_webview_event(const char *payload);
diff --git a/OpacityCore/src/main/kotlin/com/opacitylabs/opacitycore/OpacityCore.kt b/OpacityCore/src/main/kotlin/com/opacitylabs/opacitycore/OpacityCore.kt
index 0234a99..c309935 100644
--- a/OpacityCore/src/main/kotlin/com/opacitylabs/opacitycore/OpacityCore.kt
+++ b/OpacityCore/src/main/kotlin/com/opacitylabs/opacitycore/OpacityCore.kt
@@ -275,14 +275,40 @@ object OpacityCore {
     }
 
     @JvmStatic
-    suspend fun get(name: String, params: Map<String, Any?>?): Result<Map<String, Any?>> {
+    suspend fun get(
+        name: String,
+        params: Map<String, Any?>?
+    ): Result<Map<String, Any?>> {
+        return runGet(name, params, null, null)
+    }
+
+    /**
+     * Runs the flow joined to the caller's W3C trace. [traceparent] is required;
+     * [tracestate] is optional (W3C allows it to be absent).
+     */
+    @JvmStatic
+    suspend fun getWithContext(
+        name: String,
+        params: Map<String, Any?>?,
+        traceparent: String,
+        tracestate: String? = null
+    ): Result<Map<String, Any?>> {
+        return runGet(name, params, traceparent, tracestate)
+    }
+
+    private suspend fun runGet(
+        name: String,
+        params: Map<String, Any?>?,
+        traceparent: String?,
+        tracestate: String?
+    ): Result<Map<String, Any?>> {
         return withContext(Dispatchers.IO) {
             val paramsString = params?.let {
                 val jsonElement = mapToJsonElement(it)
                 Json.encodeToString(jsonElement)
             }
 
-            val res = getNative(name, paramsString)
+            val res = getNative(name, paramsString, traceparent, tracestate)
             if (res.status != 0) {
                 return@withContext Result.failure(parseOpacityError(res.err))
             }
@@ -305,7 +331,12 @@ object OpacityCore {
 
     private external fun nativeInitializeOpenTelemetry(openTelemetryEndpoint: String, grafanaInstanceId: String, grafanaApiToken: String): Int
 
-    private external fun getNative(name: String, params: String?): OpacityResponse
+    private external fun getNative(
+        name: String,
+        params: String?,
+        traceparent: String?,
+        tracestate: String?
+    ): OpacityResponse
     external fun getSdkVersions(): String
     external fun emitWebviewEvent(eventJson: String)
     external fun isBrowserOverlayEnabled(): Boolean