diff --git a/js/src/logger.ts b/js/src/logger.ts
index 8bdb8a67b..be2f9f39a 100644
--- a/js/src/logger.ts
+++ b/js/src/logger.ts
@@ -185,6 +185,7 @@ import {
   getSpanInstrumentationName,
   INSTRUMENTATION_NAMES,
   mergeSpanOriginContext,
+  SDK_VERSION,
   type SpanOriginEnvironment,
 } from "./span-origin";
 
@@ -1315,6 +1316,11 @@ class HTTPConnection {
   // As far as I can tell, you cannot set the retry/backoff factor here
   _reset() {
     this.headers = {};
+    // Identifies SDK-originated traffic so the backend can attribute object
+    // creation to the TS SDK. Ignored by browsers (User-Agent is a forbidden
+    // header there), which is acceptable since the SDK is primarily used
+    // server-side.
+    this.headers["User-Agent"] = `braintrust-ts/${SDK_VERSION}`;
     if (this.token) {
       this.headers["Authorization"] = `Bearer ${this.token}`;
     }
diff --git a/js/src/span-origin.ts b/js/src/span-origin.ts
index 0fd2f5fc8..5bd7b7878 100644
--- a/js/src/span-origin.ts
+++ b/js/src/span-origin.ts
@@ -56,7 +56,7 @@ type InternalSpanInstrumentationName = {
   [INTERNAL_SPAN_INSTRUMENTATION_NAME]?: SpanInstrumentationName;
 };
 
-const SDK_VERSION =
+export const SDK_VERSION =
   typeof __BRAINTRUST_SDK_VERSION__ !== "undefined"
     ? __BRAINTRUST_SDK_VERSION__
     : "0.0.0";