diff --git a/.sdk_metadata.json b/.sdk_metadata.json
index 2ac58272..a64339be 100644
--- a/.sdk_metadata.json
+++ b/.sdk_metadata.json
@@ -7,7 +7,7 @@
       "languages": [
         "Python"
       ],
-      "userAgents": ["PythonClient"],
+      "userAgents": ["PythonClient", "PythonAsyncClient"],
       "features": {
         "allFlags": { "introduced": "2.0" },
         "appMetadata": { "introduced": "7.6" },
diff --git a/ldclient/impl/aio/transport.py b/ldclient/impl/aio/transport.py
index da3fda7d..e9aa374f 100644
--- a/ldclient/impl/aio/transport.py
+++ b/ldclient/impl/aio/transport.py
@@ -15,7 +15,7 @@
 from ld_eventsource.config.retry_delay_strategy import RetryDelayStrategy
 
 from ldclient.impl.aio.transport_types import TransportResponse
-from ldclient.impl.http import _base_headers, _get_proxy_url
+from ldclient.impl.http import ASYNC_USER_AGENT, _base_headers, _get_proxy_url
 from ldclient.impl.util import log
 
 # Allows up to 5 minutes to elapse without any data sent across the stream.
@@ -123,7 +123,7 @@ def create(self, url: str, initial_retry_delay: float, query_params=None) -> Asy
         proxy settings, and the retry/backoff policy come from the SDK config.
         ``query_params`` is an optional zero-argument callable evaluated on
         each (re)connect to produce additional query string parameters."""
-        base_headers = _base_headers(self._config)
+        base_headers = _base_headers(self._config, ASYNC_USER_AGENT)
         aiohttp_request_options: dict = {
             "timeout": aiohttp.ClientTimeout(
                 total=None,
diff --git a/ldclient/impl/datasource/async_feature_requester.py b/ldclient/impl/datasource/async_feature_requester.py
index 8371bbd7..66a732d5 100644
--- a/ldclient/impl/datasource/async_feature_requester.py
+++ b/ldclient/impl/datasource/async_feature_requester.py
@@ -9,6 +9,7 @@
 
 from ldclient.impl.aio.transport import AsyncHTTPTransport
 from ldclient.impl.datasource.datasource_common import FDV1_POLLING_ENDPOINT
+from ldclient.impl.http import ASYNC_USER_AGENT
 from ldclient.impl.util import _headers, log, throw_if_unsuccessful_response
 from ldclient.interfaces import AsyncFeatureRequester
 from ldclient.versioned_data_kind import FEATURES, SEGMENTS
@@ -30,7 +31,7 @@ def __init__(self, config, transport: Optional[AsyncHTTPTransport] = None):
 
     async def get_all_data(self):
         uri = self._poll_uri
-        hdrs = _headers(self._config)
+        hdrs = _headers(self._config, ASYNC_USER_AGENT)
         cache_entry = self._cache.get(uri)
         hdrs['Accept-Encoding'] = 'gzip'
         if cache_entry is not None:
diff --git a/ldclient/impl/datasourcev2/async_polling.py b/ldclient/impl/datasourcev2/async_polling.py
index e93b6972..e3b6a3a3 100644
--- a/ldclient/impl/datasourcev2/async_polling.py
+++ b/ldclient/impl/datasourcev2/async_polling.py
@@ -26,6 +26,7 @@
     polling_payload_to_changeset,
     polling_result_to_basis
 )
+from ldclient.impl.http import ASYNC_USER_AGENT
 from ldclient.impl.util import (
     UnsuccessfulResponseException,
     _Fail,
@@ -192,7 +193,7 @@ async def fetch(self, selector: Optional[Selector]) -> PollingResult:
             filter_query = parse.urlencode(query_params)
             uri += f"?{filter_query}"
 
-        hdrs = _headers(self._config)
+        hdrs = _headers(self._config, ASYNC_USER_AGENT)
         hdrs["Accept-Encoding"] = "gzip"
 
         if self._etag is not None:
@@ -387,7 +388,7 @@ async def fetch(self, selector: Optional[Selector]) -> PollingResult:
             filter_query = parse.urlencode(query_params)
             uri += f"?{filter_query}"
 
-        hdrs = _headers(self._config)
+        hdrs = _headers(self._config, ASYNC_USER_AGENT)
         hdrs["Accept-Encoding"] = "gzip"
 
         if self._etag is not None:
diff --git a/ldclient/impl/events/async_event_processor.py b/ldclient/impl/events/async_event_processor.py
index 0e4e29d8..1e5b0215 100644
--- a/ldclient/impl/events/async_event_processor.py
+++ b/ldclient/impl/events/async_event_processor.py
@@ -29,6 +29,7 @@
     EventOutputFormatter
 )
 from ldclient.impl.events.types import EventInput
+from ldclient.impl.http import ASYNC_USER_AGENT
 from ldclient.impl.lru_cache import SimpleLRUCache
 from ldclient.impl.sampler import Sampler
 from ldclient.impl.util import (
@@ -277,7 +278,7 @@ async def __aexit__(self, type, value, traceback):
 
 
 async def _post_events_with_retry(http_client: AsyncHTTPTransport, config: AsyncConfig, uri: str, payload_id: Optional[str], body: str, events_description: str):
-    hdrs = _headers(config)
+    hdrs = _headers(config, ASYNC_USER_AGENT)
     hdrs['Content-Type'] = 'application/json'
     if config.enable_event_compression:
         hdrs['Content-Encoding'] = 'gzip'
diff --git a/ldclient/impl/http.py b/ldclient/impl/http.py
index 0745bf28..5fc77c56 100644
--- a/ldclient/impl/http.py
+++ b/ldclient/impl/http.py
@@ -7,6 +7,12 @@
 
 from ldclient.version import VERSION
 
+#: User-Agent product token for the synchronous client.
+SYNC_USER_AGENT = "PythonClient"
+#: User-Agent product token for the asynchronous client. Sync and async ship in
+#: one package, so the token is how LaunchDarkly tells the two apart.
+ASYNC_USER_AGENT = "PythonAsyncClient"
+
 
 def _application_header_value(application: dict) -> str:
     parts = []
@@ -22,8 +28,8 @@ def _application_header_value(application: dict) -> str:
     return " ".join(parts)
 
 
-def _base_headers(config):
-    headers = {'Authorization': config.sdk_key or '', 'User-Agent': 'PythonClient/' + VERSION}
+def _base_headers(config, user_agent=SYNC_USER_AGENT):
+    headers = {'Authorization': config.sdk_key or '', 'User-Agent': user_agent + '/' + VERSION}
 
     if config._instance_id is not None:
         headers['X-LaunchDarkly-Instance-Id'] = config._instance_id
diff --git a/ldclient/impl/util.py b/ldclient/impl/util.py
index fda0e4fd..69e7186a 100644
--- a/ldclient/impl/util.py
+++ b/ldclient/impl/util.py
@@ -7,7 +7,7 @@
 from typing import Any, Dict, Generic, Mapping, Optional, TypeVar, Union
 from urllib.parse import urlparse, urlunparse
 
-from ldclient.impl.http import _base_headers
+from ldclient.impl.http import SYNC_USER_AGENT, _base_headers
 
 
 def current_time_millis() -> int:
@@ -82,8 +82,8 @@ def validate_sdk_key_format(sdk_key: str, logger: logging.Logger) -> str:
     return sdk_key
 
 
-def _headers(config):
-    base_headers = _base_headers(config)
+def _headers(config, user_agent=SYNC_USER_AGENT):
+    base_headers = _base_headers(config, user_agent)
     base_headers.update({'Content-Type': "application/json"})
     return base_headers
 
diff --git a/ldclient/testing/impl/test_user_agent.py b/ldclient/testing/impl/test_user_agent.py
new file mode 100644
index 00000000..ef0fc63f
--- /dev/null
+++ b/ldclient/testing/impl/test_user_agent.py
@@ -0,0 +1,35 @@
+"""Tests for the sync and async User-Agent tokens.
+
+Sync and async ship in one package, so the User-Agent token is how LaunchDarkly
+tells the two clients apart. These tests lock the exact tokens sent on the wire.
+"""
+
+from ldclient.config import Config
+from ldclient.impl.http import ASYNC_USER_AGENT, SYNC_USER_AGENT, _base_headers
+from ldclient.impl.util import _headers
+from ldclient.version import VERSION
+
+
+def _config():
+    return Config(sdk_key='sdk-key')
+
+
+def test_user_agent_tokens():
+    assert SYNC_USER_AGENT == 'PythonClient'
+    assert ASYNC_USER_AGENT == 'PythonAsyncClient'
+
+
+def test_base_headers_default_user_agent_is_sync():
+    assert _base_headers(_config())['User-Agent'] == 'PythonClient/' + VERSION
+
+
+def test_base_headers_async_user_agent():
+    assert _base_headers(_config(), ASYNC_USER_AGENT)['User-Agent'] == 'PythonAsyncClient/' + VERSION
+
+
+def test_headers_default_user_agent_is_sync():
+    assert _headers(_config())['User-Agent'] == 'PythonClient/' + VERSION
+
+
+def test_headers_async_user_agent():
+    assert _headers(_config(), ASYNC_USER_AGENT)['User-Agent'] == 'PythonAsyncClient/' + VERSION