diff --git a/axme/__init__.py b/axme/__init__.py
index 687df79..8419037 100644
--- a/axme/__init__.py
+++ b/axme/__init__.py
@@ -1,4 +1,4 @@
-from axme_sdk import AxmeClient, AxmeClientConfig
+from axme_sdk import __version__, AxmeClient, AxmeClientConfig
 from axme_sdk.exceptions import (
     AxmeAuthError,
     AxmeError,
@@ -9,6 +9,7 @@
 )
 
 __all__ = [
+    "__version__",
     "AxmeClient",
     "AxmeClientConfig",
     "AxmeAuthError",
diff --git a/axme_sdk/__init__.py b/axme_sdk/__init__.py
index eea5409..fcd8cc4 100644
--- a/axme_sdk/__init__.py
+++ b/axme_sdk/__init__.py
@@ -1,3 +1,5 @@
+__version__ = "0.2.0"
+
 from .client import AxmeClient, AxmeClientConfig
 from .mesh import MeshClient
 from .exceptions import (
@@ -10,6 +12,7 @@
 )
 
 __all__ = [
+    "__version__",
     "AxmeClient",
     "AxmeClientConfig",
     "MeshClient",
diff --git a/axme_sdk/client.py b/axme_sdk/client.py
index e7bb55f..cb213a7 100644
--- a/axme_sdk/client.py
+++ b/axme_sdk/client.py
@@ -1885,9 +1885,11 @@ def _notify_mcp_observer(self, event: dict[str, Any]) -> None:
         observer(event)
 
     def _default_headers(self) -> dict[str, str]:
+        from . import __version__ as _sdk_version
         headers = {
             "x-api-key": self._config.api_key,
             "Content-Type": "application/json",
+            "X-Axme-Client": f"axme-sdk-python/{_sdk_version}",
         }
         if self._config.actor_token:
             headers["Authorization"] = f"Bearer {self._config.actor_token}"
diff --git a/tests/test_client.py b/tests/test_client.py
index b0f3ed4..1999ec2 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -32,9 +32,11 @@ def _client(
         retry_backoff_seconds=retry_backoff_seconds,
         auto_trace_id=auto_trace_id,
     )
+    from axme import __version__ as _sdk_version
     default_headers = {
         "x-api-key": cfg.api_key,
         "Content-Type": "application/json",
+        "X-Axme-Client": f"axme-sdk-python/{_sdk_version}",
     }
     if cfg.actor_token:
         default_headers["Authorization"] = f"Bearer {cfg.actor_token}"
@@ -103,6 +105,19 @@ def handler(request: httpx.Request) -> httpx.Response:
     assert client.health(trace_id="trace-123") == {"ok": True}
 
 
+def test_health_sends_x_axme_client_header() -> None:
+    """Every outgoing request must carry X-Axme-Client: axme-sdk-python/<version>."""
+    from axme_sdk import __version__ as sdk_version
+
+    def handler(request: httpx.Request) -> httpx.Response:
+        client_header = request.headers.get("x-axme-client", "")
+        assert client_header == f"axme-sdk-python/{sdk_version}", client_header
+        return httpx.Response(200, json={"ok": True})
+
+    client = _client(handler)
+    assert client.health() == {"ok": True}
+
+
 def test_health_includes_actor_token_authorization_when_configured() -> None:
     def handler(request: httpx.Request) -> httpx.Response:
         assert request.headers["x-api-key"] == "platform-key"