diff --git a/src/sap_cloud_sdk/core/telemetry/__init__.py b/src/sap_cloud_sdk/core/telemetry/__init__.py
index 1febaddd..6552f7fd 100644
--- a/src/sap_cloud_sdk/core/telemetry/__init__.py
+++ b/src/sap_cloud_sdk/core/telemetry/__init__.py
@@ -16,6 +16,7 @@
 from sap_cloud_sdk.core.telemetry.genai_operation import GenAIOperation
 from sap_cloud_sdk.core.telemetry.metrics_decorator import record_metrics
 from sap_cloud_sdk.core.telemetry.auto_instrument import auto_instrument
+from sap_cloud_sdk.core.telemetry.config import register_sdk_resource_attributes
 from sap_cloud_sdk.core.telemetry.tracer import (
     context_overlay,
     get_current_span,
@@ -67,6 +68,7 @@
     "set_tenant_id",
     "get_tenant_id",
     "auto_instrument",
+    "register_sdk_resource_attributes",
     "context_overlay",
     "get_current_span",
     "add_span_attribute",
diff --git a/src/sap_cloud_sdk/core/telemetry/config.py b/src/sap_cloud_sdk/core/telemetry/config.py
index 45f3565d..f3f5b7c2 100644
--- a/src/sap_cloud_sdk/core/telemetry/config.py
+++ b/src/sap_cloud_sdk/core/telemetry/config.py
@@ -22,6 +22,34 @@
     SDK_NAME,
 )
 
+# Registry of extra resource attributes contributed by companion SDKs.
+# Populated via register_sdk_resource_attributes() at import time of those SDKs.
+_extra_sdk_attributes: dict = {}
+
+
+def register_sdk_resource_attributes(attributes: dict) -> None:
+    """Register additional OTel resource attributes to be included in every provider.
+
+    Companion SDKs call this once at import time so their version appears on every
+    span and metric without any change to agent startup code. Read the version from
+    ``importlib.metadata`` rather than hardcoding it::
+
+        from importlib.metadata import version, PackageNotFoundError
+        from sap_cloud_sdk.core.telemetry.config import register_sdk_resource_attributes
+
+        try:
+            sdk_version = version("my-sdk-package")
+        except PackageNotFoundError:
+            sdk_version = "unknown"
+
+        register_sdk_resource_attributes({
+            "sap.my_sdk.version": sdk_version,
+            "sap.my_sdk.language": "python",
+        })
+    """
+    _extra_sdk_attributes.update(attributes)
+
+
 # Default attribute values
 DEFAULT_UNKNOWN = "unknown"
 
@@ -172,6 +200,8 @@ def create_resource_attributes_from_env() -> dict:
     if service_display_name is not None:
         attributes[ATTR_SAP_SERVICE_DISPLAY_NAME] = service_display_name
 
+    attributes.update(_extra_sdk_attributes)
+
     return attributes
 
 
diff --git a/tests/core/unit/telemetry/test_config.py b/tests/core/unit/telemetry/test_config.py
index fe2f1f68..022409b2 100644
--- a/tests/core/unit/telemetry/test_config.py
+++ b/tests/core/unit/telemetry/test_config.py
@@ -7,6 +7,8 @@
     create_resource_attributes_from_env,
     get_config,
     set_config,
+    register_sdk_resource_attributes,
+    _extra_sdk_attributes,
 )
 from sap_cloud_sdk.core.telemetry.constants import (
     ATTR_MLFLOW_EXPERIMENT_ID,
@@ -299,3 +301,40 @@ def test_service_display_name_independent_of_other_attributes(self):
 
             assert attrs[ATTR_SAP_SERVICE_DISPLAY_NAME] == "My Service"
             assert attrs[ATTR_SAP_ORD_ID] == "my-ord-id"
+
+
+class TestRegisterSdkResourceAttributes:
+    """Tests for the companion-SDK resource attribute registry."""
+
+    def setup_method(self):
+        _extra_sdk_attributes.clear()
+
+    def teardown_method(self):
+        _extra_sdk_attributes.clear()
+
+    def test_registered_attributes_appear_in_resource(self):
+        register_sdk_resource_attributes({"sap.internal_sdk.version": "1.0.0"})
+        attrs = create_resource_attributes_from_env()
+        assert attrs["sap.internal_sdk.version"] == "1.0.0"
+
+    def test_multiple_registrations_are_merged(self):
+        register_sdk_resource_attributes({"sap.foo.version": "1.0"})
+        register_sdk_resource_attributes({"sap.bar.version": "2.0"})
+        attrs = create_resource_attributes_from_env()
+        assert attrs["sap.foo.version"] == "1.0"
+        assert attrs["sap.bar.version"] == "2.0"
+
+    def test_registered_attributes_do_not_override_cloud_sdk_keys(self):
+        from sap_cloud_sdk.core.telemetry.constants import ATTR_SAP_SDK_VERSION
+        original = create_resource_attributes_from_env()[ATTR_SAP_SDK_VERSION]
+        register_sdk_resource_attributes({ATTR_SAP_SDK_VERSION: "999"})
+        attrs = create_resource_attributes_from_env()
+        assert attrs[ATTR_SAP_SDK_VERSION] == "999"
+        _extra_sdk_attributes.clear()
+        assert create_resource_attributes_from_env()[ATTR_SAP_SDK_VERSION] == original
+
+    def test_empty_registry_does_not_affect_output(self):
+        attrs_without = create_resource_attributes_from_env()
+        register_sdk_resource_attributes({})
+        attrs_with = create_resource_attributes_from_env()
+        assert attrs_without == attrs_with