diff --git a/src/sentry/api/client_kind.py b/src/sentry/api/client_kind.py
index 4e9d63e95656..1e3fd6ffd10b 100644
--- a/src/sentry/api/client_kind.py
+++ b/src/sentry/api/client_kind.py
@@ -194,6 +194,10 @@ def set_client_kind_attributes(request: Request) -> None:
     client_host = get_client_host(request)
     user_agent = get_user_agent(request)
 
+    # Stored to be available for the access log.
+    request._request.client_kind = client_kind
+    request._request.client_host = client_host
+
     _record_attribution_span(request, client_kind, client_host, user_agent)
 
     # `_test` suffix while this is a POC, to keep it out of the way of a
diff --git a/src/sentry/middleware/access_log.py b/src/sentry/middleware/access_log.py
index 983916d73e1d..4a48f81f6723 100644
--- a/src/sentry/middleware/access_log.py
+++ b/src/sentry/middleware/access_log.py
@@ -119,6 +119,8 @@ def _create_api_access_log(
         org_id = getattr(getattr(request, "organization", None), "id", None)
         entity_id = getattr(request_auth, "entity_id", None)
         status_code = getattr(response, "status_code", 500)
+        # Set during dispatch, for organizations opted into `client_kind`.
+        client_kind = getattr(request, "client_kind", None)
         log_metrics = dict(
             method=request.method,
             view=view,
@@ -132,6 +134,8 @@ def _create_api_access_log(
             path=request.path,
             caller_ip=request.META.get("REMOTE_ADDR"),
             user_agent=request.META.get("HTTP_USER_AGENT"),
+            client_kind=client_kind.value if client_kind is not None else None,
+            client_host=getattr(request, "client_host", None),
             rate_limited=getattr(request, "will_be_rate_limited", False),
             rate_limit_category=getattr(request, "rate_limit_category", None),
             request_duration_seconds=access_log_metadata.get_request_duration(),
diff --git a/tests/sentry/api/test_client_kind.py b/tests/sentry/api/test_client_kind.py
index de84417a5229..ae40c208e966 100644
--- a/tests/sentry/api/test_client_kind.py
+++ b/tests/sentry/api/test_client_kind.py
@@ -304,6 +304,38 @@ def test_records_for_the_internal_api_client_too(self) -> None:
         assert sdk.set_tag.call_args_list == [mock.call("client_kind_test", "script")]
 
 
+class AccessLogAttributesTest(TestCase):
+    """Asserted on the underlying Django request, which is all `access_log` sees."""
+
+    def stored(self, request: Request) -> tuple[Any, Any]:
+        django_request: Any = request._request
+        return (
+            getattr(django_request, "client_kind", None),
+            getattr(django_request, "client_host", None),
+        )
+
+    def test_stores_the_derived_kind(self) -> None:
+        request = make_request(auth=api_token(), user_agent="curl/8.7.1")
+        set_client_kind_attributes(request)
+        assert self.stored(request) == (ClientKind.SCRIPT, None)
+
+    def test_stores_the_client_host_for_mcp(self) -> None:
+        request = make_request(
+            auth=api_token(),
+            user_agent="sentry-mcp/1.0",
+            headers={
+                "X-Sentry-MCP-Version": "1.0",
+                "X-Sentry-MCP-Client-Family": "Claude-Code",
+            },
+        )
+        set_client_kind_attributes(request)
+        assert self.stored(request) == (ClientKind.MCP, "claude-code")
+
+    def test_absent_until_dispatch_runs(self) -> None:
+        # An un-attributed request leaves the attributes absent, not empty.
+        assert self.stored(make_request(auth=api_token())) == (None, None)
+
+
 class AttributionSpanTest(TestCase):
     def record(self, request: Request) -> tuple[Any, list[tuple[str, Any]]]:
         with (
diff --git a/tests/sentry/middleware/test_access_log_middleware.py b/tests/sentry/middleware/test_access_log_middleware.py
index 01048de169a1..b3b1e9d0d42d 100644
--- a/tests/sentry/middleware/test_access_log_middleware.py
+++ b/tests/sentry/middleware/test_access_log_middleware.py
@@ -10,6 +10,7 @@
 
 from sentry.api.base import Endpoint
 from sentry.api.bases.organization import ControlSiloOrganizationEndpoint, OrganizationEndpoint
+from sentry.api.client_kind import FEATURE_FLAG as CLIENT_KIND_FEATURE_FLAG
 from sentry.api.endpoints.internal.rpc import InternalRpcServiceEndpoint
 from sentry.api.permissions import SentryIsAuthenticated
 from sentry.models.apitoken import ApiToken
@@ -206,6 +207,9 @@ def get(self, request, organization_context, organization):
     "snuba_throttle_threshold",
     "token_last_characters",
     "gateway_proxy",
+    # Only present for organizations opted into `client_kind`.
+    "client_kind",
+    "client_host",
 )
 
 
@@ -481,6 +485,50 @@ def test_org_id_populated(self) -> None:
         assert tested_log.organization_id == str(self.organization.id)
 
 
+class TestClientKindLogged(LogCaptureAPITestCase):
+    """`client_kind` has to reach the access log, not just the span.
+
+    Span attributes stop at Snuba -- the analytics warehouse promotes a fixed
+    allow-list of span columns -- so the access log is the only path by which caller
+    attribution becomes queryable downstream.
+    """
+
+    endpoint = "sentry-api-0-organization-stats-v2"
+
+    def setUp(self) -> None:
+        self.login_as(user=self.user)
+
+    def request_stats(self) -> None:
+        self._caplog.set_level(logging.INFO, logger="sentry")
+        self.get_success_response(
+            self.organization.slug,
+            qs_params={
+                "project": [-1],
+                "category": ["error"],
+                "statsPeriod": "1d",
+                "interval": "1d",
+                "field": ["sum(quantity)"],
+            },
+        )
+
+    def test_client_kind_logged_for_an_opted_in_org(self) -> None:
+        with self.feature(CLIENT_KIND_FEATURE_FLAG):
+            self.request_stats()
+
+        tested_log = self.get_tested_log(args=[self.organization.slug])
+        # A session cookie and no token is the web UI.
+        assert tested_log.client_kind == "frontend"
+
+    def test_absent_for_an_org_that_has_not_opted_in(self) -> None:
+        with self.feature({CLIENT_KIND_FEATURE_FLAG: False}):
+            self.request_stats()
+
+        tested_log = self.get_tested_log(args=[self.organization.slug])
+        # Absent rather than "unknown": a disabled org has to stay distinguishable
+        # from one whose traffic genuinely classifies as unknown.
+        assert not hasattr(tested_log, "client_kind")
+
+
 @control_silo_test
 class TestOrganizationIdPresentForControl(LogCaptureAPITestCase):
     endpoint = "sentry-api-0-organization-members"
diff --git a/tools/mypy_helpers/plugin.py b/tools/mypy_helpers/plugin.py
index 86a05c4b0add..649dda00651c 100644
--- a/tools/mypy_helpers/plugin.py
+++ b/tools/mypy_helpers/plugin.py
@@ -139,6 +139,9 @@ def _adjust_http_request_members(ctx: ClassDefContext) -> None:
         add_attribute_to_class(ctx.api, ctx.cls, "superuser", AnyType(TypeOfAny.explicit))
         # added by OrganizationEndpoint.convert_args and similar
         add_attribute_to_class(ctx.api, ctx.cls, "organization", AnyType(TypeOfAny.explicit))
+        # added by sentry.api.client_kind.set_client_kind_attributes
+        add_attribute_to_class(ctx.api, ctx.cls, "client_kind", AnyType(TypeOfAny.explicit))
+        add_attribute_to_class(ctx.api, ctx.cls, "client_host", AnyType(TypeOfAny.explicit))
         # added by sentry.api.authentication.RelayAuthentication
         add_attribute_to_class(ctx.api, ctx.cls, "relay", AnyType(TypeOfAny.explicit))
         add_attribute_to_class(ctx.api, ctx.cls, "relay_request_data", AnyType(TypeOfAny.explicit))