diff --git a/openapi/openapiv2.json b/openapi/openapiv2.json
index fd72f79f1..b62881f41 100644
--- a/openapi/openapiv2.json
+++ b/openapi/openapiv2.json
@@ -150,6 +150,13 @@
             "in": "query",
             "required": false,
             "type": "string"
+          },
+          {
+            "name": "weakConsistency",
+            "description": "If true, the server may serve the response from an eventually-consistent\nsource instead of reading through to persistence. Defaults to false,\nwhich preserves read-after-write consistency. SDKs should set this when\nfetching namespace capabilities on worker/client startup.",
+            "in": "query",
+            "required": false,
+            "type": "boolean"
           }
         ],
         "tags": [
@@ -5013,6 +5020,13 @@
             "in": "query",
             "required": false,
             "type": "string"
+          },
+          {
+            "name": "weakConsistency",
+            "description": "If true, the server may serve the response from an eventually-consistent\nsource instead of reading through to persistence. Defaults to false,\nwhich preserves read-after-write consistency. SDKs should set this when\nfetching namespace capabilities on worker/client startup.",
+            "in": "query",
+            "required": false,
+            "type": "boolean"
           }
         ],
         "tags": [
diff --git a/openapi/openapiv3.yaml b/openapi/openapiv3.yaml
index c1f534e66..22d0bec8c 100644
--- a/openapi/openapiv3.yaml
+++ b/openapi/openapiv3.yaml
@@ -109,6 +109,15 @@ paths:
           in: query
           schema:
             type: string
+        - name: weakConsistency
+          in: query
+          description: |-
+            If true, the server may serve the response from an eventually-consistent
+             source instead of reading through to persistence. Defaults to false,
+             which preserves read-after-write consistency. SDKs should set this when
+             fetching namespace capabilities on worker/client startup.
+          schema:
+            type: boolean
       responses:
         "200":
           description: OK
@@ -4466,6 +4475,15 @@ paths:
           in: query
           schema:
             type: string
+        - name: weakConsistency
+          in: query
+          description: |-
+            If true, the server may serve the response from an eventually-consistent
+             source instead of reading through to persistence. Defaults to false,
+             which preserves read-after-write consistency. SDKs should set this when
+             fetching namespace capabilities on worker/client startup.
+          schema:
+            type: boolean
       responses:
         "200":
           description: OK
diff --git a/temporal/api/workflowservice/v1/request_response.proto b/temporal/api/workflowservice/v1/request_response.proto
index 5b7eba7f3..e9c4b0fca 100644
--- a/temporal/api/workflowservice/v1/request_response.proto
+++ b/temporal/api/workflowservice/v1/request_response.proto
@@ -86,6 +86,11 @@ message ListNamespacesResponse {
 message DescribeNamespaceRequest {
     string namespace = 1;
     string id = 2;
+    // If true, the server may serve the response from an eventually-consistent
+    // source instead of reading through to persistence. Defaults to false,
+    // which preserves read-after-write consistency. SDKs should set this when
+    // fetching namespace capabilities on worker/client startup.
+    bool weak_consistency = 3;
 }
 
 message DescribeNamespaceResponse {