diff --git a/openapi/openapiv2.json b/openapi/openapiv2.json
index fc1799d0..4f3c5fcb 100644
--- a/openapi/openapiv2.json
+++ b/openapi/openapiv2.json
@@ -11438,6 +11438,10 @@
         "inheritedBuildId": {
           "type": "string",
           "description": "Build ID inherited from a previous/parent execution. If present, assigned_build_id will be set to this, instead\nof using the assignment rules."
+        },
+        "firstRunId": {
+          "type": "string",
+          "title": "The first run ID in the execution chain.\nExecutions created via the following operations are considered to be in the same chain\n- ContinueAsNew\n- Workflow Retry\n- Workflow Reset\n- Cron Schedule"
         }
       }
     },
diff --git a/openapi/openapiv3.yaml b/openapi/openapiv3.yaml
index 97a02043..6083ef41 100644
--- a/openapi/openapiv3.yaml
+++ b/openapi/openapiv3.yaml
@@ -8904,6 +8904,15 @@ components:
           description: |-
             Build ID inherited from a previous/parent execution. If present, assigned_build_id will be set to this, instead
              of using the assignment rules.
+        firstRunId:
+          type: string
+          description: |-
+            The first run ID in the execution chain.
+             Executions created via the following operations are considered to be in the same chain
+             - ContinueAsNew
+             - Workflow Retry
+             - Workflow Reset
+             - Cron Schedule
     WorkflowExecutionSignaledEventAttributes:
       type: object
       properties:
diff --git a/temporal/api/workflow/v1/message.proto b/temporal/api/workflow/v1/message.proto
index 581c86f1..886a2359 100644
--- a/temporal/api/workflow/v1/message.proto
+++ b/temporal/api/workflow/v1/message.proto
@@ -91,6 +91,13 @@ message WorkflowExecutionInfo {
     // Build ID inherited from a previous/parent execution. If present, assigned_build_id will be set to this, instead
     // of using the assignment rules.
     string inherited_build_id = 20;
+    // The first run ID in the execution chain.
+    // Executions created via the following operations are considered to be in the same chain
+    // - ContinueAsNew
+    // - Workflow Retry
+    // - Workflow Reset
+    // - Cron Schedule
+    string first_run_id = 21;
 }
 
 message WorkflowExecutionConfig {