From d68533aa9bc1c577b677b5cbcc247fa2c130d8b3 Mon Sep 17 00:00:00 2001
From: Flashduty AI-SRE <ai-sre@noreply.flashduty>
Date: Tue, 20 Oct 2026 08:05:44 +0000
Subject: [PATCH] docs(api-reference): document high_cardinality on RUM fields

fc-rum added types.FieldItem.HighCardinality (json:"high_cardinality") in
91194b9 (2026-10-15, feat(dashboard): restrict grouping by high-cardinality
fields); /rum/field/list returns it via logic.FieldTableToItem. The field has
no apidoc:omit, so it belongs in the published RumFieldItem schema.

Adds the property and its required entry to the rum split specs and the
consolidated reference copies, EN + ZH, and to the /rum/field/list response
example.
---
 api-reference/openapi.en.json     | 6 ++++++
 api-reference/openapi.zh.json     | 6 ++++++
 api-reference/rum.openapi.en.json | 6 ++++++
 api-reference/rum.openapi.zh.json | 6 ++++++
 4 files changed, 24 insertions(+)

diff --git a/api-reference/openapi.en.json b/api-reference/openapi.en.json
index 6557ee4e..b60f13af 100644
--- a/api-reference/openapi.en.json
+++ b/api-reference/openapi.en.json
@@ -21472,6 +21472,10 @@
             "description": "Display group used to cluster fields in the console, such as `error`, `action` or `device`. Empty when the field has no group.",
             "type": "string"
           },
+          "high_cardinality": {
+            "description": "True when grouping by this field is restricted: event ID fields cannot be grouped at all, other high-cardinality fields only with count or sum.",
+            "type": "boolean"
+          },
           "is_facet": {
             "description": "True if value distribution counting is supported for this field.",
             "type": "boolean"
@@ -21551,6 +21555,7 @@
           "unit_name",
           "edit_able",
           "is_facet",
+          "high_cardinality",
           "enum_values",
           "scopes",
           "status",
@@ -58461,6 +58466,7 @@
                         "field_key": "error_type",
                         "field_name": "Error Type",
                         "group": "error",
+                        "high_cardinality": false,
                         "is_facet": true,
                         "queryable": true,
                         "scopes": [
diff --git a/api-reference/openapi.zh.json b/api-reference/openapi.zh.json
index ae1d059e..24bc1fee 100644
--- a/api-reference/openapi.zh.json
+++ b/api-reference/openapi.zh.json
@@ -21472,6 +21472,10 @@
             "description": "控制台中对字段分组展示所用的组名，如 `error`、`action`、`device`；无分组时为空。",
             "type": "string"
           },
+          "high_cardinality": {
+            "description": "为 true 时表示按该字段分组受限：事件 ID 类字段完全不可分组，其他高基数字段只能用 count 或 sum 聚合。",
+            "type": "boolean"
+          },
           "is_facet": {
             "description": "是否支持值分布统计查询。",
             "type": "boolean"
@@ -21551,6 +21555,7 @@
           "unit_name",
           "edit_able",
           "is_facet",
+          "high_cardinality",
           "enum_values",
           "scopes",
           "status",
@@ -58461,6 +58466,7 @@
                         "field_key": "error_type",
                         "field_name": "Error Type",
                         "group": "error",
+                        "high_cardinality": false,
                         "is_facet": true,
                         "queryable": true,
                         "scopes": [
diff --git a/api-reference/rum.openapi.en.json b/api-reference/rum.openapi.en.json
index d3e92799..ff0a3334 100644
--- a/api-reference/rum.openapi.en.json
+++ b/api-reference/rum.openapi.en.json
@@ -1973,6 +1973,10 @@
             "description": "Display group used to cluster fields in the console, such as `error`, `action` or `device`. Empty when the field has no group.",
             "type": "string"
           },
+          "high_cardinality": {
+            "description": "True when grouping by this field is restricted: event ID fields cannot be grouped at all, other high-cardinality fields only with count or sum.",
+            "type": "boolean"
+          },
           "is_facet": {
             "description": "True if value distribution counting is supported for this field.",
             "type": "boolean"
@@ -2052,6 +2056,7 @@
           "unit_name",
           "edit_able",
           "is_facet",
+          "high_cardinality",
           "enum_values",
           "scopes",
           "status",
@@ -10463,6 +10468,7 @@
                         "field_key": "error_type",
                         "field_name": "Error Type",
                         "group": "error",
+                        "high_cardinality": false,
                         "is_facet": true,
                         "queryable": true,
                         "scopes": [
diff --git a/api-reference/rum.openapi.zh.json b/api-reference/rum.openapi.zh.json
index 078cf127..0a5e8514 100644
--- a/api-reference/rum.openapi.zh.json
+++ b/api-reference/rum.openapi.zh.json
@@ -1973,6 +1973,10 @@
             "description": "控制台中对字段分组展示所用的组名，如 `error`、`action`、`device`；无分组时为空。",
             "type": "string"
           },
+          "high_cardinality": {
+            "description": "为 true 时表示按该字段分组受限：事件 ID 类字段完全不可分组，其他高基数字段只能用 count 或 sum 聚合。",
+            "type": "boolean"
+          },
           "is_facet": {
             "description": "是否支持值分布统计查询。",
             "type": "boolean"
@@ -2052,6 +2056,7 @@
           "unit_name",
           "edit_able",
           "is_facet",
+          "high_cardinality",
           "enum_values",
           "scopes",
           "status",
@@ -10463,6 +10468,7 @@
                         "field_key": "error_type",
                         "field_name": "Error Type",
                         "group": "error",
+                        "high_cardinality": false,
                         "is_facet": true,
                         "queryable": true,
                         "scopes": [