ConnectionMaster · pull · Jun 3, 2026 · Jun 3, 2026 · Jun 3, 2026
diff --git a/.generator/schemas/v1/openapi.yaml b/.generator/schemas/v1/openapi.yaml
diff --git a/.generator/schemas/v2/openapi.yaml b/.generator/schemas/v2/openapi.yaml
@@ -96978,6 +96978,67 @@ components:
             $ref: "#/components/schemas/UsageDataObject"
           type: array
       type: object
+    UsageSummaryAvailableFieldsAttributes:
+      description: |-
+        The lists of field names returned by `GET /api/v1/usage/summary` at each
+        of its three response levels. Each list contains every key the data endpoint
+        emits—both typed fields declared in the OpenAPI spec and untyped keys
+        exposed through `additionalProperties`.
+      properties:
+        date_fields:
+          description: |-
+            Sorted list of every key returned inside each `UsageSummaryDate`
+            entry of `usage[]` (typed fields and `additionalProperties` keys
+            combined).
+          items:
+            type: string
+          type: array
+        date_org_fields:
+          description: |-
+            Sorted list of every key returned inside each `UsageSummaryDateOrg`
+            entry of `usage[].orgs[]` (typed fields and `additionalProperties`
+            keys combined).
+          items:
+            type: string
+          type: array
+        response_fields:
+          description: |-
+            Sorted list of every key returned as a direct property of
+            `UsageSummaryResponse` (typed fields and `additionalProperties`
+            keys combined).
+          items:
+            type: string
+          type: array
+      type: object
+    UsageSummaryAvailableFieldsBody:
+      description: Available-fields data.
+      properties:
+        attributes:
+          $ref: "#/components/schemas/UsageSummaryAvailableFieldsAttributes"
+        id:
+          description: The identifier for the discovery scope. Always `"all"`.
+          example: all
+          type: string
+        type:
+          $ref: "#/components/schemas/UsageSummaryAvailableFieldsType"
+      type: object
+    UsageSummaryAvailableFieldsResponse:
+      description: |-
+        Response listing every field name returned by `GET /api/v1/usage/summary`
+        at each of its three response levels. Includes both typed fields and untyped
+        `additionalProperties` keys.
+      properties:
+        data:
+          $ref: "#/components/schemas/UsageSummaryAvailableFieldsBody"
+      type: object
+    UsageSummaryAvailableFieldsType:
+      default: usage_summary_available_fields
+      description: Type of available-fields data.
+      enum:
+        - usage_summary_available_fields
+      type: string
+      x-enum-varnames:
+        - USAGE_SUMMARY_AVAILABLE_FIELDS
     UsageTimeSeriesObject:
       description: Usage timeseries data.
       properties:
@@ -174018,6 +174079,67 @@ paths:
         permissions:
           - usage_read
           - billing_read
+  /api/v2/usage/summary/available_fields:
+    get:
+      description: |-
+        List the field names returned by `GET /api/v1/usage/summary` at each of its
+        three response levels. Each list contains every key the data endpoint
+        emits—both typed fields declared in the OpenAPI spec and untyped keys
+        exposed through `additionalProperties` (the latter used for billing
+        dimensions and usage types added after the v1 schema freeze).
+
+        This endpoint is only accessible for [parent-level organizations](https://docs.datadoghq.com/account_management/multi_organization/).
+      operationId: GetUsageSummaryAvailableFields
+      responses:
+        "200":
+          content:
+            application/json;datetime-format=rfc3339:
+              examples:
+                default:
+                  value:
+                    data:
+                      attributes:
+                        date_fields:
+                          - agent_host_top99p
+                          - aws_host_top99p
+                          - ccm_anthropic_spend_last
+                        date_org_fields:
+                          - agent_host_top99p
+                          - aws_host_top99p
+                          - ccm_anthropic_spend_last
+                        response_fields:
+                          - agent_host_top99p_sum
+                          - aws_host_top99p_sum
+                          - ccm_anthropic_spend_last_sum
+                      id: all
+                      type: usage_summary_available_fields
+              schema:
+                $ref: "#/components/schemas/UsageSummaryAvailableFieldsResponse"
+          description: OK.
+        "403":
+          content:
+            application/json;datetime-format=rfc3339:
+              schema:
+                $ref: "#/components/schemas/APIErrorResponse"
+          description: Forbidden - User is not authorized.
+        "429":
+          content:
+            application/json;datetime-format=rfc3339:
+              schema:
+                $ref: "#/components/schemas/APIErrorResponse"
+          description: Too many requests.
+      security:
+        - apiKeyAuth: []
+          appKeyAuth: []
+        - AuthZ:
+            - usage_read
+      summary: Get available fields for usage summary
+      tags:
+        - Usage Metering
+      "x-permission":
+        operator: OR
+        permissions:
+          - usage_read
   /api/v2/usage/usage-attribution-types:
     get:
       description: |-

diff --git a/...usage_metering/Get-available-fields-for-usage-summary-returns-Bad-Request-response.frozen b/...usage_metering/Get-available-fields-for-usage-summary-returns-Bad-Request-response.frozen
@@ -0,0 +1 @@
+2026-06-02T19:26:31.725Z
diff --git a/...v2/usage_metering/Get-available-fields-for-usage-summary-returns-Bad-Request-response.yml b/...v2/usage_metering/Get-available-fields-for-usage-summary-returns-Bad-Request-response.yml
diff --git a/examples/v2/usage-metering/GetUsageSummaryAvailableFields.rb b/examples/v2/usage-metering/GetUsageSummaryAvailableFields.rb
@@ -0,0 +1,5 @@
+# Get available fields for usage summary returns "OK." response
+
+require "datadog_api_client"
+api_instance = DatadogAPIClient::V2::UsageMeteringAPI.new
+p api_instance.get_usage_summary_available_fields()
diff --git a/examples/v2/usage-metering/GetUsageSummaryAvailableFields_2682263043.rb b/examples/v2/usage-metering/GetUsageSummaryAvailableFields_2682263043.rb
@@ -0,0 +1,5 @@
+# Get available fields for usage summary returns "OK" response
+
+require "datadog_api_client"
+api_instance = DatadogAPIClient::V2::UsageMeteringAPI.new
+p api_instance.get_usage_summary_available_fields()
diff --git a/features/v2/undo.json b/features/v2/undo.json
@@ -8562,6 +8562,12 @@
       "type": "safe"
     }
   },
+  "GetUsageSummaryAvailableFields": {
+    "tag": "Usage Metering",
+    "undo": {
+      "type": "safe"
+    }
+  },
   "GetUsageAttributionTypes": {
     "tag": "Usage Metering",
     "undo": {

diff --git a/features/v2/usage_metering.feature b/features/v2/usage_metering.feature
@@ -44,6 +44,29 @@ Feature: Usage Metering
     When the request is sent
     Then the response status is 200 OK
 
+  @team:DataDog/billing-hub
+  Scenario: Get available fields for usage summary returns "Bad Request" response
+    Given new "GetUsageSummaryAvailableFields" request
+    When the request is sent
+    Then the response status is 400 Bad Request
+
+  @skip @team:DataDog/billing-hub
+  Scenario: Get available fields for usage summary returns "OK" response
+    Given new "GetUsageSummaryAvailableFields" request
+    When the request is sent
+    Then the response status is 200 OK
+    And the response "data.id" is equal to "all"
+    And the response "data.type" is equal to "usage_summary_available_fields"
+    And the response "data.attributes" has field "response_fields"
+    And the response "data.attributes" has field "date_fields"
+    And the response "data.attributes" has field "date_org_fields"
+
+  @generated @skip @team:DataDog/billing-hub
+  Scenario: Get available fields for usage summary returns "OK." response
+    Given new "GetUsageSummaryAvailableFields" request
+    When the request is sent
+    Then the response status is 200 OK.
+
   @team:DataDog/billing-hub
   Scenario: Get billing dimension mapping for usage endpoints returns "Bad Request" response
     Given new "GetBillingDimensionMapping" request

diff --git a/lib/datadog_api_client/inflector.rb b/lib/datadog_api_client/inflector.rb
@@ -7102,6 +7102,10 @@ def overrides
           "v2.usage_data_object" => "UsageDataObject",
           "v2.usage_lambda_traced_invocations_response" => "UsageLambdaTracedInvocationsResponse",
           "v2.usage_observability_pipelines_response" => "UsageObservabilityPipelinesResponse",
+          "v2.usage_summary_available_fields_attributes" => "UsageSummaryAvailableFieldsAttributes",
+          "v2.usage_summary_available_fields_body" => "UsageSummaryAvailableFieldsBody",
+          "v2.usage_summary_available_fields_response" => "UsageSummaryAvailableFieldsResponse",
+          "v2.usage_summary_available_fields_type" => "UsageSummaryAvailableFieldsType",
           "v2.usage_time_series_object" => "UsageTimeSeriesObject",
           "v2.usage_time_series_type" => "UsageTimeSeriesType",
           "v2.user" => "User",

diff --git a/lib/datadog_api_client/v1/api/usage_metering_api.rb b/lib/datadog_api_client/v1/api/usage_metering_api.rb
@@ -2342,6 +2342,12 @@ def get_usage_summary(start_month, opts = {})
     #
     # Get all usage across your account.
     #
+    # Newly added billing dimensions and usage types appear as untyped keys on the
+    # `additionalProperties` map of `UsageSummaryResponse`, `UsageSummaryDate`, and
+    # `UsageSummaryDateOrg` instead of as typed fields. Call
+    # `GET /api/v2/usage/summary/available_fields` to enumerate every key returned
+    # at each response level—both typed fields and `additionalProperties` keys.
+    #
     # This endpoint is only accessible for [parent-level organizations](https://docs.datadoghq.com/account_management/multi_organization/).
     #
     # @param start_month [Time] Datetime in ISO-8601 format, UTC, precise to month: `[YYYY-MM]` for usage beginning in this month. Maximum of 15 months ago.