diff --git a/api/camunda/camunda-openapi.yaml b/api/camunda/camunda-openapi.yaml
index 947b881c362..c6a0a1b3962 100644
--- a/api/camunda/camunda-openapi.yaml
+++ b/api/camunda/camunda-openapi.yaml
@@ -26,6 +26,7 @@ servers:
         description: The schema of the Camunda 8 REST API server.
 
 tags:
+  - name: Ad-hoc subprocess
   - name: Authentication
   - name: Authorization
   - name: Clock
@@ -1391,6 +1392,10 @@ paths:
             This can happen if the `awaitCompletion` request parameter is set to `true`
             and the created process instance did not complete within the defined request timeout.
             This often happens when the created instance is not fully automated or contains wait states.
+          content:
+            application/problem+json:
+              schema:
+                $ref: "#/components/schemas/ProblemDetail"
 
   /process-instances/{processInstanceKey}:
     get:
@@ -3266,6 +3271,51 @@ paths:
         "500":
           $ref: "#/components/responses/InternalServerError"
 
+  /element-instances/ad-hoc-activities/search:
+    post:
+      tags:
+        - Ad-hoc subprocess
+      operationId: findAdHocSubprocessActivities
+      summary: Query activatable activities (alpha)
+      description: |
+        Search for activatable activities within ad-hoc subprocesses based on given criteria.
+
+        Note that this API currently requires filters for both process definition key and ad-hoc
+        subprocess ID and does not support paging or sorting.
+
+        :::note
+        This endpoint is an [alpha feature](/components/early-access/alpha/alpha-features.md) and may be subject to change
+        in future releases.
+        :::
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/AdHocSubprocessActivitySearchQuery"
+      responses:
+        "200":
+          description: >
+            The ad-hoc subprocess activities search result.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/AdHocSubprocessActivitySearchQueryResult"
+        "400":
+          description: >
+            The ad-hoc subprocess activities search query failed.
+            More details are provided in the response body.
+          content:
+            application/problem+json:
+              schema:
+                $ref: "#/components/schemas/ProblemDetail"
+        "401":
+          $ref: "#/components/responses/Unauthorized"
+        "403":
+          $ref: "#/components/responses/Forbidden"
+        "500":
+          $ref: "#/components/responses/InternalServerError"
+
   /signals/broadcast:
     post:
       tags:
@@ -4439,6 +4489,83 @@ components:
         incidentKey:
           description: Incident key associated with this flow node instance.
           type: string
+    AdHocSubprocessActivitySearchQuery:
+      description: Ad-hoc subprocess activities search request.
+      type: object
+      required:
+        - filter
+      properties:
+        filter:
+          description: The ad-hoc subprocess activity search filters.
+          allOf:
+            - $ref: "#/components/schemas/AdHocSubprocessActivityFilter"
+    AdHocSubprocessActivityFilter:
+      description: Flow node instance filter.
+      type: object
+      required:
+        - processDefinitionKey
+        - adHocSubprocessId
+      properties:
+        processDefinitionKey:
+          description: The process definition key.
+          type: string
+        adHocSubprocessId:
+          description: The ad-hoc subprocess element ID.
+          type: string
+    AdHocSubprocessActivitySearchQueryResult:
+      type: object
+      properties:
+        items:
+          description: The matching ad-hoc subprocess activities.
+          type: array
+          items:
+            $ref: "#/components/schemas/AdHocSubprocessActivityResult"
+    AdHocSubprocessActivityResult:
+      type: object
+      properties:
+        processDefinitionKey:
+          description: The process definition key associated to this activity.
+          type: string
+        processDefinitionId:
+          description: The process definition ID associated to this activity.
+          type: string
+        adHocSubprocessId:
+          description: The ad-hoc subprocess element ID.
+          type: string
+        elementId:
+          description: The element ID for this activity.
+          type: string
+        elementName:
+          description: The element name for this activity.
+          type: string
+        type:
+          description: Type of activity with a defined set of values.
+          type: string
+          enum:
+            - UNSPECIFIED
+            - PROCESS
+            - SUB_PROCESS
+            - EVENT_SUB_PROCESS
+            - INTERMEDIATE_CATCH_EVENT
+            - INTERMEDIATE_THROW_EVENT
+            - BOUNDARY_EVENT
+            - SERVICE_TASK
+            - RECEIVE_TASK
+            - USER_TASK
+            - MANUAL_TASK
+            - TASK
+            - MULTI_INSTANCE_BODY
+            - CALL_ACTIVITY
+            - BUSINESS_RULE_TASK
+            - SCRIPT_TASK
+            - SEND_TASK
+            - UNKNOWN
+        documentation:
+          description: The documentation for this activity.
+          type: string
+        tenantId:
+          description: The tenant ID for this activity.
+          type: string
     DecisionDefinitionSearchQuerySortRequest:
       type: object
       properties:
diff --git a/docs/apis-tools/camunda-api-rest/specifications/create-process-instance.api.mdx b/docs/apis-tools/camunda-api-rest/specifications/create-process-instance.api.mdx
index 7180cb087ec..80d298307e3 100644
--- a/docs/apis-tools/camunda-api-rest/specifications/create-process-instance.api.mdx
+++ b/docs/apis-tools/camunda-api-rest/specifications/create-process-instance.api.mdx
@@ -5,7 +5,7 @@ description: "Creates and starts an instance of the specified process."
 sidebar_label: "Create process instance"
 hide_title: true
 hide_table_of_contents: true
-api: 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
+api: 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
 sidebar_class_name: "post api-method"
 info_path: docs/apis-tools/camunda-api-rest/specifications/camunda-8-rest-api
 custom_edit_url: null
@@ -280,6 +280,44 @@ when awaitCompletion is enabled.
     "504": {
       description:
         "The process instance creation request timed out in the gateway.\n\nThis can happen if the `awaitCompletion` request parameter is set to `true`\nand the created process instance did not complete within the defined request timeout.\nThis often happens when the created instance is not fully automated or contains wait states.\n",
+      content: {
+        "application/problem+json": {
+          schema: {
+            description:
+              "A Problem detail object as described in [RFC 9457](https://www.rfc-editor.org/rfc/rfc9457). There may be additional properties specific to the problem type.\n",
+            type: "object",
+            properties: {
+              type: {
+                type: "string",
+                format: "uri",
+                description: "A URI identifying the problem type.",
+                default: "about:blank",
+              },
+              title: {
+                type: "string",
+                description: "A summary of the problem type.",
+              },
+              status: {
+                type: "integer",
+                format: "int32",
+                description: "The HTTP status code for this problem.",
+                minimum: 400,
+                maximum: 600,
+              },
+              detail: {
+                type: "string",
+                description: "An explanation of the problem in more detail.",
+              },
+              instance: {
+                type: "string",
+                format: "uri",
+                description: "A URI identifying the origin of the problem.",
+              },
+            },
+            title: "ProblemDetail",
+          },
+        },
+      },
     },
   }}
 ></StatusCodes>
diff --git a/docs/apis-tools/camunda-api-rest/specifications/find-ad-hoc-subprocess-activities.api.mdx b/docs/apis-tools/camunda-api-rest/specifications/find-ad-hoc-subprocess-activities.api.mdx
new file mode 100644
index 00000000000..5053f07a0b9
--- /dev/null
+++ b/docs/apis-tools/camunda-api-rest/specifications/find-ad-hoc-subprocess-activities.api.mdx
@@ -0,0 +1,342 @@
+---
+id: find-ad-hoc-subprocess-activities
+title: "Query activatable activities (alpha)"
+description: "Search for activatable activities within ad-hoc subprocesses based on given criteria."
+sidebar_label: "Query activatable activities (alpha)"
+hide_title: true
+hide_table_of_contents: true
+api: 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
+sidebar_class_name: "post api-method"
+info_path: docs/apis-tools/camunda-api-rest/specifications/camunda-8-rest-api
+custom_edit_url: null
+hide_send_button: true
+---
+
+import MethodEndpoint from "@theme/ApiExplorer/MethodEndpoint";
+import ParamsDetails from "@theme/ParamsDetails";
+import RequestSchema from "@theme/RequestSchema";
+import StatusCodes from "@theme/StatusCodes";
+import OperationTabs from "@theme/OperationTabs";
+import TabItem from "@theme/TabItem";
+import Heading from "@theme/Heading";
+
+<Heading
+  as={"h1"}
+  className={"openapi__heading"}
+  children={"Query activatable activities (alpha)"}
+></Heading>
+
+<MethodEndpoint
+  method={"post"}
+  path={"/element-instances/ad-hoc-activities/search"}
+  context={"endpoint"}
+></MethodEndpoint>
+
+Search for activatable activities within ad-hoc subprocesses based on given criteria.
+
+Note that this API currently requires filters for both process definition key and ad-hoc
+subprocess ID and does not support paging or sorting.
+
+:::note
+This endpoint is an [alpha feature](/components/early-access/alpha/alpha-features.md) and may be subject to change
+in future releases.
+:::
+
+<Heading
+  id={"request"}
+  as={"h2"}
+  className={"openapi-tabs__heading"}
+  children={"Request"}
+></Heading>
+
+<ParamsDetails parameters={undefined}></ParamsDetails>
+
+<RequestSchema
+  title={"Body"}
+  body={{
+    required: true,
+    content: {
+      "application/json": {
+        schema: {
+          description: "Ad-hoc subprocess activities search request.",
+          type: "object",
+          required: ["filter"],
+          properties: {
+            filter: {
+              description: "The ad-hoc subprocess activity search filters.",
+              allOf: [
+                {
+                  description: "Flow node instance filter.",
+                  type: "object",
+                  required: ["processDefinitionKey", "adHocSubprocessId"],
+                  properties: {
+                    processDefinitionKey: {
+                      description: "The process definition key.",
+                      type: "string",
+                    },
+                    adHocSubprocessId: {
+                      description: "The ad-hoc subprocess element ID.",
+                      type: "string",
+                    },
+                  },
+                  title: "AdHocSubprocessActivityFilter",
+                },
+              ],
+            },
+          },
+          title: "AdHocSubprocessActivitySearchQuery",
+        },
+      },
+    },
+  }}
+></RequestSchema>
+
+<StatusCodes
+  id={undefined}
+  label={undefined}
+  responses={{
+    "200": {
+      description: "The ad-hoc subprocess activities search result.\n",
+      content: {
+        "application/json": {
+          schema: {
+            type: "object",
+            properties: {
+              items: {
+                description: "The matching ad-hoc subprocess activities.",
+                type: "array",
+                items: {
+                  type: "object",
+                  properties: {
+                    processDefinitionKey: {
+                      description:
+                        "The process definition key associated to this activity.",
+                      type: "string",
+                    },
+                    processDefinitionId: {
+                      description:
+                        "The process definition ID associated to this activity.",
+                      type: "string",
+                    },
+                    adHocSubprocessId: {
+                      description: "The ad-hoc subprocess element ID.",
+                      type: "string",
+                    },
+                    elementId: {
+                      description: "The element ID for this activity.",
+                      type: "string",
+                    },
+                    elementName: {
+                      description: "The element name for this activity.",
+                      type: "string",
+                    },
+                    type: {
+                      description:
+                        "Type of activity with a defined set of values.",
+                      type: "string",
+                      enum: [
+                        "UNSPECIFIED",
+                        "PROCESS",
+                        "SUB_PROCESS",
+                        "EVENT_SUB_PROCESS",
+                        "INTERMEDIATE_CATCH_EVENT",
+                        "INTERMEDIATE_THROW_EVENT",
+                        "BOUNDARY_EVENT",
+                        "SERVICE_TASK",
+                        "RECEIVE_TASK",
+                        "USER_TASK",
+                        "MANUAL_TASK",
+                        "TASK",
+                        "MULTI_INSTANCE_BODY",
+                        "CALL_ACTIVITY",
+                        "BUSINESS_RULE_TASK",
+                        "SCRIPT_TASK",
+                        "SEND_TASK",
+                        "UNKNOWN",
+                      ],
+                    },
+                    documentation: {
+                      description: "The documentation for this activity.",
+                      type: "string",
+                    },
+                    tenantId: {
+                      description: "The tenant ID for this activity.",
+                      type: "string",
+                    },
+                  },
+                  title: "AdHocSubprocessActivityResult",
+                },
+              },
+            },
+            title: "AdHocSubprocessActivitySearchQueryResult",
+          },
+        },
+      },
+    },
+    "400": {
+      description:
+        "The ad-hoc subprocess activities search query failed. More details are provided in the response body.\n",
+      content: {
+        "application/problem+json": {
+          schema: {
+            description:
+              "A Problem detail object as described in [RFC 9457](https://www.rfc-editor.org/rfc/rfc9457). There may be additional properties specific to the problem type.\n",
+            type: "object",
+            properties: {
+              type: {
+                type: "string",
+                format: "uri",
+                description: "A URI identifying the problem type.",
+                default: "about:blank",
+              },
+              title: {
+                type: "string",
+                description: "A summary of the problem type.",
+              },
+              status: {
+                type: "integer",
+                format: "int32",
+                description: "The HTTP status code for this problem.",
+                minimum: 400,
+                maximum: 600,
+              },
+              detail: {
+                type: "string",
+                description: "An explanation of the problem in more detail.",
+              },
+              instance: {
+                type: "string",
+                format: "uri",
+                description: "A URI identifying the origin of the problem.",
+              },
+            },
+            title: "ProblemDetail",
+          },
+        },
+      },
+    },
+    "401": {
+      description: "The request lacks valid authentication credentials.",
+      content: {
+        "application/problem+json": {
+          schema: {
+            description:
+              "A Problem detail object as described in [RFC 9457](https://www.rfc-editor.org/rfc/rfc9457). There may be additional properties specific to the problem type.\n",
+            type: "object",
+            properties: {
+              type: {
+                type: "string",
+                format: "uri",
+                description: "A URI identifying the problem type.",
+                default: "about:blank",
+              },
+              title: {
+                type: "string",
+                description: "A summary of the problem type.",
+              },
+              status: {
+                type: "integer",
+                format: "int32",
+                description: "The HTTP status code for this problem.",
+                minimum: 400,
+                maximum: 600,
+              },
+              detail: {
+                type: "string",
+                description: "An explanation of the problem in more detail.",
+              },
+              instance: {
+                type: "string",
+                format: "uri",
+                description: "A URI identifying the origin of the problem.",
+              },
+            },
+            title: "ProblemDetail",
+          },
+        },
+      },
+    },
+    "403": {
+      description: "Forbidden. The request is not allowed.",
+      content: {
+        "application/problem+json": {
+          schema: {
+            description:
+              "A Problem detail object as described in [RFC 9457](https://www.rfc-editor.org/rfc/rfc9457). There may be additional properties specific to the problem type.\n",
+            type: "object",
+            properties: {
+              type: {
+                type: "string",
+                format: "uri",
+                description: "A URI identifying the problem type.",
+                default: "about:blank",
+              },
+              title: {
+                type: "string",
+                description: "A summary of the problem type.",
+              },
+              status: {
+                type: "integer",
+                format: "int32",
+                description: "The HTTP status code for this problem.",
+                minimum: 400,
+                maximum: 600,
+              },
+              detail: {
+                type: "string",
+                description: "An explanation of the problem in more detail.",
+              },
+              instance: {
+                type: "string",
+                format: "uri",
+                description: "A URI identifying the origin of the problem.",
+              },
+            },
+            title: "ProblemDetail",
+          },
+        },
+      },
+    },
+    "500": {
+      description: "An internal error occurred while processing the request.\n",
+      content: {
+        "application/problem+json": {
+          schema: {
+            description:
+              "A Problem detail object as described in [RFC 9457](https://www.rfc-editor.org/rfc/rfc9457). There may be additional properties specific to the problem type.\n",
+            type: "object",
+            properties: {
+              type: {
+                type: "string",
+                format: "uri",
+                description: "A URI identifying the problem type.",
+                default: "about:blank",
+              },
+              title: {
+                type: "string",
+                description: "A summary of the problem type.",
+              },
+              status: {
+                type: "integer",
+                format: "int32",
+                description: "The HTTP status code for this problem.",
+                minimum: 400,
+                maximum: 600,
+              },
+              detail: {
+                type: "string",
+                description: "An explanation of the problem in more detail.",
+              },
+              instance: {
+                type: "string",
+                format: "uri",
+                description: "A URI identifying the origin of the problem.",
+              },
+            },
+            title: "ProblemDetail",
+          },
+        },
+      },
+    },
+  }}
+></StatusCodes>
diff --git a/docs/apis-tools/camunda-api-rest/specifications/sidebar.ts b/docs/apis-tools/camunda-api-rest/specifications/sidebar.ts
index ae89f98deec..10a7063811e 100644
--- a/docs/apis-tools/camunda-api-rest/specifications/sidebar.ts
+++ b/docs/apis-tools/camunda-api-rest/specifications/sidebar.ts
@@ -6,6 +6,18 @@ const sidebar: SidebarsConfig = {
       type: "doc",
       id: "apis-tools/camunda-api-rest/specifications/camunda-8-rest-api",
     },
+    {
+      type: "category",
+      label: "Ad-hoc subprocess",
+      items: [
+        {
+          type: "doc",
+          id: "apis-tools/camunda-api-rest/specifications/find-ad-hoc-subprocess-activities",
+          label: "Query activatable activities (alpha)",
+          className: "api-method post",
+        },
+      ],
+    },
     {
       type: "category",
       label: "Authentication",