[null,null,["最后更新时间 (UTC):2025-07-25。"],[],[],null,["# Method: courses.posts.addOnAttachments.create\n\n| This method is deprecated; use the `course.announcements.addOnAttachments`, `course.courseWork.addOnAttachments` or `course.courseWorkMaterials.addOnAttachments` method instead.\n\n- [HTTP request](#body.HTTP_TEMPLATE)\n- [Path parameters](#body.PATH_PARAMETERS)\n- [Query parameters](#body.QUERY_PARAMETERS)\n- [Request body](#body.request_body)\n- [Response body](#body.response_body)\n- [Authorization scopes](#body.aspect)\n\nCreates an add-on attachment under a post.\n\nRequires the add-on to have permission to create new attachments on the post.\n\nThis method returns the following error codes:\n\n- `PERMISSION_DENIED` for [access errors](/workspace/classroom/reference/Access.Errors).\n- `INVALID_ARGUMENT` if the request is malformed.\n- `NOT_FOUND` if one of the identified resources does not exist.\n\n### HTTP request\n\n`POST https://classroom.googleapis.com/v1/courses/{courseId}/posts/{postId}/addOnAttachments`\n\nThe URL uses [gRPC Transcoding](https://google.aip.dev/127) syntax.\n\n### Path parameters\n\n| Parameters ||\n|---------------------------|------------------------------------------------------|\n| `courseId` | `string` Required. Identifier of the course. |\n| `postId` **(deprecated)** | `string` Optional. Deprecated, use `itemId` instead. |\n\n### Query parameters\n\n| Parameters ||\n|--------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| `itemId` | `string` Identifier of the `Announcement`, `CourseWork`, or `CourseWorkMaterial` under which to create the attachment. This field is required, but is not marked as such while we are migrating from postId. |\n| `addOnToken` | `string` Optional. Token that authorizes the request. The token is passed as a query parameter when the user is redirected from Classroom to the add-on's URL. This authorization token is required for in-Classroom attachment creation but optional for partner-first attachment creation. Returns an error if not provided for partner-first attachment creation and the developer projects that created the attachment and its parent stream item do not match. |\n\n### Request body\n\nThe request body contains an instance of [AddOnAttachment](/workspace/classroom/reference/rest/v1/courses.announcements.addOnAttachments#AddOnAttachment).\n\n### Response body\n\nIf successful, the response body contains a newly created instance of [AddOnAttachment](/workspace/classroom/reference/rest/v1/courses.announcements.addOnAttachments#AddOnAttachment).\n\n### Authorization scopes\n\nRequires the following OAuth scope:\n\n- `https://www.googleapis.com/auth/classroom.addons.teacher`\n\nFor more information, see the [Authorization guide](/workspace/guides/configure-oauth-consent)."]]