Opigno API provides possibility to add or remove “like” reactions to posts and comments, this can be done by executing togglePostLike mutation. The mutation changes the state of the “like” flag for the given user: if the post is already liked, the flag will be removed; otherwise, if the post was not liked by the current user before, the flag will be added. The mutation has only one required incoming argument - postID. 
  mutation togglePostLike {
    togglePostLike(postId: 169) {
      response {
        isLiked
      }
      errors
    }
  }
When the same mutation executed the second time, isLiked parameter in the response will be changed to false. The mutation returns a Post object. Detailed description and the full list of available properties can be found here.