allowed, err := client.Permissions.Check(ctx, &avnologyid.CheckPermissionParams{
    Subject:  "user:usr_jane",
    Relation: "editor",
    Object:   "project:proj_abc123",
})
if err != nil {
    log.Fatal(err)
}

if allowed {
    fmt.Println("User has editor access")
} else {
    fmt.Println("Access denied")
}

err := client.Permissions.Grant(ctx, &avnologyid.GrantPermissionParams{
    Subject:  "user:usr_jane",
    Relation: "editor",
    Object:   "project:proj_abc123",
})

err := client.Permissions.Revoke(ctx, &avnologyid.RevokePermissionParams{
    Subject:  "user:usr_jane",
    Relation: "editor",
    Object:   "project:proj_abc123",
})

result, err := client.Permissions.ListObjects(ctx, &avnologyid.ListObjectsParams{
    Subject:    "user:usr_jane",
    Relation:   "editor",
    ObjectType: "project",
})
if err != nil {
    log.Fatal(err)
}

for _, obj := range result.Objects {
    fmt.Println(obj) // "project:proj_abc123"
}

result, err := client.Permissions.ListSubjects(ctx, &avnologyid.ListSubjectsParams{
    Object:   "project:proj_abc123",
    Relation: "editor",
})

tree, err := client.Permissions.Expand(ctx, &avnologyid.ExpandPermissionParams{
    Object:   "project:proj_abc123",
    Relation: "viewer",
})
// tree.Type: "union"
// tree.Children: nested permission tree

func requirePermission(relation string, objectFromReq func(*http.Request) string) func(http.Handler) http.Handler {
    return func(next http.Handler) http.Handler {
        return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
            userID := r.Context().Value("userID").(string)
            object := objectFromReq(r)

            allowed, err := client.Permissions.Check(r.Context(), &avnologyid.CheckPermissionParams{
                Subject:  "user:" + userID,
                Relation: relation,
                Object:   object,
            })
            if err != nil || !allowed {
                http.Error(w, "Forbidden", http.StatusForbidden)
                return
            }

            next.ServeHTTP(w, r)
        })
    }
}