--- a
+++ b/R/zzz.R
@@ -0,0 +1,18 @@
+.onAttach <- function(libname, pkgname) {
+  version <- utils::packageDescription(pkgname, fields = "Version")
+
+  msg <- paste0("=========================================================================================
+", pkgname, " version ", version, "
+Project URL: https://github.com/ropensci/UCSCXenaTools
+Usages: https://cran.r-project.org/web/packages/UCSCXenaTools/vignettes/USCSXenaTools.html
+
+If you use it in published research, please cite:
+Wang et al., (2019). The UCSCXenaTools R package: a toolkit for accessing genomics data
+  from UCSC Xena platform, from cancer multi-omics to single-cell RNA-seq.
+  Journal of Open Source Software, 4(40), 1627, https://doi.org/10.21105/joss.01627
+=========================================================================================
+                              --Enjoy it--")
+  # Init API functions
+  .init_api()
+  base::packageStartupMessage(msg)
+}