diff --git a/NAMESPACE b/NAMESPACE
index 445c84d..8b2452b 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -12,6 +12,8 @@ export(dcrchart)
 export(geojson)
 export(html)
 export(js)
+export(pluck_key)
+export(pluck_value)
 export(reduceCount)
 export(reduceMean)
 export(reduceSum)
diff --git a/R/utils.R b/R/utils.R
index 06c0755..3e1d40d 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -120,3 +120,15 @@ y_axis <- function(...) {
 ##' @param id chart id
 ##' @export
 chartname <- function(id) dc_code(sprintf("chart%s", id))
+
+##' Get a variable in the key
+##' @param var variable
+##' @export
+##' 
+pluck_key <- function(var) simple_fun(sprintf("d.key.%s"), var)
+
+##' Get a variable in the value
+##' @param var variable
+##' @export
+##' 
+pluck_value <- function(var) simple_fun(sprintf("d.value.%s"), var)
diff --git a/man/pluck_key.Rd b/man/pluck_key.Rd
new file mode 100644
index 0000000..3f49453
--- /dev/null
+++ b/man/pluck_key.Rd
@@ -0,0 +1,15 @@
+% Generated by roxygen2 (4.1.1): do not edit by hand
+% Please edit documentation in R/utils.R
+\name{pluck_key}
+\alias{pluck_key}
+\title{Get a variable in the key}
+\usage{
+pluck_key(var)
+}
+\arguments{
+\item{var}{variable}
+}
+\description{
+Get a variable in the key
+}
+
diff --git a/man/pluck_value.Rd b/man/pluck_value.Rd
new file mode 100644
index 0000000..791f558
--- /dev/null
+++ b/man/pluck_value.Rd
@@ -0,0 +1,15 @@
+% Generated by roxygen2 (4.1.1): do not edit by hand
+% Please edit documentation in R/utils.R
+\name{pluck_value}
+\alias{pluck_value}
+\title{Get a variable in the value}
+\usage{
+pluck_value(var)
+}
+\arguments{
+\item{var}{variable}
+}
+\description{
+Get a variable in the value
+}
+