diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..e180d70
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,10 @@
+module cuelang.org/go
+
+require (
+	github.com/cockroachdb/apd v1.1.0
+	github.com/ghodss/yaml v1.0.0
+	github.com/pkg/errors v0.8.0 // indirect
+	golang.org/x/exp/errors v0.0.0-20181210123644-7d6377eee41f
+	golang.org/x/tools v0.0.0-20181210225255-6a3e9aa2ab77
+	gopkg.in/yaml.v2 v2.2.2 // indirect
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..5293807
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,13 @@
+github.com/cockroachdb/apd v1.1.0 h1:3LFP3629v+1aKXU5Q37mxmRxX/pIu1nijXydLShEq5I=
+github.com/cockroachdb/apd v1.1.0/go.mod h1:8Sl8LxpKi29FqWXR16WEFZRNSz3SoPzUzeMeY4+DwBQ=
+github.com/ghodss/yaml v1.0.0 h1:wQHKEahhL6wmXdzwWG11gIVCkOv05bNOh+Rxn0yngAk=
+github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
+github.com/pkg/errors v0.8.0 h1:WdK/asTD0HN+q6hsWO3/vpuAkAr+tw6aNJNDFFf0+qw=
+github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+golang.org/x/exp/errors v0.0.0-20181210123644-7d6377eee41f h1:B/8yFg7PHSFdahc+fMB+RUy3if9GlZmexAbcdfCwREI=
+golang.org/x/exp/errors v0.0.0-20181210123644-7d6377eee41f/go.mod h1:YgqsNsAu4fTvlab/7uiYK9LJrCIzKg/NiZUIH1/ayqo=
+golang.org/x/tools v0.0.0-20181210225255-6a3e9aa2ab77 h1:s+6psEFi3o1QryeA/qyvUoVaHMCQkYVvZ0i2ZolwSJc=
+golang.org/x/tools v0.0.0-20181210225255-6a3e9aa2ab77/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=