diff --git a/.travis.yml b/.travis.yml
index 04abaf6..78683d3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,8 @@
 language: go
 
 go:
-  - "1.10"
-  - "1.11"
+  - "1.12.x"
+  - "1.13.x"
   - tip
 
 services:
@@ -13,20 +13,22 @@ addons:
     packages:
       - docker-ce
 
+env:
+  - GO111MODULE=on
+
 before_install:
-  - go get github.com/golang/dep/...
   - go get golang.org/x/lint/golint
   - go get github.com/mattn/goveralls
 
 install:
-  - $GOPATH/bin/dep ensure
+  - go mod vendor
 
 script:
-  - make test
-  - make lint
+  - go test -cover -b `go list ./...`
+  - golint `go list ./...`
 
 after_script: |
-  if [[ $TRAVIS_GO_VERSION == 1.11* ]] && [[ "$TRAVIS_BRANCH" == "master" ]] && [[ "$TRAVIS_PULL_REQUEST" == "false" ]]; then
+  if [[ $TRAVIS_GO_VERSION == 1.13* ]] && [[ "$TRAVIS_BRANCH" == "master" ]] && [[ "$TRAVIS_PULL_REQUEST" == "false" ]]; then
     goveralls -repotoken ${COVERALLS_TOKEN}
     echo "$DOCKER_PASSWORD" | docker login -u "$DOCKER_USERNAME" --password-stdin
     docker build -t ynqa/wego:latest .
diff --git a/Dockerfile b/Dockerfile
index 39aa4a7..0574a3b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -14,7 +14,7 @@ RUN dep ensure -v -vendor-only
 RUN go build -v -o wego .
 
 FROM busybox
-COPY --from=builder /go/src/github.com/ynqa/wego/wego /usr/local/bin/wego
+COPY --from=builder /go/src/github.com/ynqa/wego/pkg/wego /usr/local/bin/wego
 
 ENTRYPOINT ["wego"]
 CMD ["help"]
diff --git a/Gopkg.lock b/Gopkg.lock
deleted file mode 100644
index 4731be8..0000000
--- a/Gopkg.lock
+++ /dev/null
@@ -1,328 +0,0 @@
-# This file is autogenerated, do not edit; changes may be undone by the next 'dep ensure'.
-
-
-[[projects]]
-  digest = "1:1c8ee7543ae60103ae543f79e6044d768e6de6cfaa245c53e45f3681c7f682a0"
-  name = "github.com/awalterschulze/gographviz"
-  packages = [
-    ".",
-    "ast",
-    "internal/errors",
-    "internal/lexer",
-    "internal/parser",
-    "internal/token",
-  ]
-  pruneopts = ""
-  revision = "c84395e536e1a1199093a4e6253d1bee99e4cd2a"
-  version = "v2.0"
-
-[[projects]]
-  digest = "1:6469c328b65de06b5e6c69f55d55599d00c67917909dfb705033b9b7c7fd66b9"
-  name = "github.com/chewxy/hm"
-  packages = ["."]
-  pruneopts = ""
-  revision = "61efb3290a086d1335e8954b3734c102126818ba"
-  version = "v1.0.0"
-
-[[projects]]
-  branch = "master"
-  digest = "1:3971d043d2f7216722fe46cb9e042f6affe19b663b2ccafff6e06bd2e1d84588"
-  name = "github.com/chewxy/lingo"
-  packages = [
-    ".",
-    "corpus",
-    "treebank",
-  ]
-  pruneopts = ""
-  revision = "8f8059f5438926f7f50e8c62135b0af85376aeca"
-
-[[projects]]
-  digest = "1:44bfa822819c2707ebc72916d24145494c778af59e91a5aa138606776fe6052b"
-  name = "github.com/chewxy/math32"
-  packages = ["."]
-  pruneopts = ""
-  revision = "d1e7b22839c693f54edf7811dd9487623abf2cd2"
-  version = "v1.0.0"
-
-[[projects]]
-  digest = "1:9f1e571696860f2b4f8a241b43ce91c6085e7aaed849ccca53f590a4dc7b95bd"
-  name = "github.com/fsnotify/fsnotify"
-  packages = ["."]
-  pruneopts = ""
-  revision = "629574ca2a5df945712d3079857300b5e4da0236"
-  version = "v1.4.2"
-
-[[projects]]
-  branch = "master"
-  digest = "1:147d671753effde6d3bcd58fc74c1d67d740196c84c280c762a5417319499972"
-  name = "github.com/hashicorp/hcl"
-  packages = [
-    ".",
-    "hcl/ast",
-    "hcl/parser",
-    "hcl/scanner",
-    "hcl/strconv",
-    "hcl/token",
-    "json/parser",
-    "json/scanner",
-    "json/token",
-  ]
-  pruneopts = ""
-  revision = "23c074d0eceb2b8a5bfdbb271ab780cde70f05a8"
-
-[[projects]]
-  digest = "1:870d441fe217b8e689d7949fef6e43efbc787e50f200cb1e70dbca9204a1d6be"
-  name = "github.com/inconshreveable/mousetrap"
-  packages = ["."]
-  pruneopts = ""
-  revision = "76626ae9c91c4f2a10f34cad8ce83ea42c93bb75"
-  version = "v1.0"
-
-[[projects]]
-  branch = "master"
-  digest = "1:cf63454c1e81409484ded047413228de0f7a3031f0fcd36d4e1db7620c3c7d1b"
-  name = "github.com/leesper/go_rng"
-  packages = ["."]
-  pruneopts = ""
-  revision = "5344a9259b21627d94279721ab1f27eb029194e7"
-
-[[projects]]
-  digest = "1:739b2038a38cebb50e922d18f4b042c042256320fea2db094814aeef8891e0c1"
-  name = "github.com/magiconair/properties"
-  packages = ["."]
-  pruneopts = ""
-  revision = "d419a98cdbed11a922bf76f257b7c4be79b50e73"
-  version = "v1.7.4"
-
-[[projects]]
-  digest = "1:81e673df85e765593a863f67cba4544cf40e8919590f04d67664940786c2b61a"
-  name = "github.com/mattn/go-runewidth"
-  packages = ["."]
-  pruneopts = ""
-  revision = "9e777a8366cce605130a531d2cd6363d07ad7317"
-  version = "v0.0.2"
-
-[[projects]]
-  branch = "master"
-  digest = "1:30a2adc78c422ebd23aac9cfece529954d5eacf9ddbe37345f2a17439f8fa849"
-  name = "github.com/mitchellh/mapstructure"
-  packages = ["."]
-  pruneopts = ""
-  revision = "06020f85339e21b2478f756a78e295255ffa4d6a"
-
-[[projects]]
-  branch = "master"
-  digest = "1:fcb36be3abd0dc761d26591aed850a4b970deea9e095c783788cebf6ccf1267b"
-  name = "github.com/olekukonko/tablewriter"
-  packages = ["."]
-  pruneopts = ""
-  revision = "65fec0d89a572b4367094e2058d3ebe667de3b60"
-
-[[projects]]
-  digest = "1:9c740db1f7015dffa093aa5c70862d277fe49f5e92b56ca5d0d69ef0e37c01db"
-  name = "github.com/pelletier/go-toml"
-  packages = ["."]
-  pruneopts = ""
-  revision = "16398bac157da96aa88f98a2df640c7f32af1da2"
-  version = "v1.0.1"
-
-[[projects]]
-  digest = "1:4aee2a94909f9d05d53281e22268c629f6eba9ddc179fdbcd6466de5a998e01e"
-  name = "github.com/peterh/liner"
-  packages = ["."]
-  pruneopts = ""
-  revision = "5a0dfa99e2aa1d433a9642e863da51402e609376"
-  version = "v1.1.0"
-
-[[projects]]
-  digest = "1:7365acd48986e205ccb8652cc746f09c8b7876030d53710ea6ef7d0bd0dcd7ca"
-  name = "github.com/pkg/errors"
-  packages = ["."]
-  pruneopts = ""
-  revision = "645ef00459ed84a119197bfb8d8205042c6df63d"
-  version = "v0.8.0"
-
-[[projects]]
-  digest = "1:d1c1e5f4064b332bd90bba7bc2ab403c0afd7b36d34b7875877a45c78d24f5c1"
-  name = "github.com/spf13/afero"
-  packages = [
-    ".",
-    "mem",
-  ]
-  pruneopts = ""
-  revision = "8d919cbe7e2627e417f3e45c3c0e489a5b7e2536"
-  version = "v1.0.0"
-
-[[projects]]
-  digest = "1:6ff9b74bfea2625f805edec59395dc37e4a06458dd3c14e3372337e3d35a2ed6"
-  name = "github.com/spf13/cast"
-  packages = ["."]
-  pruneopts = ""
-  revision = "acbeb36b902d72a7a4c18e8f3241075e7ab763e4"
-  version = "v1.1.0"
-
-[[projects]]
-  digest = "1:2208a80fc3259291e43b30f42f844d18f4218036dff510f42c653ec9890d460a"
-  name = "github.com/spf13/cobra"
-  packages = ["."]
-  pruneopts = ""
-  revision = "7b2c5ac9fc04fc5efafb60700713d4fa609b777b"
-  version = "v0.0.1"
-
-[[projects]]
-  branch = "master"
-  digest = "1:5cb42b990db5dc48b8bc23b6ee77b260713ba3244ca495cd1ed89533dc482a49"
-  name = "github.com/spf13/jwalterweatherman"
-  packages = ["."]
-  pruneopts = ""
-  revision = "12bd96e66386c1960ab0f74ced1362f66f552f7b"
-
-[[projects]]
-  digest = "1:261bc565833ef4f02121450d74eb88d5ae4bd74bfe5d0e862cddb8550ec35000"
-  name = "github.com/spf13/pflag"
-  packages = ["."]
-  pruneopts = ""
-  revision = "e57e3eeb33f795204c1ca35f56c44f83227c6e66"
-  version = "v1.0.0"
-
-[[projects]]
-  digest = "1:59354ad53dfe6ed1b941844cb029cd37c0377598eec3a0d49c03aee2375ef9c4"
-  name = "github.com/spf13/viper"
-  packages = ["."]
-  pruneopts = ""
-  revision = "25b30aa063fc18e48662b86996252eabdcf2f0c7"
-  version = "v1.0.0"
-
-[[projects]]
-  branch = "master"
-  digest = "1:f11510bf901cb0a8a23376c2be679083fe34f0b49af7e12fbe9ad5a78531c990"
-  name = "github.com/xtgo/set"
-  packages = ["."]
-  pruneopts = ""
-  revision = "4431f6b51265b1e0b76af4dafc09d6f12c2bdcd0"
-
-[[projects]]
-  branch = "master"
-  digest = "1:134679482ac3fd5ecd60c1412510d52272e29e1085bf2dd2d7e79e2d1d38acc0"
-  name = "golang.org/x/sys"
-  packages = ["unix"]
-  pruneopts = ""
-  revision = "83801418e1b59fb1880e363299581ee543af32ca"
-
-[[projects]]
-  branch = "master"
-  digest = "1:9f9562b058a594dae0c8e2388c1a802664111736845bc08885246f0e4bf99bdd"
-  name = "golang.org/x/text"
-  packages = [
-    "internal/gen",
-    "internal/triegen",
-    "internal/ucd",
-    "transform",
-    "unicode/cldr",
-    "unicode/norm",
-  ]
-  pruneopts = ""
-  revision = "e19ae1496984b1c655b8044a65c0300a3c878dd3"
-
-[[projects]]
-  branch = "master"
-  digest = "1:8f50bd9851c444ca9c217adf861f4c79e99061d6a529e57bafd2e8144a170e4a"
-  name = "gonum.org/v1/gonum"
-  packages = [
-    "blas",
-    "blas/blas64",
-    "blas/gonum",
-    "floats",
-    "graph",
-    "graph/internal/linear",
-    "graph/internal/ordered",
-    "graph/internal/set",
-    "graph/topo",
-    "graph/traverse",
-    "internal/asm/c128",
-    "internal/asm/f32",
-    "internal/asm/f64",
-    "internal/math32",
-    "lapack",
-    "lapack/gonum",
-    "lapack/lapack64",
-    "mat",
-  ]
-  pruneopts = ""
-  revision = "cd47c93d54483f54eed45cc1e2e1264d267f326c"
-
-[[projects]]
-  digest = "1:0b6bc675e713ed14b49106a6332b66c693e70c116d02209457564a68b032a075"
-  name = "gopkg.in/cheggaaa/pb.v1"
-  packages = ["."]
-  pruneopts = ""
-  revision = "18d384da9bdc1e5a08fc2a62a494c321d9ae74ea"
-  version = "v1.0.19"
-
-[[projects]]
-  branch = "v2"
-  digest = "1:f769ed60e075e4221612c2f4162fccc9d3795ef358fa463425e3b3d7a5debb27"
-  name = "gopkg.in/yaml.v2"
-  packages = ["."]
-  pruneopts = ""
-  revision = "287cf08546ab5e7e37d55a84f7ed3fd1db036de5"
-
-[[projects]]
-  digest = "1:26d2fe2bb4b4b7bdf1b8ae1b6f76535f69569cc2d2eafacf34b196895161a8a5"
-  name = "gorgonia.org/cu"
-  packages = ["."]
-  pruneopts = ""
-  revision = "32f165836e285c14a4f78c455872d069e0cc5a7d"
-  version = "v0.8.0"
-
-[[projects]]
-  digest = "1:28cb119d50a971910199ad65ca835c96ea142961296181aad4ea8e88c3759e12"
-  name = "gorgonia.org/gorgonia"
-  packages = ["."]
-  pruneopts = ""
-  revision = "55787bbd182f3d621f26c0a85e7de2e6a28ba5eb"
-  version = "v0.8.0"
-
-[[projects]]
-  digest = "1:e9b9b85cc2ea057c57940153daf24f6ffe0831c081cdc04f91b5b545ebe52210"
-  name = "gorgonia.org/tensor"
-  packages = [
-    ".",
-    "internal/execution",
-    "internal/storage",
-  ]
-  pruneopts = ""
-  revision = "863b76853934d224104ae8cc08f2d27202521242"
-  version = "v0.8.0"
-
-[[projects]]
-  branch = "master"
-  digest = "1:56036c6ea3474d2088a8778156e08aebb909a6b5ea269deabbe9907b84ccbefe"
-  name = "gorgonia.org/vecf32"
-  packages = ["."]
-  pruneopts = ""
-  revision = "9c61466a81d94e61358d0a8cf77e5d76ff5de655"
-
-[[projects]]
-  branch = "master"
-  digest = "1:ed3279740b1f34e3de46b1073723aab5417557e8a993bfab58736cb9852a49c3"
-  name = "gorgonia.org/vecf64"
-  packages = ["."]
-  pruneopts = ""
-  revision = "92cacded62a76710546770b2b86b1ca82ff76614"
-
-[solve-meta]
-  analyzer-name = "dep"
-  analyzer-version = 1
-  input-imports = [
-    "github.com/chewxy/lingo/corpus",
-    "github.com/olekukonko/tablewriter",
-    "github.com/peterh/liner",
-    "github.com/pkg/errors",
-    "github.com/spf13/cobra",
-    "github.com/spf13/pflag",
-    "github.com/spf13/viper",
-    "gopkg.in/cheggaaa/pb.v1",
-  ]
-  solver-name = "gps-cdcl"
-  solver-version = 1
diff --git a/Gopkg.toml b/Gopkg.toml
deleted file mode 100644
index 5c49d27..0000000
--- a/Gopkg.toml
+++ /dev/null
@@ -1,31 +0,0 @@
-[[constraint]]
-  branch = "master"
-  name = "github.com/chewxy/lingo"
-
-[[constraint]]
-  branch = "master"
-  name = "github.com/olekukonko/tablewriter"
-
-[[constraint]]
-  name = "github.com/pkg/errors"
-  version = "0.8.0"
-
-[[constraint]]
-  name = "github.com/spf13/cobra"
-  version = "0.0.1"
-
-[[constraint]]
-  name = "github.com/spf13/pflag"
-  version = "1.0.0"
-
-[[constraint]]
-  name = "github.com/spf13/viper"
-  version = "1.0.0"
-
-[[constraint]]
-  name = "gopkg.in/cheggaaa/pb.v1"
-  version = "1.0.18"
-
-[[constraint]]
-  name = "github.com/peterh/liner"
-  version = "1.1.0"
diff --git a/LICENSE b/LICENSE
index d645695..261eeb9 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,3 @@
-
                                  Apache License
                            Version 2.0, January 2004
                         http://www.apache.org/licenses/
diff --git a/Makefile b/Makefile
deleted file mode 100644
index 7fb1f14..0000000
--- a/Makefile
+++ /dev/null
@@ -1,30 +0,0 @@
-.PHONY: build
-build:
-	go build
-
-.PHONY: clean-vendor
-clean-vendor:
-	rm -rf vendor/
-
-.PHONY: clean-example
-clean-example:
-	rm -rf example/*.txt
-
-.PHONY: clean
-clean: clean-example clean-vendor
-
-.PHONY: ensure
-ensure:
-	dep ensure -vendor-only
-
-.PHONY: fmt
-fmt:
-	go fmt `go list ./...`
-
-.PHONY: lint
-lint:
-	golint `go list ./...`
-
-.PHONY: test
-test:
-	go test -cover -v `go list ./...`
diff --git a/README.md b/README.md
index 7f87f1d..f487f8d 100644
--- a/README.md
+++ b/README.md
@@ -85,8 +85,8 @@ package main
 import (
 	"os"
 
-	"github.com/ynqa/wego/builder"
-	"github.com/ynqa/wego/model/word2vec"
+	"github.com/ynqa/wego/pkg/builder"
+	"github.com/ynqa/wego/pkg/model/word2vec"
 )
 
 func main() {
diff --git a/cmd/glove.go b/cmd/glove.go
index b46bdde..917fd57 100644
--- a/cmd/glove.go
+++ b/cmd/glove.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package cmd
+package main
 
 import (
 	"os"
@@ -22,9 +22,9 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 
-	"github.com/ynqa/wego/builder"
-	"github.com/ynqa/wego/config"
-	"github.com/ynqa/wego/validate"
+	"github.com/ynqa/wego/pkg/builder"
+	"github.com/ynqa/wego/pkg/config"
+	"github.com/ynqa/wego/pkg/validate"
 )
 
 var gloveCmd = &cobra.Command{
diff --git a/cmd/glove_test.go b/cmd/glove_test.go
index 36bb718..67255be 100644
--- a/cmd/glove_test.go
+++ b/cmd/glove_test.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package cmd
+package main
 
 import (
 	"testing"
diff --git a/cmd/lexvec.go b/cmd/lexvec.go
index 24a5f15..4d3e3d8 100644
--- a/cmd/lexvec.go
+++ b/cmd/lexvec.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package cmd
+package main
 
 import (
 	"os"
@@ -22,9 +22,9 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 
-	"github.com/ynqa/wego/builder"
-	"github.com/ynqa/wego/config"
-	"github.com/ynqa/wego/validate"
+	"github.com/ynqa/wego/pkg/builder"
+	"github.com/ynqa/wego/pkg/config"
+	"github.com/ynqa/wego/pkg/validate"
 )
 
 var lexvecCmd = &cobra.Command{
diff --git a/cmd/repl.go b/cmd/repl.go
index 2d67453..744c02f 100644
--- a/cmd/repl.go
+++ b/cmd/repl.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package cmd
+package main
 
 import (
 	"os"
@@ -20,8 +20,8 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 
-	"github.com/ynqa/wego/config"
-	"github.com/ynqa/wego/repl"
+	"github.com/ynqa/wego/pkg/config"
+	"github.com/ynqa/wego/pkg/repl"
 )
 
 var replCmd = &cobra.Command{
diff --git a/cmd/repl_test.go b/cmd/repl_test.go
index 92e71b8..55a9be5 100644
--- a/cmd/repl_test.go
+++ b/cmd/repl_test.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package cmd
+package main
 
 import (
 	"testing"
diff --git a/cmd/root.go b/cmd/root.go
index e1fc503..736215a 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package cmd
+package main
 
 import (
 	"github.com/pkg/errors"
@@ -20,7 +20,7 @@ import (
 	"github.com/spf13/pflag"
 	"github.com/spf13/viper"
 
-	"github.com/ynqa/wego/config"
+	"github.com/ynqa/wego/pkg/config"
 )
 
 // RootCmd is the root command for word embedding.
diff --git a/cmd/root_test.go b/cmd/root_test.go
index 3c3a386..f425d2d 100644
--- a/cmd/root_test.go
+++ b/cmd/root_test.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package cmd
+package main
 
 import (
 	"testing"
diff --git a/cmd/search.go b/cmd/search.go
index 5a2f4ce..0510f43 100644
--- a/cmd/search.go
+++ b/cmd/search.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package cmd
+package main
 
 import (
 	"os"
@@ -21,8 +21,8 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 
-	"github.com/ynqa/wego/config"
-	"github.com/ynqa/wego/search"
+	"github.com/ynqa/wego/pkg/config"
+	"github.com/ynqa/wego/pkg/search"
 )
 
 var searchCmd = &cobra.Command{
diff --git a/cmd/search_test.go b/cmd/search_test.go
index 4f2672a..681ba43 100644
--- a/cmd/search_test.go
+++ b/cmd/search_test.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package cmd
+package main
 
 import (
 	"testing"
diff --git a/wego.go b/cmd/wego.go
similarity index 89%
rename from wego.go
rename to cmd/wego.go
index f906cb0..488a35c 100644
--- a/wego.go
+++ b/cmd/wego.go
@@ -16,12 +16,10 @@ package main
 
 import (
 	"os"
-
-	"github.com/ynqa/wego/cmd"
 )
 
 func main() {
-	if err := cmd.RootCmd.Execute(); err != nil {
+	if err := RootCmd.Execute(); err != nil {
 		os.Exit(1)
 	}
 }
diff --git a/cmd/word2vec.go b/cmd/word2vec.go
index a23dff1..e48f37b 100644
--- a/cmd/word2vec.go
+++ b/cmd/word2vec.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package cmd
+package main
 
 import (
 	"os"
@@ -22,9 +22,9 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 
-	"github.com/ynqa/wego/builder"
-	"github.com/ynqa/wego/config"
-	"github.com/ynqa/wego/validate"
+	"github.com/ynqa/wego/pkg/builder"
+	"github.com/ynqa/wego/pkg/config"
+	"github.com/ynqa/wego/pkg/validate"
 )
 
 var word2vecCmd = &cobra.Command{
diff --git a/cmd/word2vec_test.go b/cmd/word2vec_test.go
index c0544ca..89c604a 100644
--- a/cmd/word2vec_test.go
+++ b/cmd/word2vec_test.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package cmd
+package main
 
 import (
 	"testing"
diff --git a/example/glove/glove.go b/examples/glove/glove.go
similarity index 92%
rename from example/glove/glove.go
rename to examples/glove/glove.go
index 8440b3f..0117fd2 100644
--- a/example/glove/glove.go
+++ b/examples/glove/glove.go
@@ -17,8 +17,8 @@ package main
 import (
 	"os"
 
-	"github.com/ynqa/wego/builder"
-	"github.com/ynqa/wego/model/glove"
+	"github.com/ynqa/wego/pkg/builder"
+	"github.com/ynqa/wego/pkg/model/glove"
 )
 
 func main() {
diff --git a/example/lexvec/lexvec.go b/examples/lexvec/lexvec.go
similarity index 93%
rename from example/lexvec/lexvec.go
rename to examples/lexvec/lexvec.go
index 2371dfd..755f2e5 100644
--- a/example/lexvec/lexvec.go
+++ b/examples/lexvec/lexvec.go
@@ -17,8 +17,8 @@ package main
 import (
 	"os"
 
-	"github.com/ynqa/wego/builder"
-	"github.com/ynqa/wego/corpus"
+	"github.com/ynqa/wego/pkg/builder"
+	"github.com/ynqa/wego/pkg/corpus"
 )
 
 func main() {
diff --git a/example/word2vec/word2vec.go b/examples/word2vec/word2vec.go
similarity index 93%
rename from example/word2vec/word2vec.go
rename to examples/word2vec/word2vec.go
index ea80970..d0d04c0 100644
--- a/example/word2vec/word2vec.go
+++ b/examples/word2vec/word2vec.go
@@ -17,8 +17,8 @@ package main
 import (
 	"os"
 
-	"github.com/ynqa/wego/builder"
-	"github.com/ynqa/wego/model/word2vec"
+	"github.com/ynqa/wego/pkg/builder"
+	"github.com/ynqa/wego/pkg/model/word2vec"
 )
 
 func main() {
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..b3e5466
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,37 @@
+module github.com/ynqa/wego
+
+go 1.13
+
+require (
+	github.com/awalterschulze/gographviz v0.0.0-20170410065617-c84395e536e1 // indirect
+	github.com/chewxy/hm v1.0.0 // indirect
+	github.com/chewxy/lingo v0.0.0-20180424035724-8f8059f54389
+	github.com/chewxy/math32 v1.0.0 // indirect
+	github.com/fsnotify/fsnotify v1.4.2 // indirect
+	github.com/hashicorp/hcl v0.0.0-20171017181929-23c074d0eceb // indirect
+	github.com/inconshreveable/mousetrap v1.0.0 // indirect
+	github.com/leesper/go_rng v0.0.0-20171009123644-5344a9259b21 // indirect
+	github.com/magiconair/properties v1.7.4 // indirect
+	github.com/mitchellh/mapstructure v0.0.0-20171017171808-06020f85339e // indirect
+	github.com/olekukonko/tablewriter v0.0.0-20171203151007-65fec0d89a57
+	github.com/pelletier/go-toml v1.0.1 // indirect
+	github.com/peterh/liner v1.1.0
+	github.com/pkg/errors v0.8.0
+	github.com/spf13/afero v1.0.0 // indirect
+	github.com/spf13/cast v1.1.0 // indirect
+	github.com/spf13/cobra v0.0.1
+	github.com/spf13/jwalterweatherman v0.0.0-20170901151539-12bd96e66386 // indirect
+	github.com/spf13/pflag v1.0.0
+	github.com/spf13/viper v1.0.0
+	github.com/stretchr/testify v1.4.0 // indirect
+	github.com/xtgo/set v0.0.0-20151204082305-4431f6b51265 // indirect
+	golang.org/x/sys v0.0.0-20171222143536-83801418e1b5 // indirect
+	golang.org/x/text v0.3.1-0.20171227012246-e19ae1496984 // indirect
+	gonum.org/v1/gonum v0.0.0-20171227085449-cd47c93d5448 // indirect
+	gopkg.in/cheggaaa/pb.v1 v1.0.19
+	gorgonia.org/cu v0.8.0 // indirect
+	gorgonia.org/gorgonia v0.8.0 // indirect
+	gorgonia.org/tensor v0.8.0 // indirect
+	gorgonia.org/vecf32 v0.7.1-0.20171210012140-9c61466a81d9 // indirect
+	gorgonia.org/vecf64 v0.7.1-0.20171210012113-92cacded62a7 // indirect
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..6cfe2af
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,60 @@
+github.com/awalterschulze/gographviz v0.0.0-20170410065617-c84395e536e1 h1:r2lcIqPAm8+z4sEiWTJW3JR3/tc9WWH95hZFXLd2Y0g=
+github.com/awalterschulze/gographviz v0.0.0-20170410065617-c84395e536e1/go.mod h1:GEV5wmg4YquNw7v1kkyoX9etIk8yVmXj+AkDHuuETHs=
+github.com/chewxy/hm v1.0.0/go.mod h1:qg9YI4q6Fkj/whwHR1D+bOGeF7SniIP40VweVepLjg0=
+github.com/chewxy/lingo v0.0.0-20180424035724-8f8059f54389/go.mod h1:q5CiNpjdywd0YKLC4xgjZEWe02MRmIfpmpt4aZRf9jg=
+github.com/chewxy/math32 v1.0.0/go.mod h1:Miac6hA1ohdDUTagnvJy/q+aNnEk16qWUdb8ZVhvCN0=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/fsnotify/fsnotify v1.4.2 h1:v5tKwtf2hNhBV24eNYfQ5UmvFOGlOCmRqk7/P1olxtk=
+github.com/fsnotify/fsnotify v1.4.2/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
+github.com/hashicorp/hcl v0.0.0-20171017181929-23c074d0eceb h1:1OvvPvZkn/yCQ3xBcM8y4020wdkMXPHLB4+NfoGWh4U=
+github.com/hashicorp/hcl v0.0.0-20171017181929-23c074d0eceb/go.mod h1:oZtUIOe8dh44I2q6ScRibXws4Ajl+d+nod3AaR9vL5w=
+github.com/inconshreveable/mousetrap v1.0.0 h1:Z8tu5sraLXCXIcARxBp/8cbvlwVa7Z1NHg9XEKhtSvM=
+github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
+github.com/leesper/go_rng v0.0.0-20171009123644-5344a9259b21/go.mod h1:N0SVk0uhy+E1PZ3C9ctsPRlvOPAFPkCNlcPBDkt0N3U=
+github.com/magiconair/properties v1.7.4 h1:UVo0TkHGd4lQSN1dVDzs9URCIgReuSIcCXpAVB9nZ80=
+github.com/magiconair/properties v1.7.4/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
+github.com/mattn/go-runewidth v0.0.2/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=
+github.com/mattn/go-runewidth v0.0.3 h1:a+kO+98RDGEfo6asOGMmpodZq4FNtnGP54yps8BzLR4=
+github.com/mattn/go-runewidth v0.0.3/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=
+github.com/mitchellh/mapstructure v0.0.0-20171017171808-06020f85339e h1:PtGHLB3CX3TFPcksODQMxncoeQKWwCgTg0bJ40VLJP4=
+github.com/mitchellh/mapstructure v0.0.0-20171017171808-06020f85339e/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
+github.com/olekukonko/tablewriter v0.0.0-20171203151007-65fec0d89a57/go.mod h1:vsDQFd/mU46D+Z4whnwzcISnGGzXWMclvtLoiIKAKIo=
+github.com/pelletier/go-toml v1.0.1 h1:0nx4vKBl23+hEaCOV1mFhKS9vhhBtFYWC7rQY0vJAyE=
+github.com/pelletier/go-toml v1.0.1/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
+github.com/peterh/liner v1.1.0 h1:f+aAedNJA6uk7+6rXsYBnhdo4Xux7ESLe+kcuVUF5os=
+github.com/peterh/liner v1.1.0/go.mod h1:CRroGNssyjTd/qIG2FyxByd2S8JEAZXBl4qUrZf8GS0=
+github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/spf13/afero v1.0.0 h1:Z005C09nPzwTTsDRJCQBVnpTU0bjTr/NhyWLj1nSPP4=
+github.com/spf13/afero v1.0.0/go.mod h1:j4pytiNVoe2o6bmDsKpLACNPDBIoEAkihy7loJ1B0CQ=
+github.com/spf13/cast v1.1.0 h1:0Rhw4d6C8J9VPu6cjZLIhZ8+aAOHcDvGeKn+cq5Aq3k=
+github.com/spf13/cast v1.1.0/go.mod h1:r2rcYCSwa1IExKTDiTfzaxqT2FNHs8hODu4LnUfgKEg=
+github.com/spf13/cobra v0.0.1/go.mod h1:1l0Ry5zgKvJasoi3XT1TypsSe7PqH0Sj9dhYf7v3XqQ=
+github.com/spf13/jwalterweatherman v0.0.0-20170901151539-12bd96e66386 h1:zBoLErXXAvWnNsu+pWkRYl6Cx1KXmIfAVsIuYkPN6aY=
+github.com/spf13/jwalterweatherman v0.0.0-20170901151539-12bd96e66386/go.mod h1:cQK4TGJAtQXfYWX+Ddv3mKDzgVb68N+wFjFa4jdeBTo=
+github.com/spf13/pflag v1.0.0/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
+github.com/spf13/viper v1.0.0 h1:RUA/ghS2i64rlnn4ydTfblY8Og8QzcPtCcHvgMn+w/I=
+github.com/spf13/viper v1.0.0/go.mod h1:A8kyI5cUJhb8N+3pkfONlcEcZbueH6nhAm0Fq7SrnBM=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+github.com/xtgo/set v0.0.0-20151204082305-4431f6b51265 h1:86yslOGLdMhh3xJR1+1UleoyTbyzmBWAGDdw0qPg1HI=
+github.com/xtgo/set v0.0.0-20151204082305-4431f6b51265/go.mod h1:d3NHzGzSa0NmB2NhFyECA+QdRp29oEn2xbT+TpeFoM8=
+golang.org/x/sys v0.0.0-20171222143536-83801418e1b5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/text v0.3.1-0.20171227012246-e19ae1496984 h1:4S3Dic2vY09agWhKAjYa6buMB7HsLkVrliEHZclmmSU=
+golang.org/x/text v0.3.1-0.20171227012246-e19ae1496984/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+gonum.org/v1/gonum v0.0.0-20171227085449-cd47c93d5448 h1:sTUWU+bhQAWFzZe659aEHnUcwkw6x/chMg4u1+SFSoo=
+gonum.org/v1/gonum v0.0.0-20171227085449-cd47c93d5448/go.mod h1:cucAdkem48eM79EG1fdGOGASXorNZIYAO9duTse+1cI=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/cheggaaa/pb.v1 v1.0.19/go.mod h1:V/YB90LKu/1FcN3WVnfiiE5oMCibMjukxqG/qStrOgw=
+gopkg.in/yaml.v2 v2.0.0-20171116090243-287cf08546ab h1:yZ6iByf7GKeJ3gsd1Dr/xaj1DyJ//wxKX1Cdh8LhoAw=
+gopkg.in/yaml.v2 v2.0.0-20171116090243-287cf08546ab/go.mod h1:JAlM8MvJe8wmxCU4Bli9HhUf9+ttbYbLASfIpnQbh74=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gorgonia.org/cu v0.8.0 h1:XpTkl5IpMlTPNJl6pKQPEXVV/9TnEtiRB7j1gGkrzCI=
+gorgonia.org/cu v0.8.0/go.mod h1:RPEPIfaxxqUmeRe7T1T8a0NER+KxBI2McoLEXhP1Vd8=
+gorgonia.org/gorgonia v0.8.0/go.mod h1:qucT7YHm/2OuSHWEw/6Je/LQ5htRJNQJ1+qpB58fY8c=
+gorgonia.org/tensor v0.8.0 h1:+JDsIEnx+wQVf9brvrYyU+/uZit2PnzP9Dt4CWNeirQ=
+gorgonia.org/tensor v0.8.0/go.mod h1:05Y4laKuVlj4qFoZIZW1q/9n1jZkgDBOLmKXZdBLG1w=
+gorgonia.org/vecf32 v0.7.1-0.20171210012140-9c61466a81d9 h1:L4MiT1K2R1dTZEgy9Qo7cbPz3vnYlCXBplZvmdPi4Ko=
+gorgonia.org/vecf32 v0.7.1-0.20171210012140-9c61466a81d9/go.mod h1:iHG+kvTMqGYA0SgahfO2k62WRnxmHsqAREGbayRDzy8=
+gorgonia.org/vecf64 v0.7.1-0.20171210012113-92cacded62a7 h1:UX4nbW/6w1hRHsWVpYJZjqjlbSvql5ynxioh1z/KLTI=
+gorgonia.org/vecf64 v0.7.1-0.20171210012113-92cacded62a7/go.mod h1:1y4pmcSd+wh3phG+InwWQjYrqwyrtN9h27WLFVQfV1Q=
diff --git a/builder/glove.go b/pkg/builder/glove.go
similarity index 98%
rename from builder/glove.go
rename to pkg/builder/glove.go
index 2ad5f91..0340ff5 100644
--- a/builder/glove.go
+++ b/pkg/builder/glove.go
@@ -18,9 +18,9 @@ import (
 	"github.com/pkg/errors"
 	"github.com/spf13/viper"
 
-	"github.com/ynqa/wego/config"
-	"github.com/ynqa/wego/model"
-	"github.com/ynqa/wego/model/glove"
+	"github.com/ynqa/wego/pkg/config"
+	"github.com/ynqa/wego/pkg/model"
+	"github.com/ynqa/wego/pkg/model/glove"
 )
 
 // GloveBuilder manages the members to build Model interface.
diff --git a/builder/glove_test.go b/pkg/builder/glove_test.go
similarity index 98%
rename from builder/glove_test.go
rename to pkg/builder/glove_test.go
index 7b7df17..0fb114a 100644
--- a/builder/glove_test.go
+++ b/pkg/builder/glove_test.go
@@ -17,7 +17,7 @@ package builder
 import (
 	"testing"
 
-	"github.com/ynqa/wego/model/glove"
+	"github.com/ynqa/wego/pkg/model/glove"
 )
 
 func TestGloveDimension(t *testing.T) {
diff --git a/builder/lexvec.go b/pkg/builder/lexvec.go
similarity index 97%
rename from builder/lexvec.go
rename to pkg/builder/lexvec.go
index 3fbc631..d48c9c8 100644
--- a/builder/lexvec.go
+++ b/pkg/builder/lexvec.go
@@ -18,10 +18,10 @@ import (
 	"github.com/pkg/errors"
 	"github.com/spf13/viper"
 
-	"github.com/ynqa/wego/config"
-	"github.com/ynqa/wego/corpus"
-	"github.com/ynqa/wego/model"
-	"github.com/ynqa/wego/model/lexvec"
+	"github.com/ynqa/wego/pkg/config"
+	"github.com/ynqa/wego/pkg/corpus"
+	"github.com/ynqa/wego/pkg/model"
+	"github.com/ynqa/wego/pkg/model/lexvec"
 )
 
 // LexvecBuilder manages the members to build Model interface.
diff --git a/builder/word2vec.go b/pkg/builder/word2vec.go
similarity index 98%
rename from builder/word2vec.go
rename to pkg/builder/word2vec.go
index 24f8f2f..a6b5fe6 100644
--- a/builder/word2vec.go
+++ b/pkg/builder/word2vec.go
@@ -18,9 +18,9 @@ import (
 	"github.com/pkg/errors"
 	"github.com/spf13/viper"
 
-	"github.com/ynqa/wego/config"
-	"github.com/ynqa/wego/model"
-	"github.com/ynqa/wego/model/word2vec"
+	"github.com/ynqa/wego/pkg/config"
+	"github.com/ynqa/wego/pkg/model"
+	"github.com/ynqa/wego/pkg/model/word2vec"
 )
 
 // Word2vecBuilder manages the members to build Model interface.
diff --git a/builder/word2vec_test.go b/pkg/builder/word2vec_test.go
similarity index 99%
rename from builder/word2vec_test.go
rename to pkg/builder/word2vec_test.go
index 9b38e33..1efa3a3 100644
--- a/builder/word2vec_test.go
+++ b/pkg/builder/word2vec_test.go
@@ -15,7 +15,7 @@
 package builder
 
 import (
-	"github.com/ynqa/wego/model/word2vec"
+	"github.com/ynqa/wego/pkg/model/word2vec"
 	"testing"
 )
 
diff --git a/co/co.go b/pkg/co/co.go
similarity index 100%
rename from co/co.go
rename to pkg/co/co.go
diff --git a/config/config.go b/pkg/config/config.go
similarity index 95%
rename from config/config.go
rename to pkg/config/config.go
index 83cc449..0a4d5c9 100644
--- a/config/config.go
+++ b/pkg/config/config.go
@@ -17,10 +17,10 @@ package config
 import (
 	"runtime"
 
-	"github.com/ynqa/wego/corpus"
-	"github.com/ynqa/wego/model"
-	"github.com/ynqa/wego/model/glove"
-	"github.com/ynqa/wego/model/word2vec"
+	"github.com/ynqa/wego/pkg/corpus"
+	"github.com/ynqa/wego/pkg/model"
+	"github.com/ynqa/wego/pkg/model/glove"
+	"github.com/ynqa/wego/pkg/model/word2vec"
 )
 
 // Config is enum of the common config.
diff --git a/config/config_test.go b/pkg/config/config_test.go
similarity index 100%
rename from config/config_test.go
rename to pkg/config/config_test.go
diff --git a/corpus/core.go b/pkg/corpus/core.go
similarity index 98%
rename from corpus/core.go
rename to pkg/corpus/core.go
index bcfc55b..2325e16 100644
--- a/corpus/core.go
+++ b/pkg/corpus/core.go
@@ -23,7 +23,7 @@ import (
 	"github.com/chewxy/lingo/corpus"
 	"github.com/pkg/errors"
 
-	"github.com/ynqa/wego/timer"
+	"github.com/ynqa/wego/pkg/timer"
 )
 
 type core struct {
diff --git a/corpus/count_model.go b/pkg/corpus/count_model.go
similarity index 99%
rename from corpus/count_model.go
rename to pkg/corpus/count_model.go
index b18be20..b9cb42e 100644
--- a/corpus/count_model.go
+++ b/pkg/corpus/count_model.go
@@ -22,7 +22,7 @@ import (
 	"github.com/pkg/errors"
 	"gopkg.in/cheggaaa/pb.v1"
 
-	"github.com/ynqa/wego/co"
+	"github.com/ynqa/wego/pkg/co"
 )
 
 // CountModelCorpus stores corpus and co-occurrence values between words.
diff --git a/corpus/testing.go b/pkg/corpus/testing.go
similarity index 100%
rename from corpus/testing.go
rename to pkg/corpus/testing.go
diff --git a/corpus/word2vec.go b/pkg/corpus/word2vec.go
similarity index 97%
rename from corpus/word2vec.go
rename to pkg/corpus/word2vec.go
index 8c65c41..453b12f 100644
--- a/corpus/word2vec.go
+++ b/pkg/corpus/word2vec.go
@@ -15,7 +15,7 @@
 package corpus
 
 import (
-	"github.com/ynqa/wego/node"
+	"github.com/ynqa/wego/pkg/node"
 )
 
 // Word2vecCorpus stores corpus.
diff --git a/corpus/word2vec_test.go b/pkg/corpus/word2vec_test.go
similarity index 97%
rename from corpus/word2vec_test.go
rename to pkg/corpus/word2vec_test.go
index 0fc3b5b..8c0d0c9 100644
--- a/corpus/word2vec_test.go
+++ b/pkg/corpus/word2vec_test.go
@@ -19,7 +19,7 @@ import (
 	"strconv"
 	"testing"
 
-	"github.com/ynqa/wego/node"
+	"github.com/ynqa/wego/pkg/node"
 )
 
 func TestGetPath(t *testing.T) {
diff --git a/model/README.md b/pkg/model/README.md
similarity index 100%
rename from model/README.md
rename to pkg/model/README.md
diff --git a/model/glove/adagrad.go b/pkg/model/glove/adagrad.go
similarity index 100%
rename from model/glove/adagrad.go
rename to pkg/model/glove/adagrad.go
diff --git a/model/glove/adagrad_test.go b/pkg/model/glove/adagrad_test.go
similarity index 100%
rename from model/glove/adagrad_test.go
rename to pkg/model/glove/adagrad_test.go
diff --git a/model/glove/glove.go b/pkg/model/glove/glove.go
similarity index 98%
rename from model/glove/glove.go
rename to pkg/model/glove/glove.go
index fbc92bf..ee0715e 100644
--- a/model/glove/glove.go
+++ b/pkg/model/glove/glove.go
@@ -28,8 +28,8 @@ import (
 	"github.com/pkg/errors"
 	"gopkg.in/cheggaaa/pb.v1"
 
-	"github.com/ynqa/wego/corpus"
-	"github.com/ynqa/wego/model"
+	"github.com/ynqa/wego/pkg/corpus"
+	"github.com/ynqa/wego/pkg/model"
 )
 
 type GloveOption struct {
diff --git a/model/glove/sgd.go b/pkg/model/glove/sgd.go
similarity index 100%
rename from model/glove/sgd.go
rename to pkg/model/glove/sgd.go
diff --git a/model/glove/sgd_test.go b/pkg/model/glove/sgd_test.go
similarity index 100%
rename from model/glove/sgd_test.go
rename to pkg/model/glove/sgd_test.go
diff --git a/model/glove/solver.go b/pkg/model/glove/solver.go
similarity index 100%
rename from model/glove/solver.go
rename to pkg/model/glove/solver.go
diff --git a/model/lexvec/lexvec.go b/pkg/model/lexvec/lexvec.go
similarity index 98%
rename from model/lexvec/lexvec.go
rename to pkg/model/lexvec/lexvec.go
index 689f57a..9f3d3b3 100644
--- a/model/lexvec/lexvec.go
+++ b/pkg/model/lexvec/lexvec.go
@@ -29,9 +29,9 @@ import (
 	"github.com/pkg/errors"
 	"gopkg.in/cheggaaa/pb.v1"
 
-	"github.com/ynqa/wego/co"
-	"github.com/ynqa/wego/corpus"
-	"github.com/ynqa/wego/model"
+	"github.com/ynqa/wego/pkg/co"
+	"github.com/ynqa/wego/pkg/corpus"
+	"github.com/ynqa/wego/pkg/model"
 )
 
 type LexvecOption struct {
diff --git a/model/model.go b/pkg/model/model.go
similarity index 100%
rename from model/model.go
rename to pkg/model/model.go
diff --git a/model/option.go b/pkg/model/option.go
similarity index 100%
rename from model/option.go
rename to pkg/model/option.go
diff --git a/model/util.go b/pkg/model/util.go
similarity index 100%
rename from model/util.go
rename to pkg/model/util.go
diff --git a/model/util_test.go b/pkg/model/util_test.go
similarity index 100%
rename from model/util_test.go
rename to pkg/model/util_test.go
diff --git a/model/word2vec/cbow.go b/pkg/model/word2vec/cbow.go
similarity index 98%
rename from model/word2vec/cbow.go
rename to pkg/model/word2vec/cbow.go
index b2e0e90..2b3626d 100644
--- a/model/word2vec/cbow.go
+++ b/pkg/model/word2vec/cbow.go
@@ -15,7 +15,7 @@
 package word2vec
 
 import (
-	"github.com/ynqa/wego/model"
+	"github.com/ynqa/wego/pkg/model"
 )
 
 // Cbow behaviors as one of Word2vec solver.
diff --git a/model/word2vec/hs.go b/pkg/model/word2vec/hs.go
similarity index 96%
rename from model/word2vec/hs.go
rename to pkg/model/word2vec/hs.go
index 5abe603..d153494 100644
--- a/model/word2vec/hs.go
+++ b/pkg/model/word2vec/hs.go
@@ -15,8 +15,8 @@
 package word2vec
 
 import (
-	"github.com/ynqa/wego/corpus"
-	"github.com/ynqa/wego/node"
+	"github.com/ynqa/wego/pkg/corpus"
+	"github.com/ynqa/wego/pkg/node"
 
 	"github.com/pkg/errors"
 )
diff --git a/model/word2vec/hs_test.go b/pkg/model/word2vec/hs_test.go
similarity index 97%
rename from model/word2vec/hs_test.go
rename to pkg/model/word2vec/hs_test.go
index 236d9d5..6c23640 100644
--- a/model/word2vec/hs_test.go
+++ b/pkg/model/word2vec/hs_test.go
@@ -17,7 +17,7 @@ package word2vec
 import (
 	"testing"
 
-	"github.com/ynqa/wego/corpus"
+	"github.com/ynqa/wego/pkg/corpus"
 )
 
 func TestNewHierarchicalSoftmax(t *testing.T) {
diff --git a/model/word2vec/model.go b/pkg/model/word2vec/model.go
similarity index 100%
rename from model/word2vec/model.go
rename to pkg/model/word2vec/model.go
diff --git a/model/word2vec/ns.go b/pkg/model/word2vec/ns.go
similarity index 97%
rename from model/word2vec/ns.go
rename to pkg/model/word2vec/ns.go
index 58f9157..b97d15b 100644
--- a/model/word2vec/ns.go
+++ b/pkg/model/word2vec/ns.go
@@ -15,8 +15,8 @@
 package word2vec
 
 import (
-	"github.com/ynqa/wego/corpus"
-	"github.com/ynqa/wego/model"
+	"github.com/ynqa/wego/pkg/corpus"
+	"github.com/ynqa/wego/pkg/model"
 )
 
 // NegativeSampling is a piece of Word2Vec optimizer.
diff --git a/model/word2vec/ns_test.go b/pkg/model/word2vec/ns_test.go
similarity index 97%
rename from model/word2vec/ns_test.go
rename to pkg/model/word2vec/ns_test.go
index 2397efb..029c2be 100644
--- a/model/word2vec/ns_test.go
+++ b/pkg/model/word2vec/ns_test.go
@@ -17,7 +17,7 @@ package word2vec
 import (
 	"testing"
 
-	"github.com/ynqa/wego/corpus"
+	"github.com/ynqa/wego/pkg/corpus"
 )
 
 func TestNewNegativeSampling(t *testing.T) {
diff --git a/model/word2vec/opt.go b/pkg/model/word2vec/opt.go
similarity index 97%
rename from model/word2vec/opt.go
rename to pkg/model/word2vec/opt.go
index 1ce0dc4..8fd5354 100644
--- a/model/word2vec/opt.go
+++ b/pkg/model/word2vec/opt.go
@@ -15,7 +15,7 @@
 package word2vec
 
 import (
-	"github.com/ynqa/wego/corpus"
+	"github.com/ynqa/wego/pkg/corpus"
 )
 
 // Optimizer is the interface to initialize after scanning corpus once, and update the word vector.
diff --git a/model/word2vec/sigmoid_table.go b/pkg/model/word2vec/sigmoid_table.go
similarity index 100%
rename from model/word2vec/sigmoid_table.go
rename to pkg/model/word2vec/sigmoid_table.go
diff --git a/model/word2vec/sigmoid_table_test.go b/pkg/model/word2vec/sigmoid_table_test.go
similarity index 100%
rename from model/word2vec/sigmoid_table_test.go
rename to pkg/model/word2vec/sigmoid_table_test.go
diff --git a/model/word2vec/skipgram.go b/pkg/model/word2vec/skipgram.go
similarity index 98%
rename from model/word2vec/skipgram.go
rename to pkg/model/word2vec/skipgram.go
index 7fc5da3..0a44b46 100644
--- a/model/word2vec/skipgram.go
+++ b/pkg/model/word2vec/skipgram.go
@@ -15,7 +15,7 @@
 package word2vec
 
 import (
-	"github.com/ynqa/wego/model"
+	"github.com/ynqa/wego/pkg/model"
 )
 
 // SkipGram behaviors as one of Word2vec solver.
diff --git a/model/word2vec/word2vec.go b/pkg/model/word2vec/word2vec.go
similarity index 98%
rename from model/word2vec/word2vec.go
rename to pkg/model/word2vec/word2vec.go
index 4099706..edaf8c3 100644
--- a/model/word2vec/word2vec.go
+++ b/pkg/model/word2vec/word2vec.go
@@ -29,8 +29,8 @@ import (
 	"github.com/pkg/errors"
 	"gopkg.in/cheggaaa/pb.v1"
 
-	"github.com/ynqa/wego/corpus"
-	"github.com/ynqa/wego/model"
+	"github.com/ynqa/wego/pkg/corpus"
+	"github.com/ynqa/wego/pkg/model"
 )
 
 type Word2vecOption struct {
diff --git a/node/node.go b/pkg/node/node.go
similarity index 100%
rename from node/node.go
rename to pkg/node/node.go
diff --git a/repl/README.md b/pkg/repl/README.md
similarity index 100%
rename from repl/README.md
rename to pkg/repl/README.md
diff --git a/repl/op.go b/pkg/repl/op.go
similarity index 100%
rename from repl/op.go
rename to pkg/repl/op.go
diff --git a/repl/repl.go b/pkg/repl/repl.go
similarity index 99%
rename from repl/repl.go
rename to pkg/repl/repl.go
index 6c8baae..8d211ec 100644
--- a/repl/repl.go
+++ b/pkg/repl/repl.go
@@ -24,7 +24,7 @@ import (
 	"github.com/peterh/liner"
 	"github.com/pkg/errors"
 
-	"github.com/ynqa/wego/search"
+	"github.com/ynqa/wego/pkg/search"
 )
 
 type Repl struct {
diff --git a/search/README.md b/pkg/search/README.md
similarity index 100%
rename from search/README.md
rename to pkg/search/README.md
diff --git a/search/describer.go b/pkg/search/describer.go
similarity index 100%
rename from search/describer.go
rename to pkg/search/describer.go
diff --git a/search/describer_test.go b/pkg/search/describer_test.go
similarity index 100%
rename from search/describer_test.go
rename to pkg/search/describer_test.go
diff --git a/search/neighbor.go b/pkg/search/neighbor.go
similarity index 100%
rename from search/neighbor.go
rename to pkg/search/neighbor.go
diff --git a/search/neighbor_test.go b/pkg/search/neighbor_test.go
similarity index 100%
rename from search/neighbor_test.go
rename to pkg/search/neighbor_test.go
diff --git a/search/parser.go b/pkg/search/parser.go
similarity index 100%
rename from search/parser.go
rename to pkg/search/parser.go
diff --git a/search/parser_test.go b/pkg/search/parser_test.go
similarity index 100%
rename from search/parser_test.go
rename to pkg/search/parser_test.go
diff --git a/search/search.go b/pkg/search/search.go
similarity index 100%
rename from search/search.go
rename to pkg/search/search.go
diff --git a/search/search_test.go b/pkg/search/search_test.go
similarity index 100%
rename from search/search_test.go
rename to pkg/search/search_test.go
diff --git a/search/testing.go b/pkg/search/testing.go
similarity index 100%
rename from search/testing.go
rename to pkg/search/testing.go
diff --git a/search/util.go b/pkg/search/util.go
similarity index 100%
rename from search/util.go
rename to pkg/search/util.go
diff --git a/search/util_test.go b/pkg/search/util_test.go
similarity index 100%
rename from search/util_test.go
rename to pkg/search/util_test.go
diff --git a/timer/timer.go b/pkg/timer/timer.go
similarity index 100%
rename from timer/timer.go
rename to pkg/timer/timer.go
diff --git a/validate/validate.go b/pkg/validate/validate.go
similarity index 100%
rename from validate/validate.go
rename to pkg/validate/validate.go
diff --git a/validate/validate_test.go b/pkg/validate/validate_test.go
similarity index 100%
rename from validate/validate_test.go
rename to pkg/validate/validate_test.go
diff --git a/demo.sh b/scripts/demo.sh
similarity index 100%
rename from demo.sh
rename to scripts/demo.sh
diff --git a/e2e.sh b/scripts/e2e.sh
similarity index 100%
rename from e2e.sh
rename to scripts/e2e.sh