diff --git a/src/plugin/packer/.gitattributes b/src/plugin/packer/.gitattributes
new file mode 100644
index 0000000000..95486dfdce
--- /dev/null
+++ b/src/plugin/packer/.gitattributes
@@ -0,0 +1,2 @@
+*.js eol=lf
+/docs/dist/* binary
diff --git a/src/plugin/packer/.gitignore b/src/plugin/packer/.gitignore
new file mode 100644
index 0000000000..e53b5033f9
--- /dev/null
+++ b/src/plugin/packer/.gitignore
@@ -0,0 +1,8 @@
+node_modules
+.vault
+test/fixtures/sample-plugin/plugin.zip
+test/fixtures/sample-plugin/*.ppk
+test/.output
+docs/dist/*
+!docs/dist/.gitkeep
+/dist
diff --git a/src/plugin/packer/CHANGELOG.md b/src/plugin/packer/CHANGELOG.md
new file mode 100644
index 0000000000..de3cce44dd
--- /dev/null
+++ b/src/plugin/packer/CHANGELOG.md
@@ -0,0 +1,810 @@
+# Change Log
+
+All notable changes to this project will be documented in this file.
+See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
+
+## [8.1.3](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@8.1.2...@kintone/plugin-packer@8.1.3) (2024-06-18)
+
+
+### Bug Fixes
+
+* **deps:** update dependency @kintone/plugin-manifest-validator to ^10.2.2 ([#2819](https://github.com/kintone/js-sdk/issues/2819)) ([0bda241](https://github.com/kintone/js-sdk/commit/0bda2416ba162b2f4d9b4e997f03388b02bfc9c7))
+* **deps:** update dependency stream-buffers to ^3.0.3 ([#2828](https://github.com/kintone/js-sdk/issues/2828)) ([689489d](https://github.com/kintone/js-sdk/commit/689489d48e0a86ce9a7fe462080da525e8e65fe8))
+
+## [8.1.2](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@8.1.1...@kintone/plugin-packer@8.1.2) (2024-06-04)
+
+
+### Bug Fixes
+
+* **deps:** update dependency debug to ^4.3.5 ([#2794](https://github.com/kintone/js-sdk/issues/2794)) ([6598593](https://github.com/kintone/js-sdk/commit/659859336b406dc98d64e159409a6dd3af5c115f))
+
+## [8.1.1](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@8.1.0...@kintone/plugin-packer@8.1.1) (2024-05-31)
+
+
+### Bug Fixes
+
+* **deps:** update dependency @kintone/plugin-manifest-validator to ^10.2.1 ([#2793](https://github.com/kintone/js-sdk/issues/2793)) ([519d657](https://github.com/kintone/js-sdk/commit/519d65762557738b9892838833d1462df29c3268))
+
+## [8.1.0](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@8.0.6...@kintone/plugin-packer@8.1.0) (2024-05-31)
+
+
+### Features
+
+* **plugin-packer:** print warning messages ([#2789](https://github.com/kintone/js-sdk/issues/2789)) ([0371583](https://github.com/kintone/js-sdk/commit/037158324f7f7ba84d552a74c2c1c49bc7e5a9b1))
+
+## [8.0.6](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@8.0.5...@kintone/plugin-packer@8.0.6) (2024-05-08)
+
+
+### Bug Fixes
+
+* **deps:** update dependency yauzl to ^3.1.3 ([#2714](https://github.com/kintone/js-sdk/issues/2714)) ([06f0f23](https://github.com/kintone/js-sdk/commit/06f0f237f6120433167c086e023b0871fa382e16))
+
+## [8.0.5](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@8.0.4...@kintone/plugin-packer@8.0.5) (2024-04-02)
+
+
+### Bug Fixes
+
+* **deps:** update dependency yauzl to v3 ([#2576](https://github.com/kintone/js-sdk/issues/2576)) ([3f568c8](https://github.com/kintone/js-sdk/commit/3f568c8d16f0b7a6da493f9b16a630f1f5c54b13))
+
+## [8.0.4](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@8.0.3...@kintone/plugin-packer@8.0.4) (2024-01-17)
+
+
+### Bug Fixes
+
+* **plugin-packer:** Fix the vulnerability issue from browserify-sign ([#2503](https://github.com/kintone/js-sdk/issues/2503)) ([aa56d64](https://github.com/kintone/js-sdk/commit/aa56d640c9336e175800fbdb217ea980b3f1809d))
+
+## [8.0.3](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@8.0.2...@kintone/plugin-packer@8.0.3) (2023-12-21)
+
+
+### Bug Fixes
+
+* **deps:** update dependency @kintone/plugin-manifest-validator to ^10.1.0 ([#2469](https://github.com/kintone/js-sdk/issues/2469)) ([06916d5](https://github.com/kintone/js-sdk/commit/06916d5a885d1712a6e68fd8f6b65e3b3e83b8e1))
+
+## [8.0.2](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@8.0.1...@kintone/plugin-packer@8.0.2) (2023-12-19)
+
+
+### Bug Fixes
+
+* **deps:** update dependency prettier to v3 ([#2457](https://github.com/kintone/js-sdk/issues/2457)) ([5a0b859](https://github.com/kintone/js-sdk/commit/5a0b859807530564732caa194e9251f37268b164))
+
+## [8.0.1](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@8.0.0...@kintone/plugin-packer@8.0.1) (2023-10-24)
+
+
+### Bug Fixes
+
+* **deps:** update dependency @kintone/plugin-manifest-validator to v10 ([#2313](https://github.com/kintone/js-sdk/issues/2313)) ([0a6a655](https://github.com/kintone/js-sdk/commit/0a6a655c8d130cc451a6117f0fb36a14bc678860))
+
+## [8.0.0](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@7.1.0...@kintone/plugin-packer@8.0.0) (2023-10-03)
+
+
+### ⚠ BREAKING CHANGES
+
+* We dropped Node v16 support. Now supported versions are v18 and v20.
+
+### Build System
+
+* Drop Node v16 support version ([#2294](https://github.com/kintone/js-sdk/issues/2294)) ([767d657](https://github.com/kintone/js-sdk/commit/767d65749be66b6c2509bb737d8f45085814cc44))
+
+## [7.1.0](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@7.0.4...@kintone/plugin-packer@7.1.0) (2023-09-26)
+
+
+### Features
+
+* **plugin-packer:** Display the helpful message when manifest.json contains non-existent file ([#2254](https://github.com/kintone/js-sdk/issues/2254)) ([32d1db8](https://github.com/kintone/js-sdk/commit/32d1db878f8a9b5a8d6acdaa90772ee97117784a))
+
+
+### Bug Fixes
+
+* **deps:** update dependency mkdirp to v3 ([#2034](https://github.com/kintone/js-sdk/issues/2034)) ([cb624ef](https://github.com/kintone/js-sdk/commit/cb624ef1a79df7dd30c716d8c3f7a92d781912c3))
+
+## [7.0.4](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@7.0.3...@kintone/plugin-packer@7.0.4) (2023-07-05)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [7.0.3](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@7.0.2...@kintone/plugin-packer@7.0.3) (2023-06-28)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [7.0.2](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@7.0.1...@kintone/plugin-packer@7.0.2) (2023-06-21)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [7.0.1](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@7.0.0...@kintone/plugin-packer@7.0.1) (2023-06-15)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+# [7.0.0](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.39...@kintone/plugin-packer@7.0.0) (2023-06-07)
+
+- build!: drop Node v14 support because of the EOL (#2124) ([ef0e004](https://github.com/kintone/js-sdk/commit/ef0e004b40a518a1b5a3aa5d82446c556c742f02)), closes [#2124](https://github.com/kintone/js-sdk/issues/2124)
+
+### BREAKING CHANGES
+
+- We dropped Node v14 support. Now supported versions are v16, v18, and v20.
+
+## [6.0.39](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.38...@kintone/plugin-packer@6.0.39) (2023-05-31)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.38](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.37...@kintone/plugin-packer@6.0.38) (2023-05-24)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.37](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.36...@kintone/plugin-packer@6.0.37) (2023-05-17)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.36](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.35...@kintone/plugin-packer@6.0.36) (2023-05-10)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.35](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.34...@kintone/plugin-packer@6.0.35) (2023-04-26)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.34](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.33...@kintone/plugin-packer@6.0.34) (2023-04-21)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.33](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.32...@kintone/plugin-packer@6.0.33) (2023-04-10)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.32](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.31...@kintone/plugin-packer@6.0.32) (2023-04-06)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.31](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.30...@kintone/plugin-packer@6.0.31) (2023-04-04)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.30](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.29...@kintone/plugin-packer@6.0.30) (2023-03-29)
+
+### Bug Fixes
+
+- **deps:** update dependency mkdirp to ^2.1.6 ([#1988](https://github.com/kintone/js-sdk/issues/1988)) ([87ed9c3](https://github.com/kintone/js-sdk/commit/87ed9c38cd7962db8fcc0d116eee899c6edcd606))
+
+## [6.0.29](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.28...@kintone/plugin-packer@6.0.29) (2023-03-22)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.28](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.27...@kintone/plugin-packer@6.0.28) (2023-03-15)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.27](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.26...@kintone/plugin-packer@6.0.27) (2023-03-08)
+
+### Bug Fixes
+
+- **deps:** update dependency mkdirp to ^2.1.5 ([#1950](https://github.com/kintone/js-sdk/issues/1950)) ([154a895](https://github.com/kintone/js-sdk/commit/154a8958e78daa563cbc3c3e1e07578d13ea3cd4))
+
+## [6.0.26](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.25...@kintone/plugin-packer@6.0.26) (2023-03-03)
+
+### Bug Fixes
+
+- **deps:** update dependency mkdirp to v2 ([#1898](https://github.com/kintone/js-sdk/issues/1898)) ([b73bf6c](https://github.com/kintone/js-sdk/commit/b73bf6c0f0123c7346984d3bd21337e14ad0a36f))
+
+## [6.0.25](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.24...@kintone/plugin-packer@6.0.25) (2023-02-22)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.24](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.23...@kintone/plugin-packer@6.0.24) (2023-02-15)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.23](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.22...@kintone/plugin-packer@6.0.23) (2023-02-01)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.22](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.21...@kintone/plugin-packer@6.0.22) (2023-01-25)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.21](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.20...@kintone/plugin-packer@6.0.21) (2023-01-18)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.20](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.19...@kintone/plugin-packer@6.0.20) (2022-12-21)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.19](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.18...@kintone/plugin-packer@6.0.19) (2022-11-16)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.18](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.17...@kintone/plugin-packer@6.0.18) (2022-11-09)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.17](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.16...@kintone/plugin-packer@6.0.17) (2022-11-02)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.16](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.15...@kintone/plugin-packer@6.0.16) (2022-10-19)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.15](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.14...@kintone/plugin-packer@6.0.15) (2022-10-12)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.14](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.13...@kintone/plugin-packer@6.0.14) (2022-10-05)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.13](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.12...@kintone/plugin-packer@6.0.13) (2022-09-29)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.12](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.11...@kintone/plugin-packer@6.0.12) (2022-09-14)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.11](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.10...@kintone/plugin-packer@6.0.11) (2022-08-31)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.10](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.9...@kintone/plugin-packer@6.0.10) (2022-08-24)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.9](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.8...@kintone/plugin-packer@6.0.9) (2022-08-17)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.8](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.7...@kintone/plugin-packer@6.0.8) (2022-08-10)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.7](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.6...@kintone/plugin-packer@6.0.7) (2022-08-03)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.6](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.5...@kintone/plugin-packer@6.0.6) (2022-07-21)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.5](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.4...@kintone/plugin-packer@6.0.5) (2022-06-29)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.4](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.3...@kintone/plugin-packer@6.0.4) (2022-06-22)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.3](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.2...@kintone/plugin-packer@6.0.3) (2022-06-08)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.2](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.1...@kintone/plugin-packer@6.0.2) (2022-06-01)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [6.0.1](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@6.0.0...@kintone/plugin-packer@6.0.1) (2022-05-20)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+# [6.0.0](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.39...@kintone/plugin-packer@6.0.0) (2022-05-13)
+
+- chore!: drop Node v12 support because of the EOL (BREAKING CHANGE) (#1493) ([0d9dae1](https://github.com/kintone/js-sdk/commit/0d9dae10582fc40d89a1af8db4a2efc1d776a456)), closes [#1493](https://github.com/kintone/js-sdk/issues/1493)
+
+### BREAKING CHANGES
+
+- drop Node v12 support because of the EOL.
+
+- ci: update Node version 14 -> 16
+
+- ci: remove Node 18.x from test workflow
+
+## [5.0.39](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.38...@kintone/plugin-packer@5.0.39) (2022-04-28)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.38](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.37...@kintone/plugin-packer@5.0.38) (2022-03-25)
+
+### Bug Fixes
+
+- **deps:** update dependency debug to ^4.3.4 ([#1418](https://github.com/kintone/js-sdk/issues/1418)) ([31caa35](https://github.com/kintone/js-sdk/commit/31caa35e06ce92e56580ad03b661a5457e2751f5))
+
+## [5.0.37](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.36...@kintone/plugin-packer@5.0.37) (2022-03-18)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.36](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.35...@kintone/plugin-packer@5.0.36) (2022-03-04)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## 5.0.35 (2022-02-14)
+
+### Bug Fixes
+
+- **deps:** update dependency @kintone/rest-api-client to ^2.0.34 ([#1341](https://github.com/kintone/js-sdk/issues/1341)) ([0e01847](https://github.com/kintone/js-sdk/commit/0e018475d77c68f42d414d563377aef56a7a1d41))
+
+## 5.0.34 (2022-02-04)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## 5.0.33 (2022-01-18)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## 5.0.32 (2022-01-11)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## 5.0.31 (2021-12-24)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## 5.0.30 (2021-12-24)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.29](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.28...@kintone/plugin-packer@5.0.29) (2021-12-21)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.28](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.27...@kintone/plugin-packer@5.0.28) (2021-12-15)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.27](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.26...@kintone/plugin-packer@5.0.27) (2021-12-07)
+
+### Bug Fixes
+
+- **deps:** update dependency debug to ^4.3.3 ([#1226](https://github.com/kintone/js-sdk/issues/1226)) ([6fd58b6](https://github.com/kintone/js-sdk/commit/6fd58b699e28fde942373ea2eae1a411dd1d033a))
+
+## [5.0.26](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.25...@kintone/plugin-packer@5.0.26) (2021-12-01)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.25](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.24...@kintone/plugin-packer@5.0.25) (2021-11-17)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.24](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.23...@kintone/plugin-packer@5.0.24) (2021-11-09)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.23](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.22...@kintone/plugin-packer@5.0.23) (2021-10-27)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.22](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.21...@kintone/plugin-packer@5.0.22) (2021-10-20)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.21](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.20...@kintone/plugin-packer@5.0.21) (2021-10-13)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.20](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.19...@kintone/plugin-packer@5.0.20) (2021-10-06)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.19](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.18...@kintone/plugin-packer@5.0.19) (2021-09-29)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.18](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.17...@kintone/plugin-packer@5.0.18) (2021-09-22)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.17](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.16...@kintone/plugin-packer@5.0.17) (2021-09-15)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.16](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.15...@kintone/plugin-packer@5.0.16) (2021-09-08)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.15](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.14...@kintone/plugin-packer@5.0.15) (2021-09-01)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.14](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.13...@kintone/plugin-packer@5.0.14) (2021-08-25)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.13](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.12...@kintone/plugin-packer@5.0.13) (2021-08-11)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.12](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.11...@kintone/plugin-packer@5.0.12) (2021-08-04)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.11](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.10...@kintone/plugin-packer@5.0.11) (2021-07-28)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.10](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.9...@kintone/plugin-packer@5.0.10) (2021-07-21)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.9](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.8...@kintone/plugin-packer@5.0.9) (2021-07-12)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.8](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.7...@kintone/plugin-packer@5.0.8) (2021-07-06)
+
+### Bug Fixes
+
+- **deps:** update dependency debug to ^4.3.2 ([#993](https://github.com/kintone/js-sdk/issues/993)) ([b733ccc](https://github.com/kintone/js-sdk/commit/b733ccc9184aa1cea90649d63708ea3286efd76d))
+
+## [5.0.7](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.6...@kintone/plugin-packer@5.0.7) (2021-06-29)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.6](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.5...@kintone/plugin-packer@5.0.6) (2021-06-22)
+
+### Bug Fixes
+
+- **deps:** update dependency chokidar to ^3.5.2 ([#956](https://github.com/kintone/js-sdk/issues/956)) ([148de17](https://github.com/kintone/js-sdk/commit/148de170c2ca209510793989297de828ad77051d))
+
+## [5.0.5](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.4...@kintone/plugin-packer@5.0.5) (2021-06-15)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.4](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.3...@kintone/plugin-packer@5.0.4) (2021-06-08)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.3](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.2...@kintone/plugin-packer@5.0.3) (2021-06-01)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.2](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.1...@kintone/plugin-packer@5.0.2) (2021-05-25)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [5.0.1](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@5.0.0...@kintone/plugin-packer@5.0.1) (2021-05-18)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+# [5.0.0](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@4.0.6...@kintone/plugin-packer@5.0.0) (2021-05-11)
+
+### chore
+
+- drop Node v10 support ([#870](https://github.com/kintone/js-sdk/issues/870)) ([5263389](https://github.com/kintone/js-sdk/commit/526338928e5a89a1f24c7458fc0c7c2452e36cc1))
+
+### BREAKING CHANGES
+
+- drop Node v10 support because of the EOL.
+
+## [4.0.6](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@4.0.5...@kintone/plugin-packer@4.0.6) (2021-04-27)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [4.0.5](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@4.0.4...@kintone/plugin-packer@4.0.5) (2021-04-20)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [4.0.4](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@4.0.3...@kintone/plugin-packer@4.0.4) (2021-04-13)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [4.0.3](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@4.0.2...@kintone/plugin-packer@4.0.3) (2021-03-31)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [4.0.2](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@4.0.1...@kintone/plugin-packer@4.0.2) (2021-03-23)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [4.0.1](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@4.0.0...@kintone/plugin-packer@4.0.1) (2021-03-18)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+# [4.0.0](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@3.0.15...@kintone/plugin-packer@4.0.0) (2021-03-09)
+
+### chore
+
+- **deps:** update dependency ajv to v7 ([#636](https://github.com/kintone/js-sdk/issues/636)) ([a5490d5](https://github.com/kintone/js-sdk/commit/a5490d5702de9f32b06e1511f1e924388e7510c4))
+
+### BREAKING CHANGES
+
+- **deps:** The format of dataPath and message in an error object have been changed.
+  dataPath: .desktop.css[0] -> /desktop/css/0
+  message: **_ is a required property -> _** should have required property 'version'
+
+- fix: put maxItems in the correct location
+
+- refactor: remove unnecessary code
+
+- refactor: define SchemaValidateFunction locally
+
+- test: add a test for maxItems
+
+- chore: add a note for PR that expose SchemaValidateFunction
+
+- types: regenerate manifest-schema.d.ts
+
+- docs: update an error object format
+
+- docs: update a link to the documentation for validation errors
+
+Co-authored-by: Renovate Bot <bot@renovateapp.com>
+Co-authored-by: Toru Kobayashi <koba0004@gmail.com>
+
+## [3.0.15](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@3.0.14...@kintone/plugin-packer@3.0.15) (2021-03-02)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [3.0.14](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@3.0.13...@kintone/plugin-packer@3.0.14) (2021-02-17)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [3.0.13](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@3.0.12...@kintone/plugin-packer@3.0.13) (2021-02-09)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [3.0.12](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@3.0.11...@kintone/plugin-packer@3.0.12) (2021-02-02)
+
+### Bug Fixes
+
+- **deps:** update dependency chokidar to ^3.5.1 ([#635](https://github.com/kintone/js-sdk/issues/635)) ([85642c7](https://github.com/kintone/js-sdk/commit/85642c7946dbb4269c621882d8c13386b53fcaee))
+- **deps:** update dependency meow to v9 ([#637](https://github.com/kintone/js-sdk/issues/637)) ([09132c6](https://github.com/kintone/js-sdk/commit/09132c6fd16abb1798ca6bc6d569d4365fcb1968))
+
+## [3.0.11](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@3.0.10...@kintone/plugin-packer@3.0.11) (2021-01-26)
+
+**Note:** Version bump only for package @kintone/plugin-packer
+
+## [3.0.10](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@3.0.9...@kintone/plugin-packer@3.0.10) (2021-01-19)
+
+### Bug Fixes
+
+- **deps:** update webpack-dev-server to 3.11.1 ([#603](https://github.com/kintone/js-sdk/issues/603)) ([75b0141](https://github.com/kintone/js-sdk/commit/75b0141fc4053688aa7d13ed2abb5a386f5b52a1))
+
+## [3.0.9](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@3.0.8...@kintone/plugin-packer@3.0.9) (2020-12-16)
+
+### Bug Fixes
+
+- **deps:** update dependency debug to ^4.3.1 ([#542](https://github.com/kintone/js-sdk/issues/542)) ([b84f5b5](https://github.com/kintone/js-sdk/commit/b84f5b5544b29f6fc353d4affd87bb4b86f3bd19))
+- **deps:** update dependency meow to v8 ([#510](https://github.com/kintone/js-sdk/issues/510)) ([b064c79](https://github.com/kintone/js-sdk/commit/b064c79b056a8ca2365a33c12d4d6c8e8b419eaf))
+- **deps:** update dependency webpack to v5 ([#475](https://github.com/kintone/js-sdk/issues/475)) ([ac6af9d](https://github.com/kintone/js-sdk/commit/ac6af9d3003ff6910a663ac53ca60a27c9999d87))
+
+## [3.0.8](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@3.0.7...@kintone/plugin-packer@3.0.8) (2020-10-21)
+
+### Bug Fixes
+
+- **deps:** update dependency chokidar to ^3.4.3 ([a50de55](https://github.com/kintone/js-sdk/commit/a50de55fd2b7bd64fdafc29acf5644fed52cccee))
+
+## [3.0.7](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@3.0.6...@kintone/plugin-packer@3.0.7) (2020-10-12)
+
+### Bug Fixes
+
+- **deps:** update dependency debug to ^4.2.0 ([#429](https://github.com/kintone/js-sdk/issues/429)) ([74a0c67](https://github.com/kintone/js-sdk/commit/74a0c67662302f20473fb3bfadae57be47efcf1c))
+- **deps:** update dependency meow to ^7.1.1 ([ce6c6b3](https://github.com/kintone/js-sdk/commit/ce6c6b3cf01878a6b5b1421cb7c26c73719cd2a6))
+
+## [3.0.6](https://github.com/kintone/js-sdk/compare/@kintone/plugin-packer@3.0.5...@kintone/plugin-packer@3.0.6) (2020-08-28)
+
+### Bug Fixes
+
+- **deps:** update dependency meow to ^7.1.0 ([#349](https://github.com/kintone/js-sdk/issues/349)) ([954ebbb](https://github.com/kintone/js-sdk/commit/954ebbbbc81c8b07d8924311dd01feea0043b7ef))
+- **deps:** update dependency node-rsa to ~1.1.1 ([#352](https://github.com/kintone/js-sdk/issues/352)) ([f8a2dd3](https://github.com/kintone/js-sdk/commit/f8a2dd3b844c8242de34b313769150efc861be79))
+- do not run eslint for a test script ([972fa90](https://github.com/kintone/js-sdk/commit/972fa90936b2297953fc56e981e9803b1246889c))
+- npm-scripts for eslint ([3e19e03](https://github.com/kintone/js-sdk/commit/3e19e03fc2b6afffbe5fd8b8cbdc1128f046b142))
+- npm-scripts for eslint in plugin-packer ([049ff73](https://github.com/kintone/js-sdk/commit/049ff73bb4afc597baa511e35d731207c348a5b0))
+- pass yarn test in plugin-packer ([121ec33](https://github.com/kintone/js-sdk/commit/121ec33df675ea6a101b2cbd03b32752bb48259c))
+
+### Reverts
+
+- Revert "chore: remove an unnecessary file" ([8dc0053](https://github.com/kintone/js-sdk/commit/8dc005340765aa5286136d464078d33fb32d6442))
+
+# Changelog
+
+All notable changes to this project will be documented in this file. See [standard-version](https://github.com/conventional-changelog/standard-version) for commit guidelines.
+
+### [3.0.5](https://github.com/kintone/plugin-packer/compare/v3.0.4...v3.0.5) (2020-06-22)
+
+### Bug Fixes
+
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^3.0.4 ([#523](https://github.com/kintone/plugin-packer/issues/523)) ([3eccb4c](https://github.com/kintone/plugin-packer/commit/3eccb4c26d5db820bbb149fa86de2b2cb1c4e35f))
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^3.0.5 ([#528](https://github.com/kintone/plugin-packer/issues/528)) ([134fd15](https://github.com/kintone/plugin-packer/commit/134fd158ce04e9419601cb0c2bb8bab0f9bbbcf2))
+
+### [3.0.4](https://github.com/kintone/plugin-packer/compare/v3.0.3...v3.0.4) (2020-06-02)
+
+### Bug Fixes
+
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^3.0.3 ([#511](https://github.com/kintone/plugin-packer/issues/511)) ([9f4c94c](https://github.com/kintone/plugin-packer/commit/9f4c94cacacb3fc8fab7a31e57c9cd9df73a0534))
+- **deps:** update dependency meow to ^6.1.1 ([#513](https://github.com/kintone/plugin-packer/issues/513)) ([b463703](https://github.com/kintone/plugin-packer/commit/b4637038b8a4d79d7ff9a7103f3838341f98eb5c))
+- **deps:** update dependency meow to v7 ([#516](https://github.com/kintone/plugin-packer/issues/516)) ([0ff1900](https://github.com/kintone/plugin-packer/commit/0ff1900974d944dea980d615cc06a4e71829c4e1))
+
+### [3.0.3](https://github.com/kintone/plugin-packer/compare/v3.0.2...v3.0.3) (2020-04-28)
+
+### Bug Fixes
+
+- **deps:** update dependency chokidar to ^3.4.0 ([#508](https://github.com/kintone/plugin-packer/issues/508)) ([010ae33](https://github.com/kintone/plugin-packer/commit/010ae3383f76a6978c73048983be65938c9eb5ae))
+- **deps:** update dependency mkdirp to ^1.0.4 ([#502](https://github.com/kintone/plugin-packer/issues/502)) ([fed38fe](https://github.com/kintone/plugin-packer/commit/fed38fe180a5ac03b6d70252a93cf8f397ad3211))
+- package.json & package-lock.json to reduce vulnerabilities ([#494](https://github.com/kintone/plugin-packer/issues/494)) ([7629f53](https://github.com/kintone/plugin-packer/commit/7629f53be0ebca46f8b2fb2238be97c36621727b))
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^3.0.2 ([#498](https://github.com/kintone/plugin-packer/issues/498)) ([16841b5](https://github.com/kintone/plugin-packer/commit/16841b5006fd71d2c7d6a157e23d1f72fed47351))
+- **deps:** update dependency node-rsa to ~1.0.8 ([#500](https://github.com/kintone/plugin-packer/issues/500)) ([3b7b253](https://github.com/kintone/plugin-packer/commit/3b7b25331cb1c03d6227a3534856e7726babcfd8))
+
+### [3.0.2](https://github.com/kintone/plugin-packer/compare/v3.0.1...v3.0.2) (2020-03-24)
+
+### Bug Fixes
+
+- **deps:** update dependency meow to ^6.1.0 ([#495](https://github.com/kintone/plugin-packer/issues/495)) ([61cf5a2](https://github.com/kintone/plugin-packer/commit/61cf5a2e1ba31ff1c1a9a76d85417f110be10888))
+- unnecessary a option ([e1198ab](https://github.com/kintone/plugin-packer/commit/e1198abce9a01d33d48f7d978e104a5b56c6ccda))
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^3.0.1 ([#487](https://github.com/kintone/plugin-packer/issues/487)) ([d14438b](https://github.com/kintone/plugin-packer/commit/d14438bf9d6c204bca2b7762196bba4871a775de))
+
+### [3.0.1](https://github.com/kintone/plugin-packer/compare/v3.0.0...v3.0.1) (2020-02-25)
+
+### Bug Fixes
+
+- website build ([#471](https://github.com/kintone/plugin-packer/issues/471)) ([75285b9](https://github.com/kintone/plugin-packer/commit/75285b9a900fcc471b6caf421c8366a60a870942))
+- **deps:** update dependency @kintone/plugin-manifest-validator to v3 ([#473](https://github.com/kintone/plugin-packer/issues/473)) ([2851ab4](https://github.com/kintone/plugin-packer/commit/2851ab444191c553c13d36faf37e3f412b6c01a5))
+- **deps:** update dependency meow to ^6.0.1 ([#484](https://github.com/kintone/plugin-packer/issues/484)) ([ff19347](https://github.com/kintone/plugin-packer/commit/ff1934764986e97db1a8ae8388e4298f806c159c))
+- **deps:** update dependency mkdirp to v1 ([#468](https://github.com/kintone/plugin-packer/issues/468)) ([7bd9afc](https://github.com/kintone/plugin-packer/commit/7bd9afc218569c7ad1c4dd053572f08895db61a1))
+
+## [3.0.0](https://github.com/kintone/plugin-packer/compare/v2.0.8...v3.0.0) (2020-01-28)
+
+### ⚠ BREAKING CHANGES
+
+- drop Node v8 support
+
+### Bug Fixes
+
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^2.0.10 ([#462](https://github.com/kintone/plugin-packer/issues/462)) ([4697b7d](https://github.com/kintone/plugin-packer/commit/4697b7dc1a3ac46f2a6884e21e54fadb0d32fe0d))
+- **deps:** update dependency meow to v6 ([#452](https://github.com/kintone/plugin-packer/issues/452)) ([eb904cc](https://github.com/kintone/plugin-packer/commit/eb904cc48d59132085a330e1877381fca5786cf4))
+
+- drop Node v8 support ([#470](https://github.com/kintone/plugin-packer/issues/470)) ([33a1790](https://github.com/kintone/plugin-packer/commit/33a1790c0875fab1dcdcb4a716ba5ebc37567882))
+
+### [2.0.8](https://github.com/kintone/plugin-packer/compare/v2.0.7...v2.0.8) (2019-12-24)
+
+### Bug Fixes
+
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^2.0.8 ([#447](https://github.com/kintone/plugin-packer/issues/447)) ([80c330c](https://github.com/kintone/plugin-packer/commit/80c330cdbbe217e771f85538580116253a19d074))
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^2.0.9 ([#451](https://github.com/kintone/plugin-packer/issues/451)) ([2f6ae67](https://github.com/kintone/plugin-packer/commit/2f6ae673e54b68650074f389b11ad1c113ce4162))
+- **deps:** update dependency chokidar to ^3.3.1 ([#453](https://github.com/kintone/plugin-packer/issues/453)) ([e950085](https://github.com/kintone/plugin-packer/commit/e9500854495e6491bd59d5de1e6d5272f8de1fa4))
+- **deps:** update dependency node-rsa to ~1.0.7 ([#446](https://github.com/kintone/plugin-packer/issues/446)) ([01d7aed](https://github.com/kintone/plugin-packer/commit/01d7aed2c2e495da812d9498ababfd64004f4da0))
+
+### [2.0.7](https://github.com/kintone/plugin-packer/compare/v2.0.6...v2.0.7) (2019-11-26)
+
+### Bug Fixes
+
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^2.0.7 ([#433](https://github.com/kintone/plugin-packer/issues/433)) ([01ebb00](https://github.com/kintone/plugin-packer/commit/01ebb00))
+- **deps:** update dependency chokidar to ^3.2.3 ([#435](https://github.com/kintone/plugin-packer/issues/435)) ([f18e41b](https://github.com/kintone/plugin-packer/commit/f18e41b))
+- **deps:** update dependency chokidar to ^3.3.0 ([#439](https://github.com/kintone/plugin-packer/issues/439)) ([1e37c4c](https://github.com/kintone/plugin-packer/commit/1e37c4c))
+
+### [2.0.6](https://github.com/kintone/plugin-packer/compare/v2.0.5...v2.0.6) (2019-10-23)
+
+### Bug Fixes
+
+- **deps:** update dependency chokidar to ^3.2.1 ([#419](https://github.com/kintone/plugin-packer/issues/419)) ([3508ac9](https://github.com/kintone/plugin-packer/commit/3508ac9))
+- **deps:** update dependency chokidar to ^3.2.2 ([#428](https://github.com/kintone/plugin-packer/issues/428)) ([7462fee](https://github.com/kintone/plugin-packer/commit/7462fee))
+
+### [2.0.5](https://github.com/kintone/plugin-packer/compare/v2.0.4...v2.0.5) (2019-10-02)
+
+### Bug Fixes
+
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^2.0.5 ([#409](https://github.com/kintone/plugin-packer/issues/409)) ([448f8d6](https://github.com/kintone/plugin-packer/commit/448f8d6))
+- **deps:** update dependency chokidar to ^3.1.1 ([8c39d22](https://github.com/kintone/plugin-packer/commit/8c39d22))
+- update manifest-validator to 2.0.6 to suppress logs ([#418](https://github.com/kintone/plugin-packer/issues/418)) ([228dea0](https://github.com/kintone/plugin-packer/commit/228dea0))
+
+### [2.0.4](https://github.com/kintone/plugin-packer/compare/v2.0.3...v2.0.4) (2019-09-24)
+
+### Bug Fixes
+
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^2.0.4 ([#390](https://github.com/kintone/plugin-packer/issues/390)) ([15be9b4](https://github.com/kintone/plugin-packer/commit/15be9b4))
+- **deps:** update dependency node-rsa to ~1.0.6 ([#405](https://github.com/kintone/plugin-packer/issues/405)) ([ec05414](https://github.com/kintone/plugin-packer/commit/ec05414))
+
+## [2.0.3](https://github.com/kintone/plugin-packer/compare/v2.0.2...v2.0.3) (2019-08-27)
+
+## [2.0.2](https://github.com/kintone/plugin-packer/compare/v2.0.1...v2.0.2) (2019-08-27)
+
+### Bug Fixes
+
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^2.0.1 ([#364](https://github.com/kintone/plugin-packer/issues/364)) ([1d9625c](https://github.com/kintone/plugin-packer/commit/1d9625c))
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^2.0.2 ([#374](https://github.com/kintone/plugin-packer/issues/374)) ([094632c](https://github.com/kintone/plugin-packer/commit/094632c))
+- **deps:** update dependency chokidar to v3 ([22c15cd](https://github.com/kintone/plugin-packer/commit/22c15cd))
+
+## [2.0.1](https://github.com/kintone/plugin-packer/compare/v2.0.0...v2.0.1) (2019-06-25)
+
+### Bug Fixes
+
+- **deps:** update dependency @kintone/plugin-manifest-validator to v2 ([#361](https://github.com/kintone/plugin-packer/issues/361)) ([0779dee](https://github.com/kintone/plugin-packer/commit/0779dee))
+
+# [2.0.0](https://github.com/kintone/plugin-packer/compare/v1.1.0-alpha.0...v2.0.0) (2019-06-11)
+
+### Bug Fixes
+
+- **deps:** update dependency chokidar to ^2.1.6 ([#354](https://github.com/kintone/plugin-packer/issues/354)) ([08cb678](https://github.com/kintone/plugin-packer/commit/08cb678))
+
+### Continuous Integration
+
+- drop Node v6 and add Node v12 as supporting versions ([#358](https://github.com/kintone/plugin-packer/issues/358)) ([9bdbbf9](https://github.com/kintone/plugin-packer/commit/9bdbbf9))
+
+### BREAKING CHANGES
+
+- drop Node v6 support
+
+# [1.1.0-alpha.0](https://github.com/kintone/plugin-packer/compare/v1.0.8...v1.1.0-alpha.0) (2019-05-14)
+
+### Bug Fixes
+
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^1.0.8 ([#345](https://github.com/kintone/plugin-packer/issues/345)) ([7ebecc3](https://github.com/kintone/plugin-packer/commit/7ebecc3))
+
+### Features
+
+- update @kintone/plugin-manifest-validator to 1.1.0-alpha.0 ([ed7d631](https://github.com/kintone/plugin-packer/commit/ed7d631))
+
+## [1.0.8](https://github.com/kintone/plugin-packer/compare/v1.0.7...v1.0.8) (2019-04-23)
+
+### Bug Fixes
+
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^1.0.7 ([#329](https://github.com/kintone/plugin-packer/issues/329)) ([ac6b853](https://github.com/kintone/plugin-packer/commit/ac6b853))
+
+## [1.0.7](https://github.com/kintone/plugin-packer/compare/v1.0.6...v1.0.7) (2019-03-26)
+
+### Bug Fixes
+
+- **deps:** Fix `release` script ([c1be1e7](https://github.com/kintone/plugin-packer/commit/c1be1e7))
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^1.0.6 ([#309](https://github.com/kintone/plugin-packer/issues/309)) ([8abb4e0](https://github.com/kintone/plugin-packer/commit/8abb4e0))
+- **deps:** update dependency chokidar to ^2.1.2 ([#300](https://github.com/kintone/plugin-packer/issues/300)) ([6bd7a11](https://github.com/kintone/plugin-packer/commit/6bd7a11))
+- **deps:** update dependency chokidar to ^2.1.5 ([#327](https://github.com/kintone/plugin-packer/issues/327)) ([bbb5dd7](https://github.com/kintone/plugin-packer/commit/bbb5dd7))
+- **deps:** update dependency node-rsa to ~1.0.5 ([#318](https://github.com/kintone/plugin-packer/issues/318)) ([9b0b964](https://github.com/kintone/plugin-packer/commit/9b0b964))
+
+## [1.0.6](https://github.com/kintone/plugin-packer/compare/v1.0.5...v1.0.6) (2019-02-26)
+
+### Bug Fixes
+
+- **deps:** update dependency @kintone/plugin-manifest-validator to ^1.0.5 ([#285](https://github.com/kintone/plugin-packer/issues/285)) ([6a07788](https://github.com/kintone/plugin-packer/commit/6a07788))
+- **deps:** update dependency node-rsa to ~1.0.3 ([#296](https://github.com/kintone/plugin-packer/issues/296)) ([61c9f87](https://github.com/kintone/plugin-packer/commit/61c9f87))
+
+<a name="1.0.5"></a>
+
+## [1.0.5](https://github.com/kintone/plugin-packer/compare/v1.0.4...v1.0.5) (2018-12-26)
+
+### Bug Fixes
+
+- **ci:** convert linebreak LF only \*.js ([#271](https://github.com/kintone/plugin-packer/issues/271)) ([2482418](https://github.com/kintone/plugin-packer/commit/2482418))
+- **deps:** update dependency [@kintone](https://github.com/kintone)/plugin-manifest-validator to ^1.0.3 ([#236](https://github.com/kintone/plugin-packer/issues/236)) ([0e3cfa5](https://github.com/kintone/plugin-packer/commit/0e3cfa5))
+- **deps:** update dependency [@kintone](https://github.com/kintone)/plugin-manifest-validator to ^1.0.4 ([#260](https://github.com/kintone/plugin-packer/issues/260)) ([bff3c25](https://github.com/kintone/plugin-packer/commit/bff3c25))
+- **deps:** update dependency debug to ^4.1.1 ([#280](https://github.com/kintone/plugin-packer/issues/280)) ([f6639de](https://github.com/kintone/plugin-packer/commit/f6639de))
+- **deps:** update dependency node-rsa to ~1.0.2 ([#277](https://github.com/kintone/plugin-packer/issues/277)) ([c33ec10](https://github.com/kintone/plugin-packer/commit/c33ec10))
+- **deps:** update dependency yazl to ^2.5.1 ([#257](https://github.com/kintone/plugin-packer/issues/257)) ([4bd6b3c](https://github.com/kintone/plugin-packer/commit/4bd6b3c))
+- **test:** line break warnings ([#270](https://github.com/kintone/plugin-packer/issues/270)) ([684e65c](https://github.com/kintone/plugin-packer/commit/684e65c))
+
+<a name="1.0.4"></a>
+
+## [1.0.4](https://github.com/kintone/plugin-packer/compare/v1.0.3...v1.0.4) (2018-10-10)
+
+### Bug Fixes
+
+- **deps:** update dependency [@kintone](https://github.com/kintone)/plugin-manifest-validator to ^1.0.2 ([#218](https://github.com/kintone/plugin-packer/issues/218)) ([ce518cb](https://github.com/kintone/plugin-packer/commit/ce518cb))
+- **deps:** update dependency debug to ^4.1.0 ([#234](https://github.com/kintone/plugin-packer/issues/234)) ([38ba5e4](https://github.com/kintone/plugin-packer/commit/38ba5e4))
+- **deps:** update dependency debug to v4 ([#220](https://github.com/kintone/plugin-packer/issues/220)) ([b2caf72](https://github.com/kintone/plugin-packer/commit/b2caf72))
+
+<a name="1.0.3"></a>
+
+## [1.0.3](https://github.com/kintone/plugin-packer/compare/v1.0.2...v1.0.3) (2018-09-12)
+
+### Bug Fixes
+
+- **deps:** update dependency [@kintone](https://github.com/kintone)/plugin-manifest-validator to ^1.0.1 ([#199](https://github.com/kintone/plugin-packer/issues/199)) ([93ef081](https://github.com/kintone/plugin-packer/commit/93ef081))
+
+<a name="1.0.2"></a>
+
+## [1.0.2](https://github.com/kintone/plugin-packer/compare/v1.0.1...v1.0.2) (2018-08-07)
+
+### Bug Fixes
+
+- **deps:** update dependency chokidar to ^2.0.4 ([#172](https://github.com/kintone/plugin-packer/issues/172)) ([4e1cc11](https://github.com/kintone/plugin-packer/commit/4e1cc11))
+- **deps:** update dependency node-rsa to ~1.0.1 ([#195](https://github.com/kintone/plugin-packer/issues/195)) ([ea492fa](https://github.com/kintone/plugin-packer/commit/ea492fa))
+- **deps:** update dependency yauzl to ^2.10.0 ([#182](https://github.com/kintone/plugin-packer/issues/182)) ([a705061](https://github.com/kintone/plugin-packer/commit/a705061))
+- **eslint:** update eslintrc for eslint@5 ([#180](https://github.com/kintone/plugin-packer/issues/180)) ([862840f](https://github.com/kintone/plugin-packer/commit/862840f))
+
+<a name="1.0.1"></a>
+
+## [1.0.1](https://github.com/kintone/plugin-packer/compare/v1.0.0...v1.0.1) (2018-06-08)
+
+### Bug Fixes
+
+- **cli:** reuse a new ppk file with --watch option ([#160](https://github.com/kintone/plugin-packer/issues/160)) ([add5c71](https://github.com/kintone/plugin-packer/commit/add5c71))
+
+## Before 1.0.1
+
+The chagelogs are in the GitHub's release page.
+
+- https://github.com/kintone/plugin-packer/releases
diff --git a/src/plugin/packer/LICENSE b/src/plugin/packer/LICENSE
new file mode 100644
index 0000000000..88a5a69f6b
--- /dev/null
+++ b/src/plugin/packer/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 Cybozu, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
\ No newline at end of file
diff --git a/src/plugin/packer/README.md b/src/plugin/packer/README.md
new file mode 100644
index 0000000000..0d76548d36
--- /dev/null
+++ b/src/plugin/packer/README.md
@@ -0,0 +1,67 @@
+# kintone-plugin-packer
+
+[![npm version](https://badge.fury.io/js/%40kintone%2Fplugin-packer.svg)](https://badge.fury.io/js/%40kintone%2Fplugin-packer)
+![Node.js version](https://img.shields.io/badge/dynamic/json.svg?url=https://raw.githubusercontent.com/kintone/js-sdk/main/packages/plugin-packer/package.json&label=node&query=$.engines.node&colorB=blue)
+![License](https://img.shields.io/npm/l/@kintone/plugin-packer.svg)
+
+[kintone plugin package.sh](https://github.com/kintone-samples/plugin-samples) in JavaScript
+
+It's written in pure JavaScript, so
+
+- The CLI works with Node.js in Mac/Windows/Linux
+- [The web page](https://plugin-packer.kintone.dev/) works in any modern browsers
+- Validate your `manifest.json` with [JSON Schema](https://github.com/kintone/js-sdk/tree/main/packages/plugin-manifest-validator)
+
+# How to install
+
+```console
+$ npm install -g @kintone/plugin-packer
+```
+
+# Usage: CLI
+
+```console
+$ kintone-plugin-packer [OPTIONS] PLUGIN_DIR
+```
+
+## Options
+
+- `--ppk PPK_FILE`: The path of input private key file. If omitted, it is generated automatically into `<Plugin ID>.ppk` in the same directory of `PLUGIN_DIR` or `--out` if specified.
+- `--out PLUGIN_FILE`: The path of generated plugin file. The default is `plugin.zip` in the same directory of `PLUGIN_DIR`.
+- `--watch`, `-w`: Watch PLUGIN_DIR for the changes.
+
+## How to use with `npm run`
+
+If your private key is `./private.ppk` and the plugin directory is `./plugin`, edit `package.json`:
+
+```json
+{
+  "scripts": {
+    "package": "kintone-plugin-packer --ppk private.ppk plugin"
+  }
+}
+```
+
+and then
+
+```console
+$ npm run package
+```
+
+# Usage: Node.js API
+
+```js
+const packer = require("@kintone/plugin-packer");
+const fs = require("fs");
+
+const buffer = createContentsZipBufferInYourSelf();
+packer(buffer).then((output) => {
+  console.log(output.id);
+  fs.writeFileSync("./private.ppk", output.privateKey);
+  fs.writeFileSync("./plugin.zip", output.plugin);
+});
+```
+
+## License
+
+MIT License
diff --git a/src/plugin/packer/babel.config.js b/src/plugin/packer/babel.config.js
new file mode 100644
index 0000000000..2e023b4111
--- /dev/null
+++ b/src/plugin/packer/babel.config.js
@@ -0,0 +1,7 @@
+module.exports = {
+  presets: [
+    ["@babel/preset-env", { targets: { node: "current" } }],
+    "@babel/preset-typescript",
+  ],
+  plugins: ["babel-plugin-replace-ts-export-assignment"],
+};
diff --git a/src/plugin/packer/bin/cli.js b/src/plugin/packer/bin/cli.js
new file mode 100755
index 0000000000..2b409e1b68
--- /dev/null
+++ b/src/plugin/packer/bin/cli.js
@@ -0,0 +1,53 @@
+#!/usr/bin/env node
+
+"use strict";
+
+const meow = require("meow");
+const packer = require("../dist/cli");
+
+const USAGE = "$ kintone-plugin-packer [options] PLUGIN_DIR";
+
+const flagSpec = {
+  ppk: {
+    type: "string",
+  },
+  out: {
+    type: "string",
+  },
+  watch: {
+    type: "boolean",
+    alias: "w",
+  },
+};
+
+const cli = meow(
+  `
+Usage
+  ${USAGE}
+
+Options
+  --ppk PPK_FILE: Private key file. If omitted, it's generated into '<Plugin ID>.ppk' in the same directory of PLUGIN_DIR.
+  --out PLUGIN_FILE: The default is 'plugin.zip' in the same directory of PLUGIN_DIR.
+  --watch: Watch PLUGIN_DIR for the changes.
+`,
+  {
+    flags: flagSpec,
+  },
+);
+
+if (!cli.input[0]) {
+  console.error("Error: An argument `PLUGIN_DIR` is required.");
+  cli.showHelp();
+}
+
+const pluginDir = cli.input[0];
+const flags = Object.keys(flagSpec).reduce((prev, cur) => {
+  prev[cur] = cli.flags[cur];
+  return prev;
+}, {});
+
+if (process.env.NODE_ENV === "test") {
+  console.log(JSON.stringify({ pluginDir, flags }));
+} else {
+  packer(pluginDir, flags);
+}
diff --git a/src/plugin/packer/bin/eslint.config.mjs b/src/plugin/packer/bin/eslint.config.mjs
new file mode 100644
index 0000000000..43ca03958f
--- /dev/null
+++ b/src/plugin/packer/bin/eslint.config.mjs
@@ -0,0 +1,6 @@
+import presetsNodePrettier from "@cybozu/eslint-config/flat/presets/node-prettier.js";
+
+/** @type {import("eslint").Linter.Config[]} */
+export default [
+  ...presetsNodePrettier
+];
diff --git a/src/plugin/packer/docs/dist/.gitkeep b/src/plugin/packer/docs/dist/.gitkeep
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/plugin/packer/docs/index-ja.html b/src/plugin/packer/docs/index-ja.html
new file mode 100644
index 0000000000..a0b916f988
--- /dev/null
+++ b/src/plugin/packer/docs/index-ja.html
@@ -0,0 +1,102 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width,initial-scale=1">
+  <title>Package your kintone plug-in!</title>
+  <link rel="stylesheet" href="./dist/normalize.min.css">
+  <link rel="stylesheet" href="./style.css">
+  <script defer src="https://use.fontawesome.com/releases/v5.0.7/js/all.js"></script>
+  <!-- Google Tag Manager -->
+  <script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
+            new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
+          j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
+          'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
+  })(window,document,'script','dataLayer','GTM-5N49D3');</script>
+  <!-- End Google Tag Manager -->
+  <script src="./dist/bundle.js" defer></script>
+</head>
+<body>
+  <!-- Google Tag Manager (noscript) -->
+  <noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-5N49D3"
+                    height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>
+  <!-- End Google Tag Manager (noscript) -->
+  <header class="header">
+    <h1 class="header__title">Package your kintone plug-in!</h1>
+  </header>
+  <main>
+    <section class="description">
+      <p>
+        プラグインディレクトリをアップロードしてください。<br>
+        Chrome, Firefox以外の場合は、Zipで固めてアップロードしてください。<br>
+        秘密鍵と署名済みのプラグインファイルを生成します。<br>
+        2回目以降の場合は、秘密鍵も添付してください。
+      </p>
+    </section>
+    <section class="upload-area">
+      <div class="upload-area__droppable js-upload js-upload-zip">
+        <p class="upload-area__text">
+          <span class="hide js-zip-ok-icon ok-icon"><i class="fas fa-check-circle"></i></span>
+          <i class="far fa-folder"></i>
+          <a href="" class="upload-area__zip-link js-upload-zip-link">
+            プラグインをドラッグアンドドロップするか、ここをクリックして選択してください
+          </a>
+          <br />
+          <i class="fas fa-upload"></i>
+          <span class="js-zip-file-name"></span>
+          <input type=file class="upload-area__file-upload js-file-upload" accept=".zip" tabindex="-1" webkitdirectory>
+        </p>
+      </div>
+      <div class="upload-area__droppable js-upload js-upload-ppk">
+        <p class="upload-area__text">
+          <span class="hide js-ppk-ok-icon ok-icon"><i class="fas fa-check-circle"></i></span>
+          <i class="fas fa-key"></i>
+          <a href="" class="upload-area__ppk-link js-upload-ppk-link">
+            秘密鍵(.ppk)ファイルをドラッグアンドドロップするか、ここをクリックして選択してください（オプション）
+          </a>
+          <br />
+          <i class="fas fa-upload"></i>
+          <span class="js-ppk-file-name"></span>
+          <input type=file class="upload-area__file-upload js-file-upload" accept=".ppk" tabInde="-1">
+        </p>
+      </div>
+    </section>
+    <section class="hide download js-download">
+      <h2 class="download__title">プラグインを作成しました！</h2>
+      <ul class="download__list">
+        <li class="download__list-element">
+          ID: <span class="js-download-plugin-id"></span>
+        </li>
+        <li class="download__list-element">
+          <span class="ok-icon"><i class="fas fa-check-circle"></i></span>
+          <span><i class="far fa-folder"></i></span>
+          <a class="js-download-plugin" download="plugin.zip">
+            plugin.zip
+          </a>
+        </li>
+        <li class="download__list-element">
+          <span class="ok-icon"><i class="fas fa-check-circle"></i></span>
+          <i class="fas fa-key"></i>
+          <a class="js-download-ppk" download="private.ppk">
+            private.ppk
+          </a>
+        </li>
+      </ul>
+    </section>
+    <section class="hide error js-error">
+      <h2 class="error__title">プラグインの作成に失敗しました</h2>
+      <ul class="error__messages js-error-messages"></ul>
+    </section>
+    <section class="action">
+      <button class="action__button action__button--create js-create-btn disabled">作成する</button>
+      <button class="action__button action__button--create js-create-loading-btn hide">
+        <span class="loading"><i class="fas fa-spinner"></i></span>
+      </button>
+      <button class="action__button action__button--clear js-clear-btn">リセットする</button>
+    </section>
+  </main>
+  <footer class="footer">
+    <p>Lang: <a href="./index.html">English</a></p>
+  </footer>
+</body>
+</html>
diff --git a/src/plugin/packer/docs/index.html b/src/plugin/packer/docs/index.html
new file mode 100644
index 0000000000..63ef80f254
--- /dev/null
+++ b/src/plugin/packer/docs/index.html
@@ -0,0 +1,102 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width,initial-scale=1">
+  <title>Package your kintone plug-in!</title>
+  <link rel="stylesheet" href="./dist/normalize.min.css">
+  <link rel="stylesheet" href="./style.css">
+  <script defer src="https://use.fontawesome.com/releases/v5.0.7/js/all.js"></script>
+  <!-- Google Tag Manager -->
+  <script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
+            new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
+          j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
+          'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
+  })(window,document,'script','dataLayer','GTM-5N49D3');</script>
+  <!-- End Google Tag Manager -->
+  <script src="./dist/bundle.js" defer></script>
+</head>
+<body>
+  <!-- Google Tag Manager (noscript) -->
+  <noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-5N49D3"
+                    height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>
+  <!-- End Google Tag Manager (noscript) -->
+  <header class="header">
+    <h1 class="header__title">Package your kintone plug-in!</h1>
+  </header>
+  <main>
+    <section class="description">
+      <p>
+        Upload the plug-in directory.<br>
+        If you are using a browser except for Chrome or Firefox, upload the zipped plug-in file.<br>
+        A secret key file and a signed plug-in file will be generated.<br>
+        The secret key will also need to be uploaded when repackaging your plug-in.
+      </p>
+    </section>
+    <section class="upload-area">
+      <div class="upload-area__droppable js-upload js-upload-zip">
+        <p class="upload-area__text">
+          <span class="hide js-zip-ok-icon ok-icon"><i class="fas fa-check-circle"></i></span>
+          <i class="far fa-folder"></i>
+          <a href="" class="upload-area__zip-link js-upload-zip-link">
+            Drag and drop your kintone plug-in!
+          </a>
+          <br />
+          <i class="fas fa-upload"></i>
+          <span class="js-zip-file-name"></span>
+          <input type=file class="upload-area__file-upload js-file-upload" accept=".zip" tabindex="-1" webkitdirectory>
+        </p>
+      </div>
+      <div class="upload-area__droppable js-upload js-upload-ppk">
+        <p class="upload-area__text">
+          <span class="hide js-ppk-ok-icon ok-icon"><i class="fas fa-check-circle"></i></span>
+          <i class="fas fa-key"></i>
+          <a href="" class="upload-area__ppk-link js-upload-ppk-link">
+            Drag and drop your secret key file(.ppk)
+          </a>
+          (optional)<br />
+          <i class="fas fa-upload"></i>
+          <span class="js-ppk-file-name"></span>
+          <input type=file class="upload-area__file-upload js-file-upload" accept=".ppk" tabInde="-1">
+        </p>
+      </div>
+    </section>
+    <section class="hide download js-download">
+      <h2 class="download__title">Success!</h2>
+      <ul class="download__list">
+        <li class="download__list-element">
+          ID: <span class="js-download-plugin-id"></span>
+        </li>
+        <li class="download__list-element">
+          <span class="ok-icon"><i class="fas fa-check-circle"></i></span>
+          <span><i class="far fa-folder"></i></span>
+          <a class="js-download-plugin" download="plugin.zip">
+            plugin.zip
+          </a>
+        </li>
+        <li class="download__list-element">
+          <span class="ok-icon"><i class="fas fa-check-circle"></i></span>
+          <i class="fas fa-key"></i>
+          <a class="js-download-ppk" download="private.ppk">
+            private.ppk
+          </a>
+        </li>
+      </ul>
+    </section>
+    <section class="hide error js-error">
+      <h2 class="error__title">Failed</h2>
+      <ul class="error__messages js-error-messages"></ul>
+    </section>
+    <section class="action">
+      <button class="action__button action__button--create js-create-btn disabled">Create</button>
+      <button class="action__button action__button--create js-create-loading-btn hide">
+        <span class="loading"><i class="fas fa-spinner"></i></span>
+      </button>
+      <button class="action__button action__button--clear js-clear-btn">Reset</button>
+    </section>
+  </main>
+  <footer class="footer">
+      <p>Lang: <a href="./index-ja.html">JP</a></p>
+  </footer>
+</body>
+</html>
diff --git a/src/plugin/packer/docs/style.css b/src/plugin/packer/docs/style.css
new file mode 100644
index 0000000000..bc1f585bcc
--- /dev/null
+++ b/src/plugin/packer/docs/style.css
@@ -0,0 +1,189 @@
+* {
+  margin: 0;
+  padding: 0;
+  font-family: helvetica, arial, 'hiragino kaku gothic pro', meiryo, 'ms pgothic', sans-serif;
+}
+
+:root {
+  --ok-color: #74b816;
+  --base-color: #444;
+}
+
+.hide {
+  display: none;
+}
+
+@keyframes rotate {
+  from {
+    transform: rotate(0deg);
+  }
+  to {
+    transform: rotate(360deg);
+  }
+}
+
+.loading {
+  display: inline-block;
+  animation-name: rotate;
+  animation-duration: 1.5s;
+  animation-iteration-count: infinite;
+  animation-timing-function: linear;
+}
+
+/** font awesome */
+.ok-icon {
+  color: var(--ok-color);
+}
+
+.header {
+  background-color: var(--base-color);
+  color: #FFF;
+}
+
+.header__title {
+  margin: 0;
+  padding: 3rem;
+}
+
+.description {
+  margin: 2rem 3rem 1rem;
+  font-size: 1.2rem;
+  line-height: 1.3;
+}
+
+.upload-area {
+  display: flex;
+  margin: 0 2rem;
+}
+
+.upload-area__droppable {
+  flex: 1;
+  margin: 1rem;
+  padding: 100px 30px;
+  font-size: 1.3rem;
+  line-height: 1.5;
+  color: var(--base-color);
+  border: dashed 5px #CCC;
+}
+
+@media (max-width: 700px) {
+  .description {
+    margin: 2rem 1rem 1rem;
+    font-size: 1rem;
+    line-height: 1.3;
+  }
+
+  .upload-area {
+    margin: 0 0.5rem;
+  }
+
+  .upload-area__droppable {
+    margin: 0.5rem;
+    padding: 50px 15px;
+    font-size: 1rem;
+    line-height: 1.5;
+  }
+}
+
+.upload-area__droppable--drag {
+  background-color: #EEE;
+}
+
+.upload-area__text {
+  position: relative;
+}
+
+.upload-area__zip-link {
+  text-decoration: none;
+  color: var(--base-color);
+}
+
+.upload-area__ppk-link {
+  text-decoration: none;
+  color: var(--base-color);
+}
+
+.upload-area__file-upload {
+  position: absolute;
+  font-size: 0.8rem;
+  opacity: 0;
+  top: 0;
+  left: 0;
+}
+
+.download {
+  font-size: 1.2rem;
+  color: var(--base-color);
+  line-height: 1.5;
+}
+
+.download__title {
+  font-size: 1.4rem;
+  text-align: center;
+}
+
+.download__list {
+  width: 50%;
+  margin: 1rem auto;
+  padding: 1rem;
+  border: dashed 3px rgba(116, 184, 22, 0.4);
+}
+
+.download__list-element {
+  list-style: none;
+}
+
+.error {
+  font-size: 1.2rem;
+  line-height: 1.5;
+}
+
+.error__title {
+  font-size: 1.4rem;
+  text-align: center;
+}
+
+.error__messages {
+  width: 50%;
+  margin: 1rem auto;
+  padding: 1rem 2rem;
+  border: dashed 3px rgba(255, 0, 0, 0.4);
+  color: red;
+}
+
+.action {
+  margin: 0 auto;
+  width: 80%;
+  text-align: center;
+}
+
+.action__button {
+  width: 200px;
+  margin: 1rem;
+  padding: 1rem;
+}
+
+.action__button:hover {
+  opacity: 0.7;
+}
+
+.action__button--create {
+  background-color: #3498db;
+  color: #FFF;
+}
+
+.action__button--create.disabled {
+  opacity: 0.3;
+}
+
+.action__button--clear {
+  background-color: #EEE;
+  color: var(--base-color);
+}
+
+.footer {
+  font-size: 1.2rem;
+  padding: 3rem;
+  color: var(--base-color);
+}
+
diff --git a/src/plugin/packer/eslint.config.mjs b/src/plugin/packer/eslint.config.mjs
new file mode 100644
index 0000000000..549eef4356
--- /dev/null
+++ b/src/plugin/packer/eslint.config.mjs
@@ -0,0 +1,28 @@
+import rootConfig from "../../eslint.config.mjs";
+import siteConfig from "./site/eslint.config.mjs";
+import binConfig from "./bin/eslint.config.mjs";
+import globals from "globals";
+
+/** @type {import("eslint").Linter.Config[]} */
+export default [
+  ...siteConfig.map((configObject) => ({
+    files: ["site/**/*.{js,ts}"],
+    ...configObject,
+  })),
+  ...binConfig.map((configObject) => ({
+    files: ["bin/**/*.{js,ts}"],
+    ...configObject,
+  })),
+  ...rootConfig.map((configObject) => ({
+    ignores: ["site/*", "bin/*"],
+    ...configObject,
+  })),
+  {
+    files: ["test/**/*.{js,ts}"],
+    languageOptions: {
+      globals: {
+        ...globals.jest,
+      },
+    },
+  },
+];
diff --git a/src/plugin/packer/from-manifest.js b/src/plugin/packer/from-manifest.js
new file mode 100644
index 0000000000..9abe8adf68
--- /dev/null
+++ b/src/plugin/packer/from-manifest.js
@@ -0,0 +1,4 @@
+"use strict";
+
+module.exports =
+  require("./dist/pack-plugin-from-manifest").packPluginFromManifest;
diff --git a/src/plugin/packer/jest.config.js b/src/plugin/packer/jest.config.js
new file mode 100644
index 0000000000..95296cf6d5
--- /dev/null
+++ b/src/plugin/packer/jest.config.js
@@ -0,0 +1,7 @@
+/** @type {import('@jest/types').Config.InitialOptions} */
+const config = {
+  testRegex: "(?<!site)/test/[^\\/]*\\.spec.ts$",
+  testEnvironment: "node",
+  testTimeout: 30000,
+};
+module.exports = config;
diff --git a/src/plugin/packer/package.json b/src/plugin/packer/package.json
new file mode 100644
index 0000000000..434ac18220
--- /dev/null
+++ b/src/plugin/packer/package.json
@@ -0,0 +1,99 @@
+{
+  "name": "@kintone/plugin-packer",
+  "description": "Package your kintone plugin with pure JavaScript",
+  "version": "8.1.3",
+  "author": {
+    "name": "Cybozu, Inc.",
+    "url": "https://cybozu.co.jp"
+  },
+  "engines": {
+    "node": ">=18"
+  },
+  "main": "dist/index.js",
+  "bin": {
+    "kintone-plugin-packer": "bin/cli.js"
+  },
+  "types": "dist/index.d.ts",
+  "files": [
+    "bin",
+    "dist",
+    "from-manifest.js"
+  ],
+  "scripts": {
+    "prebuild": "pnpm clean",
+    "build": "tsc --build --force",
+    "postbuild": "run-p js css",
+    "clean": "rimraf dist",
+    "lint": "eslint \"*.{js,ts}\" bin src site test --max-warnings 0",
+    "fix": "pnpm lint --fix",
+    "test": "run-p jest site:test",
+    "test:ci": "pnpm test",
+    "build:dev": "tsc --build --force --watch",
+    "css": "postcss --config postcss.config.js ./node_modules/normalize.css/normalize.css > docs/dist/normalize.min.css",
+    "js": "webpack --mode production",
+    "js:dev": "webpack serve --mode development",
+    "jest": "jest",
+    "site": "run-p js css",
+    "site:dev": "run-p css js:dev",
+    "site:test": "jest --config site/jest.config.js",
+    "start": "npm-run-all -l -s clean build -p build:dev site:dev"
+  },
+  "dependencies": {
+    "@kintone/plugin-manifest-validator": "^10.2.2",
+    "chokidar": "^3.6.0",
+    "debug": "^4.3.7",
+    "denodeify": "^1.2.1",
+    "meow": "^9.0.0",
+    "mkdirp": "^3.0.1",
+    "node-rsa": "~1.1.1",
+    "stream-buffers": "^3.0.3",
+    "yauzl": "^3.1.3",
+    "yazl": "^2.5.1"
+  },
+  "devDependencies": {
+    "@reduxjs/toolkit": "^2.3.0",
+    "@types/debug": "^4.1.12",
+    "@types/node-rsa": "^1.1.4",
+    "@types/stream-buffers": "^3.0.7",
+    "@types/yauzl": "^2.10.3",
+    "@types/yazl": "^2.4.5",
+    "ajv": "^8.17.1",
+    "array-flatten": "^3.0.0",
+    "assert": "^2.1.0",
+    "babel-plugin-replace-ts-export-assignment": "^0.0.2",
+    "browserify-zlib": "^0.2.0",
+    "buffer": "^6.0.3",
+    "constants-browserify": "^1.0.0",
+    "crypto-browserify": "^3.12.0",
+    "cssnano": "^7.0.6",
+    "execa": "^5.1.1",
+    "glob": "^10.4.5",
+    "globals": "^15.11.0",
+    "jest-environment-jsdom": "^29.7.0",
+    "normalize.css": "^8.0.1",
+    "path-browserify": "^1.0.1",
+    "postcss": "^8.4.47",
+    "postcss-cli": "^11.0.0",
+    "process": "^0.11.10",
+    "redux-logger": "^3.0.6",
+    "redux-thunk": "^3.1.0",
+    "rimraf": "^5.0.10",
+    "setimmediate": "^1.0.5",
+    "stream-browserify": "^3.0.0",
+    "util": "^0.12.5",
+    "webpack": "^5.95.0",
+    "webpack-cli": "5.1.4",
+    "webpack-dev-server": "^5.1.0"
+  },
+  "homepage": "https://github.com/kintone/js-sdk/tree/main/packages/plugin-packer",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/kintone/js-sdk.git",
+    "directory": "packages/plugin-packer"
+  },
+  "bugs": "https://github.com/kintone/js-sdk/issues",
+  "keywords": [
+    "kintone"
+  ],
+  "license": "MIT"
+}
diff --git a/src/plugin/packer/postcss.config.js b/src/plugin/packer/postcss.config.js
new file mode 100644
index 0000000000..97f9abbdba
--- /dev/null
+++ b/src/plugin/packer/postcss.config.js
@@ -0,0 +1,7 @@
+module.exports = {
+  plugins: [
+    require("cssnano")({
+      preset: "default",
+    }),
+  ],
+};
diff --git a/src/plugin/packer/site/action.js b/src/plugin/packer/site/action.js
new file mode 100644
index 0000000000..3d8cd3d124
--- /dev/null
+++ b/src/plugin/packer/site/action.js
@@ -0,0 +1,129 @@
+"use strict";
+
+const delay = (ms) => new Promise((resolve) => setTimeout(resolve, ms));
+
+const UPLOAD_PPK_START = "UPLOAD_PPK_START";
+const UPLOAD_PPK = "UPLOAD_PPK";
+const UPLOAD_PLUGIN_START = "UPLOADING_PLUGIN_START";
+const UPLOAD_PLUGIN = "UPLOAD_PLUGIN";
+const UPLOAD_FAILURE = "UPLOAD_FAILURE";
+const CREATE_PLUGIN_ZIP = "CREATE_PLUGIN_ZIP";
+const CREATE_PLUGIN_ZIP_START = "CREATE_PLUGIN_ZIP_START";
+const CREATE_PLUGIN_ZIP_FAILURE = "CREATE_PLUGIN_ZIP_FAILURE";
+const RESET = "RESET";
+
+/**
+ * Dispatch an action for uploading an error
+ * @param {Error} error
+ * @return {{type: string, payload: Error}}
+ */
+const uploadFailure = (error) => ({
+  type: UPLOAD_FAILURE,
+  payload: error,
+});
+
+/**
+ * Dispatch an action for uploading a ppk file
+ * @param {string} fileName
+ * @param {function(): Promise<string>} fileReader
+ * @return {function(dispatch: function)}
+ */
+const uploadPPK = (fileName, fileReader) => (dispatch) => {
+  dispatch({ type: UPLOAD_PPK_START });
+  fileReader().then(
+    (text) => {
+      dispatch({
+        type: UPLOAD_PPK,
+        payload: {
+          data: text,
+          name: fileName,
+        },
+      });
+    },
+    (error) => {
+      dispatch(uploadFailure(error));
+    },
+  );
+};
+
+/**
+ * Dispatch an action for uploading a plugin zip
+ * @param {string} fileName
+ * @param {function(): Promise<ArrayBuffer>} fileReader
+ * @param {function(): Promise<void>} validateManifest
+ * @return {function(dispatch: function)}
+ */
+const uploadPlugin = (fileName, fileReader, validateManifest) => (dispatch) => {
+  dispatch({ type: UPLOAD_PLUGIN_START });
+  fileReader()
+    .then((buffer) => validateManifest(buffer).then(() => buffer))
+    .then(
+      (buffer) => {
+        dispatch({
+          type: UPLOAD_PLUGIN,
+          payload: {
+            data: buffer,
+            name: fileName,
+          },
+        });
+      },
+      (error) => {
+        dispatch(uploadFailure(error));
+      },
+    );
+};
+
+/**
+ * Dispatch an action for creating a plugin zip
+ * @param {function(contents: ArrayBuffer, ppk: string): Promise<*>} generatePluginZip
+ * @return {function(dispatch: function, getState: function)}
+ */
+const createPluginZip = (generatePluginZip) => (dispatch, getState) => {
+  dispatch({
+    type: CREATE_PLUGIN_ZIP_START,
+  });
+  const state = getState();
+  Promise.all([
+    generatePluginZip(state.contents.data, state.ppk.data),
+    // It's to guarantee to wait 300ms to recognize creating a plugin zip an user
+    delay(300),
+  ]).then(
+    ([result]) => {
+      dispatch({
+        type: CREATE_PLUGIN_ZIP,
+        payload: result,
+      });
+    },
+    (error) => {
+      dispatch({
+        type: CREATE_PLUGIN_ZIP_FAILURE,
+        payload: error,
+      });
+    },
+  );
+};
+
+/**
+ * Dispatch an action to reset the state
+ * @return {{type: string}}
+ */
+const reset = () => ({
+  type: RESET,
+});
+
+module.exports = {
+  UPLOAD_FAILURE,
+  UPLOAD_PPK,
+  UPLOAD_PPK_START,
+  UPLOAD_PLUGIN,
+  UPLOAD_PLUGIN_START,
+  CREATE_PLUGIN_ZIP,
+  CREATE_PLUGIN_ZIP_START,
+  CREATE_PLUGIN_ZIP_FAILURE,
+  RESET,
+  uploadFailure,
+  uploadPPK,
+  uploadPlugin,
+  reset,
+  createPluginZip,
+};
diff --git a/src/plugin/packer/site/dom.js b/src/plugin/packer/site/dom.js
new file mode 100644
index 0000000000..07252c52bd
--- /dev/null
+++ b/src/plugin/packer/site/dom.js
@@ -0,0 +1,205 @@
+"use strict";
+
+const { flatten } = require("array-flatten");
+const yazl = require("yazl");
+const streamBuffers = require("stream-buffers");
+
+/**
+ * Revoke an object URL
+ * @param {string} url
+ * @return {void}
+ */
+const revokeDownloadUrl = (url) => URL.revokeObjectURL(url);
+
+/**
+ * Create an object URL for the data
+ * @param {*} data
+ * @param {string} type
+ * @return {string}
+ */
+const createDownloadUrl = (data, type) =>
+  URL.createObjectURL(new Blob([data], { type }));
+
+const isDropEvent = (e) => e.type === "drop";
+
+/**
+ *  Read files from FileSystemEntry
+ * @typedef {{path: string, file: File}} FileEntry
+ * @param {FileSystemEntry} entry
+ * @return {Promise<FileEntry | FileEntry[]>}
+ * */
+const readEntries = (entry) =>
+  new Promise((resolve, reject) => {
+    if (entry.isFile) {
+      // Convert the fullPath to the relative path from the plugin directory
+      entry.file((file) =>
+        resolve({ path: entry.fullPath.replace(/^\/[^/]+?\//, ""), file }),
+      );
+    } else if (entry.isDirectory) {
+      entry.createReader().readEntries((childEntries) => {
+        Promise.all(
+          childEntries.map((childEntry) => readEntries(childEntry)),
+        ).then(resolve);
+      });
+    } else {
+      reject(new Error("Unsupported file system entry specified"));
+    }
+  });
+
+/**
+ * Get a file or a file list from Event
+ * @param {Event} e
+ * @return {Promise<File | {name: string, entries: Map<string, File>}>}
+ */
+const getFileFromEvent = (e) => {
+  if (!isDropEvent(e)) {
+    const files = e.target.files;
+    if (files.length === 1) {
+      return Promise.resolve(files[0]);
+    }
+    // Create a Map<path, File>
+    return Promise.resolve({
+      // Get a uploaded directory name from webkitRelativePath
+      name: files[0].webkitRelativePath.replace(/\/.*/, ""),
+      entries: new Map(
+        Array.from(files).map((file) => [file.webkitRelativePath, file]),
+      ),
+    });
+  }
+  if (
+    typeof e.dataTransfer.items === "undefined" ||
+    typeof e.dataTransfer.items[0].webkitGetAsEntry !== "function"
+  ) {
+    // We assume a string was dropped if we can't get the File object
+    const file = e.dataTransfer.files[0];
+    if (!file) {
+      return Promise.reject(new Error("Unsupported file type item specified"));
+    }
+    // the upload file name doesn't have any dot so we can infer the file is a directory
+    if (file.name.indexOf(".") === -1) {
+      return Promise.reject(
+        new Error("Your browser doesn't support a directory upload"),
+      );
+    }
+    return Promise.resolve(file);
+  }
+  return new Promise((resolve, reject) => {
+    const dataTransferItem = e.dataTransfer.items[0];
+    if (dataTransferItem.kind !== "file") {
+      reject(new Error("Unsupported file type item specified"));
+      return;
+    }
+    const entry = dataTransferItem.webkitGetAsEntry();
+    if (entry.isFile) {
+      entry.file(resolve);
+    } else if (entry.isDirectory) {
+      readEntries(entry).then((entries) => {
+        resolve({
+          name: entry.name,
+          // Create a Map<path, File>
+          entries: new Map(
+            flatten(entries).map(({ path, file }) => [path, file]),
+          ),
+        });
+      });
+    } else {
+      reject(new Error("Unsupported file system entry specified"));
+    }
+  });
+};
+
+/**
+ * Create an handler for an event to convert a File
+ * @param {function(promise: Promise<File>): void} cb
+ * @return {function(e: Event)}
+ */
+const createFileHanlder = (cb) => (e) => {
+  if (isDropEvent(e)) {
+    e.preventDefault();
+  }
+  cb(getFileFromEvent(e));
+};
+
+/**
+ * Read a file and return it as an text
+ * @param {File} file
+ * @return {Promise<string>}
+ */
+const readText = (file) =>
+  new Promise((resolve) => {
+    const reader = new FileReader();
+    reader.onload = () => resolve(reader.result);
+    reader.readAsText(file);
+  });
+
+/**
+ * Read a file and return it as an array buffer
+ * @param {File} file
+ * @return {Promise<ArrayBuffer>}
+ */
+const readArrayBuffer = (file) =>
+  new Promise((resolve, reject) => {
+    const reader = new FileReader();
+    reader.onload = () => resolve(reader.result);
+    reader.onerror = reject;
+    reader.readAsArrayBuffer(file);
+  });
+
+const $ = document.querySelector.bind(document);
+const $$ = document.querySelectorAll.bind(document);
+/**
+ * register an event handler
+ * @param {HTMLElement|NodeList} el
+ * @param {*} args
+ */
+const listen = (el, ...args) => {
+  if (el instanceof NodeList) {
+    el.forEach((e) => listen(...[e, ...args]));
+    return;
+  }
+  el.addEventListener(...args);
+};
+
+/**
+ * Create a buffer of the zip file
+ * @typedef {{file: File, fullPath: string}} FileEntry
+ * @param {Map<string, File>} fileMap
+ * @return {Promise<Buffer>}
+ */
+function fileMapToBuffer(fileMap) {
+  return Promise.all(
+    Array.from(fileMap.entries()).map(([path, file]) =>
+      readArrayBuffer(file).then((buffer) => ({ buffer, path })),
+    ),
+  )
+    .then((results) => {
+      const zipFile = new yazl.ZipFile();
+      results.forEach((result) => {
+        zipFile.addBuffer(Buffer.from(result.buffer), result.path);
+      });
+      zipFile.end();
+      return zipFile;
+    })
+    .then(
+      (zipFile) =>
+        new Promise((resolve) => {
+          const output = new streamBuffers.WritableStreamBuffer();
+          output.on("finish", () => {
+            resolve(output.getContents());
+          });
+          zipFile.outputStream.pipe(output);
+        }),
+    );
+}
+
+module.exports = {
+  $,
+  $$,
+  fileMapToBuffer,
+  listen,
+  revokeDownloadUrl,
+  createDownloadUrl,
+  createFileHanlder,
+  readText,
+  readArrayBuffer,
+};
diff --git a/src/plugin/packer/site/eslint.config.mjs b/src/plugin/packer/site/eslint.config.mjs
new file mode 100644
index 0000000000..c5e2e8b87d
--- /dev/null
+++ b/src/plugin/packer/site/eslint.config.mjs
@@ -0,0 +1,15 @@
+import globals from "globals";
+import presetsPrettier from "@cybozu/eslint-config/flat/presets/prettier.js";
+
+/** @type {import("eslint").Linter.Config[]} */
+export default [
+  ...presetsPrettier,
+  {
+    languageOptions: {
+      globals: {
+        ...globals.jest,
+        ...globals.node,
+      },
+    },
+  },
+];
diff --git a/src/plugin/packer/site/index.js b/src/plugin/packer/site/index.js
new file mode 100644
index 0000000000..16bdee38f8
--- /dev/null
+++ b/src/plugin/packer/site/index.js
@@ -0,0 +1,193 @@
+"use strict";
+
+require("setimmediate"); // polyfill
+
+const { configureStore } = require("@reduxjs/toolkit");
+const { thunk } = require("redux-thunk");
+const logger = require("redux-logger").default;
+
+const {
+  $,
+  $$,
+  fileMapToBuffer,
+  listen,
+  readText,
+  readArrayBuffer,
+  createFileHanlder,
+} = require("./dom");
+const View = require("./view");
+
+const { reducer } = require("./reducer");
+const {
+  uploadPPK,
+  uploadPlugin,
+  createPluginZip,
+  reset,
+  uploadFailure,
+} = require("./action");
+const {
+  generatePluginZip,
+  validatePlugin,
+  revokePluginUrls,
+} = require("./plugin");
+
+const $ppkFileUploader = $(".js-upload-ppk .js-file-upload");
+const $zipFileUploader = $(".js-upload-zip .js-file-upload");
+const $$fileUploader = $$(".js-file-upload");
+
+const $$UploadArea = $$(".js-upload");
+const $zipDropArea = $(".js-upload-zip");
+const $ppkDropArea = $(".js-upload-ppk");
+
+const $createBtn = $(".js-create-btn");
+const $createLoadingBtn = $(".js-create-loading-btn");
+const $clearBtn = $(".js-clear-btn");
+
+const $$fileUploaders = $$(".js-file-upload");
+
+const $zipOkIcon = $(".js-zip-ok-icon");
+const $ppkOkIcon = $(".js-ppk-ok-icon");
+
+const $uploadZipLink = $(".js-upload-zip-link");
+const $uploadPPKLink = $(".js-upload-ppk-link");
+
+const $download = $(".js-download");
+const $downloadPlugin = $(".js-download-plugin");
+const $downloadPluginId = $(".js-download-plugin-id");
+const $downloadPPK = $(".js-download-ppk");
+
+const $error = $(".js-error");
+const $errorMessages = $(".js-error-messages");
+
+const $zipFileName = $(".js-zip-file-name");
+const $ppkFileName = $(".js-ppk-file-name");
+
+const view = new View({
+  createLoadingBtn: $createLoadingBtn,
+  createBtn: $createBtn,
+  zipDropArea: $zipDropArea,
+  ppkDropArea: $ppkDropArea,
+  ppkOkIcon: $ppkOkIcon,
+  error: $error,
+  download: $download,
+  downloadPluginId: $downloadPluginId,
+  downloadPlugin: $downloadPlugin,
+  downloadPPK: $downloadPPK,
+  errorMessages: $errorMessages,
+  zipOkIcon: $zipOkIcon,
+  zipFileName: $zipFileName,
+  ppkFileName: $ppkFileName,
+});
+
+const middlewares = [thunk];
+if (process.env.NODE_ENV !== "production") {
+  middlewares.push(logger);
+}
+
+const store = configureStore({
+  reducer,
+  middleware: (getDefaultMiddleware) => {
+    return getDefaultMiddleware().concat(middlewares);
+  },
+});
+
+store.subscribe(() => {
+  view.render(store.getState());
+});
+
+const uploadPluginZipHandler = createFileHanlder((promise) => {
+  promise
+    .then((result) => {
+      if (result instanceof File) {
+        store.dispatch(
+          uploadPlugin(
+            result.name,
+            () => readArrayBuffer(result),
+            validatePlugin,
+          ),
+        );
+        // Uploading a directory
+      } else if (result.entries instanceof Map) {
+        fileMapToBuffer(result.entries).then((buffer) => {
+          store.dispatch(
+            uploadPlugin(
+              result.name,
+              () => Promise.resolve(buffer),
+              validatePlugin,
+            ),
+          );
+        });
+      } else {
+        throw new Error("Something went wrong.");
+      }
+    })
+    .catch((error) => {
+      store.dispatch(uploadFailure(error));
+    });
+});
+
+const uploadPPKHanlder = createFileHanlder((promise) => {
+  promise
+    .then((result) => {
+      if (result instanceof File) {
+        store.dispatch(uploadPPK(result.name, () => readText(result)));
+        // Uploading a directory
+      } else if (result.entries instanceof Map) {
+        store.dispatch(
+          uploadFailure(new Error("secret file should be a text file")),
+        );
+      } else {
+        throw new Error("Something went wrong.");
+      }
+    })
+    .catch((error) => {
+      store.dispatch(uploadFailure(error));
+    });
+});
+
+// Handle a file upload
+listen($zipFileUploader, "change", uploadPluginZipHandler);
+listen($ppkFileUploader, "change", uploadPPKHanlder);
+listen($zipDropArea, "drop", uploadPluginZipHandler);
+listen($ppkDropArea, "drop", uploadPPKHanlder);
+// Hack to allow us to reupload the same file
+listen($$fileUploader, "click", (e) => {
+  e.target.value = null;
+});
+
+// Handle click a button
+listen($createBtn, "click", () => {
+  const state = store.getState();
+  if (!state.contents.data) {
+    return;
+  }
+  revokePluginUrls(state.plugin);
+  store.dispatch(createPluginZip(generatePluginZip));
+});
+listen($clearBtn, "click", () => {
+  $$fileUploaders.forEach((el) => {
+    el.value = null;
+  });
+  store.dispatch(reset());
+});
+
+// Handle a click for a select file
+listen($uploadZipLink, "click", (e) => {
+  e.preventDefault();
+  $zipFileUploader.click();
+});
+listen($uploadPPKLink, "click", (e) => {
+  e.preventDefault();
+  $ppkFileUploader.click();
+});
+
+// Hanlde a drag and drop
+listen($$UploadArea, "dragover", (e) => {
+  e.preventDefault();
+  view.decorateDragOver(e.currentTarget);
+});
+listen($$UploadArea, "dragleave", (e) => {
+  view.decorateDragLeave(e.currentTarget);
+});
+
+store.dispatch({ type: "__INIT__" });
diff --git a/src/plugin/packer/site/jest.config.js b/src/plugin/packer/site/jest.config.js
new file mode 100644
index 0000000000..539ed33fb2
--- /dev/null
+++ b/src/plugin/packer/site/jest.config.js
@@ -0,0 +1,6 @@
+/** @type {import('@jest/types').Config.InitialOptions} */
+const config = {
+  testRegex: "/test/.*-test\\.js$",
+  testEnvironment: "jsdom",
+};
+module.exports = config;
diff --git a/src/plugin/packer/site/plugin.js b/src/plugin/packer/site/plugin.js
new file mode 100644
index 0000000000..9de822caa2
--- /dev/null
+++ b/src/plugin/packer/site/plugin.js
@@ -0,0 +1,56 @@
+"use strict";
+
+const packer = require("../dist/");
+const { rezip } = require("../dist/zip");
+const { createDownloadUrl, revokeDownloadUrl } = require("./dom");
+
+/**
+ * Generate a plugin zip
+ * @param {ArrayBuffer} contents
+ * @param {string} privateKey
+ * @return {Promise<*>}
+ */
+const generatePluginZip = (contents, privateKey) => {
+  if (!contents) {
+    return Promise.resolve();
+  }
+  return rezip(Buffer.from(contents)).then((contentsZip) =>
+    packer(contentsZip, privateKey),
+  );
+};
+
+/**
+ * Validate plugin files
+ * We use generatePlugin to validate plugin zip and ppk
+ * @param {ArrayBuffer} contents
+ * @param {string} privateKey
+ * @return {Promise<*>}
+ */
+const validatePlugin = generatePluginZip;
+
+/**
+ * Create download URLs for a plugin and ppk
+ * @param {{plugin: ArrayBuffer, privateKey: string}} result
+ * @return {{plugin: string, ppk: string}}
+ */
+const createDownloadUrls = (result) => ({
+  contents: createDownloadUrl(result.plugin, "application/zip"),
+  ppk: createDownloadUrl(result.privateKey, "text/plain"),
+});
+
+/**
+ * Create download URLs for a plugin and ppk
+ * @param {Object<string, string>} plugin
+ */
+const revokePluginUrls = (plugin) => {
+  Object.keys(plugin.url).forEach((key) => {
+    revokeDownloadUrl(plugin.url[key]);
+  });
+};
+
+module.exports = {
+  generatePluginZip,
+  validatePlugin,
+  createDownloadUrls,
+  revokePluginUrls,
+};
diff --git a/src/plugin/packer/site/reducer.js b/src/plugin/packer/site/reducer.js
new file mode 100644
index 0000000000..0446760b35
--- /dev/null
+++ b/src/plugin/packer/site/reducer.js
@@ -0,0 +1,128 @@
+"use strict";
+
+const { createDownloadUrls } = require("./plugin");
+const {
+  UPLOAD_FAILURE,
+  UPLOAD_PPK,
+  UPLOAD_PPK_START,
+  UPLOAD_PLUGIN,
+  UPLOAD_PLUGIN_START,
+  CREATE_PLUGIN_ZIP,
+  CREATE_PLUGIN_ZIP_START,
+  CREATE_PLUGIN_ZIP_FAILURE,
+  RESET,
+} = require("./action");
+
+const getInitialState = () => ({
+  contents: {
+    data: null,
+    name: null,
+  },
+  ppk: {
+    data: null,
+    name: null,
+  },
+  plugin: {
+    id: null,
+    url: {
+      contents: null,
+      ppk: null,
+    },
+  },
+  error: null,
+  loading: false,
+});
+
+/**
+ * Reducer for an application
+ * @param {Object} state
+ * @param {{type: string, payload: *}} action
+ * @return {Object}
+ */
+// eslint-disable-next-line default-param-last
+const reducer = (state = getInitialState(), action) => {
+  switch (action.type) {
+    case UPLOAD_PPK_START: {
+      const { ppk, plugin } = getInitialState();
+      return Object.assign({}, state, {
+        ppk,
+        plugin,
+        error: null,
+      });
+    }
+    case UPLOAD_PPK:
+      return Object.assign({}, state, {
+        ppk: action.payload,
+      });
+    case UPLOAD_PLUGIN_START: {
+      const { contents, plugin } = getInitialState();
+      return Object.assign({}, state, {
+        contents,
+        plugin,
+        error: null,
+      });
+    }
+    case UPLOAD_PLUGIN:
+      return Object.assign({}, state, {
+        contents: action.payload,
+      });
+    case CREATE_PLUGIN_ZIP_START:
+      return Object.assign({}, state, {
+        plugin: getInitialState().plugin,
+        error: null,
+        loading: true,
+      });
+    case CREATE_PLUGIN_ZIP:
+      return Object.assign({}, state, {
+        ppk: {
+          data: action.payload.privateKey,
+          name: state.ppk.name || `${action.payload.id}.ppk`,
+        },
+        plugin: {
+          id: action.payload.id,
+          url: createDownloadUrls(action.payload),
+        },
+        loading: false,
+      });
+    case UPLOAD_FAILURE:
+    case CREATE_PLUGIN_ZIP_FAILURE:
+      return Object.assign({}, state, {
+        error: action.payload,
+        loading: false,
+      });
+    case RESET:
+      return getInitialState();
+    default:
+      return state;
+  }
+};
+
+/**
+ * Return a basename of download files
+ * @param {Object} state
+ * @return {string}
+ */
+const getPluginBaseName = (state) =>
+  `${state.contents.name.replace(/\.\w+$/, "")}.${state.plugin.id}`;
+
+/**
+ * Return a filename for a plugin zip
+ * @param {Object} state
+ * @return {string}
+ */
+const getDownloadPluginZipName = (state) =>
+  `${getPluginBaseName(state)}.plugin.zip`;
+
+/**
+ * Return a filename for a secret file(ppk)
+ * @param {Object} state
+ * @return {string}
+ */
+const getDownloadPPKFileName = (state) =>
+  `${getPluginBaseName(state)}.private.ppk`;
+
+module.exports = {
+  reducer,
+  getDownloadPluginZipName,
+  getDownloadPPKFileName,
+};
diff --git a/src/plugin/packer/site/test/action-test.js b/src/plugin/packer/site/test/action-test.js
new file mode 100644
index 0000000000..246e6a1039
--- /dev/null
+++ b/src/plugin/packer/site/test/action-test.js
@@ -0,0 +1,185 @@
+"use strict";
+
+const {
+  UPLOAD_PPK,
+  UPLOAD_PPK_START,
+  UPLOAD_FAILURE,
+  UPLOAD_PLUGIN,
+  UPLOAD_PLUGIN_START,
+  CREATE_PLUGIN_ZIP,
+  CREATE_PLUGIN_ZIP_START,
+  CREATE_PLUGIN_ZIP_FAILURE,
+  RESET,
+  uploadFailure,
+  uploadPPK,
+  uploadPlugin,
+  reset,
+  createPluginZip,
+} = require("../action");
+
+describe("action", () => {
+  let dispatch;
+  beforeEach(() => {
+    dispatch = jest.fn();
+  });
+  describe("uploadFailure", () => {
+    it("should dispatch an UPLOAD_FAILURE action with an error", () => {
+      const error = { message: "error" };
+      expect(uploadFailure(error)).toStrictEqual({
+        type: UPLOAD_FAILURE,
+        payload: error,
+      });
+    });
+  });
+  describe("uploadPPK", () => {
+    it("should dispatch UPLOAD_PPK_START action", () => {
+      const promise = Promise.resolve("value");
+      uploadPPK("hoge.ppk", () => promise)(dispatch);
+      expect(dispatch.mock.calls.length).toBe(1);
+      // https://github.com/facebook/jest/issues/7929
+      expect([...dispatch.mock.calls[0]]).toStrictEqual([
+        { type: UPLOAD_PPK_START },
+      ]);
+    });
+    it("should dispatch an UPLOAD_PPK action with payload including data and name properties", () => {
+      const promise = Promise.resolve("value");
+      uploadPPK("hoge.ppk", () => promise)(dispatch);
+      return promise.then(() => {
+        expect(dispatch.mock.calls.length).toBe(2);
+        expect([...dispatch.mock.calls[1]]).toStrictEqual([
+          {
+            type: UPLOAD_PPK,
+            payload: {
+              data: "value",
+              name: "hoge.ppk",
+            },
+          },
+        ]);
+      });
+    });
+    it("should dispatch UPLOAD_FAILURE action if fileReader was failure", (done) => {
+      uploadPPK("hoge.ppk", () => Promise.reject("ng"))(dispatch);
+      setTimeout(() => {
+        expect(dispatch.mock.calls.length).toBe(2);
+        expect([...dispatch.mock.calls[1]]).toStrictEqual([
+          {
+            type: UPLOAD_FAILURE,
+            payload: "ng",
+          },
+        ]);
+        done();
+      });
+    });
+  });
+  describe("uploadPlugin", () => {
+    it("should dispatch UPLOAD_PLUGIN_START action", () => {
+      uploadPlugin(
+        "hoge.zip",
+        () => Promise.resolve("ok"),
+        () => Promise.resolve(),
+      )(dispatch);
+      expect(dispatch.mock.calls.length).toBe(1);
+      expect([...dispatch.mock.calls[0]]).toStrictEqual([
+        { type: UPLOAD_PLUGIN_START },
+      ]);
+    });
+    it("should dispatch UPLOAD_PLUGIN action if validateManifest was success", (done) => {
+      const validateManifestStub = jest.fn().mockResolvedValue();
+      uploadPlugin(
+        "hoge.zip",
+        () => Promise.resolve("ok"),
+        validateManifestStub,
+      )(dispatch);
+      // In order to guarantee to execute assertion after uploadPlugin has finished
+      setTimeout(() => {
+        expect(dispatch.mock.calls.length).toBe(2);
+        expect(validateManifestStub.mock.calls[0][0]).toBe("ok");
+        expect([...dispatch.mock.calls[1]]).toStrictEqual([
+          {
+            type: UPLOAD_PLUGIN,
+            payload: {
+              data: "ok",
+              name: "hoge.zip",
+            },
+          },
+        ]);
+        done();
+      });
+    });
+    it("should dispatch UPLOAD_FAILURE action if validateManifest was failure", (done) => {
+      const validateManifestStub = jest.fn().mockRejectedValue("error");
+      uploadPlugin(
+        "hoge.zip",
+        () => Promise.resolve("ng"),
+        validateManifestStub,
+      )(dispatch);
+      // In order to guarantee to execute assertion after uploadPlugin has finished
+      setTimeout(() => {
+        expect(dispatch.mock.calls.length).toBe(2);
+        expect(validateManifestStub.mock.calls[0][0]).toBe("ng");
+        expect([...dispatch.mock.calls[1]]).toStrictEqual([
+          {
+            type: UPLOAD_FAILURE,
+            payload: "error",
+          },
+        ]);
+        done();
+      });
+    });
+  });
+  describe("createPluginZip", () => {
+    it("should dispatch CREATE_PLUGIN_ZIP_START action", () => {
+      const getState = () => ({
+        contents: {},
+        ppk: {},
+      });
+      createPluginZip(() => Promise.resolve)(dispatch, getState);
+      expect([...dispatch.mock.calls[0]]).toStrictEqual([
+        { type: CREATE_PLUGIN_ZIP_START },
+      ]);
+    });
+  });
+  it("should dispatch CREATE_PLUGIN_ZIP action with the payload if generatePluginZip was success", (done) => {
+    const getState = () => ({
+      contents: {},
+      ppk: {},
+    });
+    createPluginZip(() => Promise.resolve({ foo: "bar" }))(dispatch, getState);
+    setTimeout(() => {
+      expect(dispatch.mock.calls.length).toBe(2);
+      expect([...dispatch.mock.calls[1]]).toStrictEqual([
+        {
+          type: CREATE_PLUGIN_ZIP,
+          payload: {
+            foo: "bar",
+          },
+        },
+      ]);
+      done();
+    }, 500);
+  });
+  it("should dispatch CREATE_PLUGIN_ZIP_FAILURE action with the error if generatePluginZip was failure", (done) => {
+    const getState = () => ({
+      contents: {},
+      ppk: {},
+    });
+    createPluginZip(() => Promise.reject("error"))(dispatch, getState);
+    setTimeout(() => {
+      expect(dispatch.mock.calls.length).toBe(2);
+      expect([...dispatch.mock.calls[1]]).toStrictEqual([
+        {
+          type: CREATE_PLUGIN_ZIP_FAILURE,
+          payload: "error",
+        },
+      ]);
+      done();
+    }, 500);
+  });
+  describe("reset", () => {
+    it("should dispatch RESET action", () => {
+      expect(reset()).toStrictEqual({
+        type: RESET,
+      });
+    });
+  });
+});
diff --git a/src/plugin/packer/site/test/reducer-test.js b/src/plugin/packer/site/test/reducer-test.js
new file mode 100644
index 0000000000..6d860423ca
--- /dev/null
+++ b/src/plugin/packer/site/test/reducer-test.js
@@ -0,0 +1,267 @@
+"use strict";
+
+const {
+  reducer,
+  getDownloadPluginZipName,
+  getDownloadPPKFileName,
+} = require("../reducer");
+const {
+  UPLOAD_FAILURE,
+  UPLOAD_PPK_START,
+  UPLOAD_PPK,
+  UPLOAD_PLUGIN_START,
+  UPLOAD_PLUGIN,
+  CREATE_PLUGIN_ZIP_START,
+  CREATE_PLUGIN_ZIP,
+  CREATE_PLUGIN_ZIP_FAILURE,
+  RESET,
+} = require("../action");
+
+const expectedInitialState = {
+  contents: {
+    data: null,
+    name: null,
+  },
+  ppk: {
+    data: null,
+    name: null,
+  },
+  plugin: {
+    id: null,
+    url: {
+      contents: null,
+      ppk: null,
+    },
+  },
+  error: null,
+  loading: false,
+};
+
+describe("reducer", () => {
+  beforeEach(() => {
+    global.URL = {
+      createObjectURL: (data) => data,
+    };
+  });
+  describe("initial state", () => {
+    it("should be initialized all values", () => {
+      expect(reducer(undefined, { type: "INIT_TEST" })).toStrictEqual(
+        expectedInitialState,
+      );
+    });
+  });
+  describe("UPLOAD_PPK_START", () => {
+    it("should reset state.ppk, state.plugin and state.error", () => {
+      const state = {
+        contents: {
+          data: "hoge",
+          name: "bar",
+        },
+        ppk: {
+          data: "ok",
+          name: "okok",
+        },
+        plugin: {
+          id: "hoge",
+        },
+        error: "hoge",
+      };
+      expect(reducer(state, { type: UPLOAD_PPK_START })).toStrictEqual({
+        contents: {
+          data: "hoge",
+          name: "bar",
+        },
+        ppk: {
+          data: null,
+          name: null,
+        },
+        plugin: {
+          id: null,
+          url: {
+            contents: null,
+            ppk: null,
+          },
+        },
+        error: null,
+      });
+    });
+  });
+  describe("UPLOAD_PPK", () => {
+    it("should update state.ppk with the payload", () => {
+      const state = {
+        ppk: null,
+      };
+      const ppk = { data: [], name: "hgoe.ppk" };
+      expect(reducer(state, { type: UPLOAD_PPK, payload: ppk })).toStrictEqual({
+        ppk,
+      });
+    });
+  });
+  describe("UPLOAD_PLUGIN_START", () => {
+    it("should reset state.contents, state.plugin and state.error", () => {
+      const state = {
+        contents: {
+          data: "hoge",
+          name: "bar",
+        },
+        ppk: {
+          data: "ok",
+          name: "okok",
+        },
+        plugin: {
+          id: "hoge",
+        },
+        error: "hoge",
+      };
+      expect(reducer(state, { type: UPLOAD_PLUGIN_START })).toStrictEqual({
+        contents: {
+          data: null,
+          name: null,
+        },
+        ppk: {
+          data: "ok",
+          name: "okok",
+        },
+        plugin: {
+          id: null,
+          url: {
+            contents: null,
+            ppk: null,
+          },
+        },
+        error: null,
+      });
+    });
+  });
+  describe("UPLOAD_PLUGIN", () => {
+    it("should update satte.contents with payload", () => {
+      const state = {
+        contents: null,
+      };
+      const contents = { data: [], name: "hoge.zip" };
+      expect(
+        reducer(state, { type: UPLOAD_PLUGIN, payload: contents }),
+      ).toStrictEqual({
+        contents,
+      });
+    });
+  });
+  describe("CREATE_PLUGIN_ZIP_START", () => {
+    it("should reset state.plugin and state.error and update state.loging true", () => {
+      const state = {
+        contents: "contents",
+        ppk: "ppk",
+        plugin: {
+          id: "hoge",
+          url: {
+            contents: "hogehoge",
+            ppk: "foo",
+          },
+        },
+        error: "error",
+        loading: false,
+      };
+      expect(reducer(state, { type: CREATE_PLUGIN_ZIP_START })).toStrictEqual({
+        contents: "contents",
+        ppk: "ppk",
+        plugin: expectedInitialState.plugin,
+        error: null,
+        loading: true,
+      });
+    });
+  });
+  describe("CREATE_PLUGIN_ZIP", () => {
+    it("should update state.plugin and state.ppk if it is necessary, and update loading false", () => {
+      const state = {
+        ppk: {
+          data: null,
+          name: null,
+        },
+        plugin: {
+          id: null,
+          url: {
+            contents: null,
+            ppk: null,
+          },
+          loading: true,
+        },
+      };
+      const action = {
+        type: CREATE_PLUGIN_ZIP,
+        payload: {
+          privateKey: "secret",
+          plugin: "plugin data",
+          id: "abcd",
+        },
+      };
+      const newState = reducer(state, action);
+      expect(newState.ppk).toStrictEqual({
+        data: "secret",
+        name: "abcd.ppk",
+      });
+      expect(newState.plugin.id).toBe("abcd");
+      expect(newState.plugin.url.contents).toBeInstanceOf(Blob);
+      expect(newState.plugin.url.ppk).toBeInstanceOf(Blob);
+      expect(newState.loading).toBe(false);
+    });
+  });
+  describe("UPLOAD_FAILURE and CREATE_PLUGIN_ZIP_FAILURE", () => {
+    it("should update state.error and update state.loding false", () => {
+      const state = {
+        error: null,
+        loading: true,
+      };
+      expect(
+        reducer(state, { type: UPLOAD_FAILURE, payload: "error" }),
+      ).toStrictEqual({
+        error: "error",
+        loading: false,
+      });
+      expect(
+        reducer(state, { type: CREATE_PLUGIN_ZIP_FAILURE, payload: "error" }),
+      ).toStrictEqual({
+        error: "error",
+        loading: false,
+      });
+    });
+  });
+  describe("RESET", () => {
+    it("should reset all values", () => {
+      const state = "dirty";
+      expect(reducer(state, { type: RESET })).toStrictEqual(
+        expectedInitialState,
+      );
+    });
+  });
+  describe("getDownloadPluginZipName", () => {
+    it("should return a filename to download a plugin zip", () => {
+      expect(
+        getDownloadPluginZipName({
+          contents: {
+            name: "awesome-plugin.zip",
+          },
+          plugin: {
+            id: "abcd",
+          },
+        }),
+      ).toBe("awesome-plugin.abcd.plugin.zip");
+    });
+  });
+  describe("getDownloadPPKFileName", () => {
+    it("should return a filename to download a private key", () => {
+      expect(
+        getDownloadPPKFileName({
+          contents: {
+            name: "awesome-plugin.zip",
+          },
+          ppk: {
+            name: "secret.ppk",
+          },
+          plugin: {
+            id: "abcd",
+          },
+        }),
+      ).toBe("awesome-plugin.abcd.private.ppk");
+    });
+  });
+});
diff --git a/src/plugin/packer/site/view.js b/src/plugin/packer/site/view.js
new file mode 100644
index 0000000000..1e1f256660
--- /dev/null
+++ b/src/plugin/packer/site/view.js
@@ -0,0 +1,162 @@
+"use strict";
+
+const {
+  getDownloadPluginZipName,
+  getDownloadPPKFileName,
+} = require("./reducer");
+
+/**
+ * View class
+ */
+class View {
+  /**
+   * @constructor
+   * @param {Object<string, HTMLElement>} elements
+   */
+  constructor(elements) {
+    this.$ = elements;
+  }
+  /**
+   * Show the element on the display
+   * @param {HTMLElement} el
+   */
+  show(el) {
+    el.classList.remove("hide");
+  }
+  /**
+   * Hide the element on the display
+   * @param {HTMLElement} el
+   */
+  hide(el) {
+    el.classList.add("hide");
+  }
+  /**
+   * Render the view with a passed state
+   * @param {Object} state
+   */
+  render(state) {
+    this.renderResult(state);
+    this.renderUploadPPKArea(state);
+    this.renderUploadZipArea(state);
+    this.renderBtn(state);
+  }
+  /**
+   * Decorate the element for drag over
+   * @param {HTMLElement} el
+   */
+  decorateDragOver(el) {
+    el.classList.add("upload-area__droppable--drag");
+  }
+  /**
+   * Decorate the element for drag leave
+   * @param {HTMLElement} el
+   */
+  decorateDragLeave(el) {
+    el.classList.remove("upload-area__droppable--drag");
+  }
+  /**
+   * Render a botton area with a passed state
+   * @param {Object} state
+   */
+  renderBtn(state) {
+    if (state.loading) {
+      this.show(this.$.createLoadingBtn);
+      this.hide(this.$.createBtn);
+    } else {
+      this.show(this.$.createBtn);
+      this.hide(this.$.createLoadingBtn);
+    }
+    if (state.contents.data) {
+      this.$.createBtn.classList.remove("disabled");
+    } else if (!state.loading) {
+      this.$.createBtn.classList.add("disabled");
+    }
+  }
+  /**
+   * Render an area for upload plugin zip with a passed state
+   * @param {Object} state
+   */
+  renderUploadZipArea(state) {
+    this.decorateDragLeave(this.$.zipDropArea);
+    if (state.contents.data) {
+      this.show(this.$.zipOkIcon);
+    } else {
+      this.hide(this.$.zipOkIcon);
+    }
+    if (state.contents.name) {
+      this.$.zipFileName.textContent = state.contents.name;
+    } else {
+      this.$.zipFileName.textContent = "...";
+    }
+  }
+  /**
+   * Render an area for upload ppk with a passed state
+   * @param {Object} state
+   */
+  renderUploadPPKArea(state) {
+    this.decorateDragLeave(this.$.ppkDropArea);
+    if (state.ppk.data) {
+      this.show(this.$.ppkOkIcon);
+    } else {
+      this.hide(this.$.ppkOkIcon);
+    }
+    if (state.ppk.name) {
+      this.$.ppkFileName.textContent = state.ppk.name;
+    } else {
+      this.$.ppkFileName.textContent = "...";
+    }
+  }
+  /**
+   * Render a result to create a plugin zip with a passed state
+   * @param {Object} state
+   */
+  renderResult(state) {
+    if (state.error) {
+      this.renderErrorMessages(state);
+    } else if (state.plugin.url.contents) {
+      this.renderDownloadLinks(state);
+    } else {
+      this.hide(this.$.error);
+      this.hide(this.$.download);
+    }
+  }
+  /**
+   * Render download links for a plugin zip and ppk with a passed state
+   * @param {Object} state
+   */
+  renderDownloadLinks(state) {
+    const pluginName = getDownloadPluginZipName(state);
+    const ppkName = getDownloadPPKFileName(state);
+
+    this.hide(this.$.error);
+    this.show(this.$.download);
+    this.$.downloadPluginId.textContent = state.plugin.id;
+    this.$.downloadPlugin.href = state.plugin.url.contents;
+    this.$.downloadPlugin.download = pluginName;
+    this.$.downloadPlugin.innerText = pluginName;
+    this.$.downloadPPK.href = state.plugin.url.ppk;
+    this.$.downloadPPK.download = ppkName;
+    this.$.downloadPPK.innerText = ppkName;
+  }
+  /**
+   * Render error messages for the result of creating a plugin zip with a passed state
+   * @param {Object} state
+   */
+  renderErrorMessages(state) {
+    this.hide(this.$.download);
+    this.show(this.$.error);
+    const e = state.error;
+    let errors = e.validationErrors;
+    if (!e.validationErrors) {
+      errors = [e.message];
+    }
+    const ul = this.$.errorMessages;
+    ul.innerHTML = "";
+    errors.forEach((error) => {
+      const li = document.createElement("li");
+      li.textContent = error;
+      ul.appendChild(li);
+    });
+  }
+}
+module.exports = View;
diff --git a/src/plugin/packer/src/cli.ts b/src/plugin/packer/src/cli.ts
new file mode 100644
index 0000000000..2f2494e240
--- /dev/null
+++ b/src/plugin/packer/src/cli.ts
@@ -0,0 +1,175 @@
+import path from "path";
+import fs from "fs";
+import { promisify } from "util";
+import os from "os";
+import * as chokidar from "chokidar";
+import { mkdirp } from "mkdirp";
+import _debug from "debug";
+import validate from "@kintone/plugin-manifest-validator";
+import packer from ".";
+import console from "./console";
+import { generateErrorMessages } from "./gen-error-msg";
+import { createContentsZip } from "./create-contents-zip";
+
+const debug = _debug("cli");
+const writeFile = promisify(fs.writeFile);
+
+type Options = Partial<{
+  ppk: string;
+  out: string;
+  watch: boolean;
+  packerMock_: typeof packer;
+}>;
+
+const cli = (pluginDir: string, options_?: Options) => {
+  const options = options_ || {};
+  const packerLocal = options.packerMock_ ? options.packerMock_ : packer;
+
+  return Promise.resolve()
+    .then(() => {
+      // 1. check if pluginDir is a directory
+      if (!fs.statSync(pluginDir).isDirectory()) {
+        throw new Error(`${pluginDir} should be a directory.`);
+      }
+
+      // 2. check pluginDir/manifest.json
+      const manifestJsonPath = path.join(pluginDir, "manifest.json");
+      if (!fs.statSync(manifestJsonPath).isFile()) {
+        throw new Error("Manifest file $PLUGIN_DIR/manifest.json not found.");
+      }
+
+      // 3. validate manifest.json
+      const manifest = loadJson(manifestJsonPath);
+      throwIfInvalidManifest(manifest, pluginDir);
+
+      let outputDir = path.dirname(path.resolve(pluginDir));
+      let outputFile = path.join(outputDir, "plugin.zip");
+      if (options.out) {
+        outputFile = options.out;
+        outputDir = path.dirname(path.resolve(outputFile));
+      }
+      debug(`outputDir : ${outputDir}`);
+      debug(`outputFile : ${outputFile}`);
+
+      // 4. generate new ppk if not specified
+      const ppkFile = options.ppk;
+      let privateKey: string;
+      if (ppkFile) {
+        debug(`loading an existing key: ${ppkFile}`);
+        privateKey = fs.readFileSync(ppkFile, "utf8");
+      }
+
+      // 5. package plugin.zip
+      return Promise.all([
+        mkdirp(outputDir),
+        createContentsZip(pluginDir, manifest).then((contentsZip) =>
+          packerLocal(contentsZip, privateKey),
+        ),
+      ]).then((result) => {
+        const output = result[1];
+        const ppkFilePath = path.join(outputDir, `${output.id}.ppk`);
+        if (!ppkFile) {
+          fs.writeFileSync(ppkFilePath, output.privateKey, "utf8");
+        }
+
+        if (options.watch) {
+          // change events are fired before chagned files are flushed on Windows,
+          // which generate an invalid plugin zip.
+          // in order to fix this, we use awaitWriteFinish option only on Windows.
+          const watchOptions =
+            os.platform() === "win32"
+              ? {
+                  awaitWriteFinish: {
+                    stabilityThreshold: 1000,
+                    pollInterval: 250,
+                  },
+                }
+              : {};
+          const watcher = chokidar.watch(pluginDir, watchOptions);
+          watcher.on("change", () => {
+            cli(
+              pluginDir,
+              Object.assign({}, options, {
+                watch: false,
+                ppk: options.ppk || ppkFilePath,
+              }),
+            );
+          });
+        }
+        return outputPlugin(outputFile, output.plugin);
+      });
+    })
+    .then((outputFile) => {
+      console.log("Succeeded:", outputFile);
+      return outputFile;
+    })
+    .catch((error) => {
+      console.error("Failed:", error.message);
+      return Promise.reject(error);
+    });
+};
+
+export = cli;
+
+const throwIfInvalidManifest = (manifest: any, pluginDir: string) => {
+  const result = validate(manifest, {
+    maxFileSize: validateMaxFileSize(pluginDir),
+    fileExists: validateFileExists(pluginDir),
+  });
+  debug(result);
+
+  if (result.warnings && result.warnings.length > 0) {
+    result.warnings.forEach((warning) => {
+      console.warn(`WARN: ${warning.message}`);
+    });
+  }
+
+  if (!result.valid) {
+    const msgs = generateErrorMessages(result.errors ?? []);
+    console.error("Invalid manifest.json:");
+    msgs.forEach((msg) => {
+      console.error(`- ${msg}`);
+    });
+    throw new Error("Invalid manifest.json");
+  }
+};
+
+/**
+ * Create and save plugin.zip
+ */
+const outputPlugin = (outputPath: string, plugin: Buffer): Promise<string> => {
+  return writeFile(outputPath, plugin).then((arg) => outputPath);
+};
+
+/**
+ * Load JSON file without caching
+ */
+const loadJson = (jsonPath: string) => {
+  const content = fs.readFileSync(jsonPath, "utf8");
+  return JSON.parse(content);
+};
+
+/**
+ * Return validator for `maxFileSize` keyword
+ */
+const validateMaxFileSize = (pluginDir: string) => {
+  return (maxBytes: number, filePath: string) => {
+    try {
+      const stat = fs.statSync(path.join(pluginDir, filePath));
+      return stat.size <= maxBytes;
+    } catch (e) {
+      return false;
+    }
+  };
+};
+
+const validateFileExists = (pluginDir: string) => {
+  return (filePath: string) => {
+    try {
+      const stat = fs.statSync(path.join(pluginDir, filePath));
+      return stat.isFile();
+    } catch (e) {
+      return false;
+    }
+  };
+};
diff --git a/src/plugin/packer/src/console.ts b/src/plugin/packer/src/console.ts
new file mode 100644
index 0000000000..83978d7b57
--- /dev/null
+++ b/src/plugin/packer/src/console.ts
@@ -0,0 +1,5 @@
+export = {
+  log: console.log,
+  error: console.error,
+  warn: console.warn,
+};
diff --git a/src/plugin/packer/src/create-contents-zip.ts b/src/plugin/packer/src/create-contents-zip.ts
new file mode 100644
index 0000000000..c9888e9442
--- /dev/null
+++ b/src/plugin/packer/src/create-contents-zip.ts
@@ -0,0 +1,32 @@
+import path from "path";
+import { ZipFile } from "yazl";
+import streamBuffers from "stream-buffers";
+import { sourceList } from "./sourcelist";
+import _debug from "debug";
+
+const debug = _debug("create-contents-zip");
+
+/**
+ * Create a zipped contents
+ */
+export const createContentsZip = (
+  pluginDir: string,
+  manifest: any,
+): Promise<Buffer> => {
+  return new Promise((res, rej) => {
+    const output = new streamBuffers.WritableStreamBuffer();
+    const zipFile = new ZipFile();
+    let size: any = null;
+    output.on("finish", () => {
+      debug(`plugin.zip: ${size} bytes`);
+      res(output.getContents() as any);
+    });
+    zipFile.outputStream.pipe(output);
+    sourceList(manifest).forEach((src) => {
+      zipFile.addFile(path.join(pluginDir, src), src);
+    });
+    zipFile.end(undefined, ((finalSize: number) => {
+      size = finalSize;
+    }) as any);
+  });
+};
diff --git a/src/plugin/packer/src/gen-error-msg.ts b/src/plugin/packer/src/gen-error-msg.ts
new file mode 100644
index 0000000000..cd04e5f9fe
--- /dev/null
+++ b/src/plugin/packer/src/gen-error-msg.ts
@@ -0,0 +1,14 @@
+import type * as Ajv from "ajv";
+
+export const generateErrorMessages = (errors: Ajv.ErrorObject[]): string[] => {
+  return errors.map((e) => {
+    if (e.keyword === "enum") {
+      return `"${e.instancePath}" ${e.message} (${(
+        e.params.allowedValues as any[]
+      )
+        .map((v) => `"${v}"`)
+        .join(", ")})`;
+    }
+    return `"${e.instancePath}" ${e.message}`;
+  });
+};
diff --git a/src/plugin/packer/src/hex2a.ts b/src/plugin/packer/src/hex2a.ts
new file mode 100644
index 0000000000..67bdc03aab
--- /dev/null
+++ b/src/plugin/packer/src/hex2a.ts
@@ -0,0 +1,18 @@
+const N_TO_A = "a".charCodeAt(0) - "0".charCodeAt(0);
+const A_TO_K = "k".charCodeAt(0) - "a".charCodeAt(0);
+
+/**
+ * `tr '0-9a-f' 'a-p'` in JS
+ */
+export const hex2a = (hex: string): string => {
+  return Array.from(hex)
+    .map((s) => {
+      if (s >= "0" && s <= "9") {
+        return String.fromCharCode(s.charCodeAt(0) + N_TO_A);
+      } else if (s >= "a" && s <= "f") {
+        return String.fromCharCode(s.charCodeAt(0) + A_TO_K);
+      }
+      throw new Error(`invalid char: ${s}`);
+    })
+    .join("");
+};
diff --git a/src/plugin/packer/src/index.ts b/src/plugin/packer/src/index.ts
new file mode 100644
index 0000000000..3aa14b7edd
--- /dev/null
+++ b/src/plugin/packer/src/index.ts
@@ -0,0 +1,68 @@
+import { ZipFile } from "yazl";
+import RSA from "node-rsa";
+import streamBuffers from "stream-buffers";
+import _debug from "debug";
+import { sign } from "./sign";
+import { uuid } from "./uuid";
+import { validateContentsZip } from "./zip";
+
+const debug = _debug("packer");
+
+const packer = (
+  contentsZip: Buffer,
+  privateKey_?: string,
+): Promise<{
+  plugin: Buffer;
+  privateKey: string;
+  id: string;
+}> => {
+  let privateKey = privateKey_;
+  let key;
+  if (privateKey) {
+    key = new RSA(privateKey);
+  } else {
+    debug("generating a new key");
+    key = new RSA({ b: 1024 });
+    privateKey = key.exportKey("pkcs1-private");
+  }
+
+  const signature = sign(contentsZip, privateKey);
+  const publicKey = key.exportKey("pkcs8-public-der");
+  const id = uuid(publicKey);
+  debug(`id : ${id}`);
+  return validateContentsZip(contentsZip)
+    .then(() => zip(contentsZip, publicKey, signature))
+    .then((plugin) => ({
+      plugin,
+      privateKey,
+      id,
+    })) as any;
+};
+
+export = packer;
+
+/**
+ * Create plugin.zip
+ */
+const zip = (
+  contentsZip: Buffer,
+  publicKey: Buffer,
+  signature: Buffer,
+): Promise<Buffer> => {
+  debug(`zip(): start`);
+  return new Promise((res, rej) => {
+    const output = new streamBuffers.WritableStreamBuffer();
+    const zipFile = new ZipFile();
+    output.on("finish", () => {
+      debug(`zip(): output finish event`);
+      res(output.getContents() as any);
+    });
+    zipFile.outputStream.pipe(output);
+    zipFile.addBuffer(contentsZip, "contents.zip");
+    zipFile.addBuffer(publicKey, "PUBKEY");
+    zipFile.addBuffer(signature, "SIGNATURE");
+    zipFile.end(undefined, ((finalSize: number) => {
+      debug(`zip(): ZipFile end event: finalSize ${finalSize} bytes`);
+    }) as any);
+  });
+};
diff --git a/src/plugin/packer/src/pack-plugin-from-manifest.ts b/src/plugin/packer/src/pack-plugin-from-manifest.ts
new file mode 100644
index 0000000000..ce9ee6b7c5
--- /dev/null
+++ b/src/plugin/packer/src/pack-plugin-from-manifest.ts
@@ -0,0 +1,21 @@
+import fs from "fs";
+import path from "path";
+import packer from ".";
+import { createContentsZip } from "./create-contents-zip";
+
+export const packPluginFromManifest = (
+  manifestJSONPath: string,
+  privateKey: string,
+): Promise<{ plugin: Buffer; privateKey: string; id: string }> => {
+  return new Promise((resolve, reject) => {
+    try {
+      resolve(JSON.parse(fs.readFileSync(manifestJSONPath, "utf-8")));
+    } catch (e) {
+      reject(e);
+    }
+  })
+    .then((manifest) =>
+      createContentsZip(path.dirname(manifestJSONPath), manifest),
+    )
+    .then((buffer) => packer(buffer as any, privateKey));
+};
diff --git a/src/plugin/packer/src/sign.ts b/src/plugin/packer/src/sign.ts
new file mode 100644
index 0000000000..1101455942
--- /dev/null
+++ b/src/plugin/packer/src/sign.ts
@@ -0,0 +1,8 @@
+import RSA from "node-rsa";
+
+export const sign = (contents: Buffer, privateKey: string): Buffer => {
+  const key = new RSA(privateKey, "pkcs1-private-pem", {
+    signingScheme: "pkcs1-sha1",
+  });
+  return key.sign(contents);
+};
diff --git a/src/plugin/packer/src/sourcelist.ts b/src/plugin/packer/src/sourcelist.ts
new file mode 100644
index 0000000000..2fa04139f0
--- /dev/null
+++ b/src/plugin/packer/src/sourcelist.ts
@@ -0,0 +1,27 @@
+/**
+ * Create content file list from manifest.json
+ */
+export const sourceList = (
+  // TODO: Define and use menifest type
+  manifest: any,
+): string[] => {
+  const sourceTypes = [
+    ["desktop", "js"],
+    ["desktop", "css"],
+    ["mobile", "js"],
+    ["mobile", "css"],
+    ["config", "js"],
+    ["config", "css"],
+  ];
+  const list = sourceTypes
+    .map((t) => manifest[t[0]] && manifest[t[0]][t[1]])
+    .filter((i) => !!i)
+    .reduce((a, b) => a.concat(b), [])
+    .filter((file: any) => !/^https?:\/\//.test(file));
+  if (manifest.config && manifest.config.html) {
+    list.push(manifest.config.html);
+  }
+  list.push("manifest.json", manifest.icon);
+  // Make the file list unique
+  return Array.from(new Set(list));
+};
diff --git a/src/plugin/packer/src/uuid.ts b/src/plugin/packer/src/uuid.ts
new file mode 100644
index 0000000000..8b11903eea
--- /dev/null
+++ b/src/plugin/packer/src/uuid.ts
@@ -0,0 +1,9 @@
+import crypto from "crypto";
+import { hex2a } from "./hex2a";
+
+export const uuid = (publicKey: Buffer): string => {
+  const hash = crypto.createHash("sha256");
+  hash.update(publicKey);
+  const hexId = hash.digest().toString("hex").slice(0, 32);
+  return hex2a(hexId);
+};
diff --git a/src/plugin/packer/src/zip.ts b/src/plugin/packer/src/zip.ts
new file mode 100644
index 0000000000..245bec7188
--- /dev/null
+++ b/src/plugin/packer/src/zip.ts
@@ -0,0 +1,176 @@
+import path from "path";
+import * as yazl from "yazl";
+import * as yauzl from "yauzl";
+import { promisify } from "util";
+import validate from "@kintone/plugin-manifest-validator";
+import * as streamBuffers from "stream-buffers";
+
+import { generateErrorMessages } from "./gen-error-msg";
+import { sourceList } from "./sourcelist";
+import type internal from "stream";
+
+type ManifestJson = any;
+type Entries = Map<string, any>;
+
+interface PreprocessedContentsZip {
+  zipFile: yauzl.ZipFile;
+  entries: Entries;
+  manifestJson: ManifestJson;
+  manifestPath: string;
+}
+
+/**
+ * Extract, validate and rezip contents.zip
+ */
+export const rezip = (contentsZip: Buffer): Promise<Buffer> => {
+  return preprocessToRezip(contentsZip).then(
+    ({ zipFile, entries, manifestJson, manifestPath }) => {
+      validateManifest(entries, manifestJson, manifestPath);
+      return rezipContents(zipFile, entries, manifestJson, manifestPath);
+    },
+  );
+};
+
+/**
+ * Validate a buffer of contents.zip
+ */
+export const validateContentsZip = (contentsZip: Buffer): Promise<any> => {
+  return preprocessToRezip(contentsZip).then(
+    ({ entries, manifestJson, manifestPath }) =>
+      validateManifest(entries, manifestJson, manifestPath),
+  );
+};
+
+/**
+ * Create an intermediate representation for contents.zip
+ */
+const preprocessToRezip = (
+  contentsZip: Buffer,
+): Promise<PreprocessedContentsZip> => {
+  return zipEntriesFromBuffer(contentsZip).then((result) => {
+    const manifestList = Array.from(result.entries.keys()).filter(
+      (file) => path.basename(file) === "manifest.json",
+    );
+    if (manifestList.length === 0) {
+      throw new Error("The zip file has no manifest.json");
+    } else if (manifestList.length > 1) {
+      throw new Error("The zip file has many manifest.json files");
+    }
+    (result as any).manifestPath = manifestList[0];
+    const manifestEntry = result.entries.get((result as any).manifestPath);
+    return getManifestJsonFromEntry(result.zipFile, manifestEntry).then(
+      (json: any) => Object.assign(result, { manifestJson: json }),
+    ) as any;
+  });
+};
+
+const getManifestJsonFromEntry = (
+  zipFile: yauzl.ZipFile,
+  zipEntry: yauzl.ZipFile,
+): Promise<string> => {
+  return zipEntryToString(zipFile, zipEntry).then((str) => JSON.parse(str));
+};
+
+const zipEntriesFromBuffer = (
+  contentsZip: Buffer,
+): Promise<{
+  zipFile: yauzl.ZipFile;
+  entries: Entries;
+}> => {
+  return promisify(yauzl.fromBuffer)(contentsZip).then(
+    (zipFile) =>
+      new Promise((res, rej) => {
+        const entries = new Map();
+        const result = {
+          zipFile,
+          entries,
+        };
+        zipFile?.on("entry", (entry) => {
+          entries.set(entry.fileName, entry);
+        });
+        zipFile?.on("end", () => {
+          res(result);
+        });
+        zipFile?.on("error", rej);
+      }),
+  ) as any;
+};
+
+const zipEntryToString = (
+  zipFile: yauzl.ZipFile,
+  zipEntry: any,
+): Promise<string> => {
+  return new Promise((res, rej) => {
+    zipFile.openReadStream(zipEntry, (e, stream) => {
+      if (e) {
+        rej(e);
+      } else {
+        const output = new streamBuffers.WritableStreamBuffer();
+        output.on("finish", () => {
+          res(output.getContents().toString("utf8"));
+        });
+        stream?.pipe(output);
+      }
+    });
+  });
+};
+
+const validateManifest = (
+  entries: Entries,
+  manifestJson: ManifestJson,
+  manifestPath: string,
+) => {
+  // entry.fileName is a relative path separated by posix style(/) so this makes separators always posix style.
+  const getEntryKey = (filePath: string) =>
+    path
+      .join(path.dirname(manifestPath), filePath)
+      .replace(new RegExp(`\\${path.sep}`, "g"), "/");
+  const result = validate(manifestJson, {
+    relativePath: (filePath) => entries.has(getEntryKey(filePath)),
+    maxFileSize: (maxBytes, filePath) => {
+      const entry = entries.get(getEntryKey(filePath));
+      if (entry) {
+        return entry.uncompressedSize <= maxBytes;
+      }
+      return false;
+    },
+  });
+  if (!result.valid) {
+    const errors = generateErrorMessages(result.errors ?? []);
+    const e: any = new Error(errors.join(", "));
+    e.validationErrors = errors;
+    throw e;
+  }
+};
+
+const rezipContents = (
+  zipFile: yauzl.ZipFile,
+  entries: Entries,
+  manifestJson: ManifestJson,
+  manifestPath: string,
+): Promise<Buffer> => {
+  const manifestPrefix = path.dirname(manifestPath);
+
+  return new Promise((res, rej) => {
+    const newZipFile = new yazl.ZipFile();
+    (newZipFile as any).on("error", rej);
+    const output = new streamBuffers.WritableStreamBuffer();
+    output.on("finish", () => {
+      res(output.getContents() as Buffer);
+    });
+    newZipFile.outputStream.pipe(output);
+    const openReadStream = promisify(zipFile.openReadStream.bind(zipFile));
+    Promise.all(
+      sourceList(manifestJson).map((src) => {
+        const entry = entries.get(path.join(manifestPrefix, src));
+        return openReadStream(entry).then((stream) => {
+          newZipFile.addReadStream(stream as internal.Readable, src, {
+            size: entry.uncompressedSize,
+          });
+        });
+      }),
+    ).then(() => {
+      newZipFile.end();
+    });
+  });
+};
diff --git a/src/plugin/packer/test/bin.spec.ts b/src/plugin/packer/test/bin.spec.ts
new file mode 100644
index 0000000000..15ef5ffe28
--- /dev/null
+++ b/src/plugin/packer/test/bin.spec.ts
@@ -0,0 +1,76 @@
+import path from "path";
+import execa from "execa";
+import pkg from "../package.json";
+
+describe("bin", () => {
+  it("should output version with --version", () =>
+    exec("--version").then((result) => {
+      expect(result.stdout).toBe(pkg.version);
+    }));
+
+  it("should fail without args", () =>
+    exec().then(
+      () => {
+        throw new Error("should be rejected");
+      },
+      (result) => {
+        expect(/An argument `PLUGIN_DIR` is required/.test(result.stderr)).toBe(
+          true,
+        );
+      },
+    ));
+
+  it("should recieve 1st arg as PLUGIN_DIR", () =>
+    exec("foo").then((result) => {
+      expect(JSON.parse(result.stdout)).toStrictEqual({
+        pluginDir: "foo",
+        flags: { watch: false },
+      });
+    }));
+
+  it("should recieve --ppk", () =>
+    exec("foo", "--ppk", "bar").then((result) => {
+      expect(JSON.parse(result.stdout)).toStrictEqual({
+        pluginDir: "foo",
+        flags: { watch: false, ppk: "bar" },
+      });
+    }));
+
+  it("should recieve --out", () =>
+    exec("foo", "--out", "bar").then((result) => {
+      expect(JSON.parse(result.stdout)).toStrictEqual({
+        pluginDir: "foo",
+        flags: { watch: false, out: "bar" },
+      });
+    }));
+
+  it("should recieve --watch", () =>
+    exec("foo", "--watch").then((result) => {
+      expect(JSON.parse(result.stdout)).toStrictEqual({
+        pluginDir: "foo",
+        flags: { watch: true },
+      });
+    }));
+
+  it("should recieve -w as an alias of --watch", () =>
+    exec("foo", "-w").then((result) => {
+      expect(JSON.parse(result.stdout)).toStrictEqual({
+        pluginDir: "foo",
+        flags: { watch: true },
+      });
+    }));
+
+  it("should filter unexpected option", () =>
+    exec("foo", "--bar").then((result) => {
+      expect(JSON.parse(result.stdout)).toStrictEqual({
+        pluginDir: "foo",
+        flags: { watch: false },
+      });
+    }));
+});
+
+const exec = (...args: string[]) => {
+  const binPath = path.resolve(__dirname, "../bin/cli.js");
+  const env = Object.assign({}, process.env, { NODE_ENV: "test" });
+  return execa(binPath, args, { env });
+};
diff --git a/src/plugin/packer/test/cli.spec.ts b/src/plugin/packer/test/cli.spec.ts
new file mode 100644
index 0000000000..c65c78ff19
--- /dev/null
+++ b/src/plugin/packer/test/cli.spec.ts
@@ -0,0 +1,220 @@
+import fs from "fs";
+import path from "path";
+import { rimraf } from "rimraf";
+import { globSync } from "glob";
+import { readZipContentsNames } from "./helper/zip";
+import cli from "../src/cli";
+import console from "../src/console";
+
+const fixturesDir = path.posix.join(__dirname, "fixtures");
+const sampleDir = path.posix.join(fixturesDir, "sample-plugin");
+const ppkPath = path.posix.join(fixturesDir, "private.ppk");
+
+const ID = "aaa";
+const PRIVATE_KEY = "PRIVATE_KEY";
+const PLUGIN_BUFFER = Buffer.from("foo");
+
+describe("cli", () => {
+  const consoleLog = console.log;
+  const consoleError = console.error;
+  const consoleWarn = console.warn;
+  beforeEach(() => {
+    /* eslint-disable @typescript-eslint/no-empty-function -- This is mock functions */
+    console.log = () => {};
+    console.error = () => {};
+    console.warn = () => {};
+    /* eslint-enable @typescript-eslint/no-empty-function */
+  });
+  afterEach(() => {
+    console.log = consoleLog;
+    console.error = consoleError;
+    console.warn = consoleWarn;
+  });
+
+  it("is a function", () => {
+    expect(typeof cli).toBe("function");
+  });
+
+  describe("validation", () => {
+    let packer;
+    beforeEach(() => {
+      packer = jest.fn().mockReturnValue({
+        id: ID,
+        privateKey: PRIVATE_KEY,
+        plugin: PLUGIN_BUFFER,
+      });
+    });
+
+    it("invalid `url`", (done) => {
+      cli(path.join(fixturesDir, "plugin-invalid-url"), {
+        packerMock_: packer,
+      }).catch((error) => {
+        expect(/Invalid manifest.json/.test(error.message)).toBe(true);
+        done();
+      });
+    });
+
+    it("invalid `https-url`", (done) => {
+      cli(path.join(fixturesDir, "plugin-invalid-https-url"), {
+        packerMock_: packer,
+      }).catch((error) => {
+        expect(/Invalid manifest.json/.test(error.message)).toBe(true);
+        done();
+      });
+    });
+
+    it("invalid `relative-path`", (done) => {
+      cli(path.join(fixturesDir, "plugin-invalid-relative-path"), {
+        packerMock_: packer,
+      }).catch((error) => {
+        expect(/Invalid manifest.json/.test(error.message)).toBe(true);
+        done();
+      });
+    });
+
+    it("invalid `maxFileSize`", (done) => {
+      cli(path.join(fixturesDir, "plugin-invalid-maxFileSize"), {
+        packerMock_: packer,
+      }).catch((error) => {
+        expect(/Invalid manifest.json/.test(error.message)).toBe(true);
+        done();
+      });
+    });
+
+    it("invalid `fileExists`", (done) => {
+      cli(path.join(fixturesDir, "plugin-non-file-exists"), {
+        packerMock_: packer,
+      }).catch((error) => {
+        expect(/Invalid manifest.json/.test(error.message)).toBe(true);
+        done();
+      });
+    });
+  });
+
+  describe("without ppk", () => {
+    const pluginDir = path.join(sampleDir, "plugin-dir");
+    let packer;
+    let resultPluginPath;
+    beforeEach(() => {
+      packer = jest.fn().mockReturnValue({
+        id: ID,
+        privateKey: PRIVATE_KEY,
+        plugin: PLUGIN_BUFFER,
+      });
+
+      return rimraf(`${sampleDir}/*.*(ppk|zip)`, { glob: true })
+        .then(() => cli(pluginDir, { packerMock_: packer }))
+        .then((filePath) => {
+          resultPluginPath = filePath;
+        });
+    });
+
+    it("calles `packer` with contents.zip as the 1st argument", (done) => {
+      expect(packer.mock.calls.length).toBe(1);
+      expect(packer.mock.calls[0][0]).toBeTruthy();
+      readZipContentsNames(packer.mock.calls[0][0]).then((files) => {
+        expect(files.sort()).toStrictEqual(
+          ["image/icon.png", "manifest.json"].sort(),
+        );
+        done();
+      });
+    });
+
+    it("calles `packer` with privateKey as the 2nd argument", () => {
+      expect(packer.mock.calls.length).toBe(1);
+      expect(packer.mock.calls[0][1]).toBe(undefined);
+    });
+
+    it("generates a private key file", () => {
+      const privateKey = fs.readFileSync(
+        path.join(sampleDir, `${ID}.ppk`),
+        "utf8",
+      );
+      expect(privateKey).toBe(PRIVATE_KEY);
+    });
+
+    it("generates a plugin file", () => {
+      const pluginBuffer = fs.readFileSync(resultPluginPath);
+      expect(PLUGIN_BUFFER.equals(pluginBuffer)).toBe(true);
+    });
+  });
+
+  describe("with ppk", () => {
+    const pluginDir = path.join(sampleDir, "plugin-dir");
+    let packer;
+    beforeEach(() => {
+      packer = jest.fn().mockReturnValue({
+        id: ID,
+        privateKey: PRIVATE_KEY,
+        plugin: PLUGIN_BUFFER,
+      });
+
+      return rimraf(`${sampleDir}/*.*(ppk|zip)`, { glob: true }).then(() =>
+        cli(pluginDir, { ppk: ppkPath, packerMock_: packer }),
+      );
+    });
+
+    it("calles `packer` with privateKey as the 2nd argument", () => {
+      expect(packer.mock.calls.length).toBe(1);
+      const ppkFile = fs.readFileSync(ppkPath, "utf8");
+      expect(packer.mock.calls[0][1]).toBe(ppkFile);
+    });
+
+    it("does not generate a private key file", () => {
+      const ppkFiles = globSync(`${sampleDir}/*.ppk`);
+      expect(ppkFiles).toStrictEqual([]);
+    });
+  });
+
+  it("includes files listed in manifest.json only", () => {
+    const pluginDir = path.join(fixturesDir, "plugin-full-manifest");
+    const packer = jest.fn().mockReturnValue({
+      id: ID,
+      privateKey: PRIVATE_KEY,
+      plugin: PLUGIN_BUFFER,
+    });
+
+    return rimraf(`${sampleDir}/*.*(ppk|zip)`, { glob: true })
+      .then(() => cli(pluginDir, { packerMock_: packer }))
+      .then(() => {
+        return readZipContentsNames(packer.mock.calls[0][0]).then((files) => {
+          expect(files.sort()).toStrictEqual(
+            [
+              "css/config.css",
+              "css/desktop.css",
+              "css/mobile.css",
+              "html/config.html",
+              "image/icon.png",
+              "js/config.js",
+              "js/desktop.js",
+              "js/mobile.js",
+              "manifest.json",
+            ].sort(),
+          );
+        });
+      });
+  });
+
+  it("includes files listed in manifest.json only", () => {
+    const pluginDir = path.join(sampleDir, "plugin-dir");
+    const outputDir = path.join("test", ".output");
+    const outputPluginPath = path.join(outputDir, "foo.zip");
+    const packer = jest.fn().mockReturnValue({
+      id: ID,
+      privateKey: PRIVATE_KEY,
+      plugin: PLUGIN_BUFFER,
+    });
+
+    return rimraf(outputDir)
+      .then(() =>
+        cli(pluginDir, { packerMock_: packer, out: outputPluginPath }),
+      )
+      .then((resultPluginPath) => {
+        expect(resultPluginPath).toBe(outputPluginPath);
+        const pluginBuffer = fs.readFileSync(outputPluginPath);
+        expect(PLUGIN_BUFFER.equals(pluginBuffer)).toBe(true);
+        const ppk = fs.readFileSync(path.join(outputDir, `${ID}.ppk`));
+        expect(PRIVATE_KEY).toBe(ppk.toString());
+      });
+  });
+});
diff --git a/src/plugin/packer/test/create-contents-zip.spec.ts b/src/plugin/packer/test/create-contents-zip.spec.ts
new file mode 100644
index 0000000000..867996080d
--- /dev/null
+++ b/src/plugin/packer/test/create-contents-zip.spec.ts
@@ -0,0 +1,21 @@
+import path from "path";
+import fs from "fs";
+import { readZipContentsNames } from "./helper/zip";
+import { createContentsZip } from "../src/create-contents-zip";
+
+const fixturesDir = path.join(__dirname, "fixtures");
+const pluginDir = path.join(fixturesDir, "sample-plugin", "plugin-dir");
+
+describe("create-contents-zip", () => {
+  it("should be able to create buffer from a plugin directory", (done) => {
+    const manifestJSONPath = path.join(pluginDir, "manifest.json");
+    const manifest = JSON.parse(fs.readFileSync(manifestJSONPath, "utf-8"));
+    createContentsZip(pluginDir, manifest).then((buffer) => {
+      readZipContentsNames(buffer as Buffer).then((files) => {
+        expect(files).toStrictEqual(["manifest.json", "image/icon.png"]);
+        expect(buffer).toBeInstanceOf(Buffer);
+        done();
+      });
+    });
+  });
+});
diff --git a/src/plugin/packer/test/fixtures/aaa.ppk b/src/plugin/packer/test/fixtures/aaa.ppk
new file mode 100644
index 0000000000..20a11e0ce3
--- /dev/null
+++ b/src/plugin/packer/test/fixtures/aaa.ppk
@@ -0,0 +1 @@
+PRIVATE_KEY
\ No newline at end of file
diff --git a/src/plugin/packer/test/fixtures/contents.zip b/src/plugin/packer/test/fixtures/contents.zip
new file mode 100644
index 0000000000..aa98745ead
Binary files /dev/null and b/src/plugin/packer/test/fixtures/contents.zip differ
diff --git a/src/plugin/packer/test/fixtures/invalid-maxFileSize-contents.zip b/src/plugin/packer/test/fixtures/invalid-maxFileSize-contents.zip
new file mode 100644
index 0000000000..964bdf5823
Binary files /dev/null and b/src/plugin/packer/test/fixtures/invalid-maxFileSize-contents.zip differ
diff --git a/src/plugin/packer/test/fixtures/plugin-full-manifest/css/config.css b/src/plugin/packer/test/fixtures/plugin-full-manifest/css/config.css
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/plugin/packer/test/fixtures/plugin-full-manifest/css/desktop.css b/src/plugin/packer/test/fixtures/plugin-full-manifest/css/desktop.css
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/plugin/packer/test/fixtures/plugin-full-manifest/css/mobile.css b/src/plugin/packer/test/fixtures/plugin-full-manifest/css/mobile.css
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/plugin/packer/test/fixtures/plugin-full-manifest/css/should-not-be-included.css b/src/plugin/packer/test/fixtures/plugin-full-manifest/css/should-not-be-included.css
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/plugin/packer/test/fixtures/plugin-full-manifest/html/config.html b/src/plugin/packer/test/fixtures/plugin-full-manifest/html/config.html
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/plugin/packer/test/fixtures/plugin-full-manifest/html/should-not-be-included.html b/src/plugin/packer/test/fixtures/plugin-full-manifest/html/should-not-be-included.html
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/plugin/packer/test/fixtures/plugin-full-manifest/image/icon.png b/src/plugin/packer/test/fixtures/plugin-full-manifest/image/icon.png
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/plugin/packer/test/fixtures/plugin-full-manifest/image/should-not-be-included.png b/src/plugin/packer/test/fixtures/plugin-full-manifest/image/should-not-be-included.png
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/plugin/packer/test/fixtures/plugin-full-manifest/js/config.js b/src/plugin/packer/test/fixtures/plugin-full-manifest/js/config.js
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/plugin/packer/test/fixtures/plugin-full-manifest/js/desktop.js b/src/plugin/packer/test/fixtures/plugin-full-manifest/js/desktop.js
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/plugin/packer/test/fixtures/plugin-full-manifest/js/mobile.js b/src/plugin/packer/test/fixtures/plugin-full-manifest/js/mobile.js
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/plugin/packer/test/fixtures/plugin-full-manifest/js/should-not-be-included.js b/src/plugin/packer/test/fixtures/plugin-full-manifest/js/should-not-be-included.js
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/plugin/packer/test/fixtures/plugin-full-manifest/manifest.json b/src/plugin/packer/test/fixtures/plugin-full-manifest/manifest.json
new file mode 100644
index 0000000000..bc68964518
--- /dev/null
+++ b/src/plugin/packer/test/fixtures/plugin-full-manifest/manifest.json
@@ -0,0 +1,35 @@
+{
+  "manifest_version": 1,
+  "version": 1,
+  "type": "APP",
+  "name": {
+    "ja": "サンプルプラグイン",
+    "en": "sample plugin",
+    "zh": "插件的例子"
+  },
+  "description": {
+    "ja": "これはサンプルプラグインです。",
+    "en": "This is sample plugin.",
+    "zh": "这是插件的例子"
+  },
+  "icon": "image/icon.png",
+  "homepage_url": {
+    "ja": "http://jp.example.com",
+    "en": "http://en.example.com",
+    "zh": "http://zh.example.com"
+  },
+  "desktop": {
+    "js": ["js/desktop.js", "https://example.com/js/desktop.js"],
+    "css": ["https://example.com/css/desktop.css", "css/desktop.css"]
+  },
+  "mobile": {
+    "js": ["js/mobile.js", "https://example.com/js/mobile.js"],
+    "css": ["https://example.com/css/mobile.css", "css/mobile.css"]
+  },
+  "config": {
+    "html": "html/config.html",
+    "js": ["https://example.com/js/config.js", "js/config.js"],
+    "css": ["css/config.css", "https://example.com/css/config.css"],
+    "required_params": ["Param1", "Param2"]
+  }
+}
diff --git a/src/plugin/packer/test/fixtures/plugin-full-manifest/should-not-be-included.json b/src/plugin/packer/test/fixtures/plugin-full-manifest/should-not-be-included.json
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/plugin/packer/test/fixtures/plugin-invalid-https-url/image/icon.png b/src/plugin/packer/test/fixtures/plugin-invalid-https-url/image/icon.png
new file mode 100644
index 0000000000..fe24d3aee8
Binary files /dev/null and b/src/plugin/packer/test/fixtures/plugin-invalid-https-url/image/icon.png differ
diff --git a/src/plugin/packer/test/fixtures/plugin-invalid-https-url/manifest.json b/src/plugin/packer/test/fixtures/plugin-invalid-https-url/manifest.json
new file mode 100644
index 0000000000..c76efec134
--- /dev/null
+++ b/src/plugin/packer/test/fixtures/plugin-invalid-https-url/manifest.json
@@ -0,0 +1,12 @@
+{
+  "manifest_version": 1,
+  "version": 1,
+  "type": "APP",
+  "name": {
+    "en": "sample extension"
+  },
+  "desktop": {
+    "js": ["http://example.com/http-is-invalid.js"]
+  },
+  "icon": "image/icon.png"
+}
diff --git a/src/plugin/packer/test/fixtures/plugin-invalid-maxFileSize/image/icon.png b/src/plugin/packer/test/fixtures/plugin-invalid-maxFileSize/image/icon.png
new file mode 100644
index 0000000000..0fbcf54501
Binary files /dev/null and b/src/plugin/packer/test/fixtures/plugin-invalid-maxFileSize/image/icon.png differ
diff --git a/src/plugin/packer/test/fixtures/plugin-invalid-maxFileSize/manifest.json b/src/plugin/packer/test/fixtures/plugin-invalid-maxFileSize/manifest.json
new file mode 100644
index 0000000000..e4ca3715e0
--- /dev/null
+++ b/src/plugin/packer/test/fixtures/plugin-invalid-maxFileSize/manifest.json
@@ -0,0 +1,9 @@
+{
+  "manifest_version": 1,
+  "version": 1,
+  "type": "APP",
+  "name": {
+    "en": "sample extension"
+  },
+  "icon": "image/icon.png"
+}
diff --git a/src/plugin/packer/test/fixtures/plugin-invalid-relative-path/image/icon.png b/src/plugin/packer/test/fixtures/plugin-invalid-relative-path/image/icon.png
new file mode 100644
index 0000000000..fe24d3aee8
Binary files /dev/null and b/src/plugin/packer/test/fixtures/plugin-invalid-relative-path/image/icon.png differ
diff --git a/src/plugin/packer/test/fixtures/plugin-invalid-relative-path/manifest.json b/src/plugin/packer/test/fixtures/plugin-invalid-relative-path/manifest.json
new file mode 100644
index 0000000000..b543994b0a
--- /dev/null
+++ b/src/plugin/packer/test/fixtures/plugin-invalid-relative-path/manifest.json
@@ -0,0 +1,9 @@
+{
+  "manifest_version": 1,
+  "version": 1,
+  "type": "APP",
+  "name": {
+    "en": "sample extension"
+  },
+  "icon": "image/missing-file.png"
+}
diff --git a/src/plugin/packer/test/fixtures/plugin-invalid-url/image/icon.png b/src/plugin/packer/test/fixtures/plugin-invalid-url/image/icon.png
new file mode 100644
index 0000000000..fe24d3aee8
Binary files /dev/null and b/src/plugin/packer/test/fixtures/plugin-invalid-url/image/icon.png differ
diff --git a/src/plugin/packer/test/fixtures/plugin-invalid-url/manifest.json b/src/plugin/packer/test/fixtures/plugin-invalid-url/manifest.json
new file mode 100644
index 0000000000..d0240a1db0
--- /dev/null
+++ b/src/plugin/packer/test/fixtures/plugin-invalid-url/manifest.json
@@ -0,0 +1,12 @@
+{
+  "manifest_version": 1,
+  "version": 1,
+  "type": "APP",
+  "name": {
+    "en": "sample extension"
+  },
+  "homepage_url": {
+    "ja": "ftp://example.com/ftp-is-invalid.png"
+  },
+  "icon": "image/icon.png"
+}
diff --git a/src/plugin/packer/test/fixtures/plugin-non-file-exists/image/icon.png b/src/plugin/packer/test/fixtures/plugin-non-file-exists/image/icon.png
new file mode 100644
index 0000000000..0fbcf54501
Binary files /dev/null and b/src/plugin/packer/test/fixtures/plugin-non-file-exists/image/icon.png differ
diff --git a/src/plugin/packer/test/fixtures/plugin-non-file-exists/js/config.js b/src/plugin/packer/test/fixtures/plugin-non-file-exists/js/config.js
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/plugin/packer/test/fixtures/plugin-non-file-exists/js/desktop.js b/src/plugin/packer/test/fixtures/plugin-non-file-exists/js/desktop.js
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/plugin/packer/test/fixtures/plugin-non-file-exists/manifest.json b/src/plugin/packer/test/fixtures/plugin-non-file-exists/manifest.json
new file mode 100644
index 0000000000..b011bec9da
--- /dev/null
+++ b/src/plugin/packer/test/fixtures/plugin-non-file-exists/manifest.json
@@ -0,0 +1,12 @@
+{
+  "manifest_version": 1,
+  "version": 1,
+  "type": "APP",
+  "name": {
+    "en": "sample extension"
+  },
+  "icon": "image/icon.png",
+  "config": {
+    "js": ["js/config.js", "js/desktop.js", "js/non-existent-file.js"]
+  }
+}
diff --git a/src/plugin/packer/test/fixtures/plugin.zip b/src/plugin/packer/test/fixtures/plugin.zip
new file mode 100644
index 0000000000..1910281566
--- /dev/null
+++ b/src/plugin/packer/test/fixtures/plugin.zip
@@ -0,0 +1 @@
+foo
\ No newline at end of file
diff --git a/src/plugin/packer/test/fixtures/private.ppk b/src/plugin/packer/test/fixtures/private.ppk
new file mode 100644
index 0000000000..4a87817a2a
--- /dev/null
+++ b/src/plugin/packer/test/fixtures/private.ppk
@@ -0,0 +1,15 @@
+-----BEGIN RSA PRIVATE KEY-----
+MIICWwIBAAKBgQDDH5jleaiQagMnSS6XjrOQCJIDhjutOV7fJyzrsGhIGhFnZk7y
+K5YAm+kfOMlCEUZNHavcfS3WrJRP5sanc6E0dobTXNBYVwx97pEZk1KPhPVCiVCC
+HBRPvef+Ai98o4aeSVamP6bD9aIZ51+prjcf0uh9+vzzm1XvqF9rgMkhkQIDAQAB
+AoGAT8GGmaXUxNLQXyqGpORreSBHrrEbi367zLMSpXQB7BbbrkwfUNWIBs+zxlNL
+0HmHJtZN/V4dcnYwWUiXQrL83OHdVgqgcUBKBX5znY9GJcPJoDM6ZhiYR7K79IQq
+eAzKCveFm3bhk9+mnOdiZO+q39IPE+3PPz3dQ1PNRwbCh8ECQQDtKstAHmfRcIwf
+4woOV+TllxRMDkexThxs/YWV+5Sq3lLUqOjJolLFdW1DwqQHjeyeN008C3IhNLyy
+1xeRLLydAkEA0p4gHlCnxUz9nVuRkz2Dk0GMpkdz156Opcf1nKUXar4CbdSp9gbJ
+LEBulEDRVop4nY6J4W5hW0bDjuPGnSR0hQJATpU2YVlxxtjG5S3iQBxpcJVdmVHF
++X7LNmXOZILGoNMnmOUatOy/BkRBXwlYNlSVSVtDkRityUjjGVLhsS2klQJAbkQY
+3qYtX69SK/sPuP2AkCzGPRu1e1JorkSEwzDvlJPL48JuBP9CfWdyPS2+K0etpBdG
++n32fHoM0hdQGV9HnQJAGed+BG6jxfXJe7KRhPoT3bF4lc4xmdXGfLMoutLqoZ8y
+GrKcvq1TcxsA/QSkvSGGEd0667t/9djFq1Ift02RMQ==
+-----END RSA PRIVATE KEY-----
diff --git a/src/plugin/packer/test/fixtures/sample-plugin/plugin-dir/image/icon.png b/src/plugin/packer/test/fixtures/sample-plugin/plugin-dir/image/icon.png
new file mode 100644
index 0000000000..fe24d3aee8
Binary files /dev/null and b/src/plugin/packer/test/fixtures/sample-plugin/plugin-dir/image/icon.png differ
diff --git a/src/plugin/packer/test/fixtures/sample-plugin/plugin-dir/manifest.json b/src/plugin/packer/test/fixtures/sample-plugin/plugin-dir/manifest.json
new file mode 100644
index 0000000000..e4ca3715e0
--- /dev/null
+++ b/src/plugin/packer/test/fixtures/sample-plugin/plugin-dir/manifest.json
@@ -0,0 +1,9 @@
+{
+  "manifest_version": 1,
+  "version": 1,
+  "type": "APP",
+  "name": {
+    "en": "sample extension"
+  },
+  "icon": "image/icon.png"
+}
diff --git a/src/plugin/packer/test/helper/zip.ts b/src/plugin/packer/test/helper/zip.ts
new file mode 100644
index 0000000000..0d41879ea9
--- /dev/null
+++ b/src/plugin/packer/test/helper/zip.ts
@@ -0,0 +1,20 @@
+import yauzl from "yauzl";
+
+export const readZipContentsNames = (
+  zipFilePath: Buffer,
+): Promise<string[]> => {
+  return new Promise((resolve, reject) => {
+    yauzl.fromBuffer(zipFilePath, (err, zipFile) => {
+      if (err) {
+        reject(err);
+      }
+      const files = [];
+      zipFile.on("entry", (entry) => {
+        files.push(entry.fileName);
+      });
+      zipFile.on("end", () => {
+        resolve(files);
+      });
+    });
+  });
+};
diff --git a/src/plugin/packer/test/hex2a.spec.ts b/src/plugin/packer/test/hex2a.spec.ts
new file mode 100644
index 0000000000..492029b0aa
--- /dev/null
+++ b/src/plugin/packer/test/hex2a.spec.ts
@@ -0,0 +1,34 @@
+import { hex2a } from "../src/hex2a";
+
+describe("hex2a", () => {
+  it("empty string", () => {
+    expect(hex2a("")).toBe("");
+  });
+
+  it("number", () => {
+    expect(hex2a("0")).toBe("a");
+    expect(hex2a("1")).toBe("b");
+    expect(hex2a("9")).toBe("j");
+  });
+
+  it("alphabet", () => {
+    expect(hex2a("a")).toBe("k");
+    expect(hex2a("b")).toBe("l");
+    expect(hex2a("f")).toBe("p");
+  });
+
+  it("string", () => {
+    expect(hex2a("012abc")).toBe("abcklm");
+  });
+
+  it("throws for out of range", () => {
+    expect(() => hex2a("/")).toThrow();
+    expect(() => hex2a(":")).toThrow();
+    expect(() => hex2a("`")).toThrow();
+    expect(() => hex2a("g")).toThrow();
+  });
+
+  it("upper case is out of range", () => {
+    expect(() => hex2a("A")).toThrow();
+  });
+});
diff --git a/src/plugin/packer/test/pack-plugin-from-manifest.spec.ts b/src/plugin/packer/test/pack-plugin-from-manifest.spec.ts
new file mode 100644
index 0000000000..f4b7016e14
--- /dev/null
+++ b/src/plugin/packer/test/pack-plugin-from-manifest.spec.ts
@@ -0,0 +1,32 @@
+import path from "path";
+import fs from "fs";
+import { readZipContentsNames } from "./helper/zip";
+import packer from "../src";
+import { packPluginFromManifest } from "../dist/pack-plugin-from-manifest";
+import { createContentsZip } from "../dist/create-contents-zip";
+
+const fixturesDir = path.join(__dirname, "fixtures");
+const ppkFilePath = path.join(fixturesDir, "private.ppk");
+const pluginDir = path.join(fixturesDir, "sample-plugin", "plugin-dir");
+
+describe("pack-plugin-from-manifest", () => {
+  it("should be able to create a plugin from the manifest json path", (done) => {
+    const manifestJSONPath = path.join(pluginDir, "manifest.json");
+    const privateKey = fs.readFileSync(ppkFilePath, "utf-8");
+    const manifest = JSON.parse(fs.readFileSync(manifestJSONPath, "utf-8"));
+    Promise.all([
+      packPluginFromManifest(manifestJSONPath, privateKey),
+      createContentsZip(pluginDir, manifest).then((buffer) =>
+        packer(buffer as any, privateKey),
+      ),
+    ]).then(([result1, result2]) => {
+      expect(result1.id).toBe(result2.id);
+      expect(result1.plugin.length).toBe(result2.plugin.length);
+      expect(result1.privateKey).toBe(result2.privateKey);
+      readZipContentsNames(result1.plugin).then((files) => {
+        expect(files).toStrictEqual(["contents.zip", "PUBKEY", "SIGNATURE"]);
+        done();
+      });
+    });
+  });
+});
diff --git a/src/plugin/packer/test/packer.spec.ts b/src/plugin/packer/test/packer.spec.ts
new file mode 100644
index 0000000000..44a00ba14c
--- /dev/null
+++ b/src/plugin/packer/test/packer.spec.ts
@@ -0,0 +1,154 @@
+import crypto from "crypto";
+import path from "path";
+import fs from "fs";
+import RSA from "node-rsa";
+import yauzl from "yauzl";
+
+import { readZipContentsNames } from "./helper/zip";
+
+import packer from "../src";
+
+const privateKeyPath = path.join(__dirname, "fixtures", "private.ppk");
+const contentsZipPath = path.join(__dirname, "fixtures", "contents.zip");
+const invalidMaxFileSizeContentsZipPath = path.join(
+  __dirname,
+  "fixtures",
+  "invalid-maxFileSize-contents.zip",
+);
+
+describe("packer", () => {
+  it("is a function", () => {
+    expect(typeof packer).toBe("function");
+  });
+
+  describe("without privateKey", () => {
+    let output: Awaited<ReturnType<typeof packer>>;
+    beforeEach(async () => {
+      const contentsZip = fs.readFileSync(contentsZipPath);
+      output = await packer(contentsZip);
+    });
+
+    it("the id is generated", () => {
+      expect(typeof output.id).toBe("string");
+      expect(output.id.length).toBe(32);
+    });
+
+    it("the privateKey is generated", () => {
+      expect(typeof output.privateKey).toBe("string");
+      expect(/^-----BEGIN RSA PRIVATE KEY-----/.test(output.privateKey)).toBe(
+        true,
+      );
+    });
+
+    it("the zip contains 3 files", async () => {
+      const files = await readZipContentsNames(output.plugin);
+      expect(files.sort()).toStrictEqual(
+        ["contents.zip", "PUBKEY", "SIGNATURE"].sort(),
+      );
+    });
+
+    it("the zip passes signature verification", async () => {
+      await verifyPlugin(output.plugin);
+    });
+  });
+
+  describe("with privateKey", () => {
+    let privateKey: string;
+    let output: Awaited<ReturnType<typeof packer>>;
+    beforeEach(async () => {
+      const contentsZip = fs.readFileSync(contentsZipPath);
+      privateKey = fs.readFileSync(privateKeyPath, "utf8");
+      output = await packer(contentsZip, privateKey);
+    });
+
+    it("the id is expected", () => {
+      expect(output.id).toBe("ldmhlgpmfpfhpgimbjlblmfkmcnbjnnj");
+    });
+
+    it("the privateKey is same", () => {
+      expect(output.privateKey).toBe(privateKey);
+    });
+
+    it("the zip passes signature verification", async () => {
+      await verifyPlugin(output.plugin);
+    });
+  });
+
+  describe("invalid contents.zip", () => {
+    it("throws an error if the contents.zip is invalid", async () => {
+      const contentsZip = fs.readFileSync(invalidMaxFileSizeContentsZipPath);
+      await expect(packer(contentsZip)).rejects.toThrow(
+        '"/icon" file size should be <= 20MB',
+      );
+    });
+  });
+});
+
+const streamToBuffer = (stream: NodeJS.ReadableStream) => {
+  return new Promise<Buffer>((resolve, reject) => {
+    const buffers: Buffer[] = [];
+    stream.on("data", (data) => buffers.push(data));
+    stream.on("end", () => resolve(Buffer.concat(buffers)));
+    stream.on("error", reject);
+  });
+};
+
+const readZipContents = (
+  zipEntry: yauzl.ZipFile,
+): Promise<Map<any, Buffer>> => {
+  const zipContentsMap = new Map();
+  const streamToBufferPromises: Array<Promise<void>> = [];
+  return new Promise((resolve, reject) => {
+    zipEntry.on("entry", (entry) => {
+      zipEntry.openReadStream(entry, (err, stream) => {
+        if (err) {
+          reject(err);
+        }
+        streamToBufferPromises.push(
+          streamToBuffer(stream).then((buffer) => {
+            zipContentsMap.set(entry.fileName, buffer);
+          }),
+        );
+      });
+    });
+    zipEntry.on("end", () => {
+      Promise.all(streamToBufferPromises).then(() => resolve(zipContentsMap));
+    });
+  });
+};
+
+const verifyPlugin = async (plugin: Buffer): Promise<void> => {
+  const fromBuffer = (buffer: Buffer) =>
+    new Promise<yauzl.ZipFile>((resolve, reject) => {
+      yauzl.fromBuffer(buffer, (err, zipfile) => {
+        if (err) {
+          reject(err);
+        }
+        resolve(zipfile);
+      });
+    });
+  const zipEntry = await fromBuffer(plugin);
+  const zipContentsMap = await readZipContents(zipEntry);
+  const contentZip = zipContentsMap.get("contents.zip");
+  expect(contentZip).toBeDefined();
+  if (contentZip === undefined) {
+    throw new Error("contentZip is undefined");
+  }
+  const verifier = crypto.createVerify("RSA-SHA1");
+  verifier.update(contentZip);
+
+  const publicKey = zipContentsMap.get("PUBKEY");
+  if (publicKey === undefined) {
+    throw new Error("PUBKEY is undefined");
+  }
+  const signature = zipContentsMap.get("SIGNATURE");
+  if (signature === undefined) {
+    throw new Error("SIGNATURE is undefined");
+  }
+  expect(verifier.verify(derToPem(publicKey), signature)).toBe(true);
+};
+
+const derToPem = (der: Buffer) => {
+  const key = new RSA(der, "pkcs8-public-der");
+  return key.exportKey("pkcs1-public-pem");
+};
diff --git a/src/plugin/packer/test/sourcelist.spec.ts b/src/plugin/packer/test/sourcelist.spec.ts
new file mode 100644
index 0000000000..1f2705dd9d
--- /dev/null
+++ b/src/plugin/packer/test/sourcelist.spec.ts
@@ -0,0 +1,80 @@
+import { sourceList } from "../dist/sourcelist";
+
+describe("sourcelist", () => {
+  let manifest: any;
+  beforeEach(() => {
+    manifest = {
+      icon: "image/icon.png",
+      desktop: {
+        js: ["js/desktop.js", "js/lib.js"],
+        css: ["css/desktop.css", "css/lib.css"],
+      },
+      mobile: {
+        js: ["js/mobile.js"],
+      },
+      config: {
+        js: ["js/config.js"],
+        css: ["css/config.css"],
+        html: "html/config.html",
+      },
+    };
+  });
+  it("should return a file list including the manifest", () => {
+    expect(sourceList(manifest)).toStrictEqual([
+      "js/desktop.js",
+      "js/lib.js",
+      "css/desktop.css",
+      "css/lib.css",
+      "js/mobile.js",
+      "js/config.js",
+      "css/config.css",
+      "html/config.html",
+      "manifest.json",
+      "image/icon.png",
+    ]);
+  });
+  it("should filter http(s) path", () => {
+    manifest.desktop.js.push("https://example.com/foo.js");
+    manifest.desktop.css.push("https://example.com/foo.css");
+    manifest.mobile.js.push("https://example.com/foo.js");
+    manifest.config.js.push("https://example.com/foo.js");
+    manifest.config.css.push("https://example.com/foo.css");
+    // This file should be added the list.
+    manifest.desktop.js.push("js/external.js");
+    expect(sourceList(manifest)).toStrictEqual([
+      "js/desktop.js",
+      "js/lib.js",
+      "js/external.js",
+      "css/desktop.css",
+      "css/lib.css",
+      "js/mobile.js",
+      "js/config.js",
+      "css/config.css",
+      "html/config.html",
+      "manifest.json",
+      "image/icon.png",
+    ]);
+  });
+  it("should make the file list unique", () => {
+    manifest.desktop.js.push("js/desktop.js");
+    manifest.desktop.css.push("css/desktop.css");
+    manifest.mobile.js.push("js/mobile.js");
+    manifest.config.js.push("js/config.js");
+    manifest.config.css.push("css/config.css");
+    // This file should be added the list.
+    manifest.desktop.js.push("js/external.js");
+    expect(sourceList(manifest)).toStrictEqual([
+      "js/desktop.js",
+      "js/lib.js",
+      "js/external.js",
+      "css/desktop.css",
+      "css/lib.css",
+      "js/mobile.js",
+      "js/config.js",
+      "css/config.css",
+      "html/config.html",
+      "manifest.json",
+      "image/icon.png",
+    ]);
+  });
+});
diff --git a/src/plugin/packer/tsconfig.json b/src/plugin/packer/tsconfig.json
new file mode 100644
index 0000000000..e5b5c20274
--- /dev/null
+++ b/src/plugin/packer/tsconfig.json
@@ -0,0 +1,12 @@
+{
+  "extends": "../tsconfig-base.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "dist",
+    "resolveJsonModule": true
+  },
+  "exclude": ["site/**", "test/**", "dist/**"],
+  "references": [
+    { "path": "../plugin-manifest-validator" }
+  ]
+}
diff --git a/src/plugin/packer/webpack.config.js b/src/plugin/packer/webpack.config.js
new file mode 100644
index 0000000000..5cbf81a069
--- /dev/null
+++ b/src/plugin/packer/webpack.config.js
@@ -0,0 +1,43 @@
+"use strict";
+
+const path = require("path");
+const webpack = require("webpack");
+
+module.exports = {
+  entry: "./site/index.js",
+  output: {
+    path: path.resolve(__dirname, "docs", "dist"),
+    filename: "bundle.js",
+  },
+  devServer: {
+    devMiddleware: {
+      publicPath: "/dist/",
+    },
+    static: {
+      directory: path.resolve(__dirname, "docs"),
+      watch: true,
+    },
+    open: true,
+  },
+  resolve: {
+    fallback: {
+      assert: require.resolve("assert"),
+      fs: false,
+      util: require.resolve("util"),
+      path: require.resolve("path-browserify"),
+      crypto: require.resolve("crypto-browserify"),
+      zlib: require.resolve("browserify-zlib"),
+      stream: require.resolve("stream-browserify"),
+      constants: require.resolve("constants-browserify"),
+    },
+  },
+  plugins: [
+    new webpack.DefinePlugin({
+      "process.env.NODE_DEBUG": process.env.NODE_DEBUG,
+    }),
+    new webpack.ProvidePlugin({
+      Buffer: ["buffer", "Buffer"],
+      process: "process",
+    }),
+  ],
+};