diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..b268b628d2ec325e7b842ee69e1f75f6c15b322e
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,6 @@
+repos:
+-   repo: https://github.com/ambv/black
+    rev: stable
+    hooks:
+    - id: black
+      language_version: python3.7
diff --git a/Pipfile b/Pipfile
index d79896f1e0de7881966e693bb0743cb0c73c5a83..73c2bfca254a871d9ddee695cdcf0247071a0384 100644
--- a/Pipfile
+++ b/Pipfile
@@ -13,6 +13,11 @@ PyNaCl = "*"
 "e1839a8" = {path = ".", editable = true}
 
 [dev-packages]
+pre-commit = "*"
+black = "*"
 
 [requires]
 python_version = "3.7"
+
+[pipenv]
+allow_prereleases = true
diff --git a/Pipfile.lock b/Pipfile.lock
index 92b76b266e9b3ddec64cfb6399897586c360ef28..63e2a4663cdf3f3dc0239493908788f973e918b4 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "38d781c924f23e1b2ab6ca77d7e82d27a6de370f9a3edb04d9a8059ce0f7ae5b"
+            "sha256": "213736944a7327071b08017fcc7582c17982914464a27ed6122f21fc52f3ccc6"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -102,11 +102,14 @@
                 "sha256:8abb4ef79161a5f58848b30ab6fb98d8c466da21fdd65558ce1d7afc02c70b5f",
                 "sha256:8ac1167195b32a8755de06efd5b2d2fe76fc864517dab66aaf65662cc59e1988",
                 "sha256:8f505f42f659012794414fa57c498404e64db78f1d98dfd40e318c569f3c783b",
+                "sha256:9c8a06556918ee8e3ab48c65574f318f5a0a4d31437fc135da7ee9d4f9080415",
+                "sha256:a1e25fc5650cf64f01c9e435033e53a4aca9de30eb9929d099f3bb078e18f8f2",
                 "sha256:be71cd5fce04061e1f3d39597f93619c80cdd3558a6c9ba99a546f144a8d8101",
                 "sha256:c5b1a7a680218dee9da0f1b5e24072c46b3c275d35712bc1d505b85bb03441c0",
                 "sha256:cb785db1a9468841a1265c9215c60fe5d7af2fb1b209e3316a152704607fc582",
                 "sha256:cf6877124ae6a0698404e169b3ba534542cfbc43f939d46b927d956daf0a373a",
                 "sha256:d0eb5b2795b7ee2cbcfcadacbe95a13afbda048a262bd369da9904fecb568975",
+                "sha256:d3a934e2b9f20abac009d5b6951067cfb5486889cb913192b4d8288b216842f1",
                 "sha256:d795f506bcc9463efb5ebb0f65ed77921dcc9e0a50499dedd89f208445de9ecb",
                 "sha256:d8aaf7e5d6b0e0ef7d6dbf7abeb75085713d0100b4eb1a4e4e857de76d77ac45",
                 "sha256:de2aaca8386cf4d70f1796352f2346f48ddb0bed61dc43a3ce773ba12e064031",
@@ -153,5 +156,111 @@
             "version": "==0.8.2"
         }
     },
-    "develop": {}
+    "develop": {
+        "appdirs": {
+            "hashes": [
+                "sha256:9e5896d1372858f8dd3344faf4e5014d21849c756c8d5701f78f8a103b372d92",
+                "sha256:d8b24664561d0d34ddfaec54636d502d7cea6e29c3eaf68f3df6180863e2166e"
+            ],
+            "version": "==1.4.3"
+        },
+        "aspy.yaml": {
+            "hashes": [
+                "sha256:04d26279513618f1024e1aba46471db870b3b33aef204c2d09bcf93bea9ba13f",
+                "sha256:0a77e23fafe7b242068ffc0252cee130d3e509040908fc678d9d1060e7494baa"
+            ],
+            "version": "==1.1.1"
+        },
+        "attrs": {
+            "hashes": [
+                "sha256:4b90b09eeeb9b88c35bc642cbac057e45a5fd85367b985bd2809c62b7b939265",
+                "sha256:e0d0eb91441a3b53dab4d9b743eafc1ac44476296a2053b6ca3af0b139faf87b"
+            ],
+            "version": "==18.1.0"
+        },
+        "black": {
+            "hashes": [
+                "sha256:22158b89c1a6b4eb333a1e65e791a3f8b998cf3b11ae094adb2570f31f769a44",
+                "sha256:4b475bbd528acce094c503a3d2dbc2d05a4075f6d0ef7d9e7514518e14cc5191"
+            ],
+            "index": "pypi",
+            "version": "==18.6b4"
+        },
+        "cached-property": {
+            "hashes": [
+                "sha256:630fdbf0f4ac7d371aa866016eba1c3ac43e9032246748d4994e67cb05f99bc4",
+                "sha256:f1f9028757dc40b4cb0fd2234bd7b61a302d7b84c683cb8c2c529238a24b8938"
+            ],
+            "version": "==1.4.3"
+        },
+        "cfgv": {
+            "hashes": [
+                "sha256:73f48a752bd7aab103c4b882d6596c6360b7aa63b34073dd2c35c7b4b8f93010",
+                "sha256:d1791caa9ff5c0c7bce80e7ecc1921752a2eb7c2463a08ed9b6c96b85a2f75aa"
+            ],
+            "version": "==1.1.0"
+        },
+        "click": {
+            "hashes": [
+                "sha256:29f99fc6125fbc931b758dc053b3114e55c77a6e4c6c3a2674a2dc986016381d",
+                "sha256:f15516df478d5a56180fbf80e68f206010e6d160fc39fa508b65e035fd75130b"
+            ],
+            "version": "==6.7"
+        },
+        "identify": {
+            "hashes": [
+                "sha256:0bab212939e3e83caf60788fac9bda5ea4a496f9147ed4746bb04f10ec6c0cbf",
+                "sha256:264f34cbd4002d5b2f4b323ae9e5776a16189363d82627f46570b9c703fea448"
+            ],
+            "version": "==1.1.3"
+        },
+        "nodeenv": {
+            "hashes": [
+                "sha256:0611c726af1b252908646787f4d49811aa69cd92ec19644ded06ad9d3162f88e"
+            ],
+            "version": "==1.3.1"
+        },
+        "pre-commit": {
+            "hashes": [
+                "sha256:2d57dd6b0c117ef8363233f256de8a3f26ee1c6e05ed96f9e2d9135ca5467d90",
+                "sha256:9807f29320547a8a13163c1977f6765e488a9349a01431ff4fbd196ff287b51c"
+            ],
+            "index": "pypi",
+            "version": "==1.10.3"
+        },
+        "pyyaml": {
+            "hashes": [
+                "sha256:1cbc199009e78f92d9edf554be4fe40fb7b0bef71ba688602a00e97a51909110",
+                "sha256:254bf6fda2b7c651837acb2c718e213df29d531eebf00edb54743d10bcb694eb",
+                "sha256:3108529b78577327d15eec243f0ff348a0640b0c3478d67ad7f5648f93bac3e2",
+                "sha256:3c17fb92c8ba2f525e4b5f7941d850e7a48c3a59b32d331e2502a3cdc6648e76",
+                "sha256:6f89b5c95e93945b597776163403d47af72d243f366bf4622ff08bdfd1c950b7",
+                "sha256:8d6d96001aa7f0a6a4a95e8143225b5d06e41b1131044913fecb8f85a125714b",
+                "sha256:be622cc81696e24d0836ba71f6272a2b5767669b0d79fdcf0295d51ac2e156c8",
+                "sha256:c8a88edd93ee29ede719080b2be6cb2333dfee1dccba213b422a9c8e97f2967b",
+                "sha256:f39411e380e2182ad33be039e8ee5770a5d9efe01a2bfb7ae58d9ba31c4a2a9d"
+            ],
+            "version": "==4.2b4"
+        },
+        "six": {
+            "hashes": [
+                "sha256:70e8a77beed4562e7f14fe23a786b54f6296e34344c23bc42f07b15018ff98e9",
+                "sha256:832dc0e10feb1aa2c68dcc57dbb658f1c7e65b9b61af69048abc87a2db00a0eb"
+            ],
+            "version": "==1.11.0"
+        },
+        "toml": {
+            "hashes": [
+                "sha256:8e86bd6ce8cc11b9620cb637466453d94f5d57ad86f17e98a98d1f73e3baab2d"
+            ],
+            "version": "==0.9.4"
+        },
+        "virtualenv": {
+            "hashes": [
+                "sha256:2ce32cd126117ce2c539f0134eb89de91a8413a29baac49cbab3eb50e2026669",
+                "sha256:ca07b4c0b54e14a91af9f34d0919790b016923d157afda5efdde55c96718f752"
+            ],
+            "version": "==16.0.0"
+        }
+    }
 }
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000000000000000000000000000000000000..f161db1813e61786d28211627afe67fb09e96727
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,2 @@
+[tool.black]
+include = "/(bin/*.py|sakia/*.py/)"