diff --git a/bin/silkaj b/bin/silkaj
index b5986a045e002e1cc905563bde5e0434cd05a8c0..72eb739beb6e1edfe52ee8752594bb059e393c31 100755
--- a/bin/silkaj
+++ b/bin/silkaj
@@ -1,5 +1,22 @@
 #!/usr/bin/env python3
 
+"""
+Copyright  2016-2019 Maël Azimi <m.a@moul.re>
+
+Silkaj is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Silkaj is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
+"""
+
 from sys import exit
 
 from silkaj.network_tools import check_port, best_node, EndPoint
diff --git a/silkaj/__init__.py b/silkaj/__init__.py
index 775d1576f8ea4c5ea3ed9820688908fc98e61d45..4a5c4f335e52065aeb987eceb717dc24989d726a 100644
--- a/silkaj/__init__.py
+++ b/silkaj/__init__.py
@@ -1 +1,18 @@
+"""
+Copyright  2016-2019 Maël Azimi <m.a@moul.re>
+
+Silkaj is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Silkaj is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
+"""
+
 name = "silkaj"
diff --git a/silkaj/auth.py b/silkaj/auth.py
index 23e9edec5763cdc930b97ef7c6fad43d92c21c88..92cde61a2034cff8c0d44a9c49031bc0f57b30e9 100644
--- a/silkaj/auth.py
+++ b/silkaj/auth.py
@@ -1,3 +1,20 @@
+"""
+Copyright  2016-2019 Maël Azimi <m.a@moul.re>
+
+Silkaj is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Silkaj is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
+"""
+
 from silkaj.crypto_tools import get_publickey_from_seed, b58_decode, xor_bytes
 from silkaj.tools import message_exit
 from nacl import encoding
diff --git a/silkaj/blockchain_tools.py b/silkaj/blockchain_tools.py
index 3698bd3dccf1ac2b59e57ab1d7f466af7103c8a3..fb7ad8cb6c019beb176296575d1c2e3343fcde53 100644
--- a/silkaj/blockchain_tools.py
+++ b/silkaj/blockchain_tools.py
@@ -1,3 +1,20 @@
+"""
+Copyright  2016-2019 Maël Azimi <m.a@moul.re>
+
+Silkaj is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Silkaj is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
+"""
+
 from silkaj.network_tools import get_request
 
 
diff --git a/silkaj/cert.py b/silkaj/cert.py
index 4023f7dfc83f21313355cb2fb73358c28b7b40db..32ea8b63f1d71d9f17ac47ac59f5e5bc588cdebe 100644
--- a/silkaj/cert.py
+++ b/silkaj/cert.py
@@ -1,3 +1,20 @@
+"""
+Copyright  2016-2019 Maël Azimi <m.a@moul.re>
+
+Silkaj is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Silkaj is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
+"""
+
 import urllib
 from time import time
 from tabulate import tabulate
diff --git a/silkaj/cli_tools.py b/silkaj/cli_tools.py
index d44367614c83f7d187a7931d56ba9ea7bcbb587a..6ebb7f62fe7f30572644347bc872bd77ba13a129 100644
--- a/silkaj/cli_tools.py
+++ b/silkaj/cli_tools.py
@@ -1,3 +1,20 @@
+"""
+Copyright  2016-2019 Maël Azimi <m.a@moul.re>
+
+Silkaj is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Silkaj is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
+"""
+
 # -*- coding: utf-8 -*-
 
 from sys import stderr
diff --git a/silkaj/commands.py b/silkaj/commands.py
index 74964896e67df288fbd8328aef7f8ed3112c0e03..b0af8e67fcbfa821f796b178c1d5f886d395c2c9 100644
--- a/silkaj/commands.py
+++ b/silkaj/commands.py
@@ -1,3 +1,20 @@
+"""
+Copyright  2016-2019 Maël Azimi <m.a@moul.re>
+
+Silkaj is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Silkaj is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
+"""
+
 from datetime import datetime
 from time import sleep
 from os import system, popen
diff --git a/silkaj/constants.py b/silkaj/constants.py
index b66e2b5fa78689ac71ee00d6bc303c08e616a535..3cf7e0892d4bed7e135755e9e7ddd398a450472f 100644
--- a/silkaj/constants.py
+++ b/silkaj/constants.py
@@ -1,3 +1,20 @@
+"""
+Copyright  2016-2019 Maël Azimi <m.a@moul.re>
+
+Silkaj is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Silkaj is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
+"""
+
 SILKAJ_VERSION = "silkaj 0.6.0"
 NO_MATCHING_ID = "No matching identity"
 G1_SYMBOL = "Äž1"
diff --git a/silkaj/crypto_tools.py b/silkaj/crypto_tools.py
index d9dad99134e7019dda64c2948096c0b44f466486..2951d94019aaaec12bfe2277c852952b718a9cb0 100644
--- a/silkaj/crypto_tools.py
+++ b/silkaj/crypto_tools.py
@@ -1,3 +1,20 @@
+"""
+Copyright  2016-2019 Maël Azimi <m.a@moul.re>
+
+Silkaj is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Silkaj is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
+"""
+
 from nacl import encoding, signing, hash, bindings
 from re import compile, search
 
diff --git a/silkaj/license.py b/silkaj/license.py
index cb0a19e792c97bfe4f7c56eec40cf84d3f00168f..55467fd85e930861a61816e4ac260b21fdb2c0ae 100644
--- a/silkaj/license.py
+++ b/silkaj/license.py
@@ -1,3 +1,20 @@
+"""
+Copyright  2016-2019 Maël Azimi <m.a@moul.re>
+
+Silkaj is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Silkaj is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
+"""
+
 import webbrowser
 from pydoc import pager
 from sys import exit
diff --git a/silkaj/money.py b/silkaj/money.py
index 5b33830d191a11e0febf38cb94d786c47c73c9fe..3fd2fe947c2c3df71950752322e83e93d76284d3 100644
--- a/silkaj/money.py
+++ b/silkaj/money.py
@@ -1,3 +1,20 @@
+"""
+Copyright  2016-2019 Maël Azimi <m.a@moul.re>
+
+Silkaj is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Silkaj is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
+"""
+
 from silkaj.network_tools import get_request, HeadBlock
 from silkaj.crypto_tools import get_publickey_from_seed
 from silkaj.tools import CurrencySymbol
diff --git a/silkaj/network_tools.py b/silkaj/network_tools.py
index 5b0c7f9be6e2ac6e023923f2f9cb15759870e998..938783dfb4a0c6725955d82a7bd005afffa60bf5 100644
--- a/silkaj/network_tools.py
+++ b/silkaj/network_tools.py
@@ -1,3 +1,20 @@
+"""
+Copyright  2016-2019 Maël Azimi <m.a@moul.re>
+
+Silkaj is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Silkaj is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
+"""
+
 from __future__ import unicode_literals
 from ipaddress import ip_address
 from json import loads
diff --git a/silkaj/tools.py b/silkaj/tools.py
index cf5f700a76d75bee0d81603c1ce89a0355069941..aa7355de79c845355dfc120383e6e2696b82ed3c 100644
--- a/silkaj/tools.py
+++ b/silkaj/tools.py
@@ -1,3 +1,20 @@
+"""
+Copyright  2016-2019 Maël Azimi <m.a@moul.re>
+
+Silkaj is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Silkaj is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
+"""
+
 from datetime import datetime
 from sys import exit
 
diff --git a/silkaj/tx.py b/silkaj/tx.py
index 5f14c006e5b3acdd929923c68285ee2b00a27c7c..e2f2338acb2b76a8fa7ecdb47845a8cd021704fe 100644
--- a/silkaj/tx.py
+++ b/silkaj/tx.py
@@ -1,3 +1,20 @@
+"""
+Copyright  2016-2019 Maël Azimi <m.a@moul.re>
+
+Silkaj is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Silkaj is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
+"""
+
 from re import compile, search
 import math
 from time import sleep
diff --git a/silkaj/wot.py b/silkaj/wot.py
index 5ca676955e9837d01d802470910e38cf7c1c8e6b..1ec6cff3f49edd28864872778bd6556adb281e62 100644
--- a/silkaj/wot.py
+++ b/silkaj/wot.py
@@ -1,3 +1,20 @@
+"""
+Copyright  2016-2019 Maël Azimi <m.a@moul.re>
+
+Silkaj is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Silkaj is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
+"""
+
 from time import time
 from tabulate import tabulate
 from collections import OrderedDict