diff --git a/.activate b/.activate
new file mode 100644
index 0000000..a3607ff
--- /dev/null
+++ b/.activate
@@ -0,0 +1,7 @@
+
+alias venv='source .venv/Scripts/activate'
+alias check='flake8 vpn_manager'
+alias format='black vpn_manager'
+alias test='pytest'
+
+venv
diff --git a/pyproject.toml b/pyproject.toml
index 3552b50..7f0a731 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -21,8 +21,12 @@ authors = [
 test = ["pytest"]
 lint = [
   "black",
-  "flake8"
+  "flake8",
+  "Flake8-pyproject"
 ]
 
 [project.scripts]
 example = "vpn_manager.__main__:main"
+
+[tool.flake8]
+ignore = ["E501"]
diff --git a/tests/test_app.py b/tests/test_app.py
index 725f245..4918262 100644
--- a/tests/test_app.py
+++ b/tests/test_app.py
@@ -1,3 +1,18 @@
+from vpn_manager.peers import *
+
+def test_format_static_peer():
+    sp = Peer('PUB', "PRV", '10.0.0.1/32', '12345', '127.0.0.1')
+    peer_section = format_static_peer(sp, '0.0.0.0/0')
+    assert peer_section == '[Peer]\nPublicKey = PUB\nAllowedIPs = 0.0.0.0/0\nEndpoint = 127.0.0.1:12345\nPersistentKeepAlive = 30'
+
+
 def test_true():
-    assert True
-    
\ No newline at end of file
+    assert format_interface(Peer('PUB', 'PRV', '10.0.0.1/32', 'PORT'), '1.1.1.1') \
+        == '[Interface]\nPrivateKey = PRV\nAddress = 10.0.0.1/32\nListenPort = PORT\nDNS = 1.1.1.1'
+    assert format_interface(Peer('PUB', 'PRV', '10.0.0.1/32', None), '1.1.1.1') \
+        == '[Interface]\nPrivateKey = PRV\nAddress = 10.0.0.1/32\nDNS = 1.1.1.1'
+    assert format_interface(Peer('PUB', 'PRV', '10.0.0.1/32', 'PORT'), '1.1.1.1', forward=True) \
+        == '[Interface]\nPrivateKey = PRV\nAddress = 10.0.0.1/32\nListenPort = PORT\nDNS = 1.1.1.1\nPostUp = iptables -A FORWARD -i wg0 -j ACCEPT; iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE\nPostDown = iptables -D FORWARD -i wg0 -j ACCEPT; iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE'
+    assert format_interface(Peer('PUB', 'PRV', '10.0.0.1/32', None), '1.1.1.1', forward=True) \
+        == '[Interface]\nPrivateKey = PRV\nAddress = 10.0.0.1/32\nDNS = 1.1.1.1\nPostUp = iptables -A FORWARD -i wg0 -j ACCEPT; iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE\nPostDown = iptables -D FORWARD -i wg0 -j ACCEPT; iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE'
+
diff --git a/vpn_manager/__init__.py b/vpn_manager/__init__.py
index e69de29..a03af42 100644
--- a/vpn_manager/__init__.py
+++ b/vpn_manager/__init__.py
@@ -0,0 +1,3 @@
+from . import peers
+
+__all__ = ["peers"]
diff --git a/vpn_manager/peers.py b/vpn_manager/peers.py
new file mode 100644
index 0000000..cfd2d9c
--- /dev/null
+++ b/vpn_manager/peers.py
@@ -0,0 +1,45 @@
+from dataclasses import dataclass
+
+
+@dataclass
+class Peer:
+    public_key: str
+    private_key: str
+    address_cidr: str
+    port: str
+    endpoint: str = None
+
+
+def format_static_peer(static_peer: Peer, routes, keepalive=30):
+    return (
+        "[Peer]\n"
+        f"PublicKey = {static_peer.public_key}\n"
+        f"AllowedIPs = {routes}\n"
+        f"Endpoint = {static_peer.endpoint}:{static_peer.port}\n"
+        f"PersistentKeepAlive = {keepalive}\n"
+    ).strip()
+
+
+def format_interface(peer: Peer, dns, forward=False):
+    if forward:
+        forward = (
+            "PostUp = iptables -A FORWARD -i wg0 -j ACCEPT; iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE\n"
+            "PostDown = iptables -D FORWARD -i wg0 -j ACCEPT; iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE\n"
+        )
+        # wg0 always?
+        # eth0 always?
+    else:
+        forward = ""
+    if peer.port:
+        port = f"ListenPort = {peer.port}\n"
+    else:
+        port = ""
+    dns = f"DNS = {dns}\n"
+    return (
+        "[Interface]\n"
+        f"PrivateKey = {peer.private_key}\n"
+        f"Address = {peer.address_cidr}\n"
+        f"{port}"
+        f"{dns}"
+        f"{forward}"
+    ).strip()