diff --git a/src/main/java/com/mykola2312/retracker/tracker/AnnounceEvent.java b/src/main/java/com/mykola2312/retracker/tracker/AnnounceEvent.java
new file mode 100644
index 0000000..2fe3c91
--- /dev/null
+++ b/src/main/java/com/mykola2312/retracker/tracker/AnnounceEvent.java
@@ -0,0 +1,52 @@
+package com.mykola2312.retracker.tracker;
+
+public enum AnnounceEvent {
+	NONE(0),
+	STARTED(1),
+	STOPPED(2),
+	COMPLETED(3);
+	
+	private int value;
+	
+	AnnounceEvent() {
+		this.value = 0;
+	}
+	
+	AnnounceEvent(int value) {
+		this.value = value;
+	}
+	
+	public static AnnounceEvent fromString(String value) {
+		switch (value) {
+		case "none":		return AnnounceEvent.NONE;
+		case "started":		return AnnounceEvent.STARTED;
+		case "stopped":		return AnnounceEvent.STOPPED;
+		case "completed":	return AnnounceEvent.COMPLETED;
+		default:			return null;
+		}
+	}
+	
+	public static AnnounceEvent fromInteger(int value) {
+		switch (value) {
+		case 0:				return AnnounceEvent.NONE;
+		case 1:				return AnnounceEvent.STARTED;
+		case 2:				return AnnounceEvent.STOPPED;
+		case 3:				return AnnounceEvent.COMPLETED;
+		default:			return null;
+		}
+	}
+	
+	@Override
+	public String toString() {
+		switch (this) {
+		case STARTED:		return "started";
+		case STOPPED:		return "stopped";
+		case COMPLETED:		return "completed";
+		default:			return null;
+		}
+	}
+	
+	public int toInteger() {
+		return this.value;
+	}
+}
diff --git a/src/main/java/com/mykola2312/retracker/tracker/Peer.java b/src/main/java/com/mykola2312/retracker/tracker/Peer.java
new file mode 100644
index 0000000..302ca80
--- /dev/null
+++ b/src/main/java/com/mykola2312/retracker/tracker/Peer.java
@@ -0,0 +1,8 @@
+package com.mykola2312.retracker.tracker;
+
+import java.net.InetSocketAddress;
+
+public class Peer {
+	private PeerType type;
+	private InetSocketAddress address;
+}
diff --git a/src/main/java/com/mykola2312/retracker/tracker/PeerLocalData.java b/src/main/java/com/mykola2312/retracker/tracker/PeerLocalData.java
new file mode 100644
index 0000000..209771c
--- /dev/null
+++ b/src/main/java/com/mykola2312/retracker/tracker/PeerLocalData.java
@@ -0,0 +1,12 @@
+package com.mykola2312.retracker.tracker;
+
+/* This data is available only from local announces,
+ * It shall be used for re-announces
+ */
+public class PeerLocalData {
+	private long downloaded = 0;	// 8 bytes integer
+	private long left = 0;			// 8 bytes integer
+	private long uploaded = 0;		// 8 bytes integer
+	private int event = 0;			// 4 bytes integer, enum
+	private long key = 0;			// 4 bytes integer
+}
diff --git a/src/main/java/com/mykola2312/retracker/tracker/PeerType.java b/src/main/java/com/mykola2312/retracker/tracker/PeerType.java
new file mode 100644
index 0000000..f4bcdaf
--- /dev/null
+++ b/src/main/java/com/mykola2312/retracker/tracker/PeerType.java
@@ -0,0 +1,6 @@
+package com.mykola2312.retracker.tracker;
+
+public enum PeerType {
+	LOCAL,
+	REMOTE
+}
diff --git a/src/test/java/com/mykola2312/retracker/tracker/AnnounceEventTest.java b/src/test/java/com/mykola2312/retracker/tracker/AnnounceEventTest.java
new file mode 100644
index 0000000..9db7819
--- /dev/null
+++ b/src/test/java/com/mykola2312/retracker/tracker/AnnounceEventTest.java
@@ -0,0 +1,19 @@
+package com.mykola2312.retracker.tracker;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class AnnounceEventTest {
+	@Test
+	public void testEventEqual() {
+		assertEquals(AnnounceEvent.NONE, AnnounceEvent.NONE);
+		assertEquals(AnnounceEvent.STARTED, AnnounceEvent.STARTED);
+	}
+	
+	@Test
+	public void testEventNotEqual() {
+		assertNotEquals(AnnounceEvent.STOPPED, AnnounceEvent.STARTED);
+	}
+}