diff --git a/peer/README.md b/peer/README.md
new file mode 100644
index 0000000..8a4ba3f
--- /dev/null
+++ b/peer/README.md
@@ -0,0 +1,3 @@
+# PeerStore
+
+The PeerStore contains a mapping of peer IDs to PeerData objects. Each PeerData object represents a peer, and each PeerData contains a collection of protocols, addresses, and a mapping of metadata. PeerStore implements the IPeerStore (peer protocols), IAddrBook (address book), and IPeerMetadata (peer metadata) interfaces, which allows the peer store to effectively function as a dictionary for peer ID to protocol, address, and metadata. 
diff --git a/peer/addrbook_interface.py b/peer/addrbook_interface.py
new file mode 100644
index 0000000..c27bd67
--- /dev/null
+++ b/peer/addrbook_interface.py
@@ -0,0 +1,52 @@
+from abc import ABC, abstractmethod
+
+class IAddrBook(ABC):
+
+    def __init__(self, context):
+        self.context = context
+
+    @abstractmethod
+    def add_addr(self, peer_id, addr, ttl):
+        """
+        Calls add_addrs(peer_id, [addr], ttl)
+        :param peer_id: the peer to add address for
+        :param addr: multiaddress of the peer
+        :param ttl: time-to-live for the address (after this time, address is no longer valid)
+        """
+        pass
+
+    @abstractmethod
+    def add_addrs(self, peer_id, addrs, ttl):
+        """
+        Adds addresses for a given peer all with the same time-to-live. If one of the
+        addresses already exists for the peer and has a longer TTL, no operation should take place.
+        If one of the addresses exists with a shorter TTL, extend the TTL to equal param ttl.
+        :param peer_id: the peer to add address for
+        :param addr: multiaddresses of the peer
+        :param ttl: time-to-live for the address (after this time, address is no longer valid
+        """
+        pass
+
+    @abstractmethod
+    def addrs(self, peer_id):
+        """
+        :param peer_id: peer to get addresses of
+        :return: all known (and valid) addresses for the given peer
+        """
+        pass
+
+    @abstractmethod
+    def clear_addrs(self, peer_id):
+        """
+        Removes all previously stored addresses
+        :param peer_id: peer to remove addresses of
+        """
+        pass
+
+    @abstractmethod
+    def peers_with_addrs(self):
+        """
+        :return: all of the peer IDs stored with addresses
+        """
+        pass
+        
\ No newline at end of file
diff --git a/peer/peer.py b/peer/peer.py
deleted file mode 100644
index e69de29..0000000
diff --git a/peer/peerdata.py b/peer/peerdata.py
new file mode 100644
index 0000000..d1bcf6f
--- /dev/null
+++ b/peer/peerdata.py
@@ -0,0 +1,31 @@
+from .peerdata_interface import IPeerData
+
+class PeerData(IPeerData):
+
+    def __init__(self):
+        self.metadata = {}
+        self.protocols = []
+        self.addrs = []
+
+    def get_protocols(self):
+        return self.protocols
+
+    def add_protocols(self, protocols):
+        self.protocols.extend(protocols)
+
+    def add_addrs(self, addrs):
+        self.addrs.extend(addrs)
+
+    def get_addrs(self):
+        return self.addrs
+
+    def clear_addrs(self):
+        self.addrs = []
+
+    def put_metadata(self, key, val):
+        self.metadata[key] = val
+
+    def get_metadata(self, key):
+        if key in self.metadata:
+            return self.metadata[key], None
+        return None, "key not found"
diff --git a/peer/peerdata_interface.py b/peer/peerdata_interface.py
new file mode 100644
index 0000000..f7e8b5d
--- /dev/null
+++ b/peer/peerdata_interface.py
@@ -0,0 +1,47 @@
+from abc import ABC, abstractmethod
+
+class IPeerData(ABC):
+
+    """
+    :return: all protocols associated with given peer
+    """
+    def get_protocols(self):
+        pass
+
+    """
+    :param protocols: protocols to add
+    """
+    def add_protocols(self, protocols):
+        pass
+
+    """
+    :param addrs: multiaddresses to add
+    """
+    def add_addrs(self, addrs):
+        pass
+
+    """
+    :return: all multiaddresses
+    """
+    def get_addrs(self):
+        pass
+
+    """
+    Clear all addresses
+    """
+    def clear_addrs(self):
+        pass
+
+    """
+    :param key: key in KV pair
+    :param val: val to associate with key
+    """
+    def put_metadata(self, key, val):
+        pass
+
+    """
+    :param key: key in KV pair
+    :return: val for key, error (only defined if key not found)
+    """
+    def get_metadata(self, key):
+        pass
diff --git a/peer/peermetadata_interface.py b/peer/peermetadata_interface.py
new file mode 100644
index 0000000..6fda82f
--- /dev/null
+++ b/peer/peermetadata_interface.py
@@ -0,0 +1,26 @@
+from abc import ABC, abstractmethod
+
+class IPeerMetadata(ABC):
+
+    def __init__(self, context):
+        self.context = context
+
+    @abstractmethod
+    def get(self, peer_id, key):
+        """
+        :param peer_id: peer ID to lookup key for
+        :param key: key to look up
+        :return: value at key for given peer, error
+        """
+        pass
+
+    @abstractmethod
+    def put(self, peer_id, key, val):
+        """
+        :param peer_id: peer ID to lookup key for
+        :param key: key to associate with peer
+        :param val: value to associated with key
+        :return: error
+        """
+        pass
+        
\ No newline at end of file
diff --git a/peer/peerstore.py b/peer/peerstore.py
index e69de29..3922b7f 100644
--- a/peer/peerstore.py
+++ b/peer/peerstore.py
@@ -0,0 +1,82 @@
+from .peerstore_interface import IPeerStore
+from .peerdata import PeerData
+
+class PeerStore(IPeerStore):
+
+    def __init__(self, context):
+        IPeerStore.__init__(self, context)
+        self.peer_map = {}
+
+    def __create_or_get_peer(self, peer_id):
+        """
+        Returns the peer data for peer_id or creates a new
+        peer data (and stores it in peer_map) if peer
+        data for peer_id does not yet exist
+        :param peer_id: peer ID
+        :return: peer data
+        """
+        if peer_id in self.peer_map:
+            return self.peer_map[peer_id]
+        data = PeerData()
+        self.peer_map[peer_id] = data
+        return self.peer_map[peer_id]
+
+    def peer_info(self, peer_id):
+        if peer_id in self.peer_map:
+            peer = self.peer_map[peer_id]
+            return {
+                "peer_id": peer_id,
+                "addrs": peer.get_addrs()
+            }
+        return None
+
+    def get_protocols(self, peer_id):
+        if peer_id in self.peer_map:
+            return self.peer_map[peer_id].get_protocols(), None
+        return None, peer_id + " not found"
+
+    def add_protocols(self, peer_id, protocols):
+        peer = self.__create_or_get_peer(peer_id)
+        peer.add_protocols(protocols)
+
+    def peers(self):
+        return self.peer_map.keys()
+
+    def get(self, peer_id, key):
+        if peer_id in self.peer_map:
+            val, error = self.peer_map[peer_id].get_metadata(key)
+            return val, error
+        return None, peer_id + " not found"
+
+    def put(self, peer_id, key, val):
+        # <<?>>
+        # This can output an error, not sure what the possible errors are
+        peer = self.__create_or_get_peer(peer_id)
+        peer.put_metadata(key, val)
+
+    def add_addr(self, peer_id, addr, ttl):
+        self.add_addrs(self, peer_id, [addr])
+
+    def add_addrs(self, peer_id, addrs, ttl):
+        # Ignore ttl for now
+        peer = self.__create_or_get_peer(peer_id)
+        peer.add_addrs(addrs)
+
+    def addrs(self, peer_id):
+        if peer_id in self.peer_map:
+            return self.peer_map[peer_id].get_addrs(), None
+        return None, peer_id + " not found"
+
+    def clear_addrs(self, peer_id):
+        # Only clear addresses if the peer is in peer map
+        if peer_id in self.peer_map:
+            self.peer_map[peer_id].clear_addrs()
+
+    def peers_with_addrs(self):
+        # Add all peers with addrs at least 1 to output
+        output = []
+
+        for key in self.peer_map:
+            if len(self.peer_map[key].get_addrs()) >= 1:
+                output.append(key)
+        return output
diff --git a/peer/peerstore_interface.py b/peer/peerstore_interface.py
new file mode 100644
index 0000000..67f75c1
--- /dev/null
+++ b/peer/peerstore_interface.py
@@ -0,0 +1,50 @@
+from abc import ABC, abstractmethod
+from .addrbook_interface import IAddrBook
+from .peermetadata_interface import IPeerMetadata
+
+class IPeerStore(ABC, IAddrBook, IPeerMetadata):
+
+    def __init__(self, context):
+        IPeerMetadata.__init__(self, context)
+        IAddrBook.__init__(self, context)
+
+    @abstractmethod
+    def peer_info(self, peer_id):
+        """
+        :param peer_id: peer ID to get info for
+        :return: peer info object
+        """
+        pass
+
+    @abstractmethod
+    def get_protocols(self, peer_id):
+        """
+        :param peer_id: peer ID to get protocols for
+        :return: protocols (as strings), error
+        """
+        pass
+
+    @abstractmethod
+    def add_protocols(self, peer_id, protocols):
+        """
+        :param peer_id: peer ID to add protocols for
+        :param protocols: protocols to add
+        :return: error
+        """
+        pass
+
+    @abstractmethod
+    def set_protocols(self, peer_id, protocols):
+        """
+        :param peer_id: peer ID to set protocols for
+        :param protocols: protocols to set
+        :return: error
+        """
+        pass
+
+    @abstractmethod
+    def peers(self):
+        """
+        :return: all of the peer IDs stored in peer store
+        """
+        pass