diff --git a/libp2p/host/basic_host.py b/libp2p/host/basic_host.py
index e4a54cf..99ee832 100644
--- a/libp2p/host/basic_host.py
+++ b/libp2p/host/basic_host.py
@@ -1,17 +1,17 @@
 from typing import (
     Any,
+    Awaitable,
     Callable,
-    Coroutine,
     List,
     Sequence,
 )
 
 import multiaddr
 
-from libp2p.network.swarm import Swarm
+from libp2p.network.network_interface import INetwork
 from libp2p.peer.id import ID
 from libp2p.peer.peerinfo import PeerInfo
-from libp2p.peer.peerstore import PeerStore
+from libp2p.peer.peerstore_interface import IPeerStore
 
 from libp2p.network.stream.net_stream_interface import INetStream
 from libp2p.routing.kademlia.kademlia_peer_router import KadmeliaPeerRouter
@@ -24,17 +24,17 @@ from .host_interface import IHost
 # telling it to listen on the given listen addresses.
 
 
-StreamHandlerFn = Callable[[INetStream], Coroutine[Any, Any, None]]
+StreamHandlerFn = Callable[[INetStream], Awaitable[None]]
 
 
 class BasicHost(IHost):
 
-    _network: Swarm
+    _network: INetwork
     router: KadmeliaPeerRouter
-    peerstore: PeerStore
+    peerstore: IPeerStore
 
     # default options constructor
-    def __init__(self, network: Swarm, router: KadmeliaPeerRouter = None) -> None:
+    def __init__(self, network: INetwork, router: KadmeliaPeerRouter = None) -> None:
         self._network = network
         self._router = router
         self.peerstore = self._network.peerstore
@@ -45,13 +45,13 @@ class BasicHost(IHost):
         """
         return self._network.get_peer_id()
 
-    def get_network(self) -> Swarm:
+    def get_network(self) -> INetwork:
         """
         :return: network instance of host
         """
         return self._network
 
-    def get_peerstore(self) -> PeerStore:
+    def get_peerstore(self) -> IPeerStore:
         """
         :return: peerstore of the host (same one as in its network instance)
         """
diff --git a/libp2p/host/host_interface.py b/libp2p/host/host_interface.py
index bf4fe5f..1607d0f 100644
--- a/libp2p/host/host_interface.py
+++ b/libp2p/host/host_interface.py
@@ -1,22 +1,22 @@
 from abc import ABC, abstractmethod
 from typing import (
     Any,
+    Awaitable,
     Callable,
-    Coroutine,
     List,
     Sequence,
 )
 
 import multiaddr
 
-from libp2p.network.swarm import Swarm
+from libp2p.network.network_interface import INetwork
 from libp2p.peer.id import ID
 from libp2p.peer.peerinfo import PeerInfo
 
 from libp2p.network.stream.net_stream_interface import INetStream
 
 
-StreamHandlerFn = Callable[[INetStream], Coroutine[Any, Any, None]]
+StreamHandlerFn = Callable[[INetStream], Awaitable[None]]
 
 
 class IHost(ABC):
@@ -28,7 +28,7 @@ class IHost(ABC):
         """
 
     @abstractmethod
-    def get_network(self) -> Swarm:
+    def get_network(self) -> INetwork:
         """
         :return: network instance of host
         """
@@ -58,9 +58,9 @@ class IHost(ABC):
     # protocol_id can be a list of protocol_ids
     # stream will decide which protocol_id to run on
     @abstractmethod
-    def new_stream(self,
+    async def new_stream(self,
                    peer_id: ID,
-                   protocol_ids: Sequence[str]) -> Coroutine[Any, Any, INetStream]:
+                   protocol_ids: Sequence[str]) -> INetStream:
         """
         :param peer_id: peer_id that host is connecting
         :param protocol_ids: protocol ids that stream can run on
@@ -68,7 +68,7 @@ class IHost(ABC):
         """
 
     @abstractmethod
-    def connect(self, peer_info: PeerInfo) -> Coroutine[Any, Any, None]:
+    async def connect(self, peer_info: PeerInfo) -> None:
         """
         connect ensures there is a connection between this host and the peer with
         given peer_info.peer_id. connect will absorb the addresses in peer_info into its internal
diff --git a/libp2p/network/network_interface.py b/libp2p/network/network_interface.py
index 0a4a8eb..fc1694a 100644
--- a/libp2p/network/network_interface.py
+++ b/libp2p/network/network_interface.py
@@ -4,8 +4,9 @@ from abc import (
 )
 from typing import (
     Any,
+    Awaitable,
     Callable,
-    Coroutine,
+    Dict,
     Sequence,
     TYPE_CHECKING,
 )
@@ -13,19 +14,25 @@ from typing import (
 from multiaddr import Multiaddr
 
 from libp2p.peer.id import ID
+from libp2p.peer.peerstore import PeerStore
 from libp2p.stream_muxer.muxed_connection_interface import IMuxedConn
+from libp2p.transport.listener_interface import IListener
 
-from .stream.net_stream import NetStream
+from .stream.net_stream_interface import INetStream
 
 if TYPE_CHECKING:
     from .notifee_interface import INotifee
 
 
-StreamHandlerFn = Callable[[NetStream], Coroutine[Any, Any, None]]
+StreamHandlerFn = Callable[[INetStream], Awaitable[None]]
 
 
 class INetwork(ABC):
 
+    peerstore: PeerStore
+    connections: Dict[ID, IMuxedConn]
+    listeners: Dict[str, IListener]
+
     @abstractmethod
     def get_peer_id(self) -> ID:
         """
@@ -33,7 +40,7 @@ class INetwork(ABC):
         """
 
     @abstractmethod
-    def dial_peer(self, peer_id: ID) -> Coroutine[Any, Any, IMuxedConn]:
+    async def dial_peer(self, peer_id: ID) -> IMuxedConn:
         """
         dial_peer try to create a connection to peer_id
 
@@ -51,9 +58,9 @@ class INetwork(ABC):
         """
 
     @abstractmethod
-    def new_stream(self,
+    async def new_stream(self,
                    peer_id: ID,
-                   protocol_ids: Sequence[str]) -> Coroutine[Any, Any, NetStream]:
+                   protocol_ids: Sequence[str]) -> INetStream:
         """
         :param peer_id: peer_id of destination
         :param protocol_ids: available protocol ids to use for stream
@@ -61,7 +68,7 @@ class INetwork(ABC):
         """
 
     @abstractmethod
-    def listen(self, *args: Multiaddr) -> Coroutine[Any, Any, bool]:
+    async def listen(self, *args: Multiaddr) -> bool:
         """
         :param *args: one or many multiaddrs to start listening on
         :return: True if at least one success
diff --git a/libp2p/network/stream/net_stream.py b/libp2p/network/stream/net_stream.py
index 237ad73..8ebe791 100644
--- a/libp2p/network/stream/net_stream.py
+++ b/libp2p/network/stream/net_stream.py
@@ -1,16 +1,16 @@
-from libp2p.stream_muxer.mplex.mplex import Mplex
-from libp2p.stream_muxer.mplex.mplex_stream import MplexStream
+from libp2p.stream_muxer.muxed_connection_interface import IMuxedConn
+from libp2p.stream_muxer.muxed_stream_interface import IMuxedStream
 
 from .net_stream_interface import INetStream
 
 
 class NetStream(INetStream):
 
-    muxed_stream: MplexStream
-    mplex_conn: Mplex
+    muxed_stream: IMuxedStream
+    mplex_conn: IMuxedConn
     protocol_id: str
 
-    def __init__(self, muxed_stream: MplexStream) -> None:
+    def __init__(self, muxed_stream: IMuxedStream) -> None:
         self.muxed_stream = muxed_stream
         self.mplex_conn = muxed_stream.mplex_conn
         self.protocol_id = None
diff --git a/libp2p/network/stream/net_stream_interface.py b/libp2p/network/stream/net_stream_interface.py
index 30d7ac7..31c0080 100644
--- a/libp2p/network/stream/net_stream_interface.py
+++ b/libp2p/network/stream/net_stream_interface.py
@@ -1,15 +1,14 @@
 from abc import ABC, abstractmethod
 from typing import (
     Any,
-    Coroutine,
 )
 
-from libp2p.stream_muxer.mplex.mplex import Mplex
+from libp2p.stream_muxer.muxed_connection_interface import IMuxedConn
 
 
 class INetStream(ABC):
 
-    mplex_conn: Mplex
+    mplex_conn: IMuxedConn
 
     @abstractmethod
     def get_protocol(self) -> str:
@@ -25,21 +24,21 @@ class INetStream(ABC):
         """
 
     @abstractmethod
-    def read(self) -> Coroutine[Any, Any, bytes]:
+    async def read(self) -> bytes:
         """
         reads from the underlying muxed_stream
         :return: bytes of input
         """
 
     @abstractmethod
-    def write(self, data: bytes) -> Coroutine[Any, Any, int]:
+    async def write(self, data: bytes) -> int:
         """
         write to the underlying muxed_stream
         :return: number of bytes written
         """
 
     @abstractmethod
-    def close(self) -> Coroutine[Any, Any, bool]:
+    async def close(self) -> bool:
         """
         close the underlying muxed stream
         :return: true if successful
diff --git a/libp2p/network/swarm.py b/libp2p/network/swarm.py
index 68b1892..0038360 100644
--- a/libp2p/network/swarm.py
+++ b/libp2p/network/swarm.py
@@ -1,8 +1,8 @@
 import asyncio
 from typing import (
     Any,
+    Awaitable,
     Callable,
-    Coroutine,
     Dict,
     List,
     Sequence,
@@ -18,10 +18,10 @@ from libp2p.peer.peerstore import PeerStore
 from libp2p.protocol_muxer.multiselect import Multiselect
 from libp2p.protocol_muxer.multiselect_client import MultiselectClient
 from libp2p.routing.interfaces import IPeerRouting
+from libp2p.stream_muxer.muxed_connection_interface import IMuxedConn
 from libp2p.transport.upgrader import TransportUpgrader
 from libp2p.transport.transport_interface import ITransport
 from libp2p.transport.listener_interface import IListener
-from libp2p.stream_muxer.muxed_connection_interface import IMuxedConn
 
 from libp2p.stream_muxer.mplex.mplex_stream import MplexStream
 
@@ -29,9 +29,10 @@ from .network_interface import INetwork
 from .notifee_interface import INotifee
 from .connection.raw_connection import RawConnection
 from .stream.net_stream import NetStream
+from .stream.net_stream_interface import INetStream
 
 
-StreamHandlerFn = Callable[[NetStream], Coroutine[Any, Any, None]]
+StreamHandlerFn = Callable[[INetStream], Awaitable[None]]
 
 
 class Swarm(INetwork):
@@ -44,7 +45,7 @@ class Swarm(INetwork):
     router: IPeerRouting
     connections: Dict[ID, IMuxedConn]
     listeners: Dict[str, IListener]
-    stream_handlers: Dict[NetStream, Callable[[NetStream], None]]
+    stream_handlers: Dict[INetStream, Callable[[INetStream], None]]
 
     multiselect: Multiselect
     multiselect_client: MultiselectClient
@@ -252,7 +253,7 @@ class Swarm(INetwork):
     # TODO: `disconnect`?
 
 
-GenericProtocolHandlerFn = Callable[[MplexStream], Coroutine[Any, Any, None]]
+GenericProtocolHandlerFn = Callable[[MplexStream], Awaitable[None]]
 
 
 def create_generic_protocol_handler(swarm: Swarm) -> GenericProtocolHandlerFn:
diff --git a/libp2p/peer/peerdata.py b/libp2p/peer/peerdata.py
index 696e736..bb4962b 100644
--- a/libp2p/peer/peerdata.py
+++ b/libp2p/peer/peerdata.py
@@ -39,10 +39,10 @@ class PeerData(IPeerData):
     def clear_addrs(self) -> None:
         self.addrs = []
 
-    def put_metadata(self, key: Any, val: Any) -> None:
+    def put_metadata(self, key: str, val: Any) -> None:
         self.metadata[key] = val
 
-    def get_metadata(self, key: Any) -> Any:
+    def get_metadata(self, key: str) -> Any:
         if key in self.metadata:
             return self.metadata[key]
         raise PeerDataError("key not found")
diff --git a/libp2p/peer/peerdata_interface.py b/libp2p/peer/peerdata_interface.py
index e2f150e..cefd56d 100644
--- a/libp2p/peer/peerdata_interface.py
+++ b/libp2p/peer/peerdata_interface.py
@@ -7,6 +7,8 @@ from typing import (
 
 from multiaddr import Multiaddr
 
+from .peermetadata_interface import IPeerMetadata
+
 
 class IPeerData(ABC):
 
@@ -47,7 +49,7 @@ class IPeerData(ABC):
         """
 
     @abstractmethod
-    def put_metadata(self, key: Any, val: Any) -> None:
+    def put_metadata(self, key: str, val: Any) -> None:
         """
         :param key: key in KV pair
         :param val: val to associate with key
@@ -55,7 +57,7 @@ class IPeerData(ABC):
         """
 
     @abstractmethod
-    def get_metadata(self, key: Any) -> Any:
+    def get_metadata(self, key: str) -> IPeerMetadata:
         """
         :param key: key in KV pair
         :return: val for key
diff --git a/libp2p/peer/peermetadata_interface.py b/libp2p/peer/peermetadata_interface.py
index 6fcf8de..3d60259 100644
--- a/libp2p/peer/peermetadata_interface.py
+++ b/libp2p/peer/peermetadata_interface.py
@@ -14,7 +14,7 @@ class IPeerMetadata(ABC):
         pass
 
     @abstractmethod
-    def get(self, peer_id: ID, key: Any) -> Any:
+    def get(self, peer_id: ID, key: str) -> Any:
         """
         :param peer_id: peer ID to lookup key for
         :param key: key to look up
@@ -23,7 +23,7 @@ class IPeerMetadata(ABC):
         """
 
     @abstractmethod
-    def put(self, peer_id: ID, key: Any, val: Any) -> None:
+    def put(self, peer_id: ID, key: str, val: Any) -> None:
         """
         :param peer_id: peer ID to lookup key for
         :param key: key to associate with peer
diff --git a/libp2p/peer/peerstore.py b/libp2p/peer/peerstore.py
index 3a59495..2cd1574 100644
--- a/libp2p/peer/peerstore.py
+++ b/libp2p/peer/peerstore.py
@@ -58,13 +58,13 @@ class PeerStore(IPeerStore):
     def peer_ids(self) -> List[ID]:
         return list(self.peer_map.keys())
 
-    def get(self, peer_id: ID, key: Any) -> Any:
+    def get(self, peer_id: ID, key: str) -> Any:
         if peer_id in self.peer_map:
             val = self.peer_map[peer_id].get_metadata(key)
             return val
         raise PeerStoreError("peer ID not found")
 
-    def put(self, peer_id: ID, key: Any, val: Any) -> None:
+    def put(self, peer_id: ID, key: str, val: Any) -> None:
         # <<?>>
         # This can output an error, not sure what the possible errors are
         peer = self.__create_or_get_peer(peer_id)
diff --git a/libp2p/pubsub/pubsub.py b/libp2p/pubsub/pubsub.py
index 5e86015..ddfa59c 100644
--- a/libp2p/pubsub/pubsub.py
+++ b/libp2p/pubsub/pubsub.py
@@ -306,8 +306,7 @@ class Pubsub:
         # Tell router we are leaving this topic
         await self.router.leave(topic_id)
 
-    # FIXME: `raw_msg` can be further type hinted with mypy_protobuf
-    async def message_all_peers(self, raw_msg: Any) -> None:
+    async def message_all_peers(self, raw_msg: bytes) -> None:
         """
         Broadcast a message to peers
         :param raw_msg: raw contents of the message to broadcast
diff --git a/libp2p/routing/interfaces.py b/libp2p/routing/interfaces.py
index de2ec7a..e656215 100644
--- a/libp2p/routing/interfaces.py
+++ b/libp2p/routing/interfaces.py
@@ -1,7 +1,6 @@
 from abc import ABC, abstractmethod
 from typing import (
     Any,
-    Coroutine,
     Iterable,
 )
 
@@ -31,7 +30,7 @@ class IContentRouting(ABC):
 class IPeerRouting(ABC):
 
     @abstractmethod
-    def find_peer(self, peer_id: ID) -> Coroutine[Any, Any, PeerInfo]:
+    async def find_peer(self, peer_id: ID) -> PeerInfo:
         """
         Find specific Peer
         FindPeer searches for a peer with given peer_id, returns a peer.PeerInfo
diff --git a/libp2p/routing/kademlia/kademlia_peer_router.py b/libp2p/routing/kademlia/kademlia_peer_router.py
index 5e426fe..e50ec84 100644
--- a/libp2p/routing/kademlia/kademlia_peer_router.py
+++ b/libp2p/routing/kademlia/kademlia_peer_router.py
@@ -9,6 +9,7 @@ from libp2p.kademlia.kad_peerinfo import (
 )
 from libp2p.kademlia.network import KademliaServer
 from libp2p.peer.id import ID
+from libp2p.peer.peerinfo import PeerInfo
 from libp2p.routing.interfaces import IPeerRouting
 
 
diff --git a/libp2p/stream_muxer/mplex/mplex_stream.py b/libp2p/stream_muxer/mplex/mplex_stream.py
index 3fd6961..08b30d5 100644
--- a/libp2p/stream_muxer/mplex/mplex_stream.py
+++ b/libp2p/stream_muxer/mplex/mplex_stream.py
@@ -1,7 +1,8 @@
 import asyncio
 
+from libp2p.stream_muxer.muxed_stream_interface import IMuxedStream
+
 from .utils import get_flag
-from ..muxed_stream_interface import IMuxedStream
 
 
 class MplexStream(IMuxedStream):
diff --git a/libp2p/stream_muxer/muxed_stream_interface.py b/libp2p/stream_muxer/muxed_stream_interface.py
index b15dba1..b9034ce 100644
--- a/libp2p/stream_muxer/muxed_stream_interface.py
+++ b/libp2p/stream_muxer/muxed_stream_interface.py
@@ -1,8 +1,12 @@
 from abc import ABC, abstractmethod
 
+from libp2p.stream_muxer.mplex.mplex import Mplex
+
 
 class IMuxedStream(ABC):
 
+    mplex_conn: Mplex
+
     @abstractmethod
     def read(self):
         """