diff --git a/blockchain/Cargo.toml b/blockchain/Cargo.toml
index 6e8074bf9956..202dc9a4de86 100644
--- a/blockchain/Cargo.toml
+++ b/blockchain/Cargo.toml
@@ -9,5 +9,6 @@ edition = "2018"
 [dependencies]
 vm = {path = "../vm"}
 address = {path = "../vm/address"}
+libp2p =  { git = "https://github.com/SigP/rust-libp2p", rev = "cdd5251d29e21a01aa2ffed8cb577a37a0f9e2eb" }
 cid = "0.3.1"
 multihash = "0.8.0"
\ No newline at end of file
diff --git a/blockchain/src/chain_sync/block_msg.rs b/blockchain/src/chain_sync/block_msg.rs
new file mode 100644
index 000000000000..ff8888b0b290
--- /dev/null
+++ b/blockchain/src/chain_sync/block_msg.rs
@@ -0,0 +1,39 @@
+use crate::blocks::TipSetKeys;
+use libp2p::PeerId;
+use std::fmt;
+
+/// BlockMsg is a container used to decode pubsub messages into prior to validation and propagation
+/// see https://github.com/filecoin-project/go-filecoin/blob/master/internal/pkg/block/chain_info.go for reference
+pub struct BlockMsg {
+    // the originator of the TipSetKey propagation wave
+    _source: PeerId,
+    // the peer that sent us the TipSetKey message
+    _sender: PeerId,
+    // proposed canonical tipset keys
+    _head: TipSetKeys,
+    // proposed chain height
+    _height: u64,
+}
+
+impl BlockMsg {
+    /// new creates a BlockMsg container for peer id a head tipset key and chain height
+    fn _new(_source: PeerId, _sender: PeerId, _head: TipSetKeys, _height: u64) -> Self {
+        Self {
+            _source,
+            _sender,
+            _head,
+            _height,
+        }
+    }
+}
+
+/// human-readable string representation of a block msg
+impl fmt::Display for BlockMsg {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            f,
+            "{} {} {:?} {}",
+            self._source, self._sender, self._head, self._height
+        )
+    }
+}
diff --git a/blockchain/src/chain_sync/block_proposer.rs b/blockchain/src/chain_sync/block_proposer.rs
index 712bca98a922..545db3418e61 100644
--- a/blockchain/src/chain_sync/block_proposer.rs
+++ b/blockchain/src/chain_sync/block_proposer.rs
@@ -1,7 +1,8 @@
+use super::BlockMsg;
 use std::io;
-
-trait BlockProposer {
-    fn send_hello(&self) -> Result<(), io::Error>;
-    // fn send_own_block(&self) -> Result<(), io:Error>;
-    // fn send_gossip_block(&self) -> Result<(), io:Error>;
+/// BlockProposer allows callers to propose new blocks for inclusion in the chain
+pub trait BlockProposer {
+    fn send_hello(&self, bm: BlockMsg) -> Result<(), io::Error>;
+    fn send_own_block(&self, bm: BlockMsg) -> Result<(), io::Error>;
+    fn send_gossip_block(&self, bm: BlockMsg) -> Result<(), io::Error>;
 }
diff --git a/blockchain/src/chain_sync/mod.rs b/blockchain/src/chain_sync/mod.rs
index a6763136cfcd..9f9e0ffc1fba 100644
--- a/blockchain/src/chain_sync/mod.rs
+++ b/blockchain/src/chain_sync/mod.rs
@@ -1 +1,4 @@
+mod block_msg;
 mod block_proposer;
+
+pub use block_msg::*;