diff --git a/backend/Cargo.lock b/backend/Cargo.lock
index db29d1c..4d1fffd 100644
--- a/backend/Cargo.lock
+++ b/backend/Cargo.lock
@@ -1658,6 +1658,7 @@ dependencies = [
  "clap",
  "common",
  "log",
+ "primitive-types",
  "rustc-hash",
  "serde",
  "serde_json",
diff --git a/backend/common/src/util/hash.rs b/backend/common/src/json/hash.rs
similarity index 96%
rename from backend/common/src/util/hash.rs
rename to backend/common/src/json/hash.rs
index 23b10be..01fbe1e 100644
--- a/backend/common/src/util/hash.rs
+++ b/backend/common/src/json/hash.rs
@@ -8,10 +8,16 @@ use serde::de::{self, Deserialize, Deserializer, Unexpected, Visitor, SeqAccess}
 const HASH_BYTES: usize = 32;
 
 /// Newtype wrapper for 32-byte hash values, implementing readable `Debug` and `serde::Deserialize`.
-// We could use primitive_types::H256 here, but opted for a custom type to avoid more dependencies.
+/// This can deserialize from a JSON string or array.
 #[derive(Hash, PartialEq, Eq, Clone, Copy)]
 pub struct Hash([u8; HASH_BYTES]);
 
+impl From<Hash> for crate::types::BlockHash {
+    fn from(hash: Hash) -> Self {
+        hash.0.into()
+    }
+}
+
 struct HashVisitor;
 
 impl<'de> Visitor<'de> for HashVisitor {
diff --git a/backend/common/src/json/mod.rs b/backend/common/src/json/mod.rs
new file mode 100644
index 0000000..22f233f
--- /dev/null
+++ b/backend/common/src/json/mod.rs
@@ -0,0 +1,7 @@
+//! This module contains the types we need to deserialize JSON messages from nodes
+
+mod hash;
+mod node_message;
+
+pub use node_message::*;
+pub use hash::Hash;
\ No newline at end of file
diff --git a/backend/common/src/json/node_message.rs b/backend/common/src/json/node_message.rs
new file mode 100644
index 0000000..b23ece5
--- /dev/null
+++ b/backend/common/src/json/node_message.rs
@@ -0,0 +1,192 @@
+//! The structs and enums defined in this module are largely identical to those
+//! we'll use elsewhere internally, but are kept separate so that the JSON structure
+//! is defined (almost) from just this file, and we don't have to worry about breaking
+//! compatibility with the input data when we make changes to our internal data
+//! structures (for example, to support bincode better).
+use super::hash::Hash;
+use serde::{Deserialize};
+
+/// This struct represents a telemetry message sent from a node as
+/// a JSON payload. Since JSON is self describing, we can use attributes
+/// like serde(untagged) and serde(flatten) without issue.
+///
+/// Internally, we want to minimise the amount of data sent from shards to
+/// the core node. For that reason, we use a non-self-describing serialization
+/// format like bincode, which doesn't support things like `[serde(flatten)]` (which
+/// internally wants to serialize to a map of unknown length) or `[serde(tag/untagged)]`
+/// (which relies on the data to know which variant to deserialize to.)
+///
+/// So, this can be converted fairly cheaply into an enum we'll use internally
+/// which is compatible with formats like bincode.
+#[derive(Deserialize, Debug)]
+#[serde(untagged)]
+pub enum NodeMessage {
+    V1 {
+        #[serde(flatten)]
+        payload: Payload,
+    },
+    V2 {
+        id: ConnId,
+        payload: Payload,
+    },
+}
+
+#[derive(Deserialize, Debug)]
+#[serde(tag = "msg")]
+pub enum Payload {
+    #[serde(rename = "system.connected")]
+    SystemConnected(SystemConnected),
+    #[serde(rename = "system.interval")]
+    SystemInterval(SystemInterval),
+    #[serde(rename = "block.import")]
+    BlockImport(Block),
+    #[serde(rename = "notify.finalized")]
+    NotifyFinalized(Finalized),
+    #[serde(rename = "txpool.import")]
+    TxPoolImport,
+    #[serde(rename = "afg.finalized")]
+    AfgFinalized(AfgFinalized),
+    #[serde(rename = "afg.received_precommit")]
+    AfgReceivedPrecommit(AfgReceivedPrecommit),
+    #[serde(rename = "afg.received_prevote")]
+    AfgReceivedPrevote(AfgReceivedPrevote),
+    #[serde(rename = "afg.received_commit")]
+    AfgReceivedCommit(AfgReceivedCommit),
+    #[serde(rename = "afg.authority_set")]
+    AfgAuthoritySet(AfgAuthoritySet),
+    #[serde(rename = "afg.finalized_blocks_up_to")]
+    AfgFinalizedBlocksUpTo,
+    #[serde(rename = "aura.pre_sealed_block")]
+    AuraPreSealedBlock,
+    #[serde(rename = "prepared_block_for_proposing")]
+    PreparedBlockForProposing,
+}
+
+#[derive(Deserialize, Debug)]
+pub struct SystemConnected {
+    pub genesis_hash: Hash,
+    #[serde(flatten)]
+    pub node: NodeDetails,
+}
+
+#[derive(Deserialize, Debug)]
+pub struct SystemInterval {
+    pub peers: Option<u64>,
+    pub txcount: Option<u64>,
+    pub bandwidth_upload: Option<f64>,
+    pub bandwidth_download: Option<f64>,
+    pub finalized_height: Option<BlockNumber>,
+    pub finalized_hash: Option<Hash>,
+    #[serde(flatten)]
+    pub block: Option<Block>,
+    pub used_state_cache_size: Option<f32>,
+}
+
+#[derive(Deserialize, Debug)]
+pub struct Finalized {
+    #[serde(rename = "best")]
+    pub hash: Hash,
+    pub height: Box<str>,
+}
+
+#[derive(Deserialize, Debug)]
+pub struct AfgAuthoritySet {
+    pub authority_id: Box<str>,
+    pub authorities: Box<str>,
+    pub authority_set_id: Box<str>,
+}
+
+#[derive(Deserialize, Debug, Clone)]
+pub struct AfgFinalized {
+    pub finalized_hash: Hash,
+    pub finalized_number: Box<str>,
+}
+
+#[derive(Deserialize, Debug, Clone)]
+pub struct AfgReceived {
+    pub target_hash: Hash,
+    pub target_number: Box<str>,
+    pub voter: Option<Box<str>>,
+}
+
+#[derive(Deserialize, Debug, Clone)]
+pub struct AfgReceivedPrecommit {
+    #[serde(flatten)]
+    pub received: AfgReceived,
+}
+
+#[derive(Deserialize, Debug, Clone)]
+pub struct AfgReceivedPrevote {
+    #[serde(flatten)]
+    pub received: AfgReceived,
+}
+
+#[derive(Deserialize, Debug, Clone)]
+pub struct AfgReceivedCommit {
+    #[serde(flatten)]
+    pub received: AfgReceived,
+}
+
+#[derive(Deserialize, Debug, Clone, Copy)]
+pub struct Block {
+    #[serde(rename = "best")]
+    pub hash: Hash,
+    pub height: BlockNumber,
+}
+
+#[derive(Deserialize, Debug, Clone)]
+pub struct NodeDetails {
+    pub chain: Box<str>,
+    pub name: Box<str>,
+    pub implementation: Box<str>,
+    pub version: Box<str>,
+    pub validator: Option<Box<str>>,
+    pub network_id: Option<Box<str>>,
+    pub startup_time: Option<Box<str>>,
+}
+
+type ConnId = u64;
+type BlockNumber = u64;
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn message_v1() {
+        let json = r#"{
+            "msg":"notify.finalized",
+            "level":"INFO",
+            "ts":"2021-01-13T12:38:25.410794650+01:00",
+            "best":"0x031c3521ca2f9c673812d692fc330b9a18e18a2781e3f9976992f861fd3ea0cb",
+            "height":"50"
+        }"#;
+        assert!(
+            matches!(
+                serde_json::from_str::<NodeMessage>(json).unwrap(),
+                NodeMessage::V1 { .. },
+            ),
+            "message did not match variant V1",
+        );
+    }
+
+    #[test]
+    fn message_v2() {
+        let json = r#"{
+            "id":1,
+            "ts":"2021-01-13T12:22:20.053527101+01:00",
+            "payload":{
+                "best":"0xcc41708573f2acaded9dd75e07dac2d4163d136ca35b3061c558d7a35a09dd8d",
+                "height":"209",
+                "msg":"notify.finalized"
+            }
+        }"#;
+        assert!(
+            matches!(
+                serde_json::from_str::<NodeMessage>(json).unwrap(),
+                NodeMessage::V2 { .. },
+            ),
+            "message did not match variant V2",
+        );
+    }
+}
diff --git a/backend/common/src/lib.rs b/backend/common/src/lib.rs
index dc147b4..a18980d 100644
--- a/backend/common/src/lib.rs
+++ b/backend/common/src/lib.rs
@@ -3,3 +3,4 @@ pub mod shard;
 pub mod types;
 pub mod util;
 pub mod ws;
+pub mod json;
\ No newline at end of file
diff --git a/backend/common/src/node.rs b/backend/common/src/node.rs
index 420e568..ad66da2 100644
--- a/backend/common/src/node.rs
+++ b/backend/common/src/node.rs
@@ -1,15 +1,13 @@
 use crate::types::{Block, BlockHash, BlockNumber, ConnId, NodeDetails};
-use crate::util::{Hash, NullAny};
+use crate::json;
+
 use actix::prelude::*;
 use serde::{Deserialize, Serialize};
-use serde::ser::Serializer;
 
-#[derive(Deserialize, Debug, Message)]
+#[derive(Serialize, Deserialize, Debug, Message)]
 #[rtype(result = "()")]
-#[serde(untagged)]
 pub enum NodeMessage {
     V1 {
-        #[serde(flatten)]
         payload: Payload,
     },
     V2 {
@@ -36,64 +34,98 @@ impl From<NodeMessage> for Payload {
     }
 }
 
-#[derive(Deserialize, Debug)]
-#[serde(tag = "msg")]
-pub enum Payload {
-    #[serde(rename = "system.connected")]
-    SystemConnected(SystemConnected),
-    #[serde(rename = "system.interval")]
-    SystemInterval(SystemInterval),
-    #[serde(rename = "block.import")]
-    BlockImport(Block),
-    #[serde(rename = "notify.finalized")]
-    NotifyFinalized(Finalized),
-    #[serde(rename = "txpool.import")]
-    TxPoolImport(NullAny),
-    // #[serde(rename = "afg.finalized")]
-    // AfgFinalized(AfgFinalized),
-    // #[serde(rename = "afg.received_precommit")]
-    // AfgReceivedPrecommit(AfgReceivedPrecommit),
-    // #[serde(rename = "afg.received_prevote")]
-    // AfgReceivedPrevote(AfgReceivedPrevote),
-    // #[serde(rename = "afg.received_commit")]
-    // AfgReceivedCommit(AfgReceivedCommit),
-    // #[serde(rename = "afg.authority_set")]
-    // AfgAuthoritySet(AfgAuthoritySet),
-    // #[serde(rename = "afg.finalized_blocks_up_to")]
-    // AfgFinalizedBlocksUpTo(NullAny),
-    // #[serde(rename = "aura.pre_sealed_block")]
-    // AuraPreSealedBlock(NullAny),
-    #[serde(rename = "prepared_block_for_proposing")]
-    PreparedBlockForProposing(NullAny),
-}
-
-impl Serialize for Payload {
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: Serializer,
-    {
-        use Payload::*;
-
-        match self {
-            SystemConnected(val) => serializer.serialize_newtype_variant("Payload", 0, "system.connected", val),
-            SystemInterval(val) => serializer.serialize_newtype_variant("Payload", 1, "system.interval", val),
-            BlockImport(val) => serializer.serialize_newtype_variant("Payload", 3, "block.import", val),
-            NotifyFinalized(val) => serializer.serialize_newtype_variant("Payload", 4, "notify.finalized", val),
-            TxPoolImport(_) => serializer.serialize_unit_variant("Payload", 3, "txpool.import"),
-            PreparedBlockForProposing(_) => serializer.serialize_unit_variant("Payload", 4, "prepared_block_for_proposing"),
-            _ => unimplemented!()
+impl From<json::NodeMessage> for NodeMessage {
+    fn from(msg: json::NodeMessage) -> Self {
+        match msg {
+            json::NodeMessage::V1 { payload } => {
+                NodeMessage::V1 { payload: payload.into() }
+            },
+            json::NodeMessage::V2 { id, payload } => {
+                NodeMessage::V2 { id, payload: payload.into() }
+            },
         }
     }
 }
 
-#[derive(Deserialize, Serialize, Debug)]
+#[derive(Serialize, Deserialize, Debug)]
+pub enum Payload {
+    SystemConnected(SystemConnected),
+    SystemInterval(SystemInterval),
+    BlockImport(Block),
+    NotifyFinalized(Finalized),
+    TxPoolImport,
+    AfgFinalized(AfgFinalized),
+    AfgReceivedPrecommit(AfgReceived),
+    AfgReceivedPrevote(AfgReceived),
+    AfgReceivedCommit(AfgReceived),
+    AfgAuthoritySet(AfgAuthoritySet),
+    AfgFinalizedBlocksUpTo,
+    AuraPreSealedBlock,
+    PreparedBlockForProposing,
+}
+
+impl From<json::Payload> for Payload {
+    fn from(msg: json::Payload) -> Self {
+        match msg {
+            json::Payload::SystemConnected(m) => {
+                Payload::SystemConnected(m.into())
+            },
+            json::Payload::SystemInterval(m) => {
+                Payload::SystemInterval(m.into())
+            },
+            json::Payload::BlockImport(m) => {
+                Payload::BlockImport(m.into())
+            },
+            json::Payload::NotifyFinalized(m) => {
+                Payload::NotifyFinalized(m.into())
+            },
+            json::Payload::TxPoolImport => {
+                Payload::TxPoolImport
+            },
+            json::Payload::AfgFinalized(m) => {
+                Payload::AfgFinalized(m.into())
+            },
+            json::Payload::AfgReceivedPrecommit(m) => {
+                Payload::AfgReceivedPrecommit(m.received.into())
+            },
+            json::Payload::AfgReceivedPrevote(m) => {
+                Payload::AfgReceivedPrevote(m.received.into())
+            },
+            json::Payload::AfgReceivedCommit(m) => {
+                Payload::AfgReceivedCommit(m.received.into())
+            },
+            json::Payload::AfgAuthoritySet(m) => {
+                Payload::AfgAuthoritySet(m.into())
+            },
+            json::Payload::AfgFinalizedBlocksUpTo => {
+                Payload::AfgFinalizedBlocksUpTo
+            },
+            json::Payload::AuraPreSealedBlock => {
+                Payload::AuraPreSealedBlock
+            },
+            json::Payload::PreparedBlockForProposing => {
+                Payload::PreparedBlockForProposing
+            },
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize, Debug)]
 pub struct SystemConnected {
-    pub genesis_hash: Hash,
-    #[serde(flatten)]
+    pub genesis_hash: BlockHash,
     pub node: NodeDetails,
 }
 
-#[derive(Deserialize, Serialize, Debug)]
+impl From<json::SystemConnected> for SystemConnected {
+    fn from(msg: json::SystemConnected) -> Self {
+        SystemConnected {
+            genesis_hash: msg.genesis_hash.into(),
+            node: msg.node.into()
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize, Debug)]
 pub struct SystemInterval {
     pub peers: Option<u64>,
     pub txcount: Option<u64>,
@@ -101,54 +133,87 @@ pub struct SystemInterval {
     pub bandwidth_download: Option<f64>,
     pub finalized_height: Option<BlockNumber>,
     pub finalized_hash: Option<BlockHash>,
-    #[serde(flatten)]
     pub block: Option<Block>,
     pub used_state_cache_size: Option<f32>,
 }
 
-#[derive(Deserialize, Serialize, Debug)]
+impl From<json::SystemInterval> for SystemInterval {
+    fn from(msg: json::SystemInterval) -> Self {
+        SystemInterval {
+            peers: msg.peers,
+            txcount: msg.txcount,
+            bandwidth_upload: msg.bandwidth_upload,
+            bandwidth_download: msg.bandwidth_download,
+            finalized_height: msg.finalized_height,
+            finalized_hash: msg.finalized_hash.map(|h| h.into()),
+            block: msg.block.map(|b| b.into()),
+            used_state_cache_size: msg.used_state_cache_size,
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize, Debug)]
 pub struct Finalized {
-    #[serde(rename = "best")]
     pub hash: BlockHash,
     pub height: Box<str>,
 }
 
-#[derive(Deserialize, Serialize, Debug)]
-pub struct AfgAuthoritySet {
-    pub authority_id: Box<str>,
-    pub authorities: Box<str>,
-    pub authority_set_id: Box<str>,
+impl From<json::Finalized> for Finalized {
+    fn from(msg: json::Finalized) -> Self {
+        Finalized {
+            hash: msg.hash.into(),
+            height: msg.height,
+        }
+    }
 }
 
-#[derive(Deserialize, Serialize, Debug, Clone)]
+#[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct AfgFinalized {
     pub finalized_hash: BlockHash,
     pub finalized_number: Box<str>,
 }
 
-#[derive(Deserialize, Serialize, Debug, Clone)]
+impl From<json::AfgFinalized> for AfgFinalized {
+    fn from(msg: json::AfgFinalized) -> Self {
+        AfgFinalized {
+            finalized_hash: msg.finalized_hash.into(),
+            finalized_number: msg.finalized_number,
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct AfgReceived {
     pub target_hash: BlockHash,
     pub target_number: Box<str>,
     pub voter: Option<Box<str>>,
 }
 
-#[derive(Deserialize, Serialize, Debug, Clone)]
-pub struct AfgReceivedPrecommit {
-    #[serde(flatten)]
-    pub received: AfgReceived,
+impl From<json::AfgReceived> for AfgReceived {
+    fn from(msg: json::AfgReceived) -> Self {
+        AfgReceived {
+            target_hash: msg.target_hash.into(),
+            target_number: msg.target_number,
+            voter: msg.voter,
+        }
+    }
 }
 
-#[derive(Deserialize, Serialize, Debug, Clone)]
-pub struct AfgReceivedPrevote {
-    #[serde(flatten)]
-    pub received: AfgReceived,
+#[derive(Serialize, Deserialize, Debug)]
+pub struct AfgAuthoritySet {
+    pub authority_id: Box<str>,
+    pub authorities: Box<str>,
+    pub authority_set_id: Box<str>,
 }
 
-#[derive(Deserialize, Serialize, Debug, Clone)]
-pub struct AfgReceivedCommit {
-    #[serde(flatten)]
-    pub received: AfgReceived,
+impl From<json::AfgAuthoritySet> for AfgAuthoritySet {
+    fn from(msg: json::AfgAuthoritySet) -> Self {
+        AfgAuthoritySet {
+            authority_id: msg.authority_id,
+            authorities: msg.authorities,
+            authority_set_id: msg.authority_set_id,
+        }
+    }
 }
 
 impl Payload {
@@ -180,27 +245,123 @@ mod tests {
     use super::*;
     use bincode::Options;
 
+    // Without adding a derive macro and marker trait (and enforcing their use), we don't really
+    // know whether things can (de)serialize to bincode or not at runtime without failing unless
+    // we test the different types we want to (de)serialize ourselves. We just need to test each
+    // type, not each variant.
+    fn bincode_can_serialize_and_deserialize<'de, T>(item: T)
+    where T: Serialize + serde::de::DeserializeOwned
+    {
+        let bytes = bincode::serialize(&item).expect("Serialization should work");
+        let _: T = bincode::deserialize(&bytes).expect("Deserialization should work");
+    }
+
     #[test]
-    fn message_v1() {
-        let json = r#"{"msg":"notify.finalized","level":"INFO","ts":"2021-01-13T12:38:25.410794650+01:00","best":"0x031c3521ca2f9c673812d692fc330b9a18e18a2781e3f9976992f861fd3ea0cb","height":"50"}"#;
-        assert!(
-            matches!(
-                serde_json::from_str::<NodeMessage>(json).unwrap(),
-                NodeMessage::V1 { .. },
-            ),
-            "message did not match variant V1",
+    fn bincode_can_serialize_and_deserialize_node_message_system_connected() {
+        bincode_can_serialize_and_deserialize(
+            NodeMessage::V1 {
+                payload: Payload::SystemConnected(SystemConnected {
+                    genesis_hash: BlockHash::zero(),
+                    node: NodeDetails {
+                        chain: "foo".into(),
+                        name: "foo".into(),
+                        implementation: "foo".into(),
+                        version: "foo".into(),
+                        validator: None,
+                        network_id: None,
+                        startup_time: None,
+                    },
+                })
+            }
         );
     }
 
     #[test]
-    fn message_v2() {
-        let json = r#"{"id":1,"ts":"2021-01-13T12:22:20.053527101+01:00","payload":{"best":"0xcc41708573f2acaded9dd75e07dac2d4163d136ca35b3061c558d7a35a09dd8d","height":"209","msg":"notify.finalized"}}"#;
-        assert!(
-            matches!(
-                serde_json::from_str::<NodeMessage>(json).unwrap(),
-                NodeMessage::V2 { .. },
-            ),
-            "message did not match variant V2",
+    fn bincode_can_serialize_and_deserialize_node_message_system_interval() {
+        bincode_can_serialize_and_deserialize(
+            NodeMessage::V1 {
+                payload: Payload::SystemInterval(SystemInterval {
+                    peers: None,
+                    txcount: None,
+                    bandwidth_upload: None,
+                    bandwidth_download: None,
+                    finalized_height: None,
+                    finalized_hash: None,
+                    block: None,
+                    used_state_cache_size: None,
+                })
+            }
+        );
+    }
+
+    #[test]
+    fn bincode_can_serialize_and_deserialize_node_message_block_import() {
+        bincode_can_serialize_and_deserialize(
+            NodeMessage::V1 {
+                payload: Payload::BlockImport(Block {
+                    hash: BlockHash([0; 32]),
+                    height: 0,
+                })
+            }
+        );
+    }
+
+    #[test]
+    fn bincode_can_serialize_and_deserialize_node_message_notify_finalized() {
+        bincode_can_serialize_and_deserialize(
+            NodeMessage::V1 {
+                payload: Payload::NotifyFinalized(Finalized {
+                    hash: BlockHash::zero(),
+                    height: "foo".into(),
+                })
+            }
+        );
+    }
+
+    #[test]
+    fn bincode_can_serialize_and_deserialize_node_message_tx_pool_import() {
+        bincode_can_serialize_and_deserialize(
+            NodeMessage::V1 {
+                payload: Payload::TxPoolImport
+            }
+        );
+    }
+
+    #[test]
+    fn bincode_can_serialize_and_deserialize_node_message_afg_finalized() {
+        bincode_can_serialize_and_deserialize(
+            NodeMessage::V1 {
+                payload: Payload::AfgFinalized(AfgFinalized {
+                    finalized_hash: BlockHash::zero(),
+                    finalized_number: "foo".into(),
+                })
+            }
+        );
+    }
+
+    #[test]
+    fn bincode_can_serialize_and_deserialize_node_message_afg_received() {
+        bincode_can_serialize_and_deserialize(
+            NodeMessage::V1 {
+                payload: Payload::AfgReceivedPrecommit(AfgReceived {
+                    target_hash: BlockHash::zero(),
+                    target_number: "foo".into(),
+                    voter: None,
+                })
+            }
+        );
+    }
+
+    #[test]
+    fn bincode_can_serialize_and_deserialize_node_message_afg_authority_set() {
+        bincode_can_serialize_and_deserialize(
+            NodeMessage::V1 {
+                payload: Payload::AfgAuthoritySet(AfgAuthoritySet {
+                    authority_id: "foo".into(),
+                    authorities: "foo".into(),
+                    authority_set_id: "foo".into(),
+                })
+            }
         );
     }
 
diff --git a/backend/common/src/types.rs b/backend/common/src/types.rs
index a16ce5a..aa85996 100644
--- a/backend/common/src/types.rs
+++ b/backend/common/src/types.rs
@@ -2,6 +2,7 @@ use serde::ser::{SerializeTuple, Serializer};
 use serde::{Deserialize, Serialize};
 
 use crate::util::{now, MeanList};
+use crate::json;
 
 pub type NodeId = usize;
 pub type ConnId = u64;
@@ -21,6 +22,20 @@ pub struct NodeDetails {
     pub startup_time: Option<Box<str>>,
 }
 
+impl From<json::NodeDetails> for NodeDetails {
+    fn from(details: json::NodeDetails) -> Self {
+        NodeDetails {
+            chain: details.chain,
+            name: details.name,
+            implementation: details.implementation,
+            version: details.version,
+            validator: details.validator,
+            network_id: details.network_id,
+            startup_time: details.startup_time,
+        }
+    }
+}
+
 #[derive(Deserialize, Debug, Clone, Copy, PartialEq, Eq, Default)]
 pub struct NodeStats {
     pub peers: u64,
@@ -34,11 +49,19 @@ pub struct NodeIO {
 
 #[derive(Deserialize, Serialize, Debug, Clone, Copy)]
 pub struct Block {
-    #[serde(rename = "best")]
     pub hash: BlockHash,
     pub height: BlockNumber,
 }
 
+impl From<json::Block> for Block {
+    fn from(block: json::Block) -> Self {
+        Block {
+            hash: block.hash.into(),
+            height: block.height
+        }
+    }
+}
+
 impl Block {
     pub fn zero() -> Self {
         Block {
diff --git a/backend/common/src/util.rs b/backend/common/src/util.rs
index a78310e..66dddae 100644
--- a/backend/common/src/util.rs
+++ b/backend/common/src/util.rs
@@ -1,11 +1,9 @@
 mod dense_map;
-mod hash;
 mod mean_list;
 mod null;
 mod num_stats;
 
 pub use dense_map::DenseMap;
-pub use hash::Hash;
 pub use mean_list::MeanList;
 pub use null::NullAny;
 pub use num_stats::NumStats;
diff --git a/backend/core/src/aggregator.rs b/backend/core/src/aggregator.rs
index 4e1a289..8dd3d98 100644
--- a/backend/core/src/aggregator.rs
+++ b/backend/core/src/aggregator.rs
@@ -9,11 +9,11 @@ use crate::feed::{self, FeedMessageSerializer};
 use crate::node::connector::NodeConnector;
 use common::ws::MuteReason;
 use common::shard::ShardConnId;
-use common::types::{ConnId, NodeDetails};
-use common::util::{DenseMap, Hash};
+use common::types::{ConnId, NodeDetails, BlockHash};
+use common::util::{DenseMap};
 
 pub struct Aggregator {
-    genesis_hashes: HashMap<Hash, ChainId>,
+    genesis_hashes: HashMap<BlockHash, ChainId>,
     labels: HashMap<Label, ChainId>,
     chains: DenseMap<ChainEntry>,
     feeds: DenseMap<Addr<FeedConnector>>,
@@ -26,7 +26,7 @@ pub struct ChainEntry {
     /// Address to the `Chain` agent
     addr: Addr<Chain>,
     /// Genesis [`Hash`] of the chain
-    genesis_hash: Hash,
+    genesis_hash: BlockHash,
     /// String name of the chain
     label: Label,
     /// Node count
@@ -66,7 +66,7 @@ impl Aggregator {
     /// or the address is disconnected (actor dropped), create a new one.
     pub fn lazy_chain(
         &mut self,
-        genesis_hash: Hash,
+        genesis_hash: BlockHash,
         label: &str,
         ctx: &mut <Self as Actor>::Context,
     ) -> ChainId {
@@ -125,7 +125,7 @@ pub struct AddNode {
     /// Details of the node being added to the aggregator
     pub node: NodeDetails,
     /// Genesis [`Hash`] of the chain the node is being added to.
-    pub genesis_hash: Hash,
+    pub genesis_hash: BlockHash,
     /// Source from which this node is being added (Direct | Shard)
     pub source: NodeSource,
 }
diff --git a/backend/core/src/main.rs b/backend/core/src/main.rs
index 241a577..958af9d 100644
--- a/backend/core/src/main.rs
+++ b/backend/core/src/main.rs
@@ -1,6 +1,5 @@
 use std::collections::HashSet;
 use std::iter::FromIterator;
-use std::net::Ipv4Addr;
 
 use actix::prelude::*;
 use actix_http::ws::Codec;
@@ -19,7 +18,6 @@ mod shard;
 use aggregator::{Aggregator, GetHealth};
 use feed::connector::FeedConnector;
 use location::{Locator, LocatorFactory};
-use node::connector::NodeConnector;
 use shard::connector::ShardConnector;
 
 const VERSION: &str = env!("CARGO_PKG_VERSION");
@@ -74,35 +72,6 @@ impl From<&LogLevel> for log::LevelFilter {
     }
 }
 
-/// Entry point for connecting nodes
-#[get("/submit")]
-async fn node_route(
-    req: HttpRequest,
-    stream: web::Payload,
-    aggregator: web::Data<Addr<Aggregator>>,
-    locator: web::Data<Addr<Locator>>,
-) -> Result<HttpResponse, Error> {
-    let ip = req
-        .connection_info()
-        .realip_remote_addr()
-        .and_then(|mut addr| {
-            if let Some(port_idx) = addr.find(':') {
-                addr = &addr[..port_idx];
-            }
-            addr.parse::<Ipv4Addr>().ok()
-        });
-
-    let mut res = ws::handshake(&req)?;
-    let aggregator = aggregator.get_ref().clone();
-    let locator = locator.get_ref().clone().recipient();
-
-    Ok(res.streaming(ws::WebsocketContext::with_codec(
-        NodeConnector::new(aggregator, locator, ip),
-        stream,
-        Codec::new().max_size(10 * 1024 * 1024), // 10mb frame limit
-    )))
-}
-
 #[get("/shard_submit/{chain_hash}")]
 async fn shard_route(
     req: HttpRequest,
@@ -112,7 +81,7 @@ async fn shard_route(
     path: web::Path<Box<str>>,
 ) -> Result<HttpResponse, Error> {
     let hash_str = path.into_inner();
-    let genesis_hash = hash_str.parse()?;
+    let genesis_hash = hash_str.parse::<common::json::Hash>()?.into();
 
     println!("Genesis hash {}", genesis_hash);
 
@@ -180,7 +149,6 @@ async fn main() -> std::io::Result<()> {
             .wrap(middleware::NormalizePath::default())
             .data(aggregator.clone())
             .data(locator.clone())
-            .service(node_route)
             .service(feed_route)
             .service(shard_route)
             .service(health)
diff --git a/backend/core/src/shard/connector.rs b/backend/core/src/shard/connector.rs
index 62414cd..e83912a 100644
--- a/backend/core/src/shard/connector.rs
+++ b/backend/core/src/shard/connector.rs
@@ -8,8 +8,7 @@ use crate::location::LocateRequest;
 use actix::prelude::*;
 use actix_web_actors::ws::{self, CloseReason};
 use bincode::Options;
-use common::types::NodeId;
-use common::util::Hash;
+use common::types::{BlockHash, NodeId};
 use common::ws::{MultipartHandler, WsMessage};
 use common::shard::{ShardMessage, ShardConnId, BackendMessage};
 
@@ -24,7 +23,7 @@ pub struct ShardConnector {
     /// Aggregator actor address
     aggregator: Addr<Aggregator>,
     /// Genesis hash of the chain this connection will be submitting data for
-    genesis_hash: Hash,
+    genesis_hash: BlockHash,
     /// Chain address to which this shard connector is delegating messages
     chain: Option<Addr<Chain>>,
     /// Transient mapping of `ShardConnId` to external IP address.
@@ -57,7 +56,7 @@ impl ShardConnector {
     pub fn new(
         aggregator: Addr<Aggregator>,
         locator: Recipient<LocateRequest>,
-        genesis_hash: Hash,
+        genesis_hash: BlockHash,
     ) -> Self {
         Self {
             hb: Instant::now(),
diff --git a/backend/shard/Cargo.toml b/backend/shard/Cargo.toml
index b327178..ccfc2bf 100644
--- a/backend/shard/Cargo.toml
+++ b/backend/shard/Cargo.toml
@@ -17,6 +17,7 @@ log = "0.4"
 rustc-hash = "1.1.0"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = { version = "1.0", features = ["raw_value"] }
+primitive-types = { version = "0.9.0", features = ["serde"] }
 common = { path = "../common" }
 simple_logger = "1.11.0"
 soketto = "0.4.2"
diff --git a/backend/shard/src/aggregator.rs b/backend/shard/src/aggregator.rs
index 1557c32..031a44d 100644
--- a/backend/shard/src/aggregator.rs
+++ b/backend/shard/src/aggregator.rs
@@ -6,8 +6,8 @@ use actix::prelude::*;
 use actix_http::http::Uri;
 use bincode::Options;
 use rustc_hash::FxHashMap;
-use common::util::{Hash, DenseMap};
-use common::types::{ConnId, NodeDetails, NodeId};
+use common::util::{DenseMap};
+use common::types::{ConnId, NodeDetails, NodeId, BlockHash};
 use common::node::Payload;
 use common::shard::{ShardConnId, ShardMessage, BackendMessage};
 use soketto::handshake::{Client, ServerResponse};
@@ -22,7 +22,7 @@ type WsReceiver = soketto::Receiver<Compat<TcpStream>>;
 #[derive(Default)]
 pub struct Aggregator {
     url: Uri,
-    chains: FxHashMap<Hash, UnboundedSender<ChainMessage>>,
+    chains: FxHashMap<BlockHash, UnboundedSender<ChainMessage>>,
 }
 
 impl Actor for Aggregator {
@@ -42,13 +42,13 @@ pub struct Chain {
     /// Base URL of Backend Core
     url: Uri,
     /// Genesis hash of the chain, required to construct the URL to connect to the Backend Core
-    genesis_hash: Hash,
+    genesis_hash: BlockHash,
     /// Dense mapping of SharedConnId -> Addr<NodeConnector> + multiplexing ConnId sent from the node.
     nodes: DenseMap<(Addr<NodeConnector>, ConnId)>,
 }
 
 impl Chain {
-    pub fn new(url: Uri, genesis_hash: Hash) -> Self {
+    pub fn new(url: Uri, genesis_hash: BlockHash) -> Self {
         Chain {
             url,
             genesis_hash,
@@ -188,7 +188,7 @@ impl Actor for Chain {
 #[rtype(result = "()")]
 pub struct AddNode {
     pub ip: Option<Ipv4Addr>,
-    pub genesis_hash: Hash,
+    pub genesis_hash: BlockHash,
     pub node: NodeDetails,
     pub conn_id: ConnId,
     pub node_connector: Addr<NodeConnector>,
diff --git a/backend/shard/src/node.rs b/backend/shard/src/node.rs
index 9a985a7..f6f3474 100644
--- a/backend/shard/src/node.rs
+++ b/backend/shard/src/node.rs
@@ -8,6 +8,7 @@ use actix::prelude::*;
 use actix_web_actors::ws::{self, CloseReason};
 use common::node::{NodeMessage, Payload};
 use common::types::{ConnId, NodeId};
+use common::json;
 use common::ws::{MultipartHandler, WsMessage};
 use tokio::sync::mpsc::UnboundedSender;
 
@@ -93,9 +94,10 @@ impl NodeConnector {
 
     fn handle_message(
         &mut self,
-        msg: NodeMessage,
+        msg: json::NodeMessage,
         ctx: &mut <Self as Actor>::Context,
     ) {
+        let msg: NodeMessage = msg.into();
         let conn_id = msg.id();
         let payload = msg.into();