diff --git a/Cargo.lock b/Cargo.lock
index f738d28b8..c8920f522 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -287,6 +287,7 @@ dependencies = [
  "ethash 1.4.0",
  "ethcore-bloom-journal 0.1.0",
  "ethcore-devtools 1.4.0",
+ "ethcore-hash-fetch 1.5.0",
  "ethcore-io 1.5.0",
  "ethcore-ipc 1.4.0",
  "ethcore-ipc-codegen 1.4.0",
diff --git a/ethcore/Cargo.toml b/ethcore/Cargo.toml
index 7c6576672..dd1c796a2 100644
--- a/ethcore/Cargo.toml
+++ b/ethcore/Cargo.toml
@@ -34,6 +34,7 @@ ethash = { path = "../ethash" }
 ethcore-util = { path = "../util" }
 ethcore-io = { path = "../util/io" }
 ethcore-devtools = { path = "../devtools" }
+ethcore-hash-fetch = { path = "./hash-fetch" }
 ethjson = { path = "../json" }
 ethcore-ipc = { path = "../ipc/rpc" }
 ethstore = { path = "../ethstore" }
diff --git a/ethcore/hash-fetch/src/lib.rs b/ethcore/hash-fetch/src/lib.rs
index ffb74b260..b566121f5 100644
--- a/ethcore/hash-fetch/src/lib.rs
+++ b/ethcore/hash-fetch/src/lib.rs
@@ -30,4 +30,4 @@ mod client;
 
 pub mod urlhint;
 
-pub use client::{HashFetch, Client};
+pub use client::{HashFetch, Client, Error};
diff --git a/ethcore/src/client/operations.rs b/ethcore/src/client/operations.rs
index e0408cdb0..2124884c7 100644
--- a/ethcore/src/client/operations.rs
+++ b/ethcore/src/client/operations.rs
@@ -9,10 +9,10 @@ use util::{FixedHash, Uint};
 pub struct Operations {
 	contract: ethabi::Contract,
 	address: util::Address,
-	do_call: Box<Fn(util::Address, Vec<u8>) -> Result<Vec<u8>, String> + Send + 'static>,
+	do_call: Box<Fn(util::Address, Vec<u8>) -> Result<Vec<u8>, String> + Send + Sync + 'static>,
 }
 impl Operations {
-	pub fn new<F>(address: util::Address, do_call: F) -> Self where F: Fn(util::Address, Vec<u8>) -> Result<Vec<u8>, String> + Send + 'static {
+	pub fn new<F>(address: util::Address, do_call: F) -> Self where F: Fn(util::Address, Vec<u8>) -> Result<Vec<u8>, String> + Send + Sync + 'static {
 		Operations {
 			contract: ethabi::Contract::new(ethabi::Interface::load(b"[{\"constant\":false,\"inputs\":[{\"name\":\"_client\",\"type\":\"bytes32\"},{\"name\":\"_newOwner\",\"type\":\"address\"}],\"name\":\"resetClientOwner\",\"outputs\":[],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"name\":\"_client\",\"type\":\"bytes32\"},{\"name\":\"_release\",\"type\":\"bytes32\"}],\"name\":\"isLatest\",\"outputs\":[{\"name\":\"\",\"type\":\"bool\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"_txid\",\"type\":\"bytes32\"}],\"name\":\"rejectTransaction\",\"outputs\":[],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"_newOwner\",\"type\":\"address\"}],\"name\":\"setOwner\",\"outputs\":[],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"_number\",\"type\":\"uint32\"},{\"name\":\"_name\",\"type\":\"bytes32\"},{\"name\":\"_hard\",\"type\":\"bool\"},{\"name\":\"_spec\",\"type\":\"bytes32\"}],\"name\":\"proposeFork\",\"outputs\":[],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"_client\",\"type\":\"bytes32\"}],\"name\":\"removeClient\",\"outputs\":[],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"name\":\"_client\",\"type\":\"bytes32\"},{\"name\":\"_release\",\"type\":\"bytes32\"}],\"name\":\"release\",\"outputs\":[{\"name\":\"o_forkBlock\",\"type\":\"uint32\"},{\"name\":\"o_track\",\"type\":\"uint8\"},{\"name\":\"o_semver\",\"type\":\"uint24\"},{\"name\":\"o_critical\",\"type\":\"bool\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"name\":\"_client\",\"type\":\"bytes32\"},{\"name\":\"_checksum\",\"type\":\"bytes32\"}],\"name\":\"build\",\"outputs\":[{\"name\":\"o_release\",\"type\":\"bytes32\"},{\"name\":\"o_platform\",\"type\":\"bytes32\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[],\"name\":\"rejectFork\",\"outputs\":[],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"name\":\"\",\"type\":\"bytes32\"}],\"name\":\"client\",\"outputs\":[{\"name\":\"owner\",\"type\":\"address\"},{\"name\":\"required\",\"type\":\"bool\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"_newOwner\",\"type\":\"address\"}],\"name\":\"setClientOwner\",\"outputs\":[],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"name\":\"\",\"type\":\"uint32\"}],\"name\":\"fork\",\"outputs\":[{\"name\":\"name\",\"type\":\"bytes32\"},{\"name\":\"spec\",\"type\":\"bytes32\"},{\"name\":\"hard\",\"type\":\"bool\"},{\"name\":\"ratified\",\"type\":\"bool\"},{\"name\":\"requiredCount\",\"type\":\"uint256\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"_release\",\"type\":\"bytes32\"},{\"name\":\"_platform\",\"type\":\"bytes32\"},{\"name\":\"_checksum\",\"type\":\"bytes32\"}],\"name\":\"addChecksum\",\"outputs\":[],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"_txid\",\"type\":\"bytes32\"}],\"name\":\"confirmTransaction\",\"outputs\":[{\"name\":\"txSuccess\",\"type\":\"uint256\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"name\":\"\",\"type\":\"bytes32\"}],\"name\":\"proxy\",\"outputs\":[{\"name\":\"requiredCount\",\"type\":\"uint256\"},{\"name\":\"to\",\"type\":\"address\"},{\"name\":\"data\",\"type\":\"bytes\"},{\"name\":\"value\",\"type\":\"uint256\"},{\"name\":\"gas\",\"type\":\"uint256\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"_client\",\"type\":\"bytes32\"},{\"name\":\"_owner\",\"type\":\"address\"}],\"name\":\"addClient\",\"outputs\":[],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"name\":\"\",\"type\":\"address\"}],\"name\":\"clientOwner\",\"outputs\":[{\"name\":\"\",\"type\":\"bytes32\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"_txid\",\"type\":\"bytes32\"},{\"name\":\"_to\",\"type\":\"address\"},{\"name\":\"_data\",\"type\":\"bytes\"},{\"name\":\"_value\",\"type\":\"uint256\"},{\"name\":\"_gas\",\"type\":\"uint256\"}],\"name\":\"proposeTransaction\",\"outputs\":[{\"name\":\"txSuccess\",\"type\":\"uint256\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"grandOwner\",\"outputs\":[{\"name\":\"\",\"type\":\"address\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"_release\",\"type\":\"bytes32\"},{\"name\":\"_forkBlock\",\"type\":\"uint32\"},{\"name\":\"_track\",\"type\":\"uint8\"},{\"name\":\"_semver\",\"type\":\"uint24\"},{\"name\":\"_critical\",\"type\":\"bool\"}],\"name\":\"addRelease\",\"outputs\":[],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[],\"name\":\"acceptFork\",\"outputs\":[],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"clientsRequired\",\"outputs\":[{\"name\":\"\",\"type\":\"uint32\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"name\":\"_client\",\"type\":\"bytes32\"},{\"name\":\"_release\",\"type\":\"bytes32\"}],\"name\":\"track\",\"outputs\":[{\"name\":\"\",\"type\":\"uint8\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"_client\",\"type\":\"bytes32\"},{\"name\":\"_r\",\"type\":\"bool\"}],\"name\":\"setClientRequired\",\"outputs\":[],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"latestFork\",\"outputs\":[{\"name\":\"\",\"type\":\"uint32\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"name\":\"_client\",\"type\":\"bytes32\"},{\"name\":\"_track\",\"type\":\"uint8\"}],\"name\":\"latestInTrack\",\"outputs\":[{\"name\":\"\",\"type\":\"bytes32\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"name\":\"_client\",\"type\":\"bytes32\"},{\"name\":\"_release\",\"type\":\"bytes32\"},{\"name\":\"_platform\",\"type\":\"bytes32\"}],\"name\":\"checksum\",\"outputs\":[{\"name\":\"\",\"type\":\"bytes32\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"proposedFork\",\"outputs\":[{\"name\":\"\",\"type\":\"uint32\"}],\"payable\":false,\"type\":\"function\"}]").expect("JSON is autogenerated; qed")),
 			address: address,
diff --git a/ethcore/src/client/updater.rs b/ethcore/src/client/updater.rs
index c21f47b4a..11bdc0b5c 100644
--- a/ethcore/src/client/updater.rs
+++ b/ethcore/src/client/updater.rs
@@ -14,11 +14,15 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
-use std::sync::Weak;
+use std::sync::{Mutex, Weak, Arc};
+use std::path::PathBuf;
 use util::misc::{VersionInfo, ReleaseTrack, platform};
-use util::{Address, H160, H256, FixedHash};
+use std::str::FromStr;
+use util::{Bytes, Address, H160, H256, FixedHash};
 use client::operations::Operations;
-use client::{Client, UpdatePolicy, BlockId};
+use client::{Client, BlockChainClient, UpdatePolicy, BlockId};
+use fetch::HashFetch;
+use fetch;
 
 #[derive(Debug, Clone, PartialEq)]
 pub struct ReleaseInfo {
@@ -40,6 +44,7 @@ pub struct Updater {
 	client: Weak<Client>,
 	operations: Operations,
 	update_policy: UpdatePolicy,
+	fetch_handler: Mutex<Option<fetch::Client>>,
 
 	// These don't change
 	pub this: VersionInfo,
@@ -51,12 +56,38 @@ pub struct Updater {
 
 const CLIENT_ID: &'static str = "parity";
 
+struct FetchHandler {
+	client: Weak<Client>,
+}
+
+impl fetch::urlhint::ContractClient for FetchHandler {
+	fn registrar(&self) -> Result<Address, String> {
+		self.client.upgrade().ok_or_else(|| "Client not available".to_owned())?
+			.additional_params()
+			.get("registrar")
+			.and_then(|s| Address::from_str(s).ok())
+			.ok_or_else(|| "Registrar not available".into())
+	}
+
+	fn call(&self, address: Address, data: Bytes) -> Result<Bytes, String> {
+		self.client.upgrade().ok_or_else(|| "Client not available".to_owned())?
+			.call_contract(address, data)
+	}
+}
+
+fn start_fetch(client: Weak<Client>, hash: H256, on_done: Box<Fn(Result<PathBuf, fetch::Error>) + Send>) -> Result<fetch::Client, fetch::Error> {
+	let f = fetch::Client::new(Arc::new(FetchHandler { client: client, }));
+	let r = f.fetch(hash, on_done);
+	r.map(|_| f)
+}
+
 impl Updater {
 	pub fn new(client: Weak<Client>, operations: Address, update_policy: UpdatePolicy) -> Self {
 		let mut u = Updater {
 			client: client.clone(),
 			operations: Operations::new(operations, move |a, d| client.upgrade().ok_or("No client!".into()).and_then(|c| c.call_contract(a, d))),
 			update_policy: update_policy,
+			fetch_handler: Mutex::new(None),
 			this: VersionInfo::this(),
 			this_fork: None,
 			latest: None,
@@ -140,6 +171,12 @@ impl Updater {
 		})
 	}
 
+	fn fetch_done(&self, _r: Result<PathBuf, fetch::Error>) {
+		if let Ok(mut x) = self.fetch_handler.lock() {
+			*x = None;
+		}
+	}
+
 	pub fn tick(&mut self) {
 		info!(target: "updater", "Current release is {}", self.this);
 
@@ -157,6 +194,15 @@ impl Updater {
 					 "unreleased".into()
 				 }
 			);
+			if let Some(b) = latest.track.binary {
+				if let Ok(mut fetch_handler) = self.fetch_handler.lock() {
+					if fetch_handler.is_none() {
+						let c = self.client.clone();
+						let f = move |r: Result<PathBuf, fetch::Error>| if let Some(c) = c.upgrade() { c.updater().as_ref().expect("updater exists; updater only owned by client; qed").fetch_done(r); }; 
+						*fetch_handler = start_fetch(self.client.clone(), b, Box::new(f)).ok();
+					}
+				}
+			}
 			info!(target: "updater", "Fork: this/current/latest/latest-known: {}/#{}/#{}/#{}", match self.this_fork { Some(f) => format!("#{}", f), None => "unknown".into(), }, current_number, latest.track.fork, latest.fork);
 		}
 	}
diff --git a/ethcore/src/lib.rs b/ethcore/src/lib.rs
index 26db14744..c0ad612d2 100644
--- a/ethcore/src/lib.rs
+++ b/ethcore/src/lib.rs
@@ -103,6 +103,7 @@ extern crate ethcore_bloom_journal as bloom_journal;
 extern crate byteorder;
 extern crate transient_hashmap;
 extern crate linked_hash_map;
+extern crate ethcore_hash_fetch as fetch;
 
 #[macro_use]
 extern crate log;