diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..6649c3b
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,3 @@
+default:
+	g++ main.cpp txradar.cpp util.cpp $(shell pkg-config --cflags --libs libczmq++ libbitcoin) -o txradar
+
diff --git a/README b/README
new file mode 100644
index 0000000..c69b0c0
--- /dev/null
+++ b/README
@@ -0,0 +1,11 @@
+Make sure you have libbitcoin installed.
+
+  $ make
+  $ ./txradar
+
+Check out define.hpp to change the ports and other settings.
+
+To see only txradar output use:
+
+  $ ./txradar 2>&1 | grep txradar
+
diff --git a/define.hpp b/define.hpp
new file mode 100644
index 0000000..6c4f698
--- /dev/null
+++ b/define.hpp
@@ -0,0 +1,14 @@
+#ifndef TXRADAR_DEFINE_HPP
+#define TXRADAR_DEFINE_HPP
+
+#define ONLY_LOCALHOST_CONNECTIONS
+
+const size_t notify_port = 7678;
+
+// How many connections radar should try to maintain.
+const size_t target_connections = 40;
+
+#define LOG_TXR "txradar"
+
+#endif
+
diff --git a/main.cpp b/main.cpp
new file mode 100644
index 0000000..3fa07ab
--- /dev/null
+++ b/main.cpp
@@ -0,0 +1,10 @@
+#include "txradar.hpp"
+
+int main()
+{
+    txradar radar;
+    radar.start(true, 1, target_connections);
+    pause();
+    return 0;
+}
+
diff --git a/txradar.cpp b/txradar.cpp
new file mode 100644
index 0000000..974c919
--- /dev/null
+++ b/txradar.cpp
@@ -0,0 +1,158 @@
+#include "txradar.hpp"
+
+#include "util.hpp"
+
+using std::placeholders::_1;
+using std::placeholders::_2;
+using std::placeholders::_3;
+
+void log_nothing(
+    bc::log_level level, const std::string& domain, const std::string& body)
+{
+}
+void log_to_file(std::ofstream& file,
+    bc::log_level level, const std::string& domain, const std::string& body)
+{
+    if (body.empty())
+        return;
+    file << level_repr(level);
+    if (!domain.empty())
+        file << " [" << domain << "]";
+    file << ": " << body << std::endl;
+}
+
+txradar::txradar()
+  : engine_(device_()), auth_(ctx_),
+    hosts_(pool_), handshake_(pool_), network_(pool_),
+    p2p_(pool_, hosts_, handshake_, network_)
+{
+    BITCOIN_ASSERT(ctx_.self());
+    BITCOIN_ASSERT(auth_.self());
+}
+txradar::~txradar()
+{
+    pool_.stop();
+    pool_.join();
+}
+
+void p2p_started(bc::network::protocol& p2p, const std::error_code& ec);
+
+// Start the p2p network. Is called repeatedly until connected.
+void start_p2p(bc::network::protocol& p2p)
+{
+    // Keep trying to connect until successful.
+    p2p.start(std::bind(p2p_started, std::ref(p2p), _1));
+}
+
+// If there's an error then attempt to reconnect until successful.
+void p2p_started(bc::network::protocol& p2p, const std::error_code& ec)
+{
+    if (ec)
+    {
+        bc::log_warning(LOG_TXR) << "Restarting connection...";
+        start_p2p(p2p);
+        return;
+    }
+    // Success. Call finish callback to signal success.
+    bc::log_info(LOG_TXR) << "Radar started.";
+}
+
+void txradar::start(bool display_output, size_t threads, size_t number_hosts)
+{
+#ifdef ONLY_LOCALHOST_CONNECTIONS
+    auth_.allow("127.0.0.1");
+#endif
+
+    pool_.spawn(threads);
+
+    // Set connection counts.
+    p2p_.set_max_outbound(number_hosts);
+    // Notify us of new connections so we can subscribe to 'inv' packets.
+    p2p_.subscribe_channel(
+        std::bind(&txradar::connection_started, this, _1, _2));
+    // Start connecting to p2p networks for broadcasting and monitor txs.
+    start_p2p(p2p_);
+}
+
+void txradar::connection_started(
+    const std::error_code& ec, bc::network::channel_ptr node)
+{
+    if (ec)
+    {
+        bc::log_warning(LOG_TXR)
+            << "Couldn't start connection: " << ec.message();
+        return;
+    }
+    bc::log_info(LOG_TXR) << "Connection established.";
+    node_id_type node_id =
+        engine_() % std::numeric_limits<node_id_type>::max();
+    // Subscribe to 'inv' packets.
+    node->subscribe_inventory(
+        std::bind(&txradar::inventory_received, this,
+            _1, _2, node, node_id));
+    // Resubscribe to new nodes.
+    p2p_.subscribe_channel(
+        std::bind(&txradar::connection_started, this, _1, _2));
+}
+
+template <typename Context, typename NodeID>
+void notify_transaction(
+    Context& ctx, NodeID node_id, const bc::hash_digest& tx_hash)
+{
+    static czmqpp::socket socket(ctx, ZMQ_PUB);
+    static bool is_initialized = false;
+    if (!is_initialized)
+    {
+        BITCOIN_ASSERT(socket.self());
+        int bind_rc = socket.bind(listen_transport(notify_port));
+        BITCOIN_ASSERT(bind_rc != -1);
+        is_initialized = true;
+        bc::log_info(LOG_TXR) << "Initialized ZMQ socket.";
+    }
+    bc::log_info(LOG_TXR) << "Sending (" << node_id << ", "
+        << bc::encode_hash(tx_hash) << ")";
+    // Create a message.
+    czmqpp::message msg;
+    // node_id
+    const auto data_id = bc::to_little_endian(node_id);
+    BITCOIN_ASSERT(data_id.size() == 4);
+    msg.append(bc::to_data_chunk(data_id));
+    // tx_hash
+    const czmqpp::data_chunk data_hash(tx_hash.begin(), tx_hash.end());
+    msg.append(data_hash);
+    // Send it.
+    bool rc = msg.send(socket);
+    BITCOIN_ASSERT(rc);
+}
+
+void txradar::inventory_received(
+    const std::error_code& ec, const bc::inventory_type& packet,
+    bc::network::channel_ptr node, node_id_type node_id)
+{
+    if (ec)
+    {
+        bc::log_error(LOG_TXR) << "inventory: " << ec.message();
+        return;
+    }
+    for (const bc::inventory_vector_type& ivec: packet.inventories)
+    {
+        if (ivec.type == bc::inventory_type_id::transaction)
+        {
+            notify_transaction(ctx_, node_id, ivec.hash);
+        }
+        else if (ivec.type == bc::inventory_type_id::block);
+            // Do nothing.
+        else
+            bc::log_warning(LOG_TXR) << "Ignoring unknown inventory type";
+    }
+    // Resubscribe to 'inv' packets.
+    node->subscribe_inventory(
+        std::bind(&txradar::inventory_received, this,
+            _1, _2, node, node_id));
+}
+
+size_t txradar::total_connections() const
+{
+    return p2p_.total_connections();
+}
+
diff --git a/txradar.hpp b/txradar.hpp
new file mode 100644
index 0000000..514e9f8
--- /dev/null
+++ b/txradar.hpp
@@ -0,0 +1,48 @@
+#ifndef TXRADAR_TXRADAR_HPP
+#define TXRADAR_TXRADAR_HPP
+
+#include <czmq++/czmqpp.hpp>
+#include <bitcoin/bitcoin.hpp>
+#include "define.hpp"
+
+class txradar
+{
+public:
+    txradar();
+    ~txradar();
+
+    void start(bool display_output, size_t threads, size_t number_hosts);
+
+    size_t total_connections() const;
+
+private:
+    typedef uint32_t node_id_type;
+
+    void connection_started(
+        const std::error_code& ec, bc::network::channel_ptr node);
+    void inventory_received(
+        const std::error_code& ec, const bc::inventory_type& packet,
+        bc::network::channel_ptr node, node_id_type node_id);
+
+    // Used for generating node IDs
+    std::random_device device_;
+    std::default_random_engine engine_;
+
+    // ZeroMQ stuff
+    czmqpp::context ctx_;
+    czmqpp::authenticator auth_;
+
+    // For logging
+    std::ofstream outfile_, errfile_;
+
+    // Threadpool
+    bc::threadpool pool_;
+    // Bitcoin network components.
+    bc::network::hosts hosts_;
+    bc::network::handshake handshake_;
+    bc::network::network network_;
+    bc::network::protocol p2p_;
+};
+
+#endif
+
diff --git a/util.cpp b/util.cpp
new file mode 100644
index 0000000..ebf689c
--- /dev/null
+++ b/util.cpp
@@ -0,0 +1,11 @@
+#include "util.hpp"
+
+#include <boost/lexical_cast.hpp>
+
+const std::string listen_transport(const size_t port)
+{
+    std::string transport = "tcp://*:";
+    transport += boost::lexical_cast<std::string>(port);
+    return transport;
+}
+
diff --git a/util.hpp b/util.hpp
new file mode 100644
index 0000000..0e7e753
--- /dev/null
+++ b/util.hpp
@@ -0,0 +1,9 @@
+#ifndef TXRADAR_UTIL_HPP
+#define TXRADAR_UTIL_HPP
+
+#include <string>
+
+const std::string listen_transport(const size_t port);
+
+#endif
+