diff --git a/server/Dockerfile b/server/Dockerfile
index 255b7d0..47e6e5a 100644
--- a/server/Dockerfile
+++ b/server/Dockerfile
@@ -17,6 +17,7 @@ RUN mix do deps.compile
 
 COPY lib ./lib
 COPY log ./log
+COPY config ./config
 
 ENV MIX_ENV prod
 ENV RELEASE_NODE bitfeed
diff --git a/server/lib/bitcoin_rpc.ex b/server/lib/bitcoin_rpc.ex
index d0b6660..d35c330 100644
--- a/server/lib/bitcoin_rpc.ex
+++ b/server/lib/bitcoin_rpc.ex
@@ -1,3 +1,5 @@
+require Logger
+
 defmodule BitcoinStream.RPC do
   @moduledoc """
   GenServer for bitcoin rpc requests
@@ -9,7 +11,7 @@ defmodule BitcoinStream.RPC do
   def start_link(opts) do
     {port, opts} = Keyword.pop(opts, :port);
     {host, opts} = Keyword.pop(opts, :host);
-    IO.puts("Starting Bitcoin RPC server on #{host} port #{port}")
+    Logger.info("Starting Bitcoin RPC server on #{host} port #{port}")
     GenServer.start_link(__MODULE__, {host, port, nil, nil, [], %{}}, opts)
   end
 
@@ -37,7 +39,7 @@ defmodule BitcoinStream.RPC do
         {:noreply, {host, port, status, creds, listeners, Map.put(inflight, task_ref, :status)}}
 
       :error ->
-        IO.puts("Waiting to connect to Bitcoin Core");
+        Logger.info("Waiting to connect to Bitcoin Core");
         Process.send_after(self(), :check_status, 10 * 1000);
         {:noreply, {host, port, status, creds, listeners, inflight}}
     end
@@ -45,13 +47,15 @@ defmodule BitcoinStream.RPC do
 
   @impl true
   def handle_info({:DOWN, ref, :process, _pid, _reason}, {host, port, status, creds, listeners, inflight}) do
-    # IO.puts("DOWN: #{inspect pid} #{inspect reason}")
     {_, inflight} = Map.pop(inflight, ref);
     {:noreply, {host, port, status, creds, listeners, inflight}}
   end
 
   @impl true
   def handle_info({ref, result}, {host, port, status, creds, listeners, inflight}) do
+    if Enum.count(inflight) > 2 do
+      Logger.debug("#{Enum.count(inflight)} rpc requests inflight");
+    end
     case Map.pop(inflight, ref) do
       {nil, inflight} ->
         {:noreply, {host, port, status, creds, listeners, inflight}}
@@ -61,18 +65,18 @@ defmodule BitcoinStream.RPC do
           # if node is connected and finished with the initial block download
           {:ok, 200, %{"initialblockdownload" => false}} ->
             # notify all listening processes
-            IO.puts("Bitcoin Core connected and synced");
+            Logger.info("Bitcoin Core connected and synced");
             notify_listeners(listeners);
             Process.send_after(self(), :check_status, 300 * 1000);
             {:noreply, {host, port, :ok, creds, [], inflight}}
 
           {:ok, 200, %{"initialblockdownload" => true}} ->
-            IO.puts("Bitcoin Core connected, waiting for initial block download");
+            Logger.info("Bitcoin Core connected, waiting for initial block download");
             Process.send_after(self(), :check_status, 30 * 1000);
             {:noreply, {host, port, :ibd, creds, listeners, inflight}}
 
           _ ->
-            IO.puts("Waiting to connect to Bitcoin Core");
+            Logger.info("Waiting to connect to Bitcoin Core");
             Process.send_after(self(), :check_status, 10 * 1000);
             {:noreply, {host, port, :disconnected, creds, listeners, inflight}}
         end
@@ -118,15 +122,15 @@ defmodule BitcoinStream.RPC do
             {:ok, status, info}
           else
             {:ok, status, _} ->
-              IO.puts("RPC request #{method} failed with HTTP code #{status}")
+              Logger.error("RPC request #{method} failed with HTTP code #{status}")
               {:error, status}
             {:error, reason} ->
-              IO.puts("RPC request #{method} failed");
-              IO.inspect(reason)
+              Logger.error("RPC request #{method} failed");
+              Logger.error("#{inspect(reason)}");
               {:error, reason}
             err ->
-              IO.puts("RPC request #{method} failed: (unknown reason)");
-              IO.inspect(err);
+              Logger.error("RPC request #{method} failed: (unknown reason)");
+              Logger.error("#{inspect(err)}");
               {:error, err}
           end
         end
@@ -134,8 +138,8 @@ defmodule BitcoinStream.RPC do
       {:ok, task.ref}
     else
       err ->
-        IO.puts("failed to make RPC request");
-        IO.inspect(err);
+        Logger.error("failed to make RPC request");
+        Logger.error("#{inspect(err)}");
         :error
     end
   end
@@ -171,16 +175,16 @@ defmodule BitcoinStream.RPC do
             { user, pw }
           else
             {:error, reason} ->
-              IO.puts("Failed to load bitcoin rpc cookie");
-              IO.inspect(reason)
+              Logger.error("Failed to load bitcoin rpc cookie");
+              Logger.error("#{inspect(reason)}")
               :error
             err ->
-              IO.puts("Failed to load bitcoin rpc cookie: (unknown reason)");
-              IO.inspect(err);
+              Logger.error("Failed to load bitcoin rpc cookie: (unknown reason)");
+              Logger.error("#{inspect(err)}")
               :error
           end
       true ->
-        IO.puts("Missing bitcoin rpc credentials");
+        Logger.error("Missing bitcoin rpc credentials");
         :error
     end
   end
diff --git a/server/lib/block_data.ex b/server/lib/block_data.ex
index e6ec594..67cbd9d 100644
--- a/server/lib/block_data.ex
+++ b/server/lib/block_data.ex
@@ -1,5 +1,7 @@
 Application.ensure_all_started(BitcoinStream.RPC)
 
+require Logger
+
 defmodule BitcoinStream.BlockData do
   @moduledoc """
   Block data module.
@@ -9,7 +11,7 @@ defmodule BitcoinStream.BlockData do
   use GenServer
 
   def start_link(opts) do
-    IO.puts("Starting block data link")
+    Logger.info("Starting block data link");
     # load block
 
     with {:ok, json} <- File.read("data/last_block.json"),
diff --git a/server/lib/bridge_block.ex b/server/lib/bridge_block.ex
index df39c25..59b2977 100644
--- a/server/lib/bridge_block.ex
+++ b/server/lib/bridge_block.ex
@@ -1,3 +1,5 @@
+require Logger
+
 defmodule BitcoinStream.Bridge.Block do
   @moduledoc """
   Bitcoin event bridge module.
@@ -20,7 +22,7 @@ defmodule BitcoinStream.Bridge.Block do
   end
 
   def start_link(host, port) do
-    IO.puts("Starting Bitcoin Block bridge on #{host} port #{port}")
+    Logger.info("Starting Bitcoin Block bridge on #{host} port #{port}");
     GenServer.start_link(__MODULE__, {host, port})
   end
 
@@ -38,17 +40,17 @@ defmodule BitcoinStream.Bridge.Block do
   defp connect(host, port) do
     # check rpc online & synced
     wait_for_ibd();
-    IO.puts("Node ready, connecting to block socket");
+    Logger.info("Node ready, connecting to block socket");
 
     # connect to socket
     {:ok, socket} = :chumak.socket(:sub);
-    IO.puts("Connected block zmq socket on #{host} port #{port}");
+    Logger.info("Connected block zmq socket on #{host} port #{port}");
     :chumak.subscribe(socket, 'rawblock')
-    IO.puts("Subscribed to rawblock events")
+    Logger.debug("Subscribed to rawblock events")
     case :chumak.connect(socket, :tcp, String.to_charlist(host), port) do
-      {:ok, pid} -> IO.puts("Binding ok to block socket pid #{inspect pid}");
-      {:error, reason} -> IO.puts("Binding block socket failed: #{reason}");
-      _ -> IO.puts("???");
+      {:ok, pid} -> Logger.debug("Binding ok to block socket pid #{inspect pid}");
+      {:error, reason} -> Logger.error("Binding block socket failed: #{reason}");
+      _ -> Logger.debug("???");
     end
 
     # start block loop
@@ -60,7 +62,7 @@ defmodule BitcoinStream.Bridge.Block do
       :ok -> true
 
       _ ->
-        IO.puts("Waiting for node to come online and fully sync before connecting to block socket");
+        Logger.info("Waiting for node to come online and fully sync before connecting to block socket");
         RPC.notify_on_ready(:rpc)
     end
   end
@@ -70,27 +72,27 @@ defmodule BitcoinStream.Bridge.Block do
       {:ok, payload} ->
         Registry.dispatch(Registry.BitcoinStream, "txs", fn(entries) ->
           for {pid, _} <- entries do
-            IO.puts("Forwarding to pid #{inspect pid}")
+            Logger.debug("Forwarding to pid #{inspect pid}")
             Process.send(pid, payload, []);
           end
         end)
-      {:error, reason} -> IO.puts("Error json encoding block: #{reason}");
+      {:error, reason} -> Logger.error("Error json encoding block: #{reason}");
     end
   end
 
   defp loop(socket, seq) do
-    IO.puts("waiting for block");
+    Logger.debug("waiting for block");
     with  {:ok, message} <- :chumak.recv_multipart(socket), # wait for the next zmq message in the queue
           [_topic, payload, <<sequence::little-size(32)>>] <- message,
           true <- (seq != sequence), # discard contiguous duplicate messages
-          _ <- IO.puts("block received"),
+          _ <- Logger.info("block received"),
           _ <- Mempool.set_block_locked(:mempool, true),
           {:ok, block} <- BitcoinBlock.decode(payload),
           count <- Mempool.clear_block_txs(:mempool, block),
           _ <- Mempool.set_block_locked(:mempool, false),
           {:ok, json} <- Jason.encode(block),
           :ok <- File.write("data/last_block.json", json) do
-      IO.puts("processed block #{block.id}");
+      Logger.info("processed block #{block.id}");
       BlockData.set_json_block(:block_data, block.id, json);
       send_block(block, count);
       loop(socket, sequence)
diff --git a/server/lib/bridge_sequence.ex b/server/lib/bridge_sequence.ex
index c77cf7e..b194c42 100644
--- a/server/lib/bridge_sequence.ex
+++ b/server/lib/bridge_sequence.ex
@@ -1,3 +1,5 @@
+require Logger
+
 defmodule BitcoinStream.Bridge.Sequence do
   @moduledoc """
   Bitcoin event bridge module.
@@ -18,7 +20,7 @@ defmodule BitcoinStream.Bridge.Sequence do
   end
 
   def start_link(host, port) do
-    IO.puts("Starting Bitcoin Sequence bridge on #{host} port #{port}")
+    Logger.info("Starting Bitcoin Sequence bridge on #{host} port #{port}")
     GenServer.start_link(__MODULE__, {host, port})
   end
 
@@ -36,17 +38,17 @@ defmodule BitcoinStream.Bridge.Sequence do
   defp connect(host, port) do
     # check rpc online & synced
     wait_for_ibd();
-    IO.puts("Node ready, connecting to sequence socket");
+    Logger.info("Node ready, connecting to sequence socket");
 
     # connect to socket
     {:ok, socket} = :chumak.socket(:sub);
-    IO.puts("Connected sequence zmq socket on #{host} port #{port}");
+    Logger.info("Connected sequence zmq socket on #{host} port #{port}");
     :chumak.subscribe(socket, 'sequence')
-    IO.puts("Subscribed to sequence events")
+    Logger.debug("Subscribed to sequence events")
     case :chumak.connect(socket, :tcp, String.to_charlist(host), port) do
-      {:ok, pid} -> IO.puts("Binding ok to sequence socket pid #{inspect pid}");
-      {:error, reason} -> IO.puts("Binding sequence socket failed: #{reason}");
-      _ -> IO.puts("???");
+      {:ok, pid} -> Logger.debug("Binding ok to sequence socket pid #{inspect pid}");
+      {:error, reason} -> Logger.error("Binding sequence socket failed: #{reason}");
+      _ -> Logger.info("???");
     end
 
     # start tx loop
@@ -58,13 +60,13 @@ defmodule BitcoinStream.Bridge.Sequence do
       :ok -> true
 
       _ ->
-        IO.puts("Waiting for node to come online and fully sync before connecting to sequence socket");
+        Logger.info("Waiting for node to come online and fully sync before connecting to sequence socket");
         RPC.notify_on_ready(:rpc)
     end
   end
 
   defp send_txn(txn, count) do
-    # IO.puts("Forwarding transaction to websocket clients")
+    # Logger.info("Forwarding transaction to websocket clients")
     case Jason.encode(%{type: "txn", txn: txn, count: count}) do
       {:ok, payload} ->
         Registry.dispatch(Registry.BitcoinStream, "txs", fn(entries) ->
@@ -72,7 +74,7 @@ defmodule BitcoinStream.Bridge.Sequence do
             Process.send(pid, payload, [])
           end
         end)
-      {:error, reason} -> IO.puts("Error json encoding transaction: #{reason}");
+      {:error, reason} -> Logger.error("Error json encoding transaction: #{reason}");
     end
   end
 
@@ -84,7 +86,7 @@ defmodule BitcoinStream.Bridge.Sequence do
             Process.send(pid, payload, []);
           end
         end)
-      {:error, reason} -> IO.puts("Error json encoding drop message: #{reason}");
+      {:error, reason} -> Logger.error("Error json encoding drop message: #{reason}");
     end
   end
 
@@ -93,7 +95,6 @@ defmodule BitcoinStream.Bridge.Sequence do
           [_topic, <<hash::binary-size(32), type::binary-size(1), seq::little-size(64)>>, <<_sequence::little-size(32)>>] <- message,
           txid <- Base.encode16(hash, case: :lower),
           event <- to_charlist(type) do
-      # IO.puts("loop #{sequence}");
       case event do
         # Transaction added to mempool
         'A' ->
@@ -101,7 +102,6 @@ defmodule BitcoinStream.Bridge.Sequence do
             false -> false
 
             { txn, count } ->
-              # IO.puts("*SEQ* #{txid}");
               send_txn(txn, count)
           end
 
diff --git a/server/lib/bridge_tx.ex b/server/lib/bridge_tx.ex
index f9e156f..69aa1d4 100644
--- a/server/lib/bridge_tx.ex
+++ b/server/lib/bridge_tx.ex
@@ -1,3 +1,5 @@
+require Logger
+
 defmodule BitcoinStream.Bridge.Tx do
   @moduledoc """
   Bitcoin event bridge module.
@@ -19,7 +21,7 @@ defmodule BitcoinStream.Bridge.Tx do
   end
 
   def start_link(host, port) do
-    IO.puts("Starting Bitcoin Tx bridge on #{host} port #{port}")
+    Logger.info("Starting Bitcoin Tx bridge on #{host} port #{port}")
     GenServer.start_link(__MODULE__, {host, port})
   end
 
@@ -37,17 +39,17 @@ defmodule BitcoinStream.Bridge.Tx do
   defp connect(host, port) do
     # check rpc online & synced
     wait_for_ibd();
-    IO.puts("Node ready, connecting to tx socket");
+    Logger.info("Node ready, connecting to tx socket");
 
     # connect to socket
     {:ok, socket} = :chumak.socket(:sub);
-    IO.puts("Connected tx zmq socket on #{host} port #{port}");
+    Logger.info("Connected tx zmq socket on #{host} port #{port}");
     :chumak.subscribe(socket, 'rawtx')
-    IO.puts("Subscribed to rawtx events")
+    Logger.debug("Subscribed to rawtx events")
     case :chumak.connect(socket, :tcp, String.to_charlist(host), port) do
-      {:ok, pid} -> IO.puts("Binding ok to tx socket pid #{inspect pid}");
-      {:error, reason} -> IO.puts("Binding tx socket failed: #{reason}");
-      _ -> IO.puts("???");
+      {:ok, pid} -> Logger.debug("Binding ok to tx socket pid #{inspect pid}");
+      {:error, reason} -> Logger.error("Binding tx socket failed: #{reason}");
+      _ -> Logger.info("???");
     end
 
     # start tx loop
@@ -59,13 +61,12 @@ defmodule BitcoinStream.Bridge.Tx do
       :ok -> true
 
       _ ->
-        IO.puts("Waiting for node to come online and fully sync before connecting to tx socket");
+        Logger.info("Waiting for node to come online and fully sync before connecting to tx socket");
         RPC.notify_on_ready(:rpc)
     end
   end
 
   defp send_txn(txn, count) do
-    # IO.puts("Forwarding transaction to websocket clients")
     case Jason.encode(%{type: "txn", txn: txn, count: count}) do
       {:ok, payload} ->
         Registry.dispatch(Registry.BitcoinStream, "txs", fn(entries) ->
@@ -73,7 +74,7 @@ defmodule BitcoinStream.Bridge.Tx do
             Process.send(pid, payload, [])
           end
         end)
-      {:error, reason} -> IO.puts("Error json encoding transaction: #{reason}");
+      {:error, reason} -> Logger.error("Error json encoding transaction: #{reason}");
     end
   end
 
@@ -97,12 +98,12 @@ defmodule BitcoinStream.Bridge.Tx do
         end
 
       {:err, reason} ->
-        IO.puts("Error decoding tx: #{reason}");
+        Logger.error("Error decoding tx: #{reason}");
         false
 
       error ->
-        IO.puts("Error decoding tx");
-        IO.inspect(error);
+        Logger.error("Error decoding tx");
+        Logger.error("#{inspect(error)}");
         false
     end
   end
diff --git a/server/lib/mempool.ex b/server/lib/mempool.ex
index 0f20fcd..75f2e4a 100644
--- a/server/lib/mempool.ex
+++ b/server/lib/mempool.ex
@@ -1,3 +1,5 @@
+require Logger
+
 defmodule BitcoinStream.Mempool do
   @moduledoc """
   GenServer for retrieving and maintaining mempool info
@@ -22,7 +24,7 @@ defmodule BitcoinStream.Mempool do
   connecting to a bitcoin node at RPC `host:port` for ground truth data
   """
   def start_link(opts) do
-    IO.puts("Starting Mempool Tracker");
+    Logger.info("Starting Mempool Tracker");
     # cache of all transactions in the node mempool, mapped to {inputs, total_input_value}
     :ets.new(:mempool_cache, [:set, :public, :named_table]);
     # cache of transactions ids in the mempool, but not yet synchronized with the :mempool_cache
@@ -311,7 +313,7 @@ defmodule BitcoinStream.Mempool do
             Process.send(pid, payload, []);
           end
         end)
-      {:error, reason} -> IO.puts("Error json encoding count: #{reason}");
+      {:error, reason} -> Logger.error("Error json encoding count: #{reason}");
     end
   end
 
@@ -325,7 +327,7 @@ defmodule BitcoinStream.Mempool do
   end
 
   def sync(pid) do
-    IO.puts("Preparing mempool sync");
+    Logger.info("Preparing mempool sync");
     with  {:ok, 200, %{"mempool_sequence" => sequence, "txids" => txns}} <- RPC.request(:rpc, "getrawmempool", [false, true]) do
       set_seq(pid, sequence);
       count = length(txns);
@@ -337,14 +339,14 @@ defmodule BitcoinStream.Mempool do
       sync_queue(pid, queue);
       set_queue(pid, []);
 
-      IO.puts("Loaded #{count} mempool transactions");
+      Logger.info("Loaded #{count} mempool transactions");
       send_mempool_count(pid);
       do_sync(pid, txns);
       :ok
     else
       err ->
-        IO.puts("Pool sync failed");
-        IO.inspect(err);
+        Logger.error("Pool sync failed");
+        Logger.error("#{inspect(err)}");
         #retry after 30 seconds
         :timer.sleep(10000);
         sync(pid)
@@ -352,9 +354,9 @@ defmodule BitcoinStream.Mempool do
   end
 
   def do_sync(pid, txns) do
-    IO.puts("Syncing #{length(txns)} mempool transactions");
+    Logger.info("Syncing #{length(txns)} mempool transactions");
     sync_mempool(pid, txns);
-    IO.puts("MEMPOOL SYNC FINISHED");
+    Logger.info("MEMPOOL SYNC FINISHED");
     set_done(pid);
     :ok
   end
@@ -374,11 +376,11 @@ defmodule BitcoinStream.Mempool do
           if inflated_txn.inflated do
             insert(pid, txid, inflated_txn)
           else
-            IO.puts("failed to inflate loaded mempool txn #{txid}")
+            Logger.debug("failed to inflate loaded mempool txn #{txid}")
           end
 
         else
-          _ -> IO.puts("sync_mempool_txn failed #{txid}")
+          _ -> Logger.debug("sync_mempool_txn failed #{txid}")
         end
 
       [_] -> true
@@ -390,7 +392,7 @@ defmodule BitcoinStream.Mempool do
   end
 
   defp sync_mempool_txns(pid, [head | tail], count) do
-    IO.puts("Syncing mempool tx #{count}/#{count + length(tail) + 1} | #{head}");
+    Logger.debug("Syncing mempool tx #{count}/#{count + length(tail) + 1} | #{head}");
     sync_mempool_txn(pid, head);
     sync_mempool_txns(pid, tail, count + 1)
   end
diff --git a/server/lib/mempool_sync.ex b/server/lib/mempool_sync.ex
index 0704a6a..f3f5a77 100644
--- a/server/lib/mempool_sync.ex
+++ b/server/lib/mempool_sync.ex
@@ -1,3 +1,5 @@
+require Logger
+
 defmodule BitcoinStream.Mempool.Sync do
 
   use GenServer
@@ -14,7 +16,7 @@ defmodule BitcoinStream.Mempool.Sync do
   end
 
   def start_link(args) do
-    IO.puts("Starting Mempool Synchronizer")
+    Logger.info("Starting Mempool Synchronizer")
     GenServer.start_link(__MODULE__, args)
   end
 
@@ -48,14 +50,14 @@ defmodule BitcoinStream.Mempool.Sync do
       :ok -> true
 
       _ ->
-        IO.puts("Waiting for node to come online and fully sync before synchronizing mempool");
+        Logger.info("Waiting for node to come online and fully sync before synchronizing mempool");
         RPC.notify_on_ready(:rpc)
     end
   end
 
   defp first_sync() do
     wait_for_ibd();
-    IO.puts("Preparing mempool sync");
+    Logger.info("Preparing mempool sync");
     Mempool.sync(:mempool);
     Process.send_after(self(), :resync, 20 * 1000);
   end
@@ -64,28 +66,28 @@ defmodule BitcoinStream.Mempool.Sync do
     wait_for_ibd();
     case Mempool.is_block_locked(:mempool) do
       true ->
-        IO.puts("Processing block, delay mempool health check by 5 seconds");
+        Logger.debug("Processing block, delay mempool health check by 5 seconds");
         Process.send_after(self(), :resync, 5 * 1000)
 
       false ->
         with  {:ok, 200, %{"size" => size}} when is_integer(size) <- RPC.request(:rpc, "getmempoolinfo", []),
               count when is_integer(count) <- Mempool.get(:mempool) do
-          IO.puts("Mempool health check - Core count: #{size} | Bitfeed count: #{count}");
+          Logger.debug("Mempool health check - Core count: #{size} | Bitfeed count: #{count}");
 
           # if we've diverged from the true count by more than 50 txs, then fix
           # ensures our count doesn't stray too far due to missed events & unexpected errors.
           if (abs(size - count) > 50) do
-            IO.puts("resync");
+            Logger.debug("resync");
             Mempool.set(:mempool, size);
             newcount = Mempool.get(:mempool);
-            IO.puts("updated to #{newcount}");
+            Logger.debug("updated to #{newcount}");
           end
           # next check in 1 minute
           Process.send_after(self(), :resync, 60 * 1000)
         else
           err ->
-            IO.puts("mempool health check failed");
-            IO.inspect(err);
+            Logger.error("mempool health check failed");
+            Logger.error("#{inspect(err)}");
             #retry in 10 seconds
             Process.send_after(self(), :resync, 10 * 1000)
         end
diff --git a/server/lib/protocol/block.ex b/server/lib/protocol/block.ex
index 99252a3..72352ec 100644
--- a/server/lib/protocol/block.ex
+++ b/server/lib/protocol/block.ex
@@ -1,5 +1,7 @@
 Application.ensure_all_started(BitcoinStream.RPC)
 
+require Logger
+
 defmodule BitcoinStream.Protocol.Block do
 @moduledoc """
   Summarised bitcoin block.
@@ -49,10 +51,10 @@ def decode(block_binary) do
     }}
   else
     {:error, reason} ->
-      IO.puts("Error decoding data for BitcoinBlock: #{reason}")
+      Logger.error("Error decoding data for BitcoinBlock: #{reason}")
       :error
     _ ->
-      IO.puts("Error decoding data for BitcoinBlock: (unknown reason)")
+      Logger.error("Error decoding data for BitcoinBlock: (unknown reason)")
       :error
   end
 end
@@ -81,7 +83,7 @@ defp summarise_txns([next | rest], summarised, total, fees, do_inflate) do
   if do_inflate do
     inflated_txn = BitcoinTx.inflate(extended_txn)
     if (inflated_txn.inflated) do
-      IO.puts("Processing block tx #{length(summarised)}/#{length(summarised) + length(rest) + 1} | #{next.id}");
+      Logger.debug("Processing block tx #{length(summarised)}/#{length(summarised) + length(rest) + 1} | #{next.id}");
       summarise_txns(rest, [inflated_txn | summarised], total + inflated_txn.value, fees + inflated_txn.fee, true)
     else
       summarise_txns(rest, [inflated_txn | summarised], total + inflated_txn.value, nil, false)
diff --git a/server/lib/protocol/transaction.ex b/server/lib/protocol/transaction.ex
index 768bfdf..c7a6bd2 100644
--- a/server/lib/protocol/transaction.ex
+++ b/server/lib/protocol/transaction.ex
@@ -1,5 +1,7 @@
 Application.ensure_all_started(BitcoinStream.RPC)
 
+require Logger
+
 defmodule BitcoinStream.Protocol.Transaction do
   @moduledoc """
     Extended bitcoin transaction struct
@@ -142,15 +144,15 @@ defmodule BitcoinStream.Protocol.Transaction do
           } }
         else
           {:ok, 500, reason} ->
-            IO.puts("transaction not found #{input.prev_txid}");
-            IO.inspect(reason)
+            Logger.error("transaction not found #{input.prev_txid}");
+            Logger.error("#{inspect(reason)}")
           {:error, reason} ->
-            IO.puts("Failed to inflate input:");
-            IO.inspect(reason)
+            Logger.error("Failed to inflate input:");
+            Logger.error("#{inspect(reason)}")
             :error
           err ->
-            IO.puts("Failed to inflate input: (unknown reason)");
-            IO.inspect(err);
+            Logger.error("Failed to inflate input: (unknown reason)");
+            Logger.error("#{inspect(err)}")
             :error
         end
     end
@@ -185,7 +187,7 @@ defmodule BitcoinStream.Protocol.Transaction do
         {:ok, inputs, total}
 
       other ->
-        IO.inspect(other);
+        Logger.error("#{inspect(other)}");
         inflate_inputs(inputs, [], 0)
     end
   end
diff --git a/server/lib/router.ex b/server/lib/router.ex
index 0ee4268..7e718ab 100644
--- a/server/lib/router.ex
+++ b/server/lib/router.ex
@@ -1,3 +1,5 @@
+require Logger
+
 defmodule BitcoinStream.Router do
   use Plug.Router
 
@@ -20,7 +22,7 @@ defmodule BitcoinStream.Router do
         put_resp_header(conn, "cache-control", "public, max-age=604800, immutable")
         |> send_resp(200, block)
       _ ->
-        IO.puts("Error getting block hash");
+        Logger.debug("Error getting block hash");
         send_resp(conn, 404, "Block not available")
     end
   end
diff --git a/server/lib/server.ex b/server/lib/server.ex
index 7dd8189..e31b450 100644
--- a/server/lib/server.ex
+++ b/server/lib/server.ex
@@ -1,3 +1,5 @@
+require Logger
+
 defmodule BitcoinStream.Server do
   use Application
 
@@ -9,8 +11,20 @@ defmodule BitcoinStream.Server do
     { rpc_port, "" } = Integer.parse(System.get_env("BITCOIN_RPC_PORT"));
     { rpc_pools, "" } = Integer.parse(System.get_env("RPC_POOLS"));
     { rpc_pool_size, "" } = Integer.parse(System.get_env("RPC_POOL_SIZE"));
+    log_level = System.get_env("LOG_LEVEL");
     btc_host = System.get_env("BITCOIN_HOST");
 
+    case log_level do
+      "debug" ->
+        Logger.configure(level: :debug);
+
+      "error" ->
+        Logger.configure(level: :error);
+
+      _ ->
+        Logger.configure(level: :info);
+    end
+
     children = [
       Registry.child_spec(
         keys: :duplicate,
diff --git a/server/lib/socket_handler.ex b/server/lib/socket_handler.ex
index e92e988..9d71ef5 100644
--- a/server/lib/socket_handler.ex
+++ b/server/lib/socket_handler.ex
@@ -1,3 +1,5 @@
+require Logger
+
 defmodule BitcoinStream.SocketHandler do
   @behaviour :cowboy_websocket
 
@@ -16,9 +18,9 @@ defmodule BitcoinStream.SocketHandler do
   end
 
   def get_block(last_seen) do
-    IO.puts("getting block with id #{last_seen}")
+    Logger.debug("getting block with id #{last_seen}")
     last_id = BlockData.get_block_id(:block_data)
-    IO.puts("last block id: #{last_id}")
+    Logger.debug("last block id: #{last_id}")
     cond do
       (last_seen == nil) ->
         payload = BlockData.get_json_block(:block_data);
@@ -42,12 +44,11 @@ defmodule BitcoinStream.SocketHandler do
   end
 
   def websocket_handle({:text, msg}, state) do
-    # IO.puts("message received: #{msg} | #{inspect self()}");
     case msg do
       "hb" -> {:reply, {:text, msg}, state};
 
       "block" ->
-        IO.puts('block request');
+        Logger.debug('block request');
         {:reply, {:text, "null"}, state}
 
       "count" ->
@@ -72,11 +73,11 @@ defmodule BitcoinStream.SocketHandler do
           end
         else
           {:error, reason} ->
-            IO.puts("Failed to parse websocket message");
-            IO.inspect(reason)
+            Logger.error("Failed to parse websocket message");
+            Logger.error("#{inspect(reason)}")
           reason ->
-            IO.puts("other response");
-            IO.inspect(reason)
+            Logger.error("other response");
+            Logger.error("#{inspect(reason)}")
           _ -> {:reply, {:text, "?"}, state}
         end
     end