diff --git a/Cargo.toml b/Cargo.toml
index 963a443..c6908db 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,7 +3,8 @@
 members = [
     "signer",
     "broker",
-    "parser"
+    "parser",
+    "tester"
 ]
 
 exclude = [
diff --git a/broker/Cargo.toml b/broker/Cargo.toml
index 2953f35..f789b29 100644
--- a/broker/Cargo.toml
+++ b/broker/Cargo.toml
@@ -9,13 +9,17 @@ default-run = "sphinx-key-broker"
 rumqttd = "0.11.0"
 pretty_env_logger = "0.4.0"
 confy = "0.4.0"
-tokio = "1.18"
+tokio = { version = "1.4.0", features = ["rt", "rt-multi-thread", "macros"] }
 vls-protocol = { path = "../../validating-lightning-signer/vls-protocol" }
+vls-proxy = { path = "../../validating-lightning-signer/vls-proxy" }
 sphinx-key-parser = { path = "../parser" }
 secp256k1 = { version = "0.20", features = ["rand-std", "bitcoin_hashes"] }
 anyhow = {version = "1", features = ["backtrace"]}
 log = "0.4"
+fern = { version = "0.6", features = ["colored"] }
 rumqttc = "0.12.0"
+clap = "=3.0.0-beta.2"
+clap_derive = "=3.0.0-beta.5"
 
 [features]
 default = ["std"]
diff --git a/broker/src/main.rs b/broker/src/main.rs
index e4ebb0b..8c83ac8 100644
--- a/broker/src/main.rs
+++ b/broker/src/main.rs
@@ -1,68 +1,68 @@
-use sphinx_key_parser::MsgDriver;
-use librumqttd::{async_locallink::construct_broker, Config};
-use std::thread;
-use vls_protocol::msgs;
-use vls_protocol::serde_bolt::WireString;
-use tokio::sync::mpsc;
+mod mqtt;
+mod run_test;
+mod unix_fd;
 
-const SUB_TOPIC: &str = "sphinx-return";
-const TRIGGER_TOPIC: &str = "trigger";
-const PUB_TOPIC: &str = "sphinx";
+use crate::unix_fd::SignerLoop;
+use clap::{App, AppSettings, Arg};
+use crate::mqtt::start_broker;
+use std::env;
+use tokio::sync::{mpsc, oneshot};
+use vls_proxy::client::UnixClient;
+use vls_proxy::connection::{open_parent_fd, UnixConnection};
+use vls_proxy::util::setup_logging;
 
-fn main() {
-    pretty_env_logger::init();
-    let config: Config = confy::load_path("config/rumqttd.conf").unwrap();
-
-    let (mut router, console, servers, builder) = construct_broker(config);
-
-    thread::spawn(move || {
-        router.start().unwrap();
-    });
-
-    let mut rt = tokio::runtime::Builder::new_multi_thread();
-    rt.enable_all();
-    rt.build().unwrap().block_on(async {
-        let (msg_tx, mut msg_rx): (mpsc::UnboundedSender<Vec<u8>>, mpsc::UnboundedReceiver<Vec<u8>>) = mpsc::unbounded_channel();
-        let (mut tx, mut rx) = builder.connect("localclient", 200).await.unwrap();
-        tx.subscribe([SUB_TOPIC, TRIGGER_TOPIC]).await.unwrap();
-
-        let console_task = tokio::spawn(console);
-
-        let pub_task = tokio::spawn(async move {
-            while let Some(_) = msg_rx.recv().await {
-                let sequence = 0;
-                let mut md = MsgDriver::new_empty(); 
-                msgs::write_serial_request_header(&mut md, sequence, 0).expect("failed to write_serial_request_header");
-                let ping = msgs::Ping {
-                    id: 0,
-                    message: WireString("ping".as_bytes().to_vec()),
-                };
-                msgs::write(&mut md, ping).expect("failed to serial write");
-                tx.publish(PUB_TOPIC, false, md.bytes()).await.unwrap();
-            }
-        });
-
-        let sub_task = tokio::spawn(async move {
-            loop {
-                let message = rx.recv().await.unwrap();
-                // println!("T = {}, P = {:?}", message.topic, message.payload.len());
-                // println!("count {}", message.payload.len());
-                for payload in message.payload {
-                    if let Err(e) = msg_tx.send(payload.to_vec()) {
-                        println!("pub err {:?}", e);
-                    }
-                }
-            }
-        });
-
-        servers.await;
-        println!("server awaited");
-        pub_task.await.unwrap();
-        println!("pub awaited");
-        sub_task.await.unwrap();
-        println!("sub awaited");
-        console_task.await.unwrap();
-    });
+pub struct Channel {
+    pub sequence: u16,
+    pub sender: mpsc::Sender<ChannelRequest>,
 }
 
+/// Responses are received on the oneshot sender
+pub struct ChannelRequest {
+    pub message: Vec<u8>,
+    pub reply_tx: oneshot::Sender<ChannelReply>,
+}
 
+// mpsc reply
+pub struct ChannelReply {
+    pub reply: Vec<u8>,
+}
+
+fn main() -> anyhow::Result<()> {
+    let parent_fd = open_parent_fd();
+
+    setup_logging("hsmd  ", "info");
+    let app = App::new("signer")
+        .setting(AppSettings::NoAutoVersion)
+        .about("CLN:mqtt - connects to an embedded VLS over a MQTT connection")
+        .arg(
+            Arg::new("--dev-disconnect")
+                .about("ignored dev flag")
+                .long("dev-disconnect")
+                .takes_value(true),
+        )
+        .arg(Arg::from("--log-io ignored dev flag"))
+        .arg(Arg::from("--version show a dummy version"))
+        .arg(Arg::from("--test run a test against the embedded device"));
+    let matches = app.get_matches();
+    if matches.is_present("version") {
+        // Pretend to be the right version, given to us by an env var
+        let version =
+            env::var("GREENLIGHT_VERSION").expect("set GREENLIGHT_VERSION to match c-lightning");
+        println!("{}", version);
+        return Ok(());
+    }
+
+    if matches.is_present("test") {
+        run_test::run_test();
+    } else {
+        let (tx, rx) = mpsc::channel(1000);
+        let _runtime = start_broker(true, rx);
+        // listen to reqs from CLN
+        let conn = UnixConnection::new(parent_fd);
+        let client = UnixClient::new(conn);
+        let mut signer_loop = SignerLoop::new(client, tx);
+        signer_loop.start();
+    }
+
+    Ok(())
+}
diff --git a/broker/src/mqtt.rs b/broker/src/mqtt.rs
new file mode 100644
index 0000000..3762ada
--- /dev/null
+++ b/broker/src/mqtt.rs
@@ -0,0 +1,81 @@
+use crate::{ChannelRequest,ChannelReply};
+use librumqttd::{async_locallink::construct_broker, Config};
+use std::thread;
+use tokio::sync::{oneshot, mpsc};
+
+const SUB_TOPIC: &str = "sphinx-return";
+const PUB_TOPIC: &str = "sphinx";
+
+pub fn start_broker(wait_for_ready_message: bool, mut receiver: mpsc::Receiver<ChannelRequest>) -> tokio::runtime::Runtime {
+
+    let config: Config = confy::load_path("config/rumqttd.conf").unwrap();
+
+    let (mut router, console, servers, builder) = construct_broker(config);
+
+    thread::spawn(move || {
+        router.start().expect("could not start router");
+    });
+
+    let mut rt_builder = tokio::runtime::Builder::new_multi_thread();
+    rt_builder.enable_all();
+    let rt = rt_builder.build().unwrap();
+    rt.block_on(async {
+        // channel to block until READY received
+        let (ready_tx, ready_rx) = oneshot::channel();
+        tokio::spawn(async move {
+            let (msg_tx, mut msg_rx): (mpsc::Sender<Vec<u8>>, mpsc::Receiver<Vec<u8>>) = mpsc::channel(1000);
+            let (mut tx, mut rx) = builder.connect("localclient", 200).await.unwrap();
+            tx.subscribe([SUB_TOPIC]).await.unwrap();
+
+            let console_task = tokio::spawn(console);
+
+            let sub_task = tokio::spawn(async move {
+                // ready message loop
+                // let ready_tx_ = ready_tx.clone();
+                if wait_for_ready_message {
+                    loop {
+                        let message = rx.recv().await.unwrap();
+                        if let Some(payload) = message.payload.get(0) {
+                            let content = String::from_utf8_lossy(&payload[..]);
+                            if content == "READY" {
+                                ready_tx.send(true).expect("could not send ready");
+                                break;
+                            }
+                        }
+                    }
+                }
+                loop {
+                    let message = rx.recv().await.unwrap();
+                    // println!("T = {}, P = {:?}", message.topic, message.payload.len());
+                    // println!("count {}", message.payload.len());
+                    for payload in message.payload {
+                        if let Err(e) = msg_tx.send(payload.to_vec()).await {
+                            println!("pub err {:?}", e);
+                        }
+                    }
+                }
+            });
+
+            let relay_task = tokio::spawn(async move {
+                while let Some(msg) = receiver.recv().await {
+                    tx.publish(PUB_TOPIC, false, msg.message).await.expect("could not mqtt pub");
+                    let reply = msg_rx.recv().await.expect("could not unwrap msg_rx.recv()");
+                    if let Err(_) = msg.reply_tx.send(ChannelReply { reply }) {
+                        log::warn!("could not send on reply_tx");
+                    }
+                }
+            });
+
+            servers.await;
+            sub_task.await.unwrap();
+            relay_task.await.unwrap();
+            console_task.await.unwrap();
+        });
+        if wait_for_ready_message {
+            log::info!("waiting for READY...");
+            ready_rx.await.expect("Could not receive from channel.");
+        }
+    });
+
+    rt
+}
diff --git a/broker/src/run_test.rs b/broker/src/run_test.rs
new file mode 100644
index 0000000..712fc7d
--- /dev/null
+++ b/broker/src/run_test.rs
@@ -0,0 +1,66 @@
+use crate::mqtt::start_broker;
+use crate::ChannelRequest;
+use sphinx_key_parser::MsgDriver;
+use tokio::sync::{mpsc, oneshot};
+use vls_protocol::serde_bolt::WireString;
+use vls_protocol::{msgs, msgs::Message};
+
+pub fn run_test() {
+    log::info!("TEST...");
+
+    let mut id = 0u16;
+    let mut sequence = 1;
+
+    let (tx, rx) = mpsc::channel(1000);
+    let runtime = start_broker(true, rx);
+    log::info!("======> READY received! start now");
+    runtime.block_on(async {
+        loop {
+            if let Err(e) = iteration(id, sequence, tx.clone()).await {
+                panic!("iteration failed {:?}", e);
+            }
+            sequence = sequence.wrapping_add(1);
+            id += 1;
+            tokio::time::sleep(tokio::time::Duration::from_secs(1)).await;
+        }
+    });
+}
+
+pub async fn iteration(
+    id: u16,
+    sequence: u16,
+    tx: mpsc::Sender<ChannelRequest>,
+) -> anyhow::Result<()> {
+    let mut md = MsgDriver::new_empty();
+    msgs::write_serial_request_header(&mut md, sequence, 0)?;
+    let ping = msgs::Ping {
+        id,
+        message: WireString("ping".as_bytes().to_vec()),
+    };
+    msgs::write(&mut md, ping)?;
+    let (reply_tx, reply_rx) = oneshot::channel();
+    // Send a request to the MQTT handler to send to signer
+    let request = ChannelRequest {
+        message: md.bytes(),
+        reply_tx,
+    };
+    let _ = tx.send(request).await;
+    let res = reply_rx.await?;
+    let mut ret = MsgDriver::new(res.reply);
+    msgs::read_serial_response_header(&mut ret, sequence)?;
+    let reply = msgs::read(&mut ret)?;
+    match reply {
+        Message::Pong(p) => {
+            log::info!(
+                "got reply {} {}",
+                p.id,
+                String::from_utf8(p.message.0).unwrap()
+            );
+            assert_eq!(p.id, id);
+        }
+        _ => {
+            panic!("unknown response");
+        }
+    }
+    Ok(())
+}
diff --git a/broker/src/test_client.rs b/broker/src/test_client.rs
index 9073a64..7bf0f80 100644
--- a/broker/src/test_client.rs
+++ b/broker/src/test_client.rs
@@ -27,7 +27,6 @@ async fn main() -> Result<(), Box<dyn Error>> {
         // println!("{:?}", event.unwrap());
         if let Event::Incoming(packet) = event.unwrap() {
             if let Packet::Publish(p) = packet {
-                // println!("incoming {:?}", p.payload);
                 let mut m = MsgDriver::new(p.payload.to_vec());
                 let (sequence, dbid) = msgs::read_serial_request_header(&mut m).expect("read ping header");
                 assert_eq!(dbid, 0);
diff --git a/broker/src/unix_fd.rs b/broker/src/unix_fd.rs
new file mode 100644
index 0000000..37fbf3f
--- /dev/null
+++ b/broker/src/unix_fd.rs
@@ -0,0 +1,137 @@
+use log::*;
+use secp256k1::PublicKey;
+use sphinx_key_parser::MsgDriver;
+use std::thread;
+use tokio::sync::{mpsc, oneshot};
+// use tokio::task::spawn_blocking;
+use crate::{Channel, ChannelReply, ChannelRequest};
+use vls_protocol::{msgs, msgs::Message, Error, Result};
+use vls_proxy::client::Client;
+
+#[derive(Clone, Debug)]
+pub struct ClientId {
+    pub peer_id: PublicKey,
+    pub dbid: u64,
+}
+
+impl Channel {
+    pub fn new(sender: mpsc::Sender<ChannelRequest>) -> Self {
+        Self {
+            sender,
+            sequence: 0,
+        }
+    }
+}
+
+/// Implement the hsmd UNIX fd protocol.
+pub struct SignerLoop<C: 'static + Client> {
+    client: C,
+    log_prefix: String,
+    chan: Channel,
+    client_id: Option<ClientId>,
+}
+
+impl<C: 'static + Client> SignerLoop<C> {
+    /// Create a loop for the root (lightningd) connection, but doesn't start it yet
+    pub fn new(client: C, sender: mpsc::Sender<ChannelRequest>) -> Self {
+        let log_prefix = format!("{}/{}", std::process::id(), client.id());
+        Self {
+            client,
+            log_prefix,
+            chan: Channel::new(sender),
+            client_id: None,
+        }
+    }
+
+    // Create a loop for a non-root connection
+    fn new_for_client(
+        client: C,
+        sender: mpsc::Sender<ChannelRequest>,
+        client_id: ClientId,
+    ) -> Self {
+        let log_prefix = format!("{}/{}", std::process::id(), client.id());
+        Self {
+            client,
+            log_prefix,
+            chan: Channel::new(sender),
+            client_id: Some(client_id),
+        }
+    }
+
+    /// Start the read loop
+    pub fn start(&mut self) {
+        info!("loop {}: start", self.log_prefix);
+        match self.do_loop() {
+            Ok(()) => info!("loop {}: done", self.log_prefix),
+            Err(Error::Eof) => info!("loop {}: ending", self.log_prefix),
+            Err(e) => error!("loop {}: error {:?}", self.log_prefix, e),
+        }
+    }
+
+    fn do_loop(&mut self) -> Result<()> {
+        loop {
+            let raw_msg = self.client.read_raw()?;
+            debug!("loop {}: got raw", self.log_prefix);
+            let msg = msgs::from_vec(raw_msg.clone())?;
+            info!("loop {}: got {:x?}", self.log_prefix, msg);
+            match msg {
+                Message::ClientHsmFd(m) => {
+                    self.client.write(msgs::ClientHsmFdReply {}).unwrap();
+                    let new_client = self.client.new_client();
+                    info!("new client {} -> {}", self.log_prefix, new_client.id());
+                    let peer_id = PublicKey::from_slice(&m.peer_id.0).expect("client pubkey"); // we don't expect a bad key from lightningd parent
+                    let client_id = ClientId {
+                        peer_id,
+                        dbid: m.dbid,
+                    };
+                    let mut new_loop =
+                        SignerLoop::new_for_client(new_client, self.chan.sender.clone(), client_id);
+                    thread::spawn(move || new_loop.start());
+                }
+                Message::Memleak(_) => {
+                    let reply = msgs::MemleakReply { result: false };
+                    self.client.write(reply)?;
+                }
+                _ => {
+                    let reply = self.handle_message(raw_msg)?;
+                    // Write the reply to the node
+                    self.client.write_vec(reply)?;
+                    info!("replied {}", self.log_prefix);
+                }
+            }
+        }
+    }
+
+    fn handle_message(&mut self, message: Vec<u8>) -> Result<Vec<u8>> {
+        let dbid = self.client_id.as_ref().map(|c| c.dbid).unwrap_or(0);
+        let mut md = MsgDriver::new_empty();
+        msgs::write_serial_request_header(&mut md, self.chan.sequence, dbid)?;
+        msgs::write_vec(&mut md, message)?;
+        let reply_rx = self.send_request(md.bytes())?;
+        let mut res = self.get_reply(reply_rx)?;
+        msgs::read_serial_response_header(&mut res, self.chan.sequence)?;
+        self.chan.sequence = self.chan.sequence.wrapping_add(1);
+        let reply = msgs::read_raw(&mut res)?;
+        Ok(reply)
+    }
+
+    fn send_request(&mut self, message: Vec<u8>) -> Result<oneshot::Receiver<ChannelReply>> {
+        // Create a one-shot channel to receive the reply
+        let (reply_tx, reply_rx) = oneshot::channel();
+        // Send a request to the MQTT handler to send to signer
+        let request = ChannelRequest { message, reply_tx };
+        // This can fail if MQTT shuts down
+        self.chan
+            .sender
+            .blocking_send(request)
+            .map_err(|_| Error::Eof)?;
+        Ok(reply_rx)
+    }
+
+    fn get_reply(&mut self, reply_rx: oneshot::Receiver<ChannelReply>) -> Result<Vec<u8>> {
+        // Wait for the signer reply
+        // Can fail if MQTT shuts down
+        let reply = reply_rx.blocking_recv().map_err(|_| Error::Eof)?;
+        Ok(reply.reply)
+    }
+}
diff --git a/tester/Cargo.toml b/tester/Cargo.toml
new file mode 100644
index 0000000..ed2b329
--- /dev/null
+++ b/tester/Cargo.toml
@@ -0,0 +1,16 @@
+[package]
+name = "sphinx-key-tester"
+version = "0.1.0"
+authors = ["Evan Feenstra <evanfeenstra@gmail.com>"]
+edition = "2018"
+
+[dependencies]
+sphinx-key-signer = { path = "../signer" }
+sphinx-key-parser = { path = "../parser" }
+vls-protocol = { path = "../../validating-lightning-signer/vls-protocol" }
+vls-protocol-signer = { path = "../../validating-lightning-signer/vls-protocol-signer", default-features = false, features = ["secp-lowmemory", "vls-std"] }
+anyhow = {version = "1", features = ["backtrace"]}
+log = "0.4"
+rumqttc = "0.12.0"
+tokio = { version = "1.4.0", features = ["rt", "rt-multi-thread", "macros"] }
+pretty_env_logger = "0.4.0"
diff --git a/tester/src/main.rs b/tester/src/main.rs
new file mode 100644
index 0000000..f73e223
--- /dev/null
+++ b/tester/src/main.rs
@@ -0,0 +1,66 @@
+
+use sphinx_key_parser::MsgDriver;
+
+use rumqttc::{self, AsyncClient, MqttOptions, QoS, Event, Packet};
+use std::error::Error;
+use std::time::Duration;
+use vls_protocol::msgs;
+
+const SUB_TOPIC: &str = "sphinx";
+const PUB_TOPIC: &str = "sphinx-return";
+const USERNAME: &str = "sphinx-key";
+const PASSWORD: &str = "sphinx-key-pass";
+
+#[tokio::main(worker_threads = 1)]
+async fn main() -> Result<(), Box<dyn Error>> {
+    pretty_env_logger::init();
+    // color_backtrace::install();
+
+    let mut mqttoptions = MqttOptions::new("test-1", "localhost", 1883);
+    mqttoptions.set_credentials(USERNAME, PASSWORD);
+    mqttoptions.set_keep_alive(Duration::from_secs(5));
+
+    let (client, mut eventloop) = AsyncClient::new(mqttoptions, 10);
+
+    client
+        .subscribe(SUB_TOPIC, QoS::AtMostOnce)
+        .await
+        .expect("could not mqtt subscribe");
+
+    client.publish(PUB_TOPIC, QoS::AtMostOnce, false, "READY".as_bytes().to_vec()).await.expect("could not pub");
+
+    loop {
+        let event = eventloop.poll().await;
+        // println!("{:?}", event.unwrap());
+        if let Some(mut m) = incoming_msg(event.expect("failed to unwrap event")) {
+            let (sequence, dbid) = msgs::read_serial_request_header(&mut m).expect("read ping header");
+            println!("sequence {}", sequence);
+            println!("dbid {}", dbid);
+            let ping: msgs::Ping =
+                msgs::read_message(&mut m).expect("failed to read ping message");
+            println!("INCOMING: {:?}", ping);
+            let mut md = MsgDriver::new_empty();
+            msgs::write_serial_response_header(&mut md, sequence)
+                .expect("failed to write_serial_request_header");
+            let pong = msgs::Pong {
+                id: ping.id,
+                message: ping.message
+            };
+            msgs::write(&mut md, pong).expect("failed to serial write");
+            client
+                .publish(PUB_TOPIC, QoS::AtMostOnce, false, md.bytes())
+                .await
+                .expect("could not mqtt publish");
+        }
+    }
+}
+
+fn incoming_msg(event: Event) -> Option<MsgDriver> {
+    if let Event::Incoming(packet) = event {
+        if let Packet::Publish(p) = packet {
+            let m = MsgDriver::new(p.payload.to_vec());
+            return Some(m)
+        }
+    }
+    None
+}
\ No newline at end of file