diff --git a/src/bin/bridgedb.rs b/src/bin/bridgedb.rs
index c2799e5..577c59f 100644
--- a/src/bin/bridgedb.rs
+++ b/src/bin/bridgedb.rs
@@ -19,7 +19,7 @@ async fn main() {
 
     // If bridgedb has already been created, recreate it from file.
     // Otherwise, create new bridgedb.
-    let bridgedb = if Path::new(bridgedb_filename).exists() {
+    let mut bridgedb = if Path::new(bridgedb_filename).exists() {
         // read in file
         let bridgedb_infile = File::open(bridgedb_filename).unwrap();
         serde_json::from_reader(bridgedb_infile).unwrap()
@@ -49,11 +49,16 @@ async fn main() {
         .expect("Failed to write to bridgedb pubkey file");
     }
 
-    listen(addr, to_uppercase).await;
+    let mut cmd_lambda = |cmd: Vec<u8>| perform_command(cmd, &bridgedb);
+
+    listen(addr, &mut cmd_lambda).await;
 }
 
-// This function assumes the byte vector is a valid string.
-fn to_uppercase(str_vec: Vec<u8>) -> Vec<u8> {
-    let str = std::str::from_utf8(&str_vec).unwrap();
-    str.to_uppercase().into()
+fn perform_command(cmd: Vec<u8>, bridgedb: &BridgeDb) -> Vec<u8> {
+    if cmd[0] == 1 {
+        // note, the bridgedb currently has no buckets
+        return bridgedb.invite().to_vec();
+    }
+    // default response, to deal with later
+    [].to_vec()
 }
diff --git a/src/bin/lox_auth.rs b/src/bin/lox_auth.rs
index 431d8e1..3ab52c6 100644
--- a/src/bin/lox_auth.rs
+++ b/src/bin/lox_auth.rs
@@ -25,7 +25,7 @@ async fn main() {
 
     // If lox_auth has already been created, recreate it from file.
     // Otherwise, create new lox authority.
-    let lox_auth = if Path::new(lox_auth_filename).exists() {
+    let mut lox_auth = if Path::new(lox_auth_filename).exists() {
         // read in file
         let lox_auth_infile = File::open(lox_auth_filename).unwrap();
         serde_json::from_reader(lox_auth_infile).unwrap()
@@ -65,11 +65,12 @@ async fn main() {
         .expect("Failed to write to lox_auth pubkeys file");
     }
 
-    listen(addr, reverse_string).await;
+    let mut cmd_lambda = |cmd: Vec<u8>| perform_command(cmd, &lox_auth);
+
+    listen(addr, &mut cmd_lambda).await;
 }
 
-// This function assumes the byte vector is a valid string.
-fn reverse_string(str_vec: Vec<u8>) -> Vec<u8> {
-    let str = std::str::from_utf8(&str_vec).unwrap();
-    str.trim().chars().rev().collect::<String>().into()
+fn perform_command(cmd: Vec<u8>, lox_auth: &BridgeAuth) -> Vec<u8> {
+    // just send something back for now
+    "ACK".into()
 }
diff --git a/src/bin/lox_client.rs b/src/bin/lox_client.rs
index 75d07d6..b3a268b 100644
--- a/src/bin/lox_client.rs
+++ b/src/bin/lox_client.rs
@@ -19,6 +19,7 @@ async fn main() {
     let addr = args().nth(1).unwrap();
 
     // message to send
+    // TODO: determine commands so the client sends something meaningful
     let msg = args().nth(2).unwrap();
 
     // import bridgedb pubkey
@@ -37,5 +38,5 @@ async fn main() {
 
     let s = send(addr, msg.into()).await;
 
-    println!("{}", std::str::from_utf8(&s).unwrap());
+    println!("{}", serde_json::to_string(&s).unwrap());
 }
diff --git a/src/server_net.rs b/src/server_net.rs
index d3bb604..8b43119 100644
--- a/src/server_net.rs
+++ b/src/server_net.rs
@@ -9,7 +9,7 @@ these work. */
 use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio::net::TcpListener;
 
-pub async fn listen(addr: String, fun: fn(Vec<u8>) -> Vec<u8>) {
+pub async fn listen(addr: String, fun: &mut dyn FnMut(Vec<u8>) -> Vec<u8>) {
     let listener = TcpListener::bind(&addr)
         .await
         .expect("Failed to create TcpListener");
@@ -19,7 +19,7 @@ pub async fn listen(addr: String, fun: fn(Vec<u8>) -> Vec<u8>) {
         // asynchronously wait for an inbound socket
         let (mut socket, _) = listener.accept().await.expect("Failed to create socket");
 
-        tokio::spawn(async move {
+//        tokio::spawn(async move {
             loop {
                 // get number of bytes to receive
                 let mut nbuf: [u8; 8] = [0; 8];
@@ -30,7 +30,8 @@ pub async fn listen(addr: String, fun: fn(Vec<u8>) -> Vec<u8>) {
                 let n = usize::from_be_bytes(nbuf);
 
                 if n == 0 {
-                    return;
+                    break;
+//                    return;
                 }
 
                 let mut buf = vec![0; n];
@@ -42,7 +43,8 @@ pub async fn listen(addr: String, fun: fn(Vec<u8>) -> Vec<u8>) {
                     .expect("Failed to read data from socket");
 
                 if n == 0 {
-                    return;
+                    break;
+                    // return;
                 }
 
                 let response = fun(buf);
@@ -60,6 +62,6 @@ pub async fn listen(addr: String, fun: fn(Vec<u8>) -> Vec<u8>) {
                     .await
                     .expect("Failed to write data to socket");
             }
-        });
+//        });
     }
 }