diff --git a/syndicate/broker/client.rkt b/syndicate/broker/client.rkt
index 0c8fd7d..c207294 100644
--- a/syndicate/broker/client.rkt
+++ b/syndicate/broker/client.rkt
@@ -1,71 +1,46 @@
 #lang imperative-syndicate
 
-(provide standard-localhost-broker/tcp)
+(provide generic-client-session-facet)
 
 (require "wire-protocol.rkt")
 (require "protocol.rkt")
 (require imperative-syndicate/term)
-(require imperative-syndicate/reassert)
-
-(require/activate imperative-syndicate/drivers/tcp)
-
-(define standard-localhost-broker/tcp "tcp://localhost:8001/")
 
 (define-logger syndicate/broker)
 
-(message-struct broker-packet (url packet))
-
 (spawn #:name 'client-factory
-       (during (to-broker $u _) (assert (broker-connection u)))
-       (during (observe (from-broker $u _)) (assert (broker-connection u)))
-       (during (observe (broker-connected $u)) (assert (broker-connection u)))
+       (during (to-broker $a _) (assert (broker-connection a)))
+       (during (observe (from-broker $a _)) (assert (broker-connection a)))
+       (during (observe (broker-connected $a)) (assert (broker-connection a))))
 
-       (during/spawn (broker-connection $url)
-         #:name `(client-connection ,url)
-         (match url
-           [(pregexp #px"^tcp://([^:]+):([0-9]+)/?" (list _ host portstr))
-            (define port (string->number portstr))
-            (client-tcp-session-facet url host port)]
-           [else (error 'client-factory "Invalid server URL: ~v" url)])))
+(define (generic-client-session-facet address w)
+  (on-start (log-syndicate/broker-info "Connected to ~v" address))
+  (on-stop (log-syndicate/broker-info "Disconnected from ~v" address))
+  (assert (broker-connected address))
 
-(define (client-tcp-session-facet url host port)
-  (define id (list (gensym 'client) host port))
-  (reassert-on (tcp-connection id (tcp-address host port))
-               (retracted (tcp-accepted id))
-               (asserted (tcp-rejected id _)))
-  (during (tcp-accepted id)
-    (on-start (log-syndicate/broker-info "Connected to ~v" url))
-    (on-stop (log-syndicate/broker-info "Disconnected from ~v" url))
-    (assert (broker-connected url))
+  (define next-ep
+    (let ((counter 0))
+      (lambda ()
+        (begin0 counter
+          (set! counter (+ counter 1))))))
 
-    (define accumulate!
-      (packet-accumulator (lambda (p) (send! (broker-packet url p)))))
-    (on (message (tcp-in id $bs))
-        (accumulate! bs))
+  (during (to-broker address $a)
+    (define ep (next-ep))
+    (on-start (w (Assert ep a)))
+    (on-stop (w (Clear ep))))
 
-    (define (w x) (send! (tcp-out id (encode x))))
+  (on (message (to-broker address $a))
+      (w (Message a)))
 
-    (define next-ep
-      (let ((counter 0))
-        (lambda ()
-          (begin0 counter
-            (set! counter (+ counter 1))))))
+  (on (message (broker-packet address (Ping)))
+      (w (Pong)))
 
-    (during (to-broker url $a)
-      (define ep (next-ep))
-      (on-start (w (Assert ep a)))
-      (on-stop (w (Clear ep))))
-
-    (on (message (to-broker url $a)) (w (Message a)))
-
-    (on (message (broker-packet url (Ping))) (w (Pong)))
-
-    (during (observe (from-broker url $spec))
-      (define ep (next-ep))
-      (on-start (w (Assert ep (observe spec))))
-      (on-stop (w (Clear ep)))
-      (on (message (broker-packet url (Add ep $vs)))
-          (react (assert (instantiate-term->value (from-broker url spec) vs))
-                 (stop-when (message (broker-packet url (Del ep vs))))))
-      (on (message (broker-packet url (Msg ep $vs)))
-          (send! (instantiate-term->value (from-broker url spec) vs))))))
+  (during (observe (from-broker address $spec))
+    (define ep (next-ep))
+    (on-start (w (Assert ep (observe spec))))
+    (on-stop (w (Clear ep)))
+    (on (message (broker-packet address (Add ep $vs)))
+        (react (assert (instantiate-term->value (from-broker address spec) vs))
+               (stop-when (message (broker-packet address (Del ep vs))))))
+    (on (message (broker-packet address (Msg ep $vs)))
+        (send! (instantiate-term->value (from-broker address spec) vs)))))
diff --git a/syndicate/broker/client/loopback.rkt b/syndicate/broker/client/loopback.rkt
new file mode 100644
index 0000000..45ccea7
--- /dev/null
+++ b/syndicate/broker/client/loopback.rkt
@@ -0,0 +1,18 @@
+#lang imperative-syndicate
+
+(provide (struct-out broker-loopback-connection))
+
+(require "../client.rkt")
+(require "../wire-protocol.rkt")
+(require "../protocol.rkt")
+
+(require/activate imperative-syndicate/broker/server)
+
+(assertion-struct broker-loopback-connection (scope))
+
+(spawn #:name 'loopback-client-factory
+       (during/spawn (broker-connection ($ address (broker-loopback-connection $scope)))
+         #:name address
+         (assert (server-connection address scope))
+         (on (message (server-outbound address $p)) (send! (broker-packet address p)))
+         (generic-client-session-facet address (lambda (x) (send! (server-inbound address x))))))
diff --git a/syndicate/broker/client/tcp.rkt b/syndicate/broker/client/tcp.rkt
new file mode 100644
index 0000000..53fb503
--- /dev/null
+++ b/syndicate/broker/client/tcp.rkt
@@ -0,0 +1,27 @@
+#lang imperative-syndicate
+
+(provide standard-localhost-broker/tcp
+         (struct-out broker-tcp-connection))
+
+(require "../client.rkt")
+(require "../wire-protocol.rkt")
+(require "../protocol.rkt")
+(require imperative-syndicate/reassert)
+
+(require/activate imperative-syndicate/drivers/tcp)
+
+(assertion-struct broker-tcp-connection (host port))
+
+(define standard-localhost-broker/tcp (broker-tcp-connection "localhost" 8001))
+
+(spawn #:name 'tcp-client-factory
+       (during/spawn (broker-connection ($ address (broker-tcp-connection $host $port)))
+         #:name address
+         (define id (list (gensym 'client) host port))
+         (reassert-on (tcp-connection id (tcp-address host port))
+                      (retracted (tcp-accepted id))
+                      (asserted (tcp-rejected id _)))
+         (during (tcp-accepted id)
+           (define accumulate! (packet-accumulator (lambda (p) (send! (broker-packet address p)))))
+           (on (message (tcp-in id $bs)) (accumulate! bs))
+           (generic-client-session-facet address (lambda (x) (send! (tcp-out id (encode x))))))))
diff --git a/syndicate/broker/main.rkt b/syndicate/broker/main.rkt
index 02000c6..351aaa6 100644
--- a/syndicate/broker/main.rkt
+++ b/syndicate/broker/main.rkt
@@ -2,47 +2,51 @@
 
 (provide (all-from-out "protocol.rkt")
          (all-from-out "client.rkt")
-         (all-from-out "server.rkt"))
+         (all-from-out "client/tcp.rkt")
+         (all-from-out "client/loopback.rkt")
+         (all-from-out "server.rkt")
+         (all-from-out "server/tcp.rkt")
+         (all-from-out "server/websocket.rkt"))
 
 (require "protocol.rkt")
+
 (require/activate "client.rkt")
+(require/activate "client/tcp.rkt")
+(require/activate "client/loopback.rkt")
+
 (require/activate "server.rkt")
-
-(require/activate imperative-syndicate/drivers/tcp)
-(require/activate imperative-syndicate/drivers/web)
-
-(define *default-tcp-port* 8001)
-(define *default-http-port* 8000)
-
-(define (main #:tcp-port [tcp-port *default-tcp-port*]
-              #:http-port [http-port *default-http-port*])
-  (spawn #:name 'server-listener
-         (when tcp-port
-           (define tcp-scope "broker")
-           (during/spawn (tcp-connection $id (tcp-listener tcp-port))
-             #:name `(server-connection ,tcp-scope ,id)
-             (server-facet/tcp id tcp-scope)))
-         (when http-port
-           (during/spawn (http-request $id 'get (http-resource (http-server _ http-port #f)
-                                                               `(,$scope ())) _ _ _)
-             #:name `(server-connection ,scope ,id)
-             (server-facet/websocket id scope)))))
+(require/activate "server/tcp.rkt")
+(require/activate "server/websocket.rkt")
 
 (module+ main
   (require racket/cmdline)
-  (define tcp-port *default-tcp-port*)
-  (define http-port *default-http-port*)
+  (define tcp-port default-tcp-broker-port)
+  (define http-port default-http-broker-port)
   (command-line #:once-any
                 ["--tcp" port
-                 ((format "Listen on plain TCP port (default ~a)" *default-tcp-port*))
+                 ((format "Listen on plain TCP port (default ~a)" default-tcp-broker-port))
                  (set! tcp-port (string->number port))]
                 ["--no-tcp" "Do not listen on any plain TCP port"
                  (set! tcp-port #f)]
                 #:once-any
                 ["--http" port
-                 ((format "Listen on websocket HTTP port (default ~a)" *default-http-port*))
+                 ((format "Listen on websocket HTTP port (default ~a)" default-http-broker-port))
                  (set! http-port (string->number port))]
                 ["--no-http" "Do not listen on any websocket HTTP port"
                  (set! http-port #f)])
-  (extend-ground-boot! (lambda () (main #:tcp-port tcp-port
-                                        #:http-port http-port))))
+  (extend-ground-boot! (lambda ()
+                         (when tcp-port (spawn-tcp-broker! tcp-port))
+                         (when http-port (spawn-websocket-broker! http-port)))))
+
+(define-logger syndicate/broker)
+
+(when (log-level? syndicate/broker-logger 'debug)
+  (spawn #:name 'server-debug
+         (on (asserted (server-connection $id $scope))
+             (log-syndicate/broker-debug "C+ ~v ~v" id scope))
+         (on (retracted (server-connection $id $scope))
+             (log-syndicate/broker-debug "C- ~v ~v" id scope))
+         (on (message (server-inbound $id $p))
+             (log-syndicate/broker-debug "CIN  ~v ~v" id p))
+         (on (message (server-outbound $id $p))
+             (log-syndicate/broker-debug "COUT ~v ~v" id p))))
diff --git a/syndicate/broker/protocol.rkt b/syndicate/broker/protocol.rkt
index 3b2a0a9..1fdf3aa 100644
--- a/syndicate/broker/protocol.rkt
+++ b/syndicate/broker/protocol.rkt
@@ -3,8 +3,8 @@
 (provide (all-defined-out))
 
 ;; Client protocol
-(assertion-struct to-broker (url assertion))
-(assertion-struct from-broker (url assertion))
-(assertion-struct broker-connection (url))
-(assertion-struct broker-connected (url))
-(message-struct force-broker-disconnect (url))
+(assertion-struct to-broker (address assertion))
+(assertion-struct from-broker (address assertion))
+(assertion-struct broker-connection (address))
+(assertion-struct broker-connected (address))
+(message-struct force-broker-disconnect (address))
diff --git a/syndicate/broker/server-connection.rkt b/syndicate/broker/server-connection.rkt
deleted file mode 100644
index 797e67b..0000000
--- a/syndicate/broker/server-connection.rkt
+++ /dev/null
@@ -1,59 +0,0 @@
-#lang imperative-syndicate
-
-(provide (struct-out server-connection)
-         (struct-out server-inbound)
-         (struct-out server-outbound)
-         (struct-out server-envelope))
-
-(require "wire-protocol.rkt")
-(require imperative-syndicate/term)
-(require racket/set)
-
-;; Internal connection protocol
-(assertion-struct server-connection (connection-id scope))
-(assertion-struct server-inbound (connection-id body))
-(assertion-struct server-outbound (connection-id body))
-
-;; Internal isolation
-(assertion-struct server-envelope (scope body))
-
-(spawn #:name 'server-connection-factory
-       (during/spawn (server-connection $id $scope)
-         (define endpoints (set))
-
-         (on (message (server-inbound id (Assert $ep $a)))
-             (when (not (set-member? endpoints ep))
-               (set! endpoints (set-add endpoints ep))
-               (react
-                (on-stop (set! endpoints (set-remove endpoints ep)))
-
-                (field [assertion a])
-
-                (define (recompute-endpoint)
-                  (define a (assertion))
-                  (if (observe? a)
-                      (let* ((pattern (observe-specification a))
-                             (spec (server-envelope scope pattern)))
-                        (values (observe spec)
-                                (term->skeleton-interest
-                                 spec
-                                 (capture-facet-context
-                                  (lambda (op . captured-values)
-                                    (schedule-script!
-                                     (current-actor)
-                                     (lambda ()
-                                       (define ctor (match op ['+ Add] ['- Del] ['! Msg]))
-                                       (send! (server-outbound id (ctor ep captured-values))))))))))
-                      (values (server-envelope scope a) #f)))
-                (add-endpoint! (current-facet) "server" #t recompute-endpoint)
-
-                (on (message (server-inbound id (Assert ep $new-a)))
-                    (assertion new-a))
-
-                (stop-when (message (server-inbound id (Clear ep)))))))
-
-         (on (message (server-inbound id (Message $body)))
-             (send! (server-envelope scope body)))
-
-         (on (message (server-inbound id (Ping)))
-             (send! (server-outbound id (Pong))))))
diff --git a/syndicate/broker/server.rkt b/syndicate/broker/server.rkt
index 3d54ce2..797e67b 100644
--- a/syndicate/broker/server.rkt
+++ b/syndicate/broker/server.rkt
@@ -1,51 +1,59 @@
 #lang imperative-syndicate
 
-(provide server-facet/tcp
-         server-facet/websocket)
+(provide (struct-out server-connection)
+         (struct-out server-inbound)
+         (struct-out server-outbound)
+         (struct-out server-envelope))
 
 (require "wire-protocol.rkt")
+(require imperative-syndicate/term)
+(require racket/set)
 
-(require/activate imperative-syndicate/drivers/tcp)
-(require/activate imperative-syndicate/drivers/web)
-(require/activate imperative-syndicate/drivers/timer)
-(require/activate imperative-syndicate/broker/server-connection)
+;; Internal connection protocol
+(assertion-struct server-connection (connection-id scope))
+(assertion-struct server-inbound (connection-id body))
+(assertion-struct server-outbound (connection-id body))
 
-(define-logger syndicate/broker)
+;; Internal isolation
+(assertion-struct server-envelope (scope body))
 
-(define (server-facet/tcp id scope)
-  (assert (tcp-accepted id))
-  (assert (server-connection id scope))
-  (define accumulate! (packet-accumulator (lambda (p) (send! (server-inbound id p)))))
-  (on (message (tcp-in id $bs))
-      (accumulate! bs))
-  (on (message (server-outbound id $p))
-      (send! (tcp-out id (encode p)))))
+(spawn #:name 'server-connection-factory
+       (during/spawn (server-connection $id $scope)
+         (define endpoints (set))
 
-(define (server-facet/websocket id scope)
-  (assert (http-accepted id))
-  (assert (http-response-websocket id))
-  (assert (server-connection id scope))
+         (on (message (server-inbound id (Assert $ep $a)))
+             (when (not (set-member? endpoints ep))
+               (set! endpoints (set-add endpoints ep))
+               (react
+                (on-stop (set! endpoints (set-remove endpoints ep)))
 
-  (field [ping-time-deadline 0])
-  (on (asserted (later-than (ping-time-deadline)))
-      (ping-time-deadline (+ (current-inexact-milliseconds) (ping-interval)))
-      (send! (server-outbound id (Ping))))
+                (field [assertion a])
 
-  (on (message (websocket-in id $body))
-      (define-values (packet remainder) (decode body))
-      (when (not (equal? remainder #""))
-        (error 'server-facet/websocket "Multiple packets in a single websocket message"))
-      (send! (server-inbound id packet)))
-  (on (message (server-outbound id $p))
-      (send! (websocket-out id (encode p)))))
+                (define (recompute-endpoint)
+                  (define a (assertion))
+                  (if (observe? a)
+                      (let* ((pattern (observe-specification a))
+                             (spec (server-envelope scope pattern)))
+                        (values (observe spec)
+                                (term->skeleton-interest
+                                 spec
+                                 (capture-facet-context
+                                  (lambda (op . captured-values)
+                                    (schedule-script!
+                                     (current-actor)
+                                     (lambda ()
+                                       (define ctor (match op ['+ Add] ['- Del] ['! Msg]))
+                                       (send! (server-outbound id (ctor ep captured-values))))))))))
+                      (values (server-envelope scope a) #f)))
+                (add-endpoint! (current-facet) "server" #t recompute-endpoint)
 
-(when (log-level? syndicate/broker-logger 'debug)
-  (spawn #:name 'server-debug
-         (on (asserted (server-connection $id $scope))
-             (log-syndicate/broker-debug "C+ ~v ~v" id scope))
-         (on (retracted (server-connection $id $scope))
-             (log-syndicate/broker-debug "C- ~v ~v" id scope))
-         (on (message (server-inbound $id $p))
-             (log-syndicate/broker-debug "CIN  ~v ~v" id p))
-         (on (message (server-outbound $id $p))
-             (log-syndicate/broker-debug "COUT ~v ~v" id p))))
+                (on (message (server-inbound id (Assert ep $new-a)))
+                    (assertion new-a))
+
+                (stop-when (message (server-inbound id (Clear ep)))))))
+
+         (on (message (server-inbound id (Message $body)))
+             (send! (server-envelope scope body)))
+
+         (on (message (server-inbound id (Ping)))
+             (send! (server-outbound id (Pong))))))
diff --git a/syndicate/broker/server/tcp.rkt b/syndicate/broker/server/tcp.rkt
new file mode 100644
index 0000000..d3fa0d8
--- /dev/null
+++ b/syndicate/broker/server/tcp.rkt
@@ -0,0 +1,28 @@
+#lang imperative-syndicate
+
+(provide server-facet/tcp
+         default-tcp-broker-port
+         spawn-tcp-broker!)
+
+(require "../wire-protocol.rkt")
+
+(require/activate imperative-syndicate/drivers/tcp)
+(require/activate imperative-syndicate/broker/server)
+
+(define (server-facet/tcp id scope)
+  (assert (tcp-accepted id))
+  (assert (server-connection id scope))
+  (define accumulate! (packet-accumulator (lambda (p) (send! (server-inbound id p)))))
+  (on (message (tcp-in id $bs))
+      (accumulate! bs))
+  (on (message (server-outbound id $p))
+      (send! (tcp-out id (encode p)))))
+
+(define default-tcp-broker-port 8001)
+
+(define (spawn-tcp-broker! [port default-tcp-broker-port])
+  (spawn #:name 'tcp-server-listener
+         (define tcp-scope "broker") ;; TODO: allow this to be negotiated during protocol startup
+         (during/spawn (tcp-connection $id (tcp-listener port))
+           #:name `(server-connection ,tcp-scope ,id)
+           (server-facet/tcp id tcp-scope))))
diff --git a/syndicate/broker/server/websocket.rkt b/syndicate/broker/server/websocket.rkt
new file mode 100644
index 0000000..8d2a28c
--- /dev/null
+++ b/syndicate/broker/server/websocket.rkt
@@ -0,0 +1,38 @@
+#lang imperative-syndicate
+
+(provide server-facet/websocket
+         default-http-broker-port
+         spawn-websocket-broker!)
+
+(require "../wire-protocol.rkt")
+
+(require/activate imperative-syndicate/drivers/web)
+(require/activate imperative-syndicate/drivers/timer)
+(require/activate imperative-syndicate/broker/server)
+
+(define (server-facet/websocket id scope)
+  (assert (http-accepted id))
+  (assert (http-response-websocket id))
+  (assert (server-connection id scope))
+
+  (field [ping-time-deadline 0])
+  (on (asserted (later-than (ping-time-deadline)))
+      (ping-time-deadline (+ (current-inexact-milliseconds) (ping-interval)))
+      (send! (server-outbound id (Ping))))
+
+  (on (message (websocket-in id $body))
+      (define-values (packet remainder) (decode body))
+      (when (not (equal? remainder #""))
+        (error 'server-facet/websocket "Multiple packets in a single websocket message"))
+      (send! (server-inbound id packet)))
+  (on (message (server-outbound id $p))
+      (send! (websocket-out id (encode p)))))
+
+(define default-http-broker-port 8000)
+
+(define (spawn-websocket-broker! [port default-http-broker-port])
+  (spawn #:name 'websocket-server-listener
+         (during/spawn (http-request $id 'get (http-resource (http-server _ port #f)
+                                                             `(,$scope ())) _ _ _)
+           #:name `(server-connection ,scope ,id)
+           (server-facet/websocket id scope))))
diff --git a/syndicate/broker/wire-protocol.rkt b/syndicate/broker/wire-protocol.rkt
index 02ef2bb..63a9772 100644
--- a/syndicate/broker/wire-protocol.rkt
+++ b/syndicate/broker/wire-protocol.rkt
@@ -44,3 +44,6 @@
       (handle-packet! packet)))
   (lambda (chunk)
     (buffer (bytes-append (buffer) chunk))))
+
+;; Received packets from broker are relayed via one of these.
+(message-struct broker-packet (address packet))