diff --git a/imperative/broker/server-connection.rkt b/imperative/broker/server-connection.rkt
new file mode 100644
index 0000000..797e67b
--- /dev/null
+++ b/imperative/broker/server-connection.rkt
@@ -0,0 +1,59 @@
+#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/imperative/broker/server.rkt b/imperative/broker/server.rkt
index e8d3435..3d54ce2 100644
--- a/imperative/broker/server.rkt
+++ b/imperative/broker/server.rkt
@@ -4,65 +4,14 @@
          server-facet/websocket)
 
 (require "wire-protocol.rkt")
-(require "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)
-
-;; 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 envelope (scope body))
+(require/activate imperative-syndicate/broker/server-connection)
 
 (define-logger syndicate/broker)
 
-(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 (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 (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! (envelope scope body)))
-
-         (on (message (server-inbound id (Ping)))
-             (send! (server-outbound id (Pong))))))
-
 (define (server-facet/tcp id scope)
   (assert (tcp-accepted id))
   (assert (server-connection id scope))