diff --git a/src/clj/auto_ap/server.clj b/src/clj/auto_ap/server.clj
index c2252e15..0b38c555 100644
--- a/src/clj/auto_ap/server.clj
+++ b/src/clj/auto_ap/server.clj
@@ -62,7 +62,15 @@
     (.setHandler server stats-handler))
   (.setStopAtShutdown server true))
 
-(def ^:dynamic *http-port-override* nil)
+(def ^:dynamic *http-port-override*
+  ;; In dev, `lein mcp-repl` records the chosen HTTP port in `.http-port` so it
+  ;; stays stable across reloads. `refresh` re-evaluates this def, so reading the
+  ;; file here (rather than relying solely on an alter-var-root override that gets
+  ;; reset) keeps the port from falling back to (env :port). Absent in prod.
+  (let [f (java.io.File. ".http-port")]
+    (when (.exists f)
+      (let [p (.trim ^String (slurp f))]
+        (when (seq p) p)))))
 
 (mount/defstate port :start (Integer/parseInt (str (or *http-port-override* (env :port) "3000"))))
 
diff --git a/src/clj/dev_mcp.clj b/src/clj/dev_mcp.clj
index 7e9f6b06..4bc94ce2 100644
--- a/src/clj/dev_mcp.clj
+++ b/src/clj/dev_mcp.clj
@@ -9,15 +9,29 @@
   (with-open [s (ServerSocket. 0)]
     (.getLocalPort s)))
 
-(defn- mcp-repl-task [& _args]
-  "Start nREPL server and HTTP server on random ports.
+(defn- read-port [path]
+  "Read a previously-recorded port from `path`, or nil if missing/unparseable."
+  (let [f (io/file path)]
+    (when (.exists f)
+      (try (Integer/parseInt (.trim ^String (slurp f)))
+           (catch Exception _ nil)))))
 
-  Writes ports to nrepl-port and .http-port files.
-  Connect with: clj-nrepl-eval -p $(cat nrepl-port)"
-  (let [nrepl-port (available-port)
-        http-port (available-port)]
-    (spit "nrepl-port" (str nrepl-port))
-    (spit ".http-port" (str http-port))
+(defn- stable-port [path]
+  "Reuse the port recorded in `path` if present, otherwise pick a random
+  available one. Always (re)writes the file so the port stays stable for this
+  worktree across REPL restarts and reloads."
+  (let [port (or (read-port path) (available-port))]
+    (spit path (str port))
+    port))
+
+(defn- mcp-repl-task [& _args]
+  "Start nREPL server and HTTP server.
+
+  Reuses the ports recorded in nrepl-port and .http-port if present (keeping
+  them stable per worktree), otherwise picks random available ports and records
+  them. Connect with: clj-nrepl-eval -p $(cat nrepl-port)"
+  (let [nrepl-port (stable-port "nrepl-port")
+        http-port (stable-port ".http-port")]
     (println (format "nREPL port: %d (nrepl-port)" nrepl-port))
     (println (format "HTTP port:  %d (.http-port)" http-port))
     (nrepl/start-server :port nrepl-port)