diff --git a/backend/run.sh b/backend/run.sh
index ffedede8..cf4c220a 100755
--- a/backend/run.sh
+++ b/backend/run.sh
@@ -56,7 +56,9 @@ fi
 # (compared via `dir in path.parents`). So we pass ABSOLUTE paths to
 # the dirs we want to exclude — those are the only patterns uvicorn's
 # WatchFilesReload actually honors for "anywhere under this tree".
-echo "Starting backend server on http://0.0.0.0:8324 ..."
+# Dev only: OPENSWARM_PORT lets a parallel worktree bind its own backend port instead of colliding on 8324. Packaged builds never set it.
+BACKEND_PORT="${OPENSWARM_PORT:-8324}"
+echo "Starting backend server on http://0.0.0.0:${BACKEND_PORT} ..."
 cd "$PROJECT_ROOT_ABSPATH"
 
 UVICORN_EXCLUDE_ARGS=(--reload-exclude '*.pyc')
@@ -79,10 +81,10 @@ done
 # launcher does). Packaged builds leave it unset → fast, lean,
 # single-process uvicorn.
 if [[ "${OPENSWARM_DEV:-}" == "1" ]]; then
-    echo "OPENSWARM_DEV=1 detected — running uvicorn with --reload."
-    python3 -m uvicorn backend.main:app --host 0.0.0.0 --port 8324 --reload \
+    echo "OPENSWARM_DEV=1 detected, running uvicorn with --reload."
+    python3 -m uvicorn backend.main:app --host 0.0.0.0 --port "$BACKEND_PORT" --reload \
         --reload-dir "$BACKEND_DIR_ABSPATH" \
         "${UVICORN_EXCLUDE_ARGS[@]}"
 else
-    python3 -m uvicorn backend.main:app --host 0.0.0.0 --port 8324
+    python3 -m uvicorn backend.main:app --host 0.0.0.0 --port "$BACKEND_PORT"
 fi
diff --git a/frontend/webpack.config.js b/frontend/webpack.config.js
index 1e051e72..3556793b 100644
--- a/frontend/webpack.config.js
+++ b/frontend/webpack.config.js
@@ -79,13 +79,14 @@ module.exports = (env, argv) => {
     devServer: {
       static: { directory: path.join(__dirname, 'public') },
       compress: true,
-      port: 3000,
+      // Dev only: OPENSWARM_DEV_PORT / OPENSWARM_PORT let a second worktree run its own stack without colliding on 3000/8324 (electron reads the same var names).
+      port: Number(process.env.OPENSWARM_DEV_PORT) || 3000,
       hot: true,
       open: false,
       historyApiFallback: true,
       proxy: {
         '/api': {
-          target: 'http://localhost:8324',
+          target: `http://localhost:${process.env.OPENSWARM_PORT || 8324}`,
           changeOrigin: true,
         },
       },
diff --git a/run.sh b/run.sh
index 1f2c3533..987afa4e 100755
--- a/run.sh
+++ b/run.sh
@@ -22,6 +22,14 @@ FRONTEND_PID=""
 ELECTRON_PID=""
 SHUTTING_DOWN=false
 
+# Dev ports. Override BOTH to run a second worktree in parallel without colliding on 3000/8324
+# (e.g. OPENSWARM_PORT=8425 OPENSWARM_DEV_PORT=3005 bash run.sh). Electron, backend/run.sh, and
+# webpack all read these same names, so one export each wires the whole stack.
+BACKEND_PORT="${OPENSWARM_PORT:-8324}"
+FRONTEND_PORT="${OPENSWARM_DEV_PORT:-3000}"
+export OPENSWARM_PORT="$BACKEND_PORT"
+export OPENSWARM_DEV_PORT="$FRONTEND_PORT"
+
 kill_tree() {
     local pid=$1 sig=${2:-TERM}
     local children
@@ -91,9 +99,9 @@ fi
 # That makes the next `bash run.sh` fail with Errno 48 "Address already
 # in use" and leaves the user thinking the dev loop is broken. Free the
 # port up front instead of asking the user to debug.
-if lsof -ti :8324 >/dev/null 2>&1; then
-    echo -e "${YELLOW}${BOLD}[preflight]${RESET} Port 8324 still bound from a prior run — killing stale process..."
-    lsof -ti :8324 | xargs kill -9 2>/dev/null || true
+if lsof -ti :$BACKEND_PORT >/dev/null 2>&1; then
+    echo -e "${YELLOW}${BOLD}[preflight]${RESET} Port ${BACKEND_PORT} still bound from a prior run, killing stale process..."
+    lsof -ti :$BACKEND_PORT | xargs kill -9 2>/dev/null || true
     sleep 0.3
 fi
 
@@ -119,11 +127,11 @@ bash "$PROJECT_ROOT/backend/run.sh" > >(
 BACKEND_PID=$!
 
 # --- Wait for backend to become healthy ---
-echo -e "${YELLOW}${BOLD}Waiting for backend (http://localhost:8324) to be ready...${RESET}"
+echo -e "${YELLOW}${BOLD}Waiting for backend (http://localhost:${BACKEND_PORT}) to be ready...${RESET}"
 MAX_WAIT=120
 elapsed=0
 while (( elapsed < MAX_WAIT )); do
-    if curl -s -o /dev/null --connect-timeout 1 http://localhost:8324/ 2>/dev/null; then
+    if curl -s -o /dev/null --connect-timeout 1 http://localhost:${BACKEND_PORT}/ 2>/dev/null; then
         echo -e "${GREEN}${BOLD}Backend is ready!${RESET}"
         break
     fi
@@ -150,11 +158,11 @@ bash "$PROJECT_ROOT/frontend/run.sh" > >(
 FRONTEND_PID=$!
 
 # --- Wait for frontend dev server to become available ---
-echo -e "${YELLOW}${BOLD}Waiting for frontend (http://localhost:3000) to be ready...${RESET}"
+echo -e "${YELLOW}${BOLD}Waiting for frontend (http://localhost:${FRONTEND_PORT}) to be ready...${RESET}"
 FRONTEND_MAX_WAIT=60
 frontend_elapsed=0
 while (( frontend_elapsed < FRONTEND_MAX_WAIT )); do
-    if curl -s -o /dev/null --connect-timeout 1 http://localhost:3000/ 2>/dev/null; then
+    if curl -s -o /dev/null --connect-timeout 1 http://localhost:${FRONTEND_PORT}/ 2>/dev/null; then
         echo -e "${GREEN}${BOLD}Frontend is ready!${RESET}"
         break
     fi
@@ -199,8 +207,8 @@ ELECTRON_PID=$!
 
 echo ""
 echo -e "${BOLD}All services are running. Press Ctrl+C to stop.${RESET}"
-echo -e "  Backend:  ${BLUE}http://localhost:8324${RESET}"
-echo -e "  Frontend: ${GREEN}http://localhost:3000${RESET}"
+echo -e "  Backend:  ${BLUE}http://localhost:${BACKEND_PORT}${RESET}"
+echo -e "  Frontend: ${GREEN}http://localhost:${FRONTEND_PORT}${RESET}"
 echo -e "  Electron: ${MAGENTA}dev shell (pid $ELECTRON_PID)${RESET}"
 echo ""