diff --git a/nucleares_monitor/control_board_monitor.py b/nucleares_monitor/control_board_monitor.py
new file mode 100644
index 0000000..5da46a5
--- /dev/null
+++ b/nucleares_monitor/control_board_monitor.py
@@ -0,0 +1,516 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Control Board Monitor - v0.1
+
+A lightweight Windows-friendly Python GUI to monitor server variables exposed via
+HTTP GET as "/?variable=VARNAME".
+
+- Defaults: host="localhost", port=8945 (edit globals below or use the GUI).
+- Refreshes automatically every minute.
+- Fetches variables sequentially with a configurable Requests-Per-Second (RPS) cap
+  and automatic backoff on HTTP 429/5xx to avoid overwhelming the server.
+- Attempts to discover the variable list via WEBSERVER_LIST_VARIABLES_JSON, then
+  WEBSERVER_LIST_VARIABLES. You can also paste/import a list manually in the GUI.
+- First version focuses on read-only monitoring. Next versions can add POST controls
+  to set variables and turn some values into indicator widgets.
+
+No external GUI frameworks are required (uses Tkinter from the standard library).
+No non-stdlib HTTP client is required (uses urllib).
+"""
+
+import json
+import queue
+import re
+import threading
+import time
+import urllib.parse
+import urllib.request
+from dataclasses import dataclass, field
+from datetime import datetime
+from typing import Dict, List, Optional, Tuple
+
+try:
+    import tkinter as tk
+    from tkinter import ttk, messagebox, simpledialog
+except Exception as e:
+    raise SystemExit("Tkinter is required to run this app.")
+
+
+# =====================
+# Global configuration
+# =====================
+SERVER_HOST: str = "localhost"   # default host
+SERVER_PORT: int = 8785          # default port (as requested)
+REFRESH_INTERVAL_S: int = 60     # run a full sweep roughly every minute
+MAX_RPS: float = 5.0             # cap average requests/sec to avoid overload
+REQUEST_TIMEOUT_S: float = 5.0   # per-request timeout
+USER_AGENT: str = "ControlBoardMonitor/0.1 (+tkinter)"
+CONNECT_TIMEOUT_S: float = 5.0
+
+# Backoff
+BACKOFF_BASE_S: float = 1.0      # initial backoff
+BACKOFF_MAX_S: float = 15.0      # max backoff between retries
+MAX_RETRIES: int = 2             # retries per variable within a cycle
+
+
+# =====================
+# Helper utilities
+# =====================
+def http_get(base_url: str, params: Dict[str, str]) -> Tuple[int, str, Dict[str, str]]:
+    """Perform a GET with urllib. Returns (status, text, headers)."""
+    url = base_url + "?" + urllib.parse.urlencode(params)
+    req = urllib.request.Request(url, headers={"User-Agent": USER_AGENT})
+    try:
+        with urllib.request.urlopen(req, timeout=REQUEST_TIMEOUT_S) as resp:
+            status = resp.getcode()
+            body_bytes = resp.read()
+            try:
+                body = body_bytes.decode("utf-8", errors="replace")
+            except Exception:
+                body = body_bytes.decode("latin-1", errors="replace")
+            headers = {k.lower(): v for k, v in resp.getheaders()}
+            return status, body, headers
+    except urllib.error.HTTPError as e:
+        try:
+            body = e.read().decode("utf-8", errors="replace")
+        except Exception:
+            body = str(e)
+        return e.code, body, dict(e.headers or {})
+    except Exception as e:
+        return 0, str(e), {}
+
+
+def build_base_url(host: str, port: int) -> str:
+    scheme = "http"
+    return f"{scheme}://{host}:{port}/"
+
+
+def parse_variable_names_from_html_index(html_text: str) -> List[str]:
+    """Best-effort extraction of variable names from the simple HTML index page style."""
+    vars_found: List[str] = []
+    for m in re.finditer(r"[?&]variable=([A-Z0-9_]+)", html_text):
+        vars_found.append(m.group(1))
+    # De-duplicate preserving order
+    seen = set()
+    uniq = []
+    for v in vars_found:
+        if v not in seen:
+            uniq.append(v)
+            seen.add(v)
+    return uniq
+
+
+def coerce_preview(value: str, maxlen: int = 80) -> str:
+    v = value.strip().replace("\r", " ").replace("\n", " ")
+    if len(v) > maxlen:
+        return v[:maxlen - 1] + "…"
+    return v
+
+
+def infer_status_color(value: str) -> str:
+    """Very simple status → tag mapping to mimic control-board feel."""
+    val = value.strip().lower()
+    if val in {"1", "true", "on", "open", "active", "ok", "running", "enabled"}:
+        return "ok"
+    if val in {"0", "false", "off", "closed", "inactive", "error", "fault", "disabled"}:
+        return "bad"
+    # Warn if it's empty or has obvious error keywords
+    if val == "" or "exception" in val or "error" in val:
+        return "bad"
+    return "neutral"
+
+
+# =====================
+# Data model
+# =====================
+@dataclass
+class VarInfo:
+    name: str
+    last_value: str = ""
+    last_updated: float = 0.0
+    last_status: int = 0
+    error: Optional[str] = None
+
+
+# =====================
+# Poller thread
+# =====================
+class Poller(threading.Thread):
+    def __init__(
+        self,
+        host: str,
+        port: int,
+        variables: List[str],
+        ui_queue: queue.Queue,
+        refresh_interval: int,
+        max_rps: float,
+        stop_event: threading.Event,
+        paused_event: threading.Event,
+    ) -> None:
+        super().__init__(daemon=True)
+        self.host = host
+        self.port = port
+        self.variables = variables
+        self.ui_queue = ui_queue
+        self.refresh_interval = int(max(5, refresh_interval))
+        self.max_rps = max(0.5, max_rps)
+        self.stop_event = stop_event
+        self.paused_event = paused_event
+
+    def run(self) -> None:
+        base_url = build_base_url(self.host, self.port)
+        min_spacing = 1.0 / self.max_rps  # seconds between requests
+        while not self.stop_event.is_set():
+            cycle_start = time.time()
+            self.ui_queue.put(("cycle_start", datetime.now().strftime("%H:%M:%S")))
+            for name in list(self.variables):
+                # Allow pausing mid-cycle
+                while self.paused_event.is_set() and not self.stop_event.is_set():
+                    time.sleep(0.1)
+                if self.stop_event.is_set():
+                    break
+
+                attempt = 0
+                backoff = BACKOFF_BASE_S
+                while attempt <= MAX_RETRIES and not self.stop_event.is_set():
+                    attempt += 1
+                    t0 = time.time()
+                    status, body, headers = http_get(base_url, {"variable": name})
+
+                    # Success path
+                    if status == 200:
+                        self.ui_queue.put(("update", name, body, status))
+                        break
+
+                    # Backoff on overload or server error
+                    if status in (429, 500, 502, 503, 504, 0):
+                        self.ui_queue.put(("error", name, status, coerce_preview(body, 200)))
+                        time.sleep(backoff)
+                        backoff = min(BACKOFF_MAX_S, backoff * 2.0)
+                    else:
+                        # Other HTTP errors: report once and stop retrying
+                        self.ui_queue.put(("error", name, status, coerce_preview(body, 200)))
+                        break
+
+                    # Respect RPS even with errors
+                    dt = time.time() - t0
+                    if dt < min_spacing:
+                        time.sleep(min_spacing - dt)
+
+                # Spacing between requests
+                dt = time.time() - t0
+                if dt < min_spacing:
+                    time.sleep(min_spacing - dt)
+
+            # Sleep to align roughly to the refresh interval
+            cycle_dt = time.time() - cycle_start
+            remaining = self.refresh_interval - cycle_dt
+            if remaining > 0:
+                for _ in range(int(remaining * 10)):
+                    if self.stop_event.is_set():
+                        break
+                    time.sleep(0.1)
+
+        self.ui_queue.put(("stopped", ""))
+
+
+# =====================
+# GUI
+# =====================
+class App(tk.Tk):
+    def __init__(self) -> None:
+        super().__init__()
+        self.title("Control Board Monitor")
+        self.geometry("1100x700")
+        try:
+            self.iconbitmap(default="")  # no icon file bundled
+        except Exception:
+            pass
+
+        # State
+        self.vars: Dict[str, VarInfo] = {}
+        self.stop_event = threading.Event()
+        self.paused_event = threading.Event()
+        self.ui_queue: queue.Queue = queue.Queue()
+        self.poller: Optional[Poller] = None
+        self.variables_list: List[str] = []
+
+        # Top controls
+        controls = ttk.Frame(self, padding=10)
+        controls.pack(side=tk.TOP, fill=tk.X)
+
+        self.host_var = tk.StringVar(value=SERVER_HOST)
+        self.port_var = tk.IntVar(value=SERVER_PORT)
+        self.refresh_var = tk.IntVar(value=REFRESH_INTERVAL_S)
+        self.rps_var = tk.DoubleVar(value=MAX_RPS)
+
+        ttk.Label(controls, text="Host:").grid(row=0, column=0, sticky="w")
+        ttk.Entry(controls, textvariable=self.host_var, width=16).grid(row=0, column=1, padx=(0, 12))
+        ttk.Label(controls, text="Port:").grid(row=0, column=2, sticky="w")
+        ttk.Entry(controls, textvariable=self.port_var, width=8).grid(row=0, column=3, padx=(0, 12))
+        ttk.Label(controls, text="Refresh (s):").grid(row=0, column=4, sticky="w")
+        ttk.Entry(controls, textvariable=self.refresh_var, width=8).grid(row=0, column=5, padx=(0, 12))
+        ttk.Label(controls, text="Max RPS:").grid(row=0, column=6, sticky="w")
+        ttk.Entry(controls, textvariable=self.rps_var, width=8).grid(row=0, column=7, padx=(0, 12))
+
+        self.status_lbl = ttk.Label(controls, text="Idle", foreground="#666")
+        self.status_lbl.grid(row=0, column=8, padx=(10, 0))
+
+        btns = ttk.Frame(controls)
+        btns.grid(row=0, column=9, padx=10, sticky="e")
+        self.start_btn = ttk.Button(btns, text="Start", command=self.start_polling)
+        self.start_btn.grid(row=0, column=0, padx=4)
+        self.pause_btn = ttk.Button(btns, text="Pause", command=self.toggle_pause, state="disabled")
+        self.pause_btn.grid(row=0, column=1, padx=4)
+        self.reload_btn = ttk.Button(btns, text="Reload Vars", command=self.reload_variables)
+        self.reload_btn.grid(row=0, column=2, padx=4)
+        self.import_btn = ttk.Button(btns, text="Import List", command=self.import_list_dialog)
+        self.import_btn.grid(row=0, column=3, padx=4)
+
+        # Filter/Search
+        search_frame = ttk.Frame(self, padding=(10, 0, 10, 10))
+        search_frame.pack(side=tk.TOP, fill=tk.X)
+        ttk.Label(search_frame, text="Filter:").pack(side=tk.LEFT)
+        self.filter_var = tk.StringVar(value="")
+        self.filter_var.trace_add("write", lambda *_: self.refresh_tree())
+        ttk.Entry(search_frame, textvariable=self.filter_var, width=50).pack(side=tk.LEFT, padx=8)
+
+        # Tree (control-board style with groups)
+        columns = ("value", "updated", "status")
+        self.tree = ttk.Treeview(self, columns=columns, show="tree headings", height=26)
+        self.tree.pack(side=tk.TOP, fill=tk.BOTH, expand=True, padx=10, pady=10)
+
+        self.tree.heading("#0", text="Variable")
+        self.tree.heading("value", text="Value")
+        self.tree.heading("updated", text="Updated")
+        self.tree.heading("status", text="HTTP")
+
+        self.tree.column("#0", width=420, anchor="w")
+        self.tree.column("value", width=420, anchor="w")
+        self.tree.column("updated", width=120, anchor="center")
+        self.tree.column("status", width=60, anchor="center")
+
+        # Style tags for a control-board feel
+        style = ttk.Style(self)
+        try:
+            style.theme_use("clam")
+        except Exception:
+            pass
+        self.tree.tag_configure("ok", background="#eaffea")       # soft green
+        self.tree.tag_configure("bad", background="#ffecec")      # soft red
+        self.tree.tag_configure("neutral", background="#f5f7fb")  # soft gray-blue
+
+        # Footer
+        footer = ttk.Frame(self, padding=10)
+        footer.pack(side=tk.BOTTOM, fill=tk.X)
+        self.cycle_lbl = ttk.Label(footer, text="Last cycle: —")
+        self.cycle_lbl.pack(side=tk.LEFT)
+
+        self.protocol("WM_DELETE_WINDOW", self.on_close)
+
+        # Initial discovery
+        self.after(200, self.reload_variables)
+
+    # ------------- Variable discovery -------------
+    def reload_variables(self) -> None:
+        host = self.host_var.get().strip()
+        port = int(self.port_var.get())
+        base = build_base_url(host, port)
+
+        discovered: List[str] = []
+        # Try JSON list first
+        status, body, _ = http_get(base, {"variable": "WEBSERVER_LIST_VARIABLES_JSON"})
+        if status == 200:
+            try:
+                data = json.loads(body)
+                if isinstance(data, list) and all(isinstance(x, str) for x in data):
+                    discovered = list(dict.fromkeys(data))  # preserve order, unique
+            except Exception:
+                discovered = []
+
+        # Fallback: parse the human/HTML list
+        if not discovered:
+            status, body, _ = http_get(base, {"variable": "WEBSERVER_LIST_VARIABLES"})
+            if status == 200 and body:
+                cand = parse_variable_names_from_html_index(body)
+                if cand:
+                    discovered = cand
+
+        # If still empty, offer a minimal starter set
+        if not discovered:
+            discovered = [
+                "TIME", "TIME_STAMP", "CORE_TEMP", "CORE_PRESSURE", "CORE_STATE",
+                "COOLANT_CORE_PRESSURE", "COOLANT_CORE_FLOW_IN", "COOLANT_CORE_FLOW_OUT",
+                "STEAM_TURBINE_0_RPM", "POWER_FROM_TURBINE_KW", "POWER_DEMAND_MW",
+            ]
+
+        # Update local state
+        self.variables_list = discovered
+        self.vars.clear()
+        for v in discovered:
+            self.vars[v] = VarInfo(name=v)
+
+        self.status_lbl.configure(text=f"Loaded {len(discovered)} vars")
+        self.refresh_tree()
+
+    def import_list_dialog(self) -> None:
+        txt = simpledialog.askstring(
+            "Import variable names",
+            "Paste variable names separated by spaces, commas, or newlines:",
+            parent=self,
+        )
+        if not txt:
+            return
+        names = re.findall(r"[A-Z0-9_]+", txt.upper())
+        if not names:
+            messagebox.showwarning("Nothing found", "No variable-like tokens found.")
+            return
+        # Deduplicate while preserving order
+        uniq = []
+        seen = set()
+        for n in names:
+            if n not in seen:
+                uniq.append(n); seen.add(n)
+        self.variables_list = uniq
+        self.vars.clear()
+        for v in uniq:
+            self.vars[v] = VarInfo(name=v)
+        self.status_lbl.configure(text=f"Imported {len(uniq)} vars")
+        self.refresh_tree()
+
+    # ------------- Poller control -------------
+    def start_polling(self) -> None:
+        if self.poller and self.poller.is_alive():
+            messagebox.showinfo("Already running", "Polling is already active.")
+            return
+        if not self.variables_list:
+            messagebox.showwarning("No variables", "Variable list is empty. Reload or import a list first.")
+            return
+        self.stop_event.clear()
+        self.paused_event.clear()
+        self.poller = Poller(
+            host=self.host_var.get().strip(),
+            port=int(self.port_var.get()),
+            variables=self.variables_list,
+            ui_queue=self.ui_queue,
+            refresh_interval=int(self.refresh_var.get()),
+            max_rps=float(self.rps_var.get()),
+            stop_event=self.stop_event,
+            paused_event=self.paused_event,
+        )
+        self.poller.start()
+        self.start_btn.configure(state="disabled")
+        self.pause_btn.configure(state="normal", text="Pause")
+        self.status_lbl.configure(text="Running…")
+        self.after(100, self.drain_queue)
+
+    def toggle_pause(self) -> None:
+        if not (self.poller and self.poller.is_alive()):
+            return
+        if self.paused_event.is_set():
+            self.paused_event.clear()
+            self.pause_btn.configure(text="Pause")
+            self.status_lbl.configure(text="Running…")
+        else:
+            self.paused_event.set()
+            self.pause_btn.configure(text="Resume")
+            self.status_lbl.configure(text="Paused")
+
+    def drain_queue(self) -> None:
+        """Receive updates from the poller and apply to the UI safely from the main thread."""
+        try:
+            while True:
+                item = self.ui_queue.get_nowait()
+                kind = item[0]
+                if kind == "update":
+                    _, name, value, status = item
+                    vi = self.vars.get(name) or VarInfo(name=name)
+                    vi.last_value = value
+                    vi.last_updated = time.time()
+                    vi.last_status = status
+                    vi.error = None
+                    self.vars[name] = vi
+                elif kind == "error":
+                    _, name, status, msg = item
+                    vi = self.vars.get(name) or VarInfo(name=name)
+                    vi.last_status = status
+                    vi.error = msg
+                    vi.last_updated = time.time()
+                    self.vars[name] = vi
+                elif kind == "cycle_start":
+                    _, hhmmss = item
+                    self.cycle_lbl.configure(text=f"Last cycle start: {hhmmss}")
+                elif kind == "stopped":
+                    self.status_lbl.configure(text="Stopped")
+                self.ui_queue.task_done()
+        except queue.Empty:
+            pass
+        self.refresh_tree()
+        if self.poller and self.poller.is_alive():
+            self.after(250, self.drain_queue)  # continue pumping
+
+    def stop_polling(self) -> None:
+        if self.poller and self.poller.is_alive():
+            self.stop_event.set()
+            # give it a moment to end gracefully
+            for _ in range(20):
+                if not self.poller.is_alive():
+                    break
+                time.sleep(0.05)
+        self.start_btn.configure(state="normal")
+        self.pause_btn.configure(state="disabled", text="Pause")
+
+    # ------------- Tree rendering -------------
+    def refresh_tree(self) -> None:
+        # Clear existing
+        self.tree.delete(*self.tree.get_children())
+
+        # Group by prefix (e.g. CORE_, COOLANT_, STEAM_)
+        groups: Dict[str, List[VarInfo]] = {}
+        filt = self.filter_var.get().strip().upper()
+
+        for name, vi in self.vars.items():
+            if filt and filt not in name.upper():
+                # Also allow filtering by value preview
+                if vi.last_value and filt not in vi.last_value.upper():
+                    continue
+            prefix = name.split("_", 1)[0] if "_" in name else "MISC"
+            groups.setdefault(prefix, []).append(vi)
+
+        # Sort groups alphabetically, vars within group by name
+        for g in sorted(groups.keys()):
+            parent = self.tree.insert("", "end", text=g, values=("", "", ""), open=True)
+            for vi in sorted(groups[g], key=lambda x: x.name):
+                updated_str = "—"
+                if vi.last_updated:
+                    updated_str = datetime.fromtimestamp(vi.last_updated).strftime("%H:%M:%S")
+
+                if vi.error:
+                    value_preview = f"[ERR] {vi.error}"
+                else:
+                    # Compact preview of first line
+                    value_preview = coerce_preview(vi.last_value, 120)
+
+                tag = infer_status_color(vi.last_value if not vi.error else "error")
+                self.tree.insert(
+                    parent,
+                    "end",
+                    text=vi.name,
+                    values=(value_preview, updated_str, vi.last_status or "—"),
+                    tags=(tag,),
+                )
+
+    # ------------- Shutdown -------------
+    def on_close(self) -> None:
+        self.stop_polling()
+        self.destroy()
+
+
+def main() -> None:
+    app = App()
+    app.mainloop()
+
+
+if __name__ == "__main__":
+    main()
diff --git a/nucleares_monitor/version.nfo b/nucleares_monitor/version.nfo
new file mode 100644
index 0000000..49d5957
--- /dev/null
+++ b/nucleares_monitor/version.nfo
@@ -0,0 +1 @@
+0.1