diff --git a/tools/command_builder/__init__.py b/tools/command_builder/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tools/command_builder/schema.py b/tools/command_builder/schema.py
new file mode 100644
index 0000000..60c0e5f
--- /dev/null
+++ b/tools/command_builder/schema.py
@@ -0,0 +1,237 @@
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from typing import Any, List, Optional, Union
+
+
+class SchemaError(ValueError):
+    pass
+
+
+@dataclass
+class ExeAction:
+    file: str
+    wait: Optional[bool] = None
+    delay_ms: Optional[int] = None
+
+    type: str = "exe"
+
+    def to_dict(self) -> dict:
+        out: dict = {"type": "exe", "file": self.file}
+        if self.wait is not None:
+            out["wait"] = bool(self.wait)
+        if self.delay_ms is not None:
+            out["delay_ms"] = int(self.delay_ms)
+        return out
+
+
+@dataclass
+class PlaySoundAction:
+    name: str
+    type: str = "play_sound"
+
+    def to_dict(self) -> dict:
+        return {"type": "play_sound", "name": self.name}
+
+
+@dataclass
+class SystemAction:
+    op: str
+    type: str = "system"
+
+    def to_dict(self) -> dict:
+        return {"type": "system", "op": self.op}
+
+
+@dataclass
+class SleepAction:
+    ms: int
+    type: str = "sleep"
+
+    def to_dict(self) -> dict:
+        return {"type": "sleep", "ms": int(self.ms)}
+
+
+@dataclass
+class ShellAction:
+    cmd: str
+    wait: Optional[bool] = None
+    type: str = "shell"
+
+    def to_dict(self) -> dict:
+        out: dict = {"type": "shell", "cmd": self.cmd}
+        if self.wait is not None:
+            out["wait"] = bool(self.wait)
+        return out
+
+
+@dataclass
+class UrlAction:
+    href: str
+    type: str = "url"
+
+    def to_dict(self) -> dict:
+        return {"type": "url", "href": self.href}
+
+
+@dataclass
+class KeysAction:
+    sequence: Optional[str] = None
+    text: Optional[str] = None
+    type: str = "keys"
+
+    def to_dict(self) -> dict:
+        out: dict = {"type": "keys"}
+        if self.sequence is not None:
+            out["sequence"] = self.sequence
+        if self.text is not None:
+            out["text"] = self.text
+        return out
+
+
+Action = Union[
+    "ExeAction",
+    "PlaySoundAction",
+    "SystemAction",
+    "SleepAction",
+    "ShellAction",
+    "UrlAction",
+    "KeysAction",
+    "MultiAction",
+]
+
+
+@dataclass
+class MultiAction:
+    steps: List[Action] = field(default_factory=list)
+    type: str = "multi"
+
+    def to_dict(self) -> dict:
+        return {"type": "multi", "steps": [s.to_dict() for s in self.steps]}
+
+
+VALID_SYSTEM_OPS = ("volume_mute", "volume_unmute", "exit")
+VALID_SOUND_NAMES = (
+    "ok", "ready", "thanks", "not_found", "greet", "run", "stupid", "off",
+)
+
+
+def action_from_dict(data: Any) -> Action:
+    if not isinstance(data, dict):
+        raise SchemaError("action must be a mapping")
+    t = data.get("type")
+    if not t:
+        raise SchemaError("action is missing 'type'")
+
+    if t == "exe":
+        if not data.get("file"):
+            raise SchemaError("exe action requires 'file'")
+        return ExeAction(
+            file=data["file"],
+            wait=data.get("wait"),
+            delay_ms=data.get("delay_ms"),
+        )
+    if t == "play_sound":
+        name = data.get("name")
+        if not name:
+            raise SchemaError("play_sound action requires 'name'")
+        if name not in VALID_SOUND_NAMES:
+            raise SchemaError(f"unknown sound name: {name}")
+        return PlaySoundAction(name=name)
+    if t == "system":
+        op = data.get("op")
+        if op not in VALID_SYSTEM_OPS:
+            raise SchemaError(f"unknown system op: {op}")
+        return SystemAction(op=op)
+    if t == "sleep":
+        ms = data.get("ms")
+        if not isinstance(ms, int) or ms < 0:
+            raise SchemaError("sleep action requires non-negative integer 'ms'")
+        return SleepAction(ms=ms)
+    if t == "shell":
+        cmd = data.get("cmd")
+        if not cmd or not isinstance(cmd, str):
+            raise SchemaError("shell action requires non-empty 'cmd' string")
+        return ShellAction(cmd=cmd, wait=data.get("wait"))
+    if t == "url":
+        href = data.get("href")
+        if not href or not isinstance(href, str):
+            raise SchemaError("url action requires non-empty 'href' string")
+        return UrlAction(href=href)
+    if t == "keys":
+        sequence = data.get("sequence")
+        text = data.get("text")
+        if not sequence and not text:
+            raise SchemaError("keys action requires 'sequence' or 'text'")
+        if sequence and text:
+            raise SchemaError("keys action cannot have both 'sequence' and 'text'")
+        return KeysAction(sequence=sequence, text=text)
+    if t == "multi":
+        steps_raw = data.get("steps")
+        if not isinstance(steps_raw, list) or not steps_raw:
+            raise SchemaError("multi action requires non-empty 'steps' list")
+        steps = [action_from_dict(s) for s in steps_raw]
+        return MultiAction(steps=steps)
+
+    raise SchemaError(f"unknown action type: {t}")
+
+
+@dataclass
+class CommandEntry:
+    cmd_id: str
+    phrases: List[str]
+    action: Action
+    confirm_sound: Optional[str] = None
+
+    def to_dict(self) -> dict:
+        body: dict = {
+            "phrases": list(self.phrases),
+            "action": self.action.to_dict(),
+        }
+        if self.confirm_sound is not None:
+            body["confirm_sound"] = self.confirm_sound
+        return body
+
+
+def command_from_dict(cmd_id: str, data: Any) -> CommandEntry:
+    if not isinstance(data, dict):
+        raise SchemaError(f"command {cmd_id!r} body must be a mapping")
+    phrases = data.get("phrases")
+    if not isinstance(phrases, list) or not phrases:
+        raise SchemaError(f"command {cmd_id!r} requires non-empty 'phrases' list")
+    if not all(isinstance(p, str) and p.strip() for p in phrases):
+        raise SchemaError(f"command {cmd_id!r} phrases must be non-empty strings")
+    action_raw = data.get("action")
+    if action_raw is None:
+        raise SchemaError(f"command {cmd_id!r} requires 'action'")
+    action = action_from_dict(action_raw)
+    confirm = data.get("confirm_sound")
+    if confirm is not None and confirm not in VALID_SOUND_NAMES:
+        raise SchemaError(f"command {cmd_id!r} has unknown confirm_sound: {confirm}")
+    return CommandEntry(cmd_id=cmd_id, phrases=phrases, action=action, confirm_sound=confirm)
+
+
+_SLUG_TRANSLIT = {
+    "а": "a", "б": "b", "в": "v", "г": "g", "д": "d", "е": "e", "ё": "e",
+    "ж": "zh", "з": "z", "и": "i", "й": "y", "к": "k", "л": "l", "м": "m",
+    "н": "n", "о": "o", "п": "p", "р": "r", "с": "s", "т": "t", "у": "u",
+    "ф": "f", "х": "h", "ц": "ts", "ч": "ch", "ш": "sh", "щ": "sch",
+    "ъ": "", "ы": "y", "ь": "", "э": "e", "ю": "yu", "я": "ya",
+}
+
+
+def slugify(phrase: str) -> str:
+    lowered = phrase.lower().strip()
+    out_chars: list = []
+    for ch in lowered:
+        if ch in _SLUG_TRANSLIT:
+            out_chars.append(_SLUG_TRANSLIT[ch])
+        elif ch.isalnum() and ord(ch) < 128:
+            out_chars.append(ch)
+        elif ch in (" ", "_", "-"):
+            out_chars.append("_")
+    slug = "".join(out_chars)
+    while "__" in slug:
+        slug = slug.replace("__", "_")
+    slug = slug.strip("_")
+    return slug or "cmd"
diff --git a/tools/command_builder/tests/__init__.py b/tools/command_builder/tests/__init__.py
new file mode 100644
index 0000000..e69de29