fix(gateway/discord): add safe startup slash sync policy

Replaces blind tree.sync() on every Discord reconnect with a diff-based
reconcile. In safe mode (default), fetch existing global commands,
compare desired vs existing payloads, skip unchanged, PATCH changed,
recreate when non-patchable metadata differs, POST missing, and delete
stale commands one-by-one. Keeps 'bulk' for legacy behavior and 'off'
to skip startup sync entirely.

Fixes restart-heavy workflows that burn Discord's command write budget
and can surface 429s when iterating on native slash commands.

Env var: DISCORD_COMMAND_SYNC_POLICY (safe|bulk|off), default 'safe'.

Co-authored-by: Codex <codex@openai.invalid>

gateway/platforms/discord.py

@@ -23,6 +23,7 @@ from typing import Callable, Dict, Optional, Any
 logger = logging.getLogger(__name__)
 
 VALID_THREAD_AUTO_ARCHIVE_MINUTES = {60, 1440, 4320, 10080}
+_DISCORD_COMMAND_SYNC_POLICIES = {"safe", "bulk", "off"}
 
 try:
     import discord
@@ -802,8 +803,27 @@ class DiscordAdapter(BasePlatformAdapter):
         if not self._client:
             return
         try:
-            synced = await asyncio.wait_for(self._client.tree.sync(), timeout=30)
-            logger.info("[%s] Synced %d slash command(s)", self.name, len(synced))
+            sync_policy = self._get_discord_command_sync_policy()
+            if sync_policy == "off":
+                logger.info("[%s] Skipping Discord slash command sync (policy=off)", self.name)
+                return
+
+            if sync_policy == "bulk":
+                synced = await asyncio.wait_for(self._client.tree.sync(), timeout=30)
+                logger.info("[%s] Synced %d slash command(s) via bulk tree sync", self.name, len(synced))
+                return
+
+            summary = await asyncio.wait_for(self._safe_sync_slash_commands(), timeout=30)
+            logger.info(
+                "[%s] Safely reconciled %d slash command(s): unchanged=%d updated=%d recreated=%d created=%d deleted=%d",
+                self.name,
+                summary["total"],
+                summary["unchanged"],
+                summary["updated"],
+                summary["recreated"],
+                summary["created"],
+                summary["deleted"],
+            )
         except asyncio.TimeoutError:
             logger.warning("[%s] Slash command sync timed out after 30s", self.name)
         except asyncio.CancelledError:
@@ -811,6 +831,143 @@ class DiscordAdapter(BasePlatformAdapter):
         except Exception as e:  # pragma: no cover - defensive logging
             logger.warning("[%s] Slash command sync failed: %s", self.name, e, exc_info=True)
 
+    def _get_discord_command_sync_policy(self) -> str:
+        raw = str(os.getenv("DISCORD_COMMAND_SYNC_POLICY", "safe") or "").strip().lower()
+        if raw in _DISCORD_COMMAND_SYNC_POLICIES:
+            return raw
+        if raw:
+            logger.warning(
+                "[%s] Invalid DISCORD_COMMAND_SYNC_POLICY=%r; falling back to 'safe'",
+                self.name,
+                raw,
+            )
+        return "safe"
+
+    def _canonicalize_app_command_payload(self, payload: Dict[str, Any]) -> Dict[str, Any]:
+        """Reduce command payloads to the semantic fields Hermes manages."""
+        return {
+            "type": int(payload.get("type", 1) or 1),
+            "name": str(payload.get("name", "") or ""),
+            "description": str(payload.get("description", "") or ""),
+            "default_member_permissions": payload.get("default_member_permissions"),
+            "dm_permission": payload.get("dm_permission", True),
+            "nsfw": bool(payload.get("nsfw", False)),
+            "options": [
+                self._canonicalize_app_command_option(item)
+                for item in payload.get("options", []) or []
+                if isinstance(item, dict)
+            ],
+        }
+
+    def _canonicalize_app_command_option(self, payload: Dict[str, Any]) -> Dict[str, Any]:
+        return {
+            "type": int(payload.get("type", 0) or 0),
+            "name": str(payload.get("name", "") or ""),
+            "description": str(payload.get("description", "") or ""),
+            "required": bool(payload.get("required", False)),
+            "autocomplete": bool(payload.get("autocomplete", False)),
+            "choices": [
+                {
+                    "name": str(choice.get("name", "") or ""),
+                    "value": choice.get("value"),
+                }
+                for choice in payload.get("choices", []) or []
+                if isinstance(choice, dict)
+            ],
+            "channel_types": list(payload.get("channel_types", []) or []),
+            "min_value": payload.get("min_value"),
+            "max_value": payload.get("max_value"),
+            "min_length": payload.get("min_length"),
+            "max_length": payload.get("max_length"),
+            "options": [
+                self._canonicalize_app_command_option(item)
+                for item in payload.get("options", []) or []
+                if isinstance(item, dict)
+            ],
+        }
+
+    def _patchable_app_command_payload(self, payload: Dict[str, Any]) -> Dict[str, Any]:
+        """Fields supported by discord.py's edit_global_command route."""
+        canonical = self._canonicalize_app_command_payload(payload)
+        return {
+            "name": canonical["name"],
+            "description": canonical["description"],
+            "options": canonical["options"],
+        }
+
+    async def _safe_sync_slash_commands(self) -> Dict[str, int]:
+        """Diff existing global commands and only mutate the commands that changed."""
+        if not self._client:
+            return {
+                "total": 0,
+                "unchanged": 0,
+                "updated": 0,
+                "recreated": 0,
+                "created": 0,
+                "deleted": 0,
+            }
+
+        tree = self._client.tree
+        app_id = getattr(self._client, "application_id", None) or getattr(getattr(self._client, "user", None), "id", None)
+        if not app_id:
+            raise RuntimeError("Discord application ID is unavailable for slash command sync")
+
+        desired_payloads = [command.to_dict(tree) for command in tree.get_commands()]
+        desired_by_key = {
+            (int(payload.get("type", 1) or 1), str(payload.get("name", "") or "").lower()): payload
+            for payload in desired_payloads
+        }
+        existing_commands = await tree.fetch_commands()
+        existing_by_key = {
+            (
+                int(getattr(getattr(command, "type", None), "value", getattr(command, "type", 1)) or 1),
+                str(command.name or "").lower(),
+            ): command
+            for command in existing_commands
+        }
+
+        unchanged = 0
+        updated = 0
+        recreated = 0
+        created = 0
+        deleted = 0
+        http = self._client.http
+
+        for key, desired in desired_by_key.items():
+            current = existing_by_key.pop(key, None)
+            if current is None:
+                await http.upsert_global_command(app_id, desired)
+                created += 1
+                continue
+
+            current_payload = self._canonicalize_app_command_payload(current.to_dict())
+            desired_payload = self._canonicalize_app_command_payload(desired)
+            if current_payload == desired_payload:
+                unchanged += 1
+                continue
+
+            if self._patchable_app_command_payload(current.to_dict()) == self._patchable_app_command_payload(desired):
+                await http.delete_global_command(app_id, current.id)
+                await http.upsert_global_command(app_id, desired)
+                recreated += 1
+                continue
+
+            await http.edit_global_command(app_id, current.id, desired)
+            updated += 1
+
+        for current in existing_by_key.values():
+            await http.delete_global_command(app_id, current.id)
+            deleted += 1
+
+        return {
+            "total": len(desired_payloads),
+            "unchanged": unchanged,
+            "updated": updated,
+            "recreated": recreated,
+            "created": created,
+            "deleted": deleted,
+        }
+
     async def _add_reaction(self, message: Any, emoji: str) -> bool:
         """Add an emoji reaction to a Discord message."""
         if not message or not hasattr(message, "add_reaction"):

tests/gateway/test_discord_connect.py

@@ -73,18 +73,29 @@ from gateway.platforms.discord import DiscordAdapter  # noqa: E402
 class FakeTree:
     def __init__(self):
         self.sync = AsyncMock(return_value=[])
+        self.fetch_commands = AsyncMock(return_value=[])
+        self._commands = []
 
     def command(self, *args, **kwargs):
         return lambda fn: fn
 
+    def get_commands(self, *args, **kwargs):
+        return list(self._commands)
+
 
 class FakeBot:
     def __init__(self, *, intents, proxy=None, allowed_mentions=None, **_):
         self.intents = intents
         self.allowed_mentions = allowed_mentions
+        self.application_id = 999
         self.user = SimpleNamespace(id=999, name="Hermes")
         self._events = {}
         self.tree = FakeTree()
+        self.http = SimpleNamespace(
+            upsert_global_command=AsyncMock(),
+            edit_global_command=AsyncMock(),
+            delete_global_command=AsyncMock(),
+        )
 
     def event(self, fn):
         self._events[fn.__name__] = fn
@@ -199,6 +210,7 @@ async def test_connect_releases_token_lock_on_timeout(monkeypatch):
 async def test_connect_does_not_wait_for_slash_sync(monkeypatch):
     adapter = DiscordAdapter(PlatformConfig(enabled=True, token="test-token"))
 
+    monkeypatch.setenv("DISCORD_COMMAND_SYNC_POLICY", "bulk")
     monkeypatch.setattr("gateway.status.acquire_scoped_lock", lambda scope, identity, metadata=None: (True, None))
     monkeypatch.setattr("gateway.status.release_scoped_lock", lambda scope, identity: None)
 
@@ -226,3 +238,236 @@ async def test_connect_does_not_wait_for_slash_sync(monkeypatch):
     created["bot"].tree.allow_finish.set()
     await asyncio.sleep(0)
     await adapter.disconnect()
+
+
+@pytest.mark.asyncio
+async def test_connect_respects_slash_commands_opt_out(monkeypatch):
+    adapter = DiscordAdapter(
+        PlatformConfig(enabled=True, token="test-token", extra={"slash_commands": False})
+    )
+
+    monkeypatch.setenv("DISCORD_COMMAND_SYNC_POLICY", "off")
+    monkeypatch.setattr("gateway.status.acquire_scoped_lock", lambda scope, identity, metadata=None: (True, None))
+    monkeypatch.setattr("gateway.status.release_scoped_lock", lambda scope, identity: None)
+
+    intents = SimpleNamespace(message_content=False, dm_messages=False, guild_messages=False, members=False, voice_states=False)
+    monkeypatch.setattr(discord_platform.Intents, "default", lambda: intents)
+    monkeypatch.setattr(
+        discord_platform.commands,
+        "Bot",
+        lambda **kwargs: FakeBot(
+            intents=kwargs["intents"],
+            proxy=kwargs.get("proxy"),
+            allowed_mentions=kwargs.get("allowed_mentions"),
+        ),
+    )
+    register_mock = MagicMock()
+    monkeypatch.setattr(adapter, "_register_slash_commands", register_mock)
+    monkeypatch.setattr(adapter, "_resolve_allowed_usernames", AsyncMock())
+
+    ok = await adapter.connect()
+
+    assert ok is True
+    register_mock.assert_not_called()
+
+    await adapter.disconnect()
+
+
+@pytest.mark.asyncio
+async def test_safe_sync_slash_commands_only_mutates_diffs():
+    adapter = DiscordAdapter(PlatformConfig(enabled=True, token="test-token"))
+
+    class _DesiredCommand:
+        def __init__(self, payload):
+            self._payload = payload
+
+        def to_dict(self, tree):
+            assert tree is not None
+            return dict(self._payload)
+
+    class _ExistingCommand:
+        def __init__(self, command_id, payload):
+            self.id = command_id
+            self.name = payload["name"]
+            self.type = SimpleNamespace(value=payload["type"])
+            self._payload = payload
+
+        def to_dict(self):
+            return {
+                "id": self.id,
+                "application_id": 999,
+                **self._payload,
+                "name_localizations": {},
+                "description_localizations": {},
+            }
+
+    desired_same = {
+        "name": "status",
+        "description": "Show Hermes session status",
+        "type": 1,
+        "options": [],
+        "nsfw": False,
+        "dm_permission": True,
+        "default_member_permissions": None,
+    }
+    desired_updated = {
+        "name": "help",
+        "description": "Show available commands",
+        "type": 1,
+        "options": [],
+        "nsfw": False,
+        "dm_permission": True,
+        "default_member_permissions": None,
+    }
+    desired_created = {
+        "name": "metricas",
+        "description": "Show Colmeio metrics dashboard",
+        "type": 1,
+        "options": [],
+        "nsfw": False,
+        "dm_permission": True,
+        "default_member_permissions": None,
+    }
+    existing_same = _ExistingCommand(11, desired_same)
+    existing_updated = _ExistingCommand(
+        12,
+        {
+            **desired_updated,
+            "description": "Old help text",
+        },
+    )
+    existing_deleted = _ExistingCommand(
+        13,
+        {
+            "name": "old-command",
+            "description": "To be deleted",
+            "type": 1,
+            "options": [],
+            "nsfw": False,
+            "dm_permission": True,
+            "default_member_permissions": None,
+        },
+    )
+
+    fake_tree = SimpleNamespace(
+        get_commands=lambda: [
+            _DesiredCommand(desired_same),
+            _DesiredCommand(desired_updated),
+            _DesiredCommand(desired_created),
+        ],
+        fetch_commands=AsyncMock(return_value=[existing_same, existing_updated, existing_deleted]),
+    )
+    fake_http = SimpleNamespace(
+        upsert_global_command=AsyncMock(),
+        edit_global_command=AsyncMock(),
+        delete_global_command=AsyncMock(),
+    )
+    adapter._client = SimpleNamespace(
+        tree=fake_tree,
+        http=fake_http,
+        application_id=999,
+        user=SimpleNamespace(id=999),
+    )
+
+    summary = await adapter._safe_sync_slash_commands()
+
+    assert summary == {
+        "total": 3,
+        "unchanged": 1,
+        "updated": 1,
+        "recreated": 0,
+        "created": 1,
+        "deleted": 1,
+    }
+    fake_http.edit_global_command.assert_awaited_once_with(999, 12, desired_updated)
+    fake_http.upsert_global_command.assert_awaited_once_with(999, desired_created)
+    fake_http.delete_global_command.assert_awaited_once_with(999, 13)
+
+
+@pytest.mark.asyncio
+async def test_safe_sync_slash_commands_recreates_metadata_only_diffs():
+    adapter = DiscordAdapter(PlatformConfig(enabled=True, token="test-token"))
+
+    class _DesiredCommand:
+        def __init__(self, payload):
+            self._payload = payload
+
+        def to_dict(self, tree):
+            assert tree is not None
+            return dict(self._payload)
+
+    class _ExistingCommand:
+        def __init__(self, command_id, payload):
+            self.id = command_id
+            self.name = payload["name"]
+            self.type = SimpleNamespace(value=payload["type"])
+            self._payload = payload
+
+        def to_dict(self):
+            return {
+                "id": self.id,
+                "application_id": 999,
+                **self._payload,
+                "name_localizations": {},
+                "description_localizations": {},
+            }
+
+    desired = {
+        "name": "help",
+        "description": "Show available commands",
+        "type": 1,
+        "options": [],
+        "nsfw": False,
+        "dm_permission": True,
+        "default_member_permissions": "8",
+    }
+    existing = _ExistingCommand(
+        12,
+        {
+            **desired,
+            "default_member_permissions": None,
+        },
+    )
+
+    fake_tree = SimpleNamespace(
+        get_commands=lambda: [_DesiredCommand(desired)],
+        fetch_commands=AsyncMock(return_value=[existing]),
+    )
+    fake_http = SimpleNamespace(
+        upsert_global_command=AsyncMock(),
+        edit_global_command=AsyncMock(),
+        delete_global_command=AsyncMock(),
+    )
+    adapter._client = SimpleNamespace(
+        tree=fake_tree,
+        http=fake_http,
+        application_id=999,
+        user=SimpleNamespace(id=999),
+    )
+
+    summary = await adapter._safe_sync_slash_commands()
+
+    assert summary == {
+        "total": 1,
+        "unchanged": 0,
+        "updated": 0,
+        "recreated": 1,
+        "created": 0,
+        "deleted": 0,
+    }
+    fake_http.edit_global_command.assert_not_awaited()
+    fake_http.delete_global_command.assert_awaited_once_with(999, 12)
+    fake_http.upsert_global_command.assert_awaited_once_with(999, desired)
+
+
+@pytest.mark.asyncio
+async def test_post_connect_initialization_skips_sync_when_policy_off(monkeypatch):
+    adapter = DiscordAdapter(PlatformConfig(enabled=True, token="test-token"))
+    monkeypatch.setenv("DISCORD_COMMAND_SYNC_POLICY", "off")
+
+    fake_tree = SimpleNamespace(sync=AsyncMock())
+    adapter._client = SimpleNamespace(tree=fake_tree)
+
+    await adapter._run_post_connect_initialization()
+
+    fake_tree.sync.assert_not_called()

website/docs/reference/environment-variables.md

@@ -206,6 +206,7 @@ For cloud sandbox backends, persistence is filesystem-oriented. `TERMINAL_LIFETI
 | `DISCORD_PROXY` | Proxy URL for Discord connections — overrides `HTTPS_PROXY`. Supports `http://`, `https://`, `socks5://` |
 | `DISCORD_HOME_CHANNEL` | Default Discord channel for cron delivery |
 | `DISCORD_HOME_CHANNEL_NAME` | Display name for the Discord home channel |
+| `DISCORD_COMMAND_SYNC_POLICY` | Discord slash-command startup sync policy: `safe` (diff and reconcile), `bulk` (legacy `tree.sync()`), or `off` |
 | `DISCORD_REQUIRE_MENTION` | Require an @mention before responding in server channels |
 | `DISCORD_FREE_RESPONSE_CHANNELS` | Comma-separated channel IDs where mention is not required |
 | `DISCORD_AUTO_THREAD` | Auto-thread long replies when supported |

website/docs/user-guide/messaging/discord.md

@@ -275,6 +275,7 @@ Discord behavior is controlled through two files: **`~/.hermes/.env`** for crede
 | `DISCORD_ALLOWED_ROLES` | No | — | Comma-separated Discord role IDs. Any member with one of these roles is authorized — OR semantics with `DISCORD_ALLOWED_USERS`. Auto-enables the **Server Members Intent** on connect. Useful when moderation teams churn: new mods get access as soon as the role is granted, no config push needed. |
 | `DISCORD_HOME_CHANNEL` | No | — | Channel ID where the bot sends proactive messages (cron output, reminders, notifications). |
 | `DISCORD_HOME_CHANNEL_NAME` | No | `"Home"` | Display name for the home channel in logs and status output. |
+| `DISCORD_COMMAND_SYNC_POLICY` | No | `"safe"` | Controls native slash-command startup sync. `"safe"` diffs existing global commands and only updates what changed, recreating commands when Discord metadata changes cannot be applied via patch. `"bulk"` preserves the old `tree.sync()` behavior. `"off"` skips startup sync entirely. |
 | `DISCORD_REQUIRE_MENTION` | No | `true` | When `true`, the bot only responds in server channels when `@mentioned`. Set to `false` to respond to all messages in every channel. |
 | `DISCORD_FREE_RESPONSE_CHANNELS` | No | — | Comma-separated channel IDs where the bot responds without requiring an `@mention`, even when `DISCORD_REQUIRE_MENTION` is `true`. |
 | `DISCORD_IGNORE_NO_MENTION` | No | `true` | When `true`, the bot stays silent if a message `@mentions` other users but does **not** mention the bot. Prevents the bot from jumping into conversations directed at other people. Only applies in server channels, not DMs. |
@@ -628,4 +629,3 @@ Leave `everyone` and `roles` at `false` unless you know exactly why you need the
 For more information on securing your Hermes Agent deployment, see the [Security Guide](../security.md).
 
 
-