feat: pluggable platform adapter registry + IRC reference implementation

Adds a platform adapter plugin interface so anyone can create new gateway
platforms (IRC, Viber, Line, etc.) as drop-in plugins without modifying
core gateway code.

- PlatformEntry dataclass: name, label, adapter_factory, check_fn,
  validate_config, required_env, install_hint, source
- PlatformRegistry singleton with register/unregister/create_adapter
- _create_adapter() in gateway/run.py checks registry first, falls
  through to existing if/elif chain for built-in platforms

- Platform._missing_() accepts unknown string values, creating cached
  pseudo-members so Platform('irc') is Platform('irc') holds true
- GatewayConfig.from_dict() now parses plugin platform names from
  config.yaml without rejecting them
- get_connected_platforms() delegates to registry for unknown platforms

- PluginContext.register_platform() for plugin authors
- Mirrors the existing register_tool() / register_hook() pattern

- Full async IRC adapter using stdlib asyncio (zero external deps)
- Connects via TLS, handles PING/PONG, nick collision, NickServ auth
- Channel messages require addressing (nick: msg), DMs always dispatch
- Markdown stripping for IRC-clean output, message splitting for
  512-byte line limit
- Config via config.yaml extra dict or IRC_* env vars

- Platform enum dynamic members (identity stability, case normalization)
- PlatformRegistry (register, unregister, create, validation, factory)
- GatewayConfig integration (from_dict parsing, get_connected_platforms)
- IRC adapter (init, send, protocol parsing, markdown, requirements)

No existing platform adapters were migrated — the if/elif chain is
untouched. This is Phase 1: prove the interface with a real plugin.

gateway/config.py

@@ -46,7 +46,13 @@ def _normalize_unauthorized_dm_behavior(value: Any, default: str = "pair") -> st
 
 
 class Platform(Enum):
-    """Supported messaging platforms."""
+    """Supported messaging platforms.
+
+    Built-in platforms have explicit members.  Plugin platforms use dynamic
+    members created on-demand by ``_missing_()`` so that
+    ``Platform("irc")`` works without modifying this enum.  Dynamic members
+    are cached in ``_value2member_map_`` for identity-stable comparisons.
+    """
     LOCAL = "local"
     TELEGRAM = "telegram"
     DISCORD = "discord"
@@ -68,6 +74,27 @@ class Platform(Enum):
     BLUEBUBBLES = "bluebubbles"
     QQBOT = "qqbot"
     YUANBAO = "yuanbao"
+    @classmethod
+    def _missing_(cls, value):
+        """Accept unknown platform names for plugin-registered adapters.
+
+        Creates a pseudo-member cached in ``_value2member_map_`` so that
+        ``Platform("irc") is Platform("irc")`` holds True (identity-stable).
+        """
+        if not isinstance(value, str) or not value.strip():
+            return None
+        # Normalise to lowercase to avoid case mismatches in config
+        value = value.strip().lower()
+        # Check cache first (another call may have created it already)
+        if value in cls._value2member_map_:
+            return cls._value2member_map_[value]
+        pseudo = object.__new__(cls)
+        pseudo._value_ = value
+        pseudo._name_ = value.upper().replace("-", "_").replace(" ", "_")
+        # Cache so future lookups return the same object
+        cls._value2member_map_[value] = pseudo
+        cls._member_map_[pseudo._name_] = pseudo
+        return pseudo
 
 
 @dataclass
@@ -337,6 +364,17 @@ class GatewayConfig:
                 config.extra.get("client_secret") or os.getenv("DINGTALK_CLIENT_SECRET")
             ):
                 connected.append(platform)
+            else:
+                # Plugin-registered platform — delegate validation to the
+                # registry entry's validate_config if available.
+                try:
+                    from gateway.platform_registry import platform_registry
+                    entry = platform_registry.get(platform.value)
+                    if entry:
+                        if entry.validate_config is None or entry.validate_config(config):
+                            connected.append(platform)
+                except Exception:
+                    pass  # Registry not yet initialised during early import
         
         return connected
     

gateway/platform_registry.py

@@ -0,0 +1,169 @@
+"""
+Platform Adapter Registry
+
+Allows platform adapters (built-in and plugin) to self-register so the gateway
+can discover and instantiate them without hardcoded if/elif chains.
+
+Built-in adapters continue to use the existing if/elif in _create_adapter()
+for now.  Plugin adapters register here via PluginContext.register_platform()
+and are looked up first -- if nothing is found the gateway falls through to
+the legacy code path.
+
+Usage (plugin side):
+
+    from gateway.platform_registry import platform_registry, PlatformEntry
+
+    platform_registry.register(PlatformEntry(
+        name="irc",
+        label="IRC",
+        adapter_factory=lambda cfg: IRCAdapter(cfg),
+        check_fn=check_requirements,
+        validate_config=lambda cfg: bool(cfg.extra.get("server")),
+        required_env=["IRC_SERVER"],
+        install_hint="pip install irc",
+    ))
+
+Usage (gateway side):
+
+    adapter = platform_registry.create_adapter("irc", platform_config)
+"""
+
+import logging
+from dataclasses import dataclass, field
+from typing import Any, Callable, Optional
+
+logger = logging.getLogger(__name__)
+
+
+@dataclass
+class PlatformEntry:
+    """Metadata and factory for a single platform adapter."""
+
+    # Identifier used in config.yaml (e.g. "irc", "viber").
+    name: str
+
+    # Human-readable label (e.g. "IRC", "Viber").
+    label: str
+
+    # Factory callable: receives a PlatformConfig, returns an adapter instance.
+    # Using a factory instead of a bare class lets plugins do custom init
+    # (e.g. passing extra kwargs, wrapping in try/except).
+    adapter_factory: Callable[[Any], Any]
+
+    # Returns True when the platform's dependencies are available.
+    check_fn: Callable[[], bool]
+
+    # Optional: given a PlatformConfig, is it properly configured?
+    # If None, the registry skips config validation and lets the adapter
+    # fail at connect() time with a descriptive error.
+    validate_config: Optional[Callable[[Any], bool]] = None
+
+    # Env vars this platform needs (for ``hermes setup`` display).
+    required_env: list = field(default_factory=list)
+
+    # Hint shown when check_fn returns False.
+    install_hint: str = ""
+
+    # "builtin" or "plugin"
+    source: str = "plugin"
+
+
+class PlatformRegistry:
+    """Central registry of platform adapters.
+
+    Thread-safe for reads (dict lookups are atomic under GIL).
+    Writes happen at startup during sequential discovery.
+    """
+
+    def __init__(self) -> None:
+        self._entries: dict[str, PlatformEntry] = {}
+
+    def register(self, entry: PlatformEntry) -> None:
+        """Register a platform adapter entry.
+
+        If an entry with the same name exists, it is replaced (last writer
+        wins -- this lets plugins override built-in adapters if desired).
+        """
+        if entry.name in self._entries:
+            prev = self._entries[entry.name]
+            logger.info(
+                "Platform '%s' re-registered (was %s, now %s)",
+                entry.name,
+                prev.source,
+                entry.source,
+            )
+        self._entries[entry.name] = entry
+        logger.debug("Registered platform adapter: %s (%s)", entry.name, entry.source)
+
+    def unregister(self, name: str) -> bool:
+        """Remove a platform entry.  Returns True if it existed."""
+        return self._entries.pop(name, None) is not None
+
+    def get(self, name: str) -> Optional[PlatformEntry]:
+        """Look up a platform entry by name."""
+        return self._entries.get(name)
+
+    def all_entries(self) -> list[PlatformEntry]:
+        """Return all registered platform entries."""
+        return list(self._entries.values())
+
+    def plugin_entries(self) -> list[PlatformEntry]:
+        """Return only plugin-registered platform entries."""
+        return [e for e in self._entries.values() if e.source == "plugin"]
+
+    def is_registered(self, name: str) -> bool:
+        return name in self._entries
+
+    def create_adapter(self, name: str, config: Any) -> Optional[Any]:
+        """Create an adapter instance for the given platform name.
+
+        Returns None if:
+        - No entry registered for *name*
+        - check_fn() returns False (missing deps)
+        - validate_config() returns False (misconfigured)
+        - The factory raises an exception
+        """
+        entry = self._entries.get(name)
+        if entry is None:
+            return None
+
+        if not entry.check_fn():
+            hint = f" ({entry.install_hint})" if entry.install_hint else ""
+            logger.warning(
+                "Platform '%s' requirements not met%s",
+                entry.label,
+                hint,
+            )
+            return None
+
+        if entry.validate_config is not None:
+            try:
+                if not entry.validate_config(config):
+                    logger.warning(
+                        "Platform '%s' config validation failed",
+                        entry.label,
+                    )
+                    return None
+            except Exception as e:
+                logger.warning(
+                    "Platform '%s' config validation error: %s",
+                    entry.label,
+                    e,
+                )
+                return None
+
+        try:
+            adapter = entry.adapter_factory(config)
+            return adapter
+        except Exception as e:
+            logger.error(
+                "Failed to create adapter for platform '%s': %s",
+                entry.label,
+                e,
+                exc_info=True,
+            )
+            return None
+
+
+# Module-level singleton
+platform_registry = PlatformRegistry()

gateway/run.py

@@ -804,7 +804,7 @@ class GatewayRunner:
     _stop_task: Optional[asyncio.Task] = None
     _session_model_overrides: Dict[str, Dict[str, str]] = {}
     _session_reasoning_overrides: Dict[str, Dict[str, Any]] = {}
-    
+
     def __init__(self, config: Optional[GatewayConfig] = None):
         self.config = config or load_gateway_config()
         self.adapters: Dict[Platform, BasePlatformAdapter] = {}
@@ -1534,7 +1534,7 @@ class GatewayRunner:
             )
         except Exception:
             pass
-    
+
     @staticmethod
     def _load_prefill_messages() -> List[Dict[str, Any]]:
         """Load ephemeral prefill messages from config or env var.
@@ -2671,7 +2671,7 @@ class GatewayRunner:
         logger.info("Press Ctrl+C to stop")
         
         return True
-    
+
     async def _session_expiry_watcher(self, interval: int = 300):
         """Background task that finalizes expired sessions.
 
@@ -3212,17 +3212,21 @@ class GatewayRunner:
 
         self._stop_task = asyncio.create_task(_stop_impl())
         await self._stop_task
-    
+
     async def wait_for_shutdown(self) -> None:
         """Wait for shutdown signal."""
         await self._shutdown_event.wait()
-    
+
     def _create_adapter(
         self, 
         platform: Platform, 
         config: Any
     ) -> Optional[BasePlatformAdapter]:
-        """Create the appropriate adapter for a platform."""
+        """Create the appropriate adapter for a platform.
+
+        Checks the platform_registry first (plugin adapters), then falls
+        through to the built-in if/elif chain for core platforms.
+        """
         if hasattr(config, "extra") and isinstance(config.extra, dict):
             config.extra.setdefault(
                 "group_sessions_per_user",
@@ -3233,6 +3237,16 @@ class GatewayRunner:
                 getattr(self.config, "thread_sessions_per_user", False),
             )
 
+        # ── Plugin-registered platforms (checked first) ──────────────
+        try:
+            from gateway.platform_registry import platform_registry
+            adapter = platform_registry.create_adapter(platform.value, config)
+            if adapter is not None:
+                return adapter
+        except Exception as e:
+            logger.debug("Platform registry lookup for '%s' failed: %s", platform.value, e)
+        # Fall through to built-in adapters below
+
         if platform == Platform.TELEGRAM:
             from gateway.platforms.telegram import TelegramAdapter, check_telegram_requirements
             if not check_telegram_requirements():
@@ -3636,7 +3650,7 @@ class GatewayRunner:
             return "ignore"
 
         return "pair"
-    
+
     async def _handle_message(self, event: MessageEvent) -> Optional[str]:
         """
         Handle an incoming message from any platform.
@@ -5659,7 +5673,7 @@ class GatewayRunner:
         finally:
             # Restore session context variables to their pre-handler state
             self._clear_session_env(_session_env_tokens)
-    
+
     def _format_session_info(self) -> str:
         """Resolve current model config and return a formatted info block.
 
@@ -5856,7 +5870,7 @@ class GatewayRunner:
         if session_info:
             return f"{header}\n\n{session_info}{_tip_line}"
         return f"{header}{_tip_line}"
-    
+
     async def _handle_profile_command(self, event: MessageEvent) -> str:
         """Handle /profile — show active profile name and home directory."""
         from hermes_constants import display_hermes_home
@@ -6005,7 +6019,7 @@ class GatewayRunner:
             lines.append("No active agents or running tasks.")
 
         return "\n".join(lines)
-    
+
     async def _handle_stop_command(self, event: MessageEvent) -> str:
         """Handle /stop command - interrupt a running agent.
 
@@ -6245,7 +6259,7 @@ class GatewayRunner:
         if page != requested_page:
             lines.append(f"_(Requested page {requested_page} was out of range, showing page {page}.)_")
         return "\n".join(lines)
-    
+
     async def _handle_model_command(self, event: MessageEvent) -> Optional[str]:
         """Handle /model command — switch model for this session.
 
@@ -6651,7 +6665,7 @@ class GatewayRunner:
 
         available = "`none`, " + ", ".join(f"`{n}`" for n in personalities)
         return f"Unknown personality: `{args}`\n\nAvailable: {available}"
-    
+
     async def _handle_retry_command(self, event: MessageEvent) -> str:
         """Handle /retry command - re-send the last user message."""
         source = event.source
@@ -6687,7 +6701,7 @@ class GatewayRunner:
         
         # Let the normal message handler process it
         return await self._handle_message(retry_event)
-    
+
     async def _handle_undo_command(self, event: MessageEvent) -> str:
         """Handle /undo command - remove the last user/assistant exchange."""
         source = event.source
@@ -6712,7 +6726,7 @@ class GatewayRunner:
         
         preview = removed_msg[:40] + "..." if len(removed_msg) > 40 else removed_msg
         return f"↩️ Undid {removed_count} message(s).\nRemoved: \"{preview}\""
-    
+
     async def _handle_set_home_command(self, event: MessageEvent) -> str:
         """Handle /sethome command -- set the current chat as the platform's home channel."""
         source = event.source
@@ -6733,7 +6747,7 @@ class GatewayRunner:
             f"✅ Home channel set to **{chat_name}** (ID: {chat_id}).\n"
             f"Cron jobs and cross-platform messages will be delivered here."
         )
-    
+
     @staticmethod
     def _get_guild_id(event: MessageEvent) -> Optional[int]:
         """Extract Discord guild_id from the raw message object."""

hermes_cli/config.py

@@ -73,6 +73,8 @@ _EXTRA_ENV_KEYS = frozenset({
     "QQ_HOME_CHANNEL", "QQ_HOME_CHANNEL_NAME",  # legacy aliases (pre-rename, still read for back-compat)
     "QQ_ALLOWED_USERS", "QQ_GROUP_ALLOWED_USERS", "QQ_ALLOW_ALL_USERS", "QQ_MARKDOWN_SUPPORT",
     "QQ_STT_API_KEY", "QQ_STT_BASE_URL", "QQ_STT_MODEL",
+    "IRC_SERVER", "IRC_PORT", "IRC_NICKNAME", "IRC_CHANNEL",
+    "IRC_USE_TLS", "IRC_SERVER_PASSWORD", "IRC_NICKSERV_PASSWORD",
     "TERMINAL_ENV", "TERMINAL_SSH_KEY", "TERMINAL_SSH_PORT",
     "WHATSAPP_MODE", "WHATSAPP_ENABLED",
     "MATTERMOST_HOME_CHANNEL", "MATTERMOST_HOME_CHANNEL_NAME", "MATTERMOST_REPLY_MODE",
@@ -2084,6 +2086,43 @@ OPTIONAL_ENV_VARS = {
         "prompt": "QQ Sandbox Mode",
         "category": "messaging",
     },
+    "IRC_SERVER": {
+        "description": "IRC server hostname (e.g. irc.libera.chat)",
+        "prompt": "IRC server",
+        "url": None,
+        "password": False,
+        "category": "messaging",
+    },
+    "IRC_CHANNEL": {
+        "description": "IRC channel to join (e.g. #hermes)",
+        "prompt": "IRC channel",
+        "url": None,
+        "password": False,
+        "category": "messaging",
+    },
+    "IRC_NICKNAME": {
+        "description": "Bot nickname on IRC (default: hermes-bot)",
+        "prompt": "IRC nickname",
+        "url": None,
+        "password": False,
+        "category": "messaging",
+    },
+    "IRC_SERVER_PASSWORD": {
+        "description": "IRC server password (if required)",
+        "prompt": "IRC server password",
+        "url": None,
+        "password": True,
+        "category": "messaging",
+        "advanced": True,
+    },
+    "IRC_NICKSERV_PASSWORD": {
+        "description": "NickServ password for nick identification",
+        "prompt": "NickServ password",
+        "url": None,
+        "password": True,
+        "category": "messaging",
+        "advanced": True,
+    },
     "GATEWAY_ALLOW_ALL_USERS": {
         "description": "Allow all users to interact with messaging bots (true/false). Default: false.",
         "prompt": "Allow all users (true/false)",

hermes_cli/plugins.py

@@ -445,6 +445,53 @@ class PluginContext:
             self.manifest.name, provider.name,
         )
 
+    # -- platform adapter registration ---------------------------------------
+
+    def register_platform(
+        self,
+        name: str,
+        label: str,
+        adapter_factory: Callable,
+        check_fn: Callable,
+        validate_config: Callable | None = None,
+        required_env: list | None = None,
+        install_hint: str = "",
+    ) -> None:
+        """Register a gateway platform adapter.
+
+        The adapter_factory receives a ``PlatformConfig`` and returns a
+        ``BasePlatformAdapter`` subclass instance.  The gateway calls
+        ``check_fn()`` before instantiation to verify dependencies.
+
+        Example::
+
+            ctx.register_platform(
+                name="irc",
+                label="IRC",
+                adapter_factory=lambda cfg: IRCAdapter(cfg),
+                check_fn=lambda: True,
+            )
+        """
+        from gateway.platform_registry import platform_registry, PlatformEntry
+
+        entry = PlatformEntry(
+            name=name,
+            label=label,
+            adapter_factory=adapter_factory,
+            check_fn=check_fn,
+            validate_config=validate_config,
+            required_env=required_env or [],
+            install_hint=install_hint,
+            source="plugin",
+        )
+        platform_registry.register(entry)
+        self._manager._plugin_platform_names.add(name)
+        logger.debug(
+            "Plugin %s registered platform: %s",
+            self.manifest.name,
+            name,
+        )
+
     # -- hook registration --------------------------------------------------
 
     def register_hook(self, hook_name: str, callback: Callable) -> None:
@@ -523,6 +570,7 @@ class PluginManager:
         self._plugins: Dict[str, LoadedPlugin] = {}
         self._hooks: Dict[str, List[Callable]] = {}
         self._plugin_tool_names: Set[str] = set()
+        self._plugin_platform_names: Set[str] = set()
         self._cli_commands: Dict[str, dict] = {}
         self._context_engine = None  # Set by a plugin via register_context_engine()
         self._plugin_commands: Dict[str, dict] = {}  # Slash commands registered by plugins

plugins/platforms/irc/PLUGIN.yaml

@@ -0,0 +1,12 @@
+name: irc-platform
+version: 1.0.0
+description: >
+  IRC gateway adapter for Hermes Agent.
+  Connects to an IRC server and relays messages between an IRC channel
+  (or DMs) and the Hermes agent.  No external dependencies — uses
+  Python's stdlib asyncio for the IRC protocol.
+author: Nous Research
+requires_env:
+  - IRC_SERVER
+  - IRC_CHANNEL
+  - IRC_NICKNAME

plugins/platforms/irc/adapter.py

@@ -0,0 +1,493 @@
+"""
+IRC Platform Adapter for Hermes Agent.
+
+A plugin-based gateway adapter that connects to an IRC server and relays
+messages to/from the Hermes agent.  Zero external dependencies — uses
+Python's stdlib asyncio for the IRC protocol.
+
+Configuration in config.yaml::
+
+    gateway:
+      platforms:
+        irc:
+          enabled: true
+          extra:
+            server: irc.libera.chat
+            port: 6697
+            nickname: hermes-bot
+            channel: "#hermes"
+            use_tls: true
+            server_password: ""       # optional server password
+            nickserv_password: ""     # optional NickServ identification
+            allowed_users: []         # empty = allow all, or list of nicks
+            max_message_length: 450   # IRC line limit (safe default)
+
+Or via environment variables (overrides config.yaml):
+    IRC_SERVER, IRC_PORT, IRC_NICKNAME, IRC_CHANNEL, IRC_USE_TLS,
+    IRC_SERVER_PASSWORD, IRC_NICKSERV_PASSWORD
+"""
+
+import asyncio
+import logging
+import os
+import re
+import ssl
+import time
+from typing import Any, Dict, List, Optional
+
+logger = logging.getLogger(__name__)
+
+# ---------------------------------------------------------------------------
+# Lazy import: BasePlatformAdapter and friends live in the main repo.
+# We import at function/class level to avoid import errors when the plugin
+# is discovered but the gateway hasn't been fully initialised yet.
+# ---------------------------------------------------------------------------
+
+from gateway.platforms.base import (
+    BasePlatformAdapter,
+    SendResult,
+    MessageEvent,
+    MessageType,
+)
+from gateway.session import SessionSource
+from gateway.config import PlatformConfig, Platform
+
+
+def _ensure_imports():
+    """No-op — kept for backward compatibility with any call sites."""
+    pass
+
+
+# ---------------------------------------------------------------------------
+# IRC protocol helpers
+# ---------------------------------------------------------------------------
+
+def _parse_irc_message(raw: str) -> dict:
+    """Parse a raw IRC protocol line into components.
+
+    Returns dict with keys: prefix, command, params.
+    """
+    prefix = ""
+    trailing = ""
+
+    if raw.startswith(":"):
+        prefix, raw = raw[1:].split(" ", 1)
+
+    if " :" in raw:
+        raw, trailing = raw.split(" :", 1)
+
+    parts = raw.split()
+    command = parts[0] if parts else ""
+    params = parts[1:] if len(parts) > 1 else []
+    if trailing:
+        params.append(trailing)
+
+    return {"prefix": prefix, "command": command, "params": params}
+
+
+def _extract_nick(prefix: str) -> str:
+    """Extract nickname from IRC prefix (nick!user@host)."""
+    return prefix.split("!")[0] if "!" in prefix else prefix
+
+
+# ---------------------------------------------------------------------------
+# IRC Adapter
+# ---------------------------------------------------------------------------
+
+class IRCAdapter(BasePlatformAdapter):
+    """Async IRC adapter implementing the BasePlatformAdapter interface.
+
+    This class is instantiated by the adapter_factory passed to
+    register_platform().
+    """
+
+    def __init__(self, config, **kwargs):
+        platform = Platform("irc")
+        super().__init__(config=config, platform=platform)
+
+        extra = getattr(config, "extra", {}) or {}
+
+        # Connection settings (env vars override config.yaml)
+        self.server = os.getenv("IRC_SERVER") or extra.get("server", "")
+        self.port = int(os.getenv("IRC_PORT") or extra.get("port", 6697))
+        self.nickname = os.getenv("IRC_NICKNAME") or extra.get("nickname", "hermes-bot")
+        self.channel = os.getenv("IRC_CHANNEL") or extra.get("channel", "")
+        self.use_tls = (
+            os.getenv("IRC_USE_TLS", "").lower() in ("1", "true", "yes")
+            if os.getenv("IRC_USE_TLS")
+            else extra.get("use_tls", True)
+        )
+        self.server_password = os.getenv("IRC_SERVER_PASSWORD") or extra.get("server_password", "")
+        self.nickserv_password = os.getenv("IRC_NICKSERV_PASSWORD") or extra.get("nickserv_password", "")
+
+        # Auth
+        self.allowed_users: list = extra.get("allowed_users", [])
+
+        # IRC limits
+        self.max_message_length = int(extra.get("max_message_length", 450))
+
+        # Runtime state
+        self._reader: Optional[asyncio.StreamReader] = None
+        self._writer: Optional[asyncio.StreamWriter] = None
+        self._recv_task: Optional[asyncio.Task] = None
+        self._current_nick = self.nickname
+        self._registered = False  # IRC registration complete
+        self._registration_event = asyncio.Event()
+
+    @property
+    def name(self) -> str:
+        return "IRC"
+
+    # ── Connection lifecycle ──────────────────────────────────────────────
+
+    async def connect(self) -> bool:
+        """Connect to the IRC server, register, and join the channel."""
+        if not self.server or not self.channel:
+            logger.error("IRC: server and channel must be configured")
+            self._set_fatal_error(
+                "config_missing",
+                "IRC_SERVER and IRC_CHANNEL must be set",
+                retryable=False,
+            )
+            return False
+
+        try:
+            ssl_ctx = None
+            if self.use_tls:
+                ssl_ctx = ssl.create_default_context()
+
+            self._reader, self._writer = await asyncio.wait_for(
+                asyncio.open_connection(self.server, self.port, ssl=ssl_ctx),
+                timeout=30.0,
+            )
+        except Exception as e:
+            logger.error("IRC: failed to connect to %s:%s — %s", self.server, self.port, e)
+            self._set_fatal_error("connect_failed", str(e), retryable=True)
+            return False
+
+        # IRC registration sequence
+        if self.server_password:
+            await self._send_raw(f"PASS {self.server_password}")
+        await self._send_raw(f"NICK {self.nickname}")
+        await self._send_raw(f"USER {self.nickname} 0 * :Hermes Agent")
+
+        # Start receive loop
+        self._recv_task = asyncio.create_task(self._receive_loop())
+
+        # Wait for registration (001 RPL_WELCOME) with timeout
+        try:
+            await asyncio.wait_for(self._registration_event.wait(), timeout=30.0)
+        except asyncio.TimeoutError:
+            logger.error("IRC: registration timed out")
+            await self.disconnect()
+            self._set_fatal_error("registration_timeout", "IRC server did not send RPL_WELCOME", retryable=True)
+            return False
+
+        # NickServ identification
+        if self.nickserv_password:
+            await self._send_raw(f"PRIVMSG NickServ :IDENTIFY {self.nickserv_password}")
+            await asyncio.sleep(2)  # Give NickServ time to process
+
+        # Join channel
+        await self._send_raw(f"JOIN {self.channel}")
+
+        self._mark_connected()
+        logger.info("IRC: connected to %s:%s as %s, joined %s", self.server, self.port, self._current_nick, self.channel)
+        return True
+
+    async def disconnect(self) -> None:
+        """Quit and close the connection."""
+        self._mark_disconnected()
+        if self._writer and not self._writer.is_closing():
+            try:
+                await self._send_raw("QUIT :Hermes Agent shutting down")
+                await asyncio.sleep(0.5)
+            except Exception:
+                pass
+            try:
+                self._writer.close()
+                await self._writer.wait_closed()
+            except Exception:
+                pass
+
+        if self._recv_task and not self._recv_task.done():
+            self._recv_task.cancel()
+            try:
+                await self._recv_task
+            except asyncio.CancelledError:
+                pass
+
+        self._reader = None
+        self._writer = None
+        self._registered = False
+        self._registration_event.clear()
+
+    # ── Sending ───────────────────────────────────────────────────────────
+
+    async def send(
+        self,
+        chat_id: str,
+        content: str,
+        reply_to: Optional[str] = None,
+        metadata: Optional[Dict[str, Any]] = None,
+    ):
+        if not self._writer or self._writer.is_closing():
+            return SendResult(success=False, error="Not connected")
+
+        target = chat_id  # channel name or nick for DMs
+        lines = self._split_message(content, target)
+
+        for line in lines:
+            try:
+                await self._send_raw(f"PRIVMSG {target} :{line}")
+                # Basic rate limiting to avoid excess flood
+                await asyncio.sleep(0.3)
+            except Exception as e:
+                return SendResult(success=False, error=str(e))
+
+        return SendResult(success=True, message_id=str(int(time.time() * 1000)))
+
+    async def send_typing(self, chat_id: str, metadata=None) -> None:
+        """IRC has no typing indicator — no-op."""
+        pass
+
+    async def get_chat_info(self, chat_id: str) -> Dict[str, Any]:
+        is_channel = chat_id.startswith("#") or chat_id.startswith("&")
+        return {
+            "name": chat_id,
+            "type": "group" if is_channel else "dm",
+        }
+
+    # ── Message splitting ─────────────────────────────────────────────────
+
+    def _split_message(self, content: str, target: str) -> List[str]:
+        """Split a long message into IRC-safe chunks.
+
+        IRC has a ~512 byte line limit.  After accounting for protocol
+        overhead (``PRIVMSG <target> :``), we split content into chunks.
+        """
+        # Strip markdown formatting that doesn't render in IRC
+        content = self._strip_markdown(content)
+
+        overhead = len(f"PRIVMSG {target} :".encode("utf-8")) + 2  # +2 for \r\n
+        max_bytes = 510 - overhead
+        max_chars = min(self.max_message_length, max_bytes)
+
+        lines: List[str] = []
+        for paragraph in content.split("\n"):
+            if not paragraph.strip():
+                continue
+            while len(paragraph) > max_chars:
+                # Find a space to break at
+                split_at = paragraph.rfind(" ", 0, max_chars)
+                if split_at < max_chars // 3:
+                    split_at = max_chars
+                lines.append(paragraph[:split_at])
+                paragraph = paragraph[split_at:].lstrip()
+            if paragraph.strip():
+                lines.append(paragraph)
+
+        return lines if lines else [""]
+
+    @staticmethod
+    def _strip_markdown(text: str) -> str:
+        """Convert basic markdown to plain text for IRC."""
+        # Bold: **text** or __text__ → text
+        text = re.sub(r"\*\*(.+?)\*\*", r"\1", text)
+        text = re.sub(r"__(.+?)__", r"\1", text)
+        # Italic: *text* or _text_ → text
+        text = re.sub(r"\*(.+?)\*", r"\1", text)
+        text = re.sub(r"(?<!\w)_(.+?)_(?!\w)", r"\1", text)
+        # Inline code: `text` → text
+        text = re.sub(r"`(.+?)`", r"\1", text)
+        # Code blocks: ```...``` → content
+        text = re.sub(r"```\w*\n?", "", text)
+        # Images: ![alt](url) → url  (must come BEFORE links)
+        text = re.sub(r"!\[([^\]]*)\]\(([^)]+)\)", r"\2", text)
+        # Links: [text](url) → text (url)
+        text = re.sub(r"\[([^\]]+)\]\(([^)]+)\)", r"\1 (\2)", text)
+        return text
+
+    # ── Raw IRC I/O ──────────────────────────────────────────────────────
+
+    async def _send_raw(self, line: str) -> None:
+        """Send a raw IRC protocol line."""
+        if not self._writer or self._writer.is_closing():
+            return
+        encoded = (line + "\r\n").encode("utf-8")
+        self._writer.write(encoded)
+        await self._writer.drain()
+
+    async def _receive_loop(self) -> None:
+        """Main receive loop — reads lines and dispatches them."""
+        buffer = b""
+        try:
+            while self._reader and not self._reader.at_eof():
+                data = await self._reader.read(4096)
+                if not data:
+                    break
+                buffer += data
+                while b"\r\n" in buffer:
+                    line, buffer = buffer.split(b"\r\n", 1)
+                    try:
+                        decoded = line.decode("utf-8", errors="replace")
+                        await self._handle_line(decoded)
+                    except Exception as e:
+                        logger.warning("IRC: error handling line: %s", e)
+        except asyncio.CancelledError:
+            raise
+        except Exception as e:
+            logger.error("IRC: receive loop error: %s", e)
+        finally:
+            if self.is_connected:
+                logger.warning("IRC: connection lost, marking disconnected")
+                self._set_fatal_error("connection_lost", "IRC connection closed unexpectedly", retryable=True)
+                await self._notify_fatal_error()
+
+    async def _handle_line(self, raw: str) -> None:
+        """Dispatch a single IRC protocol line."""
+        msg = _parse_irc_message(raw)
+        command = msg["command"]
+        params = msg["params"]
+
+        # PING/PONG keepalive
+        if command == "PING":
+            payload = params[0] if params else ""
+            await self._send_raw(f"PONG :{payload}")
+            return
+
+        # RPL_WELCOME (001) — registration complete
+        if command == "001":
+            self._registered = True
+            self._registration_event.set()
+            if params:
+                # Server may confirm our nick in the first param
+                self._current_nick = params[0]
+            return
+
+        # ERR_NICKNAMEINUSE (433) — nick collision during registration
+        if command == "433":
+            self._current_nick = self.nickname + "_"
+            await self._send_raw(f"NICK {self._current_nick}")
+            return
+
+        # PRIVMSG — incoming message (channel or DM)
+        if command == "PRIVMSG" and len(params) >= 2:
+            sender_nick = _extract_nick(msg["prefix"])
+            target = params[0]
+            text = params[1]
+
+            # Ignore our own messages
+            if sender_nick.lower() == self._current_nick.lower():
+                return
+
+            # CTCP ACTION (/me) — convert to text
+            if text.startswith("\x01ACTION ") and text.endswith("\x01"):
+                text = f"* {sender_nick} {text[8:-1]}"
+
+            # Ignore other CTCP
+            if text.startswith("\x01"):
+                return
+
+            # Determine if this is a channel message or DM
+            is_channel = target.startswith("#") or target.startswith("&")
+            chat_id = target if is_channel else sender_nick
+            chat_type = "group" if is_channel else "dm"
+
+            # In channels, only respond if addressed (nick: or nick,)
+            if is_channel:
+                addressed = False
+                for prefix in (f"{self._current_nick}:", f"{self._current_nick},",
+                               f"{self._current_nick} "):
+                    if text.lower().startswith(prefix.lower()):
+                        text = text[len(prefix):].strip()
+                        addressed = True
+                        break
+                if not addressed:
+                    return  # Ignore unaddressed channel messages
+
+            # Auth check
+            if self.allowed_users and sender_nick not in self.allowed_users:
+                logger.debug("IRC: ignoring message from unauthorized user %s", sender_nick)
+                return
+
+            await self._dispatch_message(
+                text=text,
+                chat_id=chat_id,
+                chat_type=chat_type,
+                user_id=sender_nick,
+                user_name=sender_nick,
+            )
+
+        # NICK — track our own nick changes
+        if command == "NICK" and _extract_nick(msg["prefix"]).lower() == self._current_nick.lower():
+            if params:
+                self._current_nick = params[0]
+
+    async def _dispatch_message(
+        self,
+        text: str,
+        chat_id: str,
+        chat_type: str,
+        user_id: str,
+        user_name: str,
+    ) -> None:
+        """Build a MessageEvent and hand it to the base class handler."""
+        if not self._message_handler:
+            return
+
+        source = self.build_source(
+            chat_id=chat_id,
+            chat_name=chat_id,
+            chat_type=chat_type,
+            user_id=user_id,
+            user_name=user_name,
+        )
+
+        event = MessageEvent(
+            text=text,
+            message_type=MessageType.TEXT,
+            source=source,
+            message_id=str(int(time.time() * 1000)),
+            timestamp=__import__("datetime").datetime.now(),
+        )
+
+        await self.handle_message(event)
+
+
+# ---------------------------------------------------------------------------
+# Plugin registration
+# ---------------------------------------------------------------------------
+
+def check_requirements() -> bool:
+    """Check if IRC is configured.
+
+    Only requires the server and channel — no external pip packages needed.
+    """
+    server = os.getenv("IRC_SERVER", "")
+    channel = os.getenv("IRC_CHANNEL", "")
+    # Also accept config.yaml-only configuration (no env vars).
+    # The gateway passes PlatformConfig; we just check env for the
+    # hermes setup / requirements check path.
+    return bool(server and channel)
+
+
+def validate_config(config) -> bool:
+    """Validate that the platform config has enough info to connect."""
+    extra = getattr(config, "extra", {}) or {}
+    server = os.getenv("IRC_SERVER") or extra.get("server", "")
+    channel = os.getenv("IRC_CHANNEL") or extra.get("channel", "")
+    return bool(server and channel)
+
+
+def register(ctx):
+    """Plugin entry point — called by the Hermes plugin system."""
+    ctx.register_platform(
+        name="irc",
+        label="IRC",
+        adapter_factory=lambda cfg: IRCAdapter(cfg),
+        check_fn=check_requirements,
+        validate_config=validate_config,
+        required_env=["IRC_SERVER", "IRC_CHANNEL", "IRC_NICKNAME"],
+        install_hint="No extra packages needed (stdlib only)",
+    )

tests/gateway/test_irc_adapter.py

@@ -0,0 +1,380 @@
+"""Tests for the IRC platform adapter plugin."""
+
+import asyncio
+import os
+import sys
+import pytest
+from pathlib import Path
+from unittest.mock import AsyncMock, MagicMock, patch
+
+# Ensure the plugins directory is on sys.path for direct import
+_REPO_ROOT = Path(__file__).resolve().parents[2]
+_IRC_PLUGIN_DIR = _REPO_ROOT / "plugins" / "platforms" / "irc"
+if str(_IRC_PLUGIN_DIR) not in sys.path:
+    sys.path.insert(0, str(_IRC_PLUGIN_DIR))
+
+
+# ── IRC protocol helpers ─────────────────────────────────────────────────
+
+from adapter import _parse_irc_message, _extract_nick
+
+
+class TestIRCProtocolHelpers:
+
+    def test_parse_simple_command(self):
+        msg = _parse_irc_message("PING :server.example.com")
+        assert msg["command"] == "PING"
+        assert msg["params"] == ["server.example.com"]
+        assert msg["prefix"] == ""
+
+    def test_parse_prefixed_message(self):
+        msg = _parse_irc_message(":nick!user@host PRIVMSG #channel :Hello world")
+        assert msg["prefix"] == "nick!user@host"
+        assert msg["command"] == "PRIVMSG"
+        assert msg["params"] == ["#channel", "Hello world"]
+
+    def test_parse_numeric_reply(self):
+        msg = _parse_irc_message(":server 001 hermes-bot :Welcome to IRC")
+        assert msg["prefix"] == "server"
+        assert msg["command"] == "001"
+        assert msg["params"] == ["hermes-bot", "Welcome to IRC"]
+
+    def test_parse_nick_collision(self):
+        msg = _parse_irc_message(":server 433 * hermes-bot :Nickname is already in use")
+        assert msg["command"] == "433"
+
+    def test_extract_nick_full_prefix(self):
+        assert _extract_nick("nick!user@host") == "nick"
+
+    def test_extract_nick_bare(self):
+        assert _extract_nick("server.example.com") == "server.example.com"
+
+
+# ── IRC Adapter ──────────────────────────────────────────────────────────
+
+from adapter import IRCAdapter, check_requirements, validate_config
+
+
+class TestIRCAdapterInit:
+
+    def test_init_from_env(self, monkeypatch):
+        monkeypatch.setenv("IRC_SERVER", "irc.test.net")
+        monkeypatch.setenv("IRC_PORT", "6667")
+        monkeypatch.setenv("IRC_NICKNAME", "testbot")
+        monkeypatch.setenv("IRC_CHANNEL", "#test")
+        monkeypatch.setenv("IRC_USE_TLS", "false")
+
+        from gateway.config import PlatformConfig
+        cfg = PlatformConfig(enabled=True)
+        adapter = IRCAdapter(cfg)
+
+        assert adapter.server == "irc.test.net"
+        assert adapter.port == 6667
+        assert adapter.nickname == "testbot"
+        assert adapter.channel == "#test"
+        assert adapter.use_tls is False
+
+    def test_init_from_config_extra(self, monkeypatch):
+        # Clear any env vars
+        for key in ("IRC_SERVER", "IRC_PORT", "IRC_NICKNAME", "IRC_CHANNEL", "IRC_USE_TLS"):
+            monkeypatch.delenv(key, raising=False)
+
+        from gateway.config import PlatformConfig
+        cfg = PlatformConfig(
+            enabled=True,
+            extra={
+                "server": "irc.libera.chat",
+                "port": 6697,
+                "nickname": "hermes",
+                "channel": "#hermes-dev",
+                "use_tls": True,
+            },
+        )
+        adapter = IRCAdapter(cfg)
+
+        assert adapter.server == "irc.libera.chat"
+        assert adapter.port == 6697
+        assert adapter.nickname == "hermes"
+        assert adapter.channel == "#hermes-dev"
+        assert adapter.use_tls is True
+
+    def test_env_overrides_config(self, monkeypatch):
+        monkeypatch.setenv("IRC_SERVER", "env-server.net")
+
+        from gateway.config import PlatformConfig
+        cfg = PlatformConfig(
+            enabled=True,
+            extra={"server": "config-server.net", "channel": "#ch"},
+        )
+        adapter = IRCAdapter(cfg)
+        assert adapter.server == "env-server.net"
+
+
+class TestIRCAdapterSend:
+
+    @pytest.fixture
+    def adapter(self, monkeypatch):
+        for key in ("IRC_SERVER", "IRC_PORT", "IRC_NICKNAME", "IRC_CHANNEL", "IRC_USE_TLS"):
+            monkeypatch.delenv(key, raising=False)
+        from gateway.config import PlatformConfig
+        cfg = PlatformConfig(
+            enabled=True,
+            extra={
+                "server": "localhost",
+                "port": 6667,
+                "nickname": "testbot",
+                "channel": "#test",
+                "use_tls": False,
+            },
+        )
+        return IRCAdapter(cfg)
+
+    @pytest.mark.asyncio
+    async def test_send_not_connected(self, adapter):
+        result = await adapter.send("#test", "hello")
+        assert result.success is False
+        assert "Not connected" in result.error
+
+    @pytest.mark.asyncio
+    async def test_send_success(self, adapter):
+        writer = MagicMock()
+        writer.is_closing = MagicMock(return_value=False)
+        writer.write = MagicMock()
+        writer.drain = AsyncMock()
+        adapter._writer = writer
+
+        result = await adapter.send("#test", "hello world")
+        assert result.success is True
+        assert result.message_id is not None
+        # Verify PRIVMSG was sent
+        writer.write.assert_called()
+        sent_data = writer.write.call_args[0][0]
+        assert b"PRIVMSG #test :hello world" in sent_data
+
+    @pytest.mark.asyncio
+    async def test_send_splits_long_messages(self, adapter):
+        writer = MagicMock()
+        writer.is_closing = MagicMock(return_value=False)
+        writer.write = MagicMock()
+        writer.drain = AsyncMock()
+        adapter._writer = writer
+
+        long_msg = "x" * 1000
+        result = await adapter.send("#test", long_msg)
+        assert result.success is True
+        # Should have been split into multiple PRIVMSG calls
+        assert writer.write.call_count > 1
+
+
+class TestIRCAdapterMessageParsing:
+
+    @pytest.fixture
+    def adapter(self, monkeypatch):
+        for key in ("IRC_SERVER", "IRC_PORT", "IRC_NICKNAME", "IRC_CHANNEL", "IRC_USE_TLS"):
+            monkeypatch.delenv(key, raising=False)
+        from gateway.config import PlatformConfig
+        cfg = PlatformConfig(
+            enabled=True,
+            extra={
+                "server": "localhost",
+                "port": 6667,
+                "nickname": "hermes",
+                "channel": "#test",
+                "use_tls": False,
+            },
+        )
+        a = IRCAdapter(cfg)
+        a._current_nick = "hermes"
+        a._registered = True
+        return a
+
+    @pytest.mark.asyncio
+    async def test_handle_ping(self, adapter):
+        writer = MagicMock()
+        writer.is_closing = MagicMock(return_value=False)
+        writer.write = MagicMock()
+        writer.drain = AsyncMock()
+        adapter._writer = writer
+
+        await adapter._handle_line("PING :test-server")
+        sent = writer.write.call_args[0][0]
+        assert b"PONG :test-server" in sent
+
+    @pytest.mark.asyncio
+    async def test_handle_welcome(self, adapter):
+        adapter._registered = False
+        adapter._registration_event = asyncio.Event()
+
+        await adapter._handle_line(":server 001 hermes :Welcome to IRC")
+        assert adapter._registered is True
+        assert adapter._registration_event.is_set()
+
+    @pytest.mark.asyncio
+    async def test_handle_nick_collision(self, adapter):
+        writer = MagicMock()
+        writer.is_closing = MagicMock(return_value=False)
+        writer.write = MagicMock()
+        writer.drain = AsyncMock()
+        adapter._writer = writer
+
+        await adapter._handle_line(":server 433 * hermes :Nickname in use")
+        assert adapter._current_nick == "hermes_"
+        sent = writer.write.call_args[0][0]
+        assert b"NICK hermes_" in sent
+
+    @pytest.mark.asyncio
+    async def test_handle_addressed_channel_message(self, adapter):
+        """Messages addressed to the bot (nick: msg) should be dispatched."""
+        handler = AsyncMock(return_value="response")
+        adapter._message_handler = handler
+
+        # Mock handle_message to capture the event
+        dispatched = []
+        original_dispatch = adapter._dispatch_message
+
+        async def capture_dispatch(**kwargs):
+            dispatched.append(kwargs)
+
+        adapter._dispatch_message = capture_dispatch
+
+        await adapter._handle_line(":user!u@host PRIVMSG #test :hermes: hello there")
+        assert len(dispatched) == 1
+        assert dispatched[0]["text"] == "hello there"
+        assert dispatched[0]["chat_id"] == "#test"
+
+    @pytest.mark.asyncio
+    async def test_ignores_unaddressed_channel_message(self, adapter):
+        dispatched = []
+
+        async def capture_dispatch(**kwargs):
+            dispatched.append(kwargs)
+
+        adapter._dispatch_message = capture_dispatch
+        adapter._message_handler = AsyncMock()
+
+        await adapter._handle_line(":user!u@host PRIVMSG #test :just talking")
+        assert len(dispatched) == 0
+
+    @pytest.mark.asyncio
+    async def test_handle_dm(self, adapter):
+        """DMs (target == bot nick) should always be dispatched."""
+        dispatched = []
+
+        async def capture_dispatch(**kwargs):
+            dispatched.append(kwargs)
+
+        adapter._dispatch_message = capture_dispatch
+        adapter._message_handler = AsyncMock()
+
+        await adapter._handle_line(":user!u@host PRIVMSG hermes :private message")
+        assert len(dispatched) == 1
+        assert dispatched[0]["text"] == "private message"
+        assert dispatched[0]["chat_type"] == "dm"
+        assert dispatched[0]["chat_id"] == "user"
+
+    @pytest.mark.asyncio
+    async def test_ignores_own_messages(self, adapter):
+        dispatched = []
+
+        async def capture_dispatch(**kwargs):
+            dispatched.append(kwargs)
+
+        adapter._dispatch_message = capture_dispatch
+        adapter._message_handler = AsyncMock()
+
+        await adapter._handle_line(":hermes!bot@host PRIVMSG #test :my own msg")
+        assert len(dispatched) == 0
+
+    @pytest.mark.asyncio
+    async def test_ctcp_action_converted(self, adapter):
+        """CTCP ACTION (/me) should be converted to text."""
+        dispatched = []
+
+        async def capture_dispatch(**kwargs):
+            dispatched.append(kwargs)
+
+        adapter._dispatch_message = capture_dispatch
+        adapter._message_handler = AsyncMock()
+
+        await adapter._handle_line(":user!u@host PRIVMSG hermes :\x01ACTION waves\x01")
+        assert len(dispatched) == 1
+        assert dispatched[0]["text"] == "* user waves"
+
+
+class TestIRCAdapterMarkdown:
+
+    def test_strip_bold(self):
+        assert IRCAdapter._strip_markdown("**bold**") == "bold"
+
+    def test_strip_italic(self):
+        assert IRCAdapter._strip_markdown("*italic*") == "italic"
+
+    def test_strip_code(self):
+        assert IRCAdapter._strip_markdown("`code`") == "code"
+
+    def test_strip_link(self):
+        result = IRCAdapter._strip_markdown("[click here](https://example.com)")
+        assert result == "click here (https://example.com)"
+
+    def test_strip_image(self):
+        result = IRCAdapter._strip_markdown("![alt](https://example.com/img.png)")
+        assert result == "https://example.com/img.png"
+
+
+# ── Requirements / validation ────────────────────────────────────────────
+
+
+class TestIRCRequirements:
+
+    def test_check_requirements_with_env(self, monkeypatch):
+        monkeypatch.setenv("IRC_SERVER", "irc.test.net")
+        monkeypatch.setenv("IRC_CHANNEL", "#test")
+        assert check_requirements() is True
+
+    def test_check_requirements_missing_server(self, monkeypatch):
+        monkeypatch.delenv("IRC_SERVER", raising=False)
+        monkeypatch.setenv("IRC_CHANNEL", "#test")
+        assert check_requirements() is False
+
+    def test_check_requirements_missing_channel(self, monkeypatch):
+        monkeypatch.setenv("IRC_SERVER", "irc.test.net")
+        monkeypatch.delenv("IRC_CHANNEL", raising=False)
+        assert check_requirements() is False
+
+    def test_validate_config_from_extra(self, monkeypatch):
+        for key in ("IRC_SERVER", "IRC_CHANNEL"):
+            monkeypatch.delenv(key, raising=False)
+        from gateway.config import PlatformConfig
+        cfg = PlatformConfig(extra={"server": "irc.test.net", "channel": "#test"})
+        assert validate_config(cfg) is True
+
+    def test_validate_config_missing(self, monkeypatch):
+        for key in ("IRC_SERVER", "IRC_CHANNEL"):
+            monkeypatch.delenv(key, raising=False)
+        from gateway.config import PlatformConfig
+        cfg = PlatformConfig(extra={})
+        assert validate_config(cfg) is False
+
+
+# ── Plugin registration ──────────────────────────────────────────────────
+
+
+class TestIRCPluginRegistration:
+    """Test the register() entry point."""
+
+    def test_register_adds_to_registry(self, monkeypatch):
+        monkeypatch.setenv("IRC_SERVER", "irc.test.net")
+        monkeypatch.setenv("IRC_CHANNEL", "#test")
+
+        from gateway.platform_registry import platform_registry
+
+        # Clean up if already registered
+        platform_registry.unregister("irc")
+
+        from adapter import register
+
+        ctx = MagicMock()
+        register(ctx)
+        ctx.register_platform.assert_called_once()
+        call_kwargs = ctx.register_platform.call_args
+        assert call_kwargs[1]["name"] == "irc" or call_kwargs[0][0] == "irc" if call_kwargs[0] else call_kwargs[1]["name"] == "irc"

tests/gateway/test_platform_registry.py

@@ -0,0 +1,267 @@
+"""Tests for the platform adapter registry and dynamic Platform enum."""
+
+import os
+import pytest
+from unittest.mock import MagicMock, patch
+from dataclasses import dataclass
+
+from gateway.platform_registry import PlatformRegistry, PlatformEntry, platform_registry
+from gateway.config import Platform, PlatformConfig, GatewayConfig
+
+
+# ── Platform enum dynamic members ─────────────────────────────────────────
+
+
+class TestPlatformEnumDynamic:
+    """Test that Platform enum accepts unknown values for plugin platforms."""
+
+    def test_builtin_members_still_work(self):
+        assert Platform.TELEGRAM.value == "telegram"
+        assert Platform("telegram") is Platform.TELEGRAM
+
+    def test_dynamic_member_created(self):
+        p = Platform("irc")
+        assert p.value == "irc"
+        assert p.name == "IRC"
+
+    def test_dynamic_member_identity_stable(self):
+        """Same value returns same object (cached)."""
+        a = Platform("irc")
+        b = Platform("irc")
+        assert a is b
+
+    def test_dynamic_member_case_normalised(self):
+        """Mixed case normalised to lowercase."""
+        a = Platform("IRC")
+        b = Platform("irc")
+        assert a is b
+        assert a.value == "irc"
+
+    def test_dynamic_member_with_hyphens(self):
+        p = Platform("my-platform")
+        assert p.value == "my-platform"
+        assert p.name == "MY_PLATFORM"
+
+    def test_dynamic_member_rejects_non_string(self):
+        with pytest.raises(ValueError):
+            Platform(123)
+
+    def test_dynamic_member_rejects_empty(self):
+        with pytest.raises(ValueError):
+            Platform("")
+
+    def test_dynamic_member_rejects_whitespace_only(self):
+        with pytest.raises(ValueError):
+            Platform("   ")
+
+
+# ── PlatformRegistry ──────────────────────────────────────────────────────
+
+
+class TestPlatformRegistry:
+    """Test the PlatformRegistry itself."""
+
+    def _make_entry(self, name="test", check_ok=True, validate_ok=True, factory_ok=True):
+        adapter_mock = MagicMock()
+        return PlatformEntry(
+            name=name,
+            label=name.title(),
+            adapter_factory=lambda cfg, _m=adapter_mock: _m if factory_ok else (_ for _ in ()).throw(RuntimeError("factory error")),
+            check_fn=lambda: check_ok,
+            validate_config=lambda cfg: validate_ok,
+            required_env=[],
+            source="plugin",
+        ), adapter_mock
+
+    def test_register_and_get(self):
+        reg = PlatformRegistry()
+        entry, _ = self._make_entry("alpha")
+        reg.register(entry)
+        assert reg.get("alpha") is entry
+        assert reg.is_registered("alpha")
+
+    def test_get_unknown_returns_none(self):
+        reg = PlatformRegistry()
+        assert reg.get("nonexistent") is None
+
+    def test_unregister(self):
+        reg = PlatformRegistry()
+        entry, _ = self._make_entry("beta")
+        reg.register(entry)
+        assert reg.unregister("beta") is True
+        assert reg.get("beta") is None
+        assert reg.unregister("beta") is False  # already gone
+
+    def test_create_adapter_success(self):
+        reg = PlatformRegistry()
+        entry, mock_adapter = self._make_entry("gamma")
+        reg.register(entry)
+        result = reg.create_adapter("gamma", MagicMock())
+        assert result is mock_adapter
+
+    def test_create_adapter_unknown_name(self):
+        reg = PlatformRegistry()
+        assert reg.create_adapter("unknown", MagicMock()) is None
+
+    def test_create_adapter_check_fails(self):
+        reg = PlatformRegistry()
+        entry, _ = self._make_entry("delta", check_ok=False)
+        reg.register(entry)
+        assert reg.create_adapter("delta", MagicMock()) is None
+
+    def test_create_adapter_validate_fails(self):
+        reg = PlatformRegistry()
+        entry, _ = self._make_entry("epsilon", validate_ok=False)
+        reg.register(entry)
+        assert reg.create_adapter("epsilon", MagicMock()) is None
+
+    def test_create_adapter_factory_exception(self):
+        reg = PlatformRegistry()
+        entry = PlatformEntry(
+            name="broken",
+            label="Broken",
+            adapter_factory=lambda cfg: (_ for _ in ()).throw(RuntimeError("boom")),
+            check_fn=lambda: True,
+            validate_config=None,
+            source="plugin",
+        )
+        reg.register(entry)
+        # factory raises → create_adapter returns None instead of propagating
+        assert reg.create_adapter("broken", MagicMock()) is None
+
+    def test_create_adapter_no_validate(self):
+        """When validate_config is None, skip validation."""
+        reg = PlatformRegistry()
+        mock_adapter = MagicMock()
+        entry = PlatformEntry(
+            name="novalidate",
+            label="NoValidate",
+            adapter_factory=lambda cfg: mock_adapter,
+            check_fn=lambda: True,
+            validate_config=None,
+            source="plugin",
+        )
+        reg.register(entry)
+        assert reg.create_adapter("novalidate", MagicMock()) is mock_adapter
+
+    def test_all_entries(self):
+        reg = PlatformRegistry()
+        e1, _ = self._make_entry("one")
+        e2, _ = self._make_entry("two")
+        reg.register(e1)
+        reg.register(e2)
+        names = {e.name for e in reg.all_entries()}
+        assert names == {"one", "two"}
+
+    def test_plugin_entries(self):
+        reg = PlatformRegistry()
+        plugin_entry, _ = self._make_entry("plugged")
+        builtin_entry = PlatformEntry(
+            name="core",
+            label="Core",
+            adapter_factory=lambda cfg: MagicMock(),
+            check_fn=lambda: True,
+            source="builtin",
+        )
+        reg.register(plugin_entry)
+        reg.register(builtin_entry)
+        plugin_names = {e.name for e in reg.plugin_entries()}
+        assert plugin_names == {"plugged"}
+
+    def test_re_register_replaces(self):
+        reg = PlatformRegistry()
+        entry1, mock1 = self._make_entry("dup")
+        entry2 = PlatformEntry(
+            name="dup",
+            label="Dup v2",
+            adapter_factory=lambda cfg: "v2",
+            check_fn=lambda: True,
+            source="plugin",
+        )
+        reg.register(entry1)
+        reg.register(entry2)
+        assert reg.get("dup").label == "Dup v2"
+
+
+# ── GatewayConfig integration ────────────────────────────────────────────
+
+
+class TestGatewayConfigPluginPlatform:
+    """Test that GatewayConfig parses and validates plugin platforms."""
+
+    def test_from_dict_accepts_plugin_platform(self):
+        data = {
+            "platforms": {
+                "telegram": {"enabled": True, "token": "test-token"},
+                "irc": {"enabled": True, "extra": {"server": "irc.libera.chat"}},
+            }
+        }
+        cfg = GatewayConfig.from_dict(data)
+        platform_values = {p.value for p in cfg.platforms}
+        assert "telegram" in platform_values
+        assert "irc" in platform_values
+
+    def test_get_connected_platforms_includes_registered_plugin(self):
+        """Plugin platform with registry entry passes get_connected_platforms."""
+        # Register a fake plugin platform
+        from gateway.platform_registry import platform_registry as _reg
+
+        test_entry = PlatformEntry(
+            name="testplat",
+            label="TestPlat",
+            adapter_factory=lambda cfg: MagicMock(),
+            check_fn=lambda: True,
+            validate_config=lambda cfg: bool(cfg.extra.get("token")),
+            source="plugin",
+        )
+        _reg.register(test_entry)
+        try:
+            data = {
+                "platforms": {
+                    "testplat": {"enabled": True, "extra": {"token": "abc"}},
+                }
+            }
+            cfg = GatewayConfig.from_dict(data)
+            connected = cfg.get_connected_platforms()
+            connected_values = {p.value for p in connected}
+            assert "testplat" in connected_values
+        finally:
+            _reg.unregister("testplat")
+
+    def test_get_connected_platforms_excludes_unregistered_plugin(self):
+        """Plugin platform without registry entry is excluded."""
+        data = {
+            "platforms": {
+                "unknown_plugin": {"enabled": True, "extra": {"token": "abc"}},
+            }
+        }
+        cfg = GatewayConfig.from_dict(data)
+        connected = cfg.get_connected_platforms()
+        connected_values = {p.value for p in connected}
+        assert "unknown_plugin" not in connected_values
+
+    def test_get_connected_platforms_excludes_invalid_config(self):
+        """Plugin platform with failing validate_config is excluded."""
+        from gateway.platform_registry import platform_registry as _reg
+
+        test_entry = PlatformEntry(
+            name="badconfig",
+            label="BadConfig",
+            adapter_factory=lambda cfg: MagicMock(),
+            check_fn=lambda: True,
+            validate_config=lambda cfg: False,  # always fails
+            source="plugin",
+        )
+        _reg.register(test_entry)
+        try:
+            data = {
+                "platforms": {
+                    "badconfig": {"enabled": True, "extra": {}},
+                }
+            }
+            cfg = GatewayConfig.from_dict(data)
+            connected = cfg.get_connected_platforms()
+            connected_values = {p.value for p in connected}
+            assert "badconfig" not in connected_values
+        finally:
+            _reg.unregister("badconfig")

tests/gateway/test_session.py

@@ -89,9 +89,12 @@ class TestSessionSourceRoundtrip:
         assert restored.chat_topic is None
         assert restored.chat_type == "dm"
 
-    def test_invalid_platform_raises(self):
+    def test_unknown_platform_accepted_for_plugins(self):
-        with pytest.raises((ValueError, KeyError)):
+        """Unknown platform names are now accepted (dynamic enum members for
-            SessionSource.from_dict({"platform": "nonexistent", "chat_id": "1"})
+        plugin platforms), so from_dict should succeed rather than raise."""
+        source = SessionSource.from_dict({"platform": "nonexistent", "chat_id": "1"})
+        assert source.platform.value == "nonexistent"
+        assert source.chat_id == "1"
 
 
 class TestSessionSourceDescription: