feat(channels): add IRC channel integration

Add IRC as a new channel for picoclaw, supporting server connections,
channel joins, DMs, mention-based group triggers, and IRCv3 typing
indicators. Uses ergochat/irc-go for connection management with SASL,
NickServ, and automatic reconnection support.

Closes #1137

cmd/picoclaw/internal/gateway/helpers.go

@@ -14,6 +14,7 @@ import (
 	"github.com/sipeed/picoclaw/pkg/bus"
 	"github.com/sipeed/picoclaw/pkg/channels"
 	_ "github.com/sipeed/picoclaw/pkg/channels/dingtalk"
+	_ "github.com/sipeed/picoclaw/pkg/channels/irc"
 	_ "github.com/sipeed/picoclaw/pkg/channels/discord"
 	_ "github.com/sipeed/picoclaw/pkg/channels/feishu"
 	_ "github.com/sipeed/picoclaw/pkg/channels/line"

config/config.example.json

@@ -164,6 +164,25 @@
       "max_steps": 10,
       "welcome_message": "Hello! I'm your AI assistant. How can I help you today?",
       "reasoning_channel_id": ""
+    },
+    "irc": {
+      "enabled": false,
+      "server": "irc.libera.chat:6697",
+      "tls": true,
+      "nick": "mybot",
+      "password": "",
+      "nickserv_password": "",
+      "sasl_user": "",
+      "sasl_password": "",
+      "channels": ["#mychannel"],
+      "allow_from": [],
+      "group_trigger": {
+        "mention_only": true
+      },
+      "typing": {
+        "enabled": false
+      },
+      "reasoning_channel_id": ""
     }
   },
   "providers": {

go.mod

@@ -36,6 +36,7 @@ require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/dustin/go-humanize v1.0.1 // indirect
 	github.com/elliotchance/orderedmap/v3 v3.1.0 // indirect
+	github.com/ergochat/irc-go v0.5.0 // indirect
 	github.com/gdamore/encoding v1.0.1 // indirect
 	github.com/h2non/filetype v1.1.3 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect

go.sum

@@ -48,6 +48,8 @@ github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkp
 github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
 github.com/elliotchance/orderedmap/v3 v3.1.0 h1:j4DJ5ObEmMBt/lcwIecKcoRxIQUEnw0L804lXYDt/pg=
 github.com/elliotchance/orderedmap/v3 v3.1.0/go.mod h1:G+Hc2RwaZvJMcS4JpGCOyViCnGeKf0bTYCGTO4uhjSo=
+github.com/ergochat/irc-go v0.5.0 h1:woQ1RS9YbfgqPgSpPBBQeczXGIGzR0aC7dEgk469fTw=
+github.com/ergochat/irc-go v0.5.0/go.mod h1:2vi7KNpIPWnReB5hmLpl92eMywQvuIeIIGdt/FQCph0=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/fsnotify/fsnotify v1.4.9/go.mod h1:znqG4EE+3YCdAaPaxE2ZRY/06pZUdp0tY4IgpuI1SZQ=
 github.com/gdamore/encoding v1.0.1 h1:YzKZckdBL6jVt2Gc+5p82qhrGiqMdG/eNs6Wy0u3Uhw=

pkg/channels/irc/handler.go

@@ -0,0 +1,140 @@
+package irc
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/ergochat/irc-go/ircevent"
+	"github.com/ergochat/irc-go/ircmsg"
+
+	"github.com/sipeed/picoclaw/pkg/bus"
+	"github.com/sipeed/picoclaw/pkg/identity"
+	"github.com/sipeed/picoclaw/pkg/logger"
+)
+
+// onConnect is called after a successful connection (and on reconnect).
+func (c *IRCChannel) onConnect(conn *ircevent.Connection) {
+	// NickServ auth (only if SASL is not configured)
+	if c.config.NickServPassword != "" && c.config.SASLUser == "" {
+		conn.Privmsg("NickServ", "IDENTIFY "+c.config.NickServPassword)
+	}
+
+	// Join configured channels
+	for _, ch := range c.config.Channels {
+		conn.Join(ch)
+		logger.InfoCF("irc", "Joined IRC channel", map[string]any{
+			"channel": ch,
+		})
+	}
+}
+
+// onPrivmsg handles incoming PRIVMSG events.
+func (c *IRCChannel) onPrivmsg(conn *ircevent.Connection, e ircmsg.Message) {
+	if len(e.Params) < 2 {
+		return
+	}
+
+	nick := e.Nick()
+	currentNick := conn.CurrentNick()
+
+	// Ignore own messages
+	if strings.EqualFold(nick, currentNick) {
+		return
+	}
+
+	target := e.Params[0]  // channel name or bot's nick
+	content := e.Params[1] // message text
+
+	// Determine if this is a DM or channel message
+	isDM := !strings.HasPrefix(target, "#") && !strings.HasPrefix(target, "&")
+
+	var chatID string
+	var peer bus.Peer
+
+	if isDM {
+		chatID = nick
+		peer = bus.Peer{Kind: "direct", ID: nick}
+	} else {
+		chatID = target
+		peer = bus.Peer{Kind: "group", ID: target}
+	}
+
+	sender := bus.SenderInfo{
+		Platform:    "irc",
+		PlatformID:  nick,
+		CanonicalID: identity.BuildCanonicalID("irc", nick),
+		Username:    nick,
+		DisplayName: nick,
+	}
+
+	if !c.IsAllowedSender(sender) {
+		return
+	}
+
+	// For channel messages, check group trigger (mention detection)
+	if !isDM {
+		isMentioned := isBotMentioned(content, currentNick)
+		if isMentioned {
+			content = stripBotMention(content, currentNick)
+		}
+		respond, cleaned := c.ShouldRespondInGroup(isMentioned, content)
+		if !respond {
+			return
+		}
+		content = cleaned
+	}
+
+	if strings.TrimSpace(content) == "" {
+		return
+	}
+
+	messageID := fmt.Sprintf("%s-%d", nick, time.Now().UnixNano())
+
+	metadata := map[string]string{
+		"platform": "irc",
+		"server":   c.config.Server,
+	}
+	if !isDM {
+		metadata["channel"] = target
+	}
+
+	c.HandleMessage(c.ctx, peer, messageID, nick, chatID, content, nil, metadata, sender)
+}
+
+// isBotMentioned checks if the bot's nick appears in the message.
+func isBotMentioned(content, botNick string) bool {
+	lower := strings.ToLower(content)
+	lowerNick := strings.ToLower(botNick)
+
+	// "nick: " or "nick, " at start (most common IRC convention)
+	if strings.HasPrefix(lower, lowerNick+":") || strings.HasPrefix(lower, lowerNick+",") {
+		return true
+	}
+
+	// Word-boundary match anywhere in the message
+	idx := strings.Index(lower, lowerNick)
+	if idx < 0 {
+		return false
+	}
+	before := idx == 0 || !isAlphanumeric(lower[idx-1])
+	after := idx+len(lowerNick) >= len(lower) || !isAlphanumeric(lower[idx+len(lowerNick)])
+	return before && after
+}
+
+// stripBotMention removes "nick: " or "nick, " prefix from content.
+func stripBotMention(content, botNick string) string {
+	lower := strings.ToLower(content)
+	lowerNick := strings.ToLower(botNick)
+	for _, sep := range []string{":", ","} {
+		prefix := lowerNick + sep
+		if strings.HasPrefix(lower, prefix) {
+			return strings.TrimSpace(content[len(prefix):])
+		}
+	}
+	return content
+}
+
+func isAlphanumeric(b byte) bool {
+	return (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || (b >= '0' && b <= '9') || b == '_'
+}

pkg/channels/irc/init.go

@@ -0,0 +1,16 @@
+package irc
+
+import (
+	"github.com/sipeed/picoclaw/pkg/bus"
+	"github.com/sipeed/picoclaw/pkg/channels"
+	"github.com/sipeed/picoclaw/pkg/config"
+)
+
+func init() {
+	channels.RegisterFactory("irc", func(cfg *config.Config, b *bus.MessageBus) (channels.Channel, error) {
+		if !cfg.Channels.IRC.Enabled {
+			return nil, nil
+		}
+		return NewIRCChannel(cfg.Channels.IRC, b)
+	})
+}

pkg/channels/irc/irc.go

@@ -0,0 +1,181 @@
+package irc
+
+import (
+	"context"
+	"crypto/tls"
+	"fmt"
+	"strings"
+
+	"github.com/ergochat/irc-go/ircevent"
+	"github.com/ergochat/irc-go/ircmsg"
+
+	"github.com/sipeed/picoclaw/pkg/bus"
+	"github.com/sipeed/picoclaw/pkg/channels"
+	"github.com/sipeed/picoclaw/pkg/config"
+	"github.com/sipeed/picoclaw/pkg/logger"
+)
+
+// IRCChannel implements the Channel interface for IRC servers.
+type IRCChannel struct {
+	*channels.BaseChannel
+	config config.IRCConfig
+	conn   *ircevent.Connection
+	ctx    context.Context
+	cancel context.CancelFunc
+}
+
+// NewIRCChannel creates a new IRC channel.
+func NewIRCChannel(cfg config.IRCConfig, messageBus *bus.MessageBus) (*IRCChannel, error) {
+	if cfg.Server == "" {
+		return nil, fmt.Errorf("irc server is required")
+	}
+	if cfg.Nick == "" {
+		return nil, fmt.Errorf("irc nick is required")
+	}
+
+	base := channels.NewBaseChannel("irc", cfg, messageBus, cfg.AllowFrom,
+		channels.WithMaxMessageLength(400),
+		channels.WithGroupTrigger(cfg.GroupTrigger),
+		channels.WithReasoningChannelID(cfg.ReasoningChannelID),
+	)
+
+	return &IRCChannel{
+		BaseChannel: base,
+		config:      cfg,
+	}, nil
+}
+
+// Start connects to the IRC server and begins listening.
+func (c *IRCChannel) Start(ctx context.Context) error {
+	logger.InfoC("irc", "Starting IRC channel")
+	c.ctx, c.cancel = context.WithCancel(ctx)
+
+	conn := &ircevent.Connection{
+		Server:       c.config.Server,
+		Nick:         c.config.Nick,
+		User:         c.config.Nick,
+		RealName:     c.config.Nick,
+		Password:     c.config.Password,
+		UseTLS:       c.config.TLS,
+		RequestCaps:  []string{"server-time", "message-tags"},
+		QuitMessage:  "Goodbye",
+		Debug:        false,
+		Log:          nil,
+	}
+
+	if c.config.TLS {
+		conn.TLSConfig = &tls.Config{
+			ServerName: extractHost(c.config.Server),
+		}
+	}
+
+	// SASL auth (takes priority over NickServ)
+	if c.config.SASLUser != "" && c.config.SASLPassword != "" {
+		conn.SASLLogin = c.config.SASLUser
+		conn.SASLPassword = c.config.SASLPassword
+	}
+
+	// Register event handlers
+	conn.AddConnectCallback(func(e ircmsg.Message) {
+		c.onConnect(conn)
+	})
+	conn.AddCallback("PRIVMSG", func(e ircmsg.Message) {
+		c.onPrivmsg(conn, e)
+	})
+
+	if err := conn.Connect(); err != nil {
+		return fmt.Errorf("irc connect failed: %w", err)
+	}
+
+	c.conn = conn
+
+	// ircevent.Connection.Loop() handles reconnection internally.
+	go conn.Loop()
+
+	c.SetRunning(true)
+	logger.InfoCF("irc", "IRC channel started", map[string]any{
+		"server": c.config.Server,
+		"nick":   c.config.Nick,
+	})
+	return nil
+}
+
+// Stop disconnects from the IRC server.
+func (c *IRCChannel) Stop(ctx context.Context) error {
+	logger.InfoC("irc", "Stopping IRC channel")
+	c.SetRunning(false)
+
+	if c.conn != nil {
+		c.conn.Quit()
+	}
+	if c.cancel != nil {
+		c.cancel()
+	}
+
+	logger.InfoC("irc", "IRC channel stopped")
+	return nil
+}
+
+// Send sends a message to an IRC channel or user.
+func (c *IRCChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+	if !c.IsRunning() {
+		return channels.ErrNotRunning
+	}
+
+	target := msg.ChatID
+	if target == "" {
+		return fmt.Errorf("chat ID is empty: %w", channels.ErrSendFailed)
+	}
+
+	if strings.TrimSpace(msg.Content) == "" {
+		return nil
+	}
+
+	// Send each line separately (IRC is line-oriented)
+	lines := strings.Split(msg.Content, "\n")
+	for _, line := range lines {
+		line = strings.TrimRight(line, "\r")
+		if line == "" {
+			continue
+		}
+		c.conn.Privmsg(target, line)
+	}
+
+	logger.DebugCF("irc", "Message sent", map[string]any{
+		"target": target,
+		"lines":  len(lines),
+	})
+	return nil
+}
+
+// StartTyping implements channels.TypingCapable using IRCv3 +typing client tag.
+// Requires typing.enabled in config and server support for message-tags capability.
+func (c *IRCChannel) StartTyping(ctx context.Context, chatID string) (func(), error) {
+	noop := func() {}
+
+	if !c.config.Typing.Enabled || !c.IsRunning() || c.conn == nil {
+		return noop, nil
+	}
+
+	// Check if server supports message-tags (required for TAGMSG)
+	if _, ok := c.conn.AcknowledgedCaps()["message-tags"]; !ok {
+		return noop, nil
+	}
+
+	c.conn.SendWithTags(map[string]string{"+typing": "active"}, "TAGMSG", chatID)
+
+	return func() {
+		if c.IsRunning() && c.conn != nil {
+			c.conn.SendWithTags(map[string]string{"+typing": "done"}, "TAGMSG", chatID)
+		}
+	}, nil
+}
+
+// extractHost returns the hostname portion of a host:port string.
+func extractHost(server string) string {
+	host, _, found := strings.Cut(server, ":")
+	if found {
+		return host
+	}
+	return server
+}

pkg/channels/manager.go

@@ -62,6 +62,7 @@ var channelRateConfig = map[string]float64{
 	"discord":  1,
 	"slack":    1,
 	"line":     10,
+	"irc":      2,
 }
 
 type channelWorker struct {
@@ -267,6 +268,10 @@ func (m *Manager) initChannels() error {
 		m.initChannel("pico", "Pico")
 	}
 
+	if m.config.Channels.IRC.Enabled && m.config.Channels.IRC.Server != "" {
+		m.initChannel("irc", "IRC")
+	}
+
 	logger.InfoCF("channels", "Channel initialization completed", map[string]any{
 		"enabled_channels": len(m.channels),
 	})

pkg/config/config.go

@@ -218,6 +218,7 @@ type ChannelsConfig struct {
 	WeComApp   WeComAppConfig   `json:"wecom_app"`
 	WeComAIBot WeComAIBotConfig `json:"wecom_aibot"`
 	Pico       PicoConfig       `json:"pico"`
+	IRC        IRCConfig        `json:"irc"`
 }
 
 // GroupTriggerConfig controls when the bot responds in group chats.
@@ -401,6 +402,22 @@ type PicoConfig struct {
 	Placeholder     PlaceholderConfig   `json:"placeholder,omitempty"`
 }
 
+type IRCConfig struct {
+	Enabled            bool                `json:"enabled"                 env:"PICOCLAW_CHANNELS_IRC_ENABLED"`
+	Server             string              `json:"server"                  env:"PICOCLAW_CHANNELS_IRC_SERVER"`
+	TLS                bool                `json:"tls"                     env:"PICOCLAW_CHANNELS_IRC_TLS"`
+	Nick               string              `json:"nick"                    env:"PICOCLAW_CHANNELS_IRC_NICK"`
+	Password           string              `json:"password"                env:"PICOCLAW_CHANNELS_IRC_PASSWORD"`
+	NickServPassword   string              `json:"nickserv_password"       env:"PICOCLAW_CHANNELS_IRC_NICKSERV_PASSWORD"`
+	SASLUser           string              `json:"sasl_user"               env:"PICOCLAW_CHANNELS_IRC_SASL_USER"`
+	SASLPassword       string              `json:"sasl_password"           env:"PICOCLAW_CHANNELS_IRC_SASL_PASSWORD"`
+	Channels           FlexibleStringSlice `json:"channels"                env:"PICOCLAW_CHANNELS_IRC_CHANNELS"`
+	AllowFrom          FlexibleStringSlice `json:"allow_from"              env:"PICOCLAW_CHANNELS_IRC_ALLOW_FROM"`
+	GroupTrigger       GroupTriggerConfig  `json:"group_trigger,omitempty"`
+	Typing             TypingConfig        `json:"typing,omitempty"`
+	ReasoningChannelID string              `json:"reasoning_channel_id"    env:"PICOCLAW_CHANNELS_IRC_REASONING_CHANNEL_ID"`
+}
+
 type HeartbeatConfig struct {
 	Enabled  bool `json:"enabled"  env:"PICOCLAW_HEARTBEAT_ENABLED"`
 	Interval int  `json:"interval" env:"PICOCLAW_HEARTBEAT_INTERVAL"` // minutes, min 5

scripts/test-irc.sh

@@ -0,0 +1,56 @@
+#!/bin/sh
+# Starts a local Ergo IRC server for testing the IRC channel.
+#
+# Requirements: docker
+# Usage: ./scripts/test-irc.sh
+
+set -e
+
+CONTAINER_NAME="picoclaw-test-ergo"
+IRC_PORT=6667
+
+# Clean up any previous instance
+docker rm -f "$CONTAINER_NAME" >/dev/null 2>&1 || true
+
+echo "Starting Ergo IRC server on port $IRC_PORT..."
+docker run -d \
+    --name "$CONTAINER_NAME" \
+    -p "$IRC_PORT:6667" \
+    ghcr.io/ergochat/ergo:stable
+
+for i in $(seq 1 10); do
+    if nc -z localhost "$IRC_PORT" 2>/dev/null; then
+        break
+    fi
+    if [ "$i" -eq 10 ]; then
+        echo "ERROR: Server did not start within 10s"
+        exit 1
+    fi
+    sleep 1
+done
+
+echo ""
+echo "IRC server ready on localhost:$IRC_PORT"
+echo ""
+echo "Add this to your ~/.picoclaw/config.json under \"channels\":"
+echo ""
+echo '  "irc": {'
+echo '    "enabled": true,'
+echo '    "server": "localhost:6667",'
+echo '    "tls": false,'
+echo '    "nick": "picobot",'
+echo '    "channels": ["#test"],'
+echo '    "allow_from": [],'
+echo '    "group_trigger": { "mention_only": true }'
+echo '  }'
+echo ""
+echo "Then run picoclaw:"
+echo "  cd packages/picoclaw && go run ./cmd/picoclaw gateway"
+echo ""
+echo "Connect with an IRC client:"
+echo "  irssi:   /connect localhost $IRC_PORT"
+echo "  weechat: /server add test localhost/$IRC_PORT && /connect test"
+echo "  Join #test, then: picobot: hello"
+echo ""
+echo "To stop the IRC server:"
+echo "  docker rm -f $CONTAINER_NAME"