diff --git a/chatapps/base/types.go b/chatapps/base/types.go
index 37d3ae3d..b6552b89 100644
--- a/chatapps/base/types.go
+++ b/chatapps/base/types.go
@@ -23,6 +23,14 @@ type RichContent struct {
 	Blocks         []any
 	Embeds         []any
 	Attachments    []Attachment
+	Reactions      []Reaction
+}
+
+// Reaction represents a reaction to add to a message
+type Reaction struct {
+	Name      string // emoji name (e.g., "thumbsup", "+1")
+	Channel   string
+	Timestamp string // message timestamp to react to
 }
 
 type Attachment struct {
diff --git a/chatapps/slack/adapter.go b/chatapps/slack/adapter.go
index 9424ecf6..bbbd6fa1 100644
--- a/chatapps/slack/adapter.go
+++ b/chatapps/slack/adapter.go
@@ -19,12 +19,14 @@ import (
 
 type Adapter struct {
 	*base.Adapter
-	config          Config
-	eventPath       string
-	interactivePath string
-	sender          *base.SenderWithMutex
-	webhook         *base.WebhookRunner
-	socketMode      *SocketModeConnection
+	config              Config
+	eventPath           string
+	interactivePath     string
+	slashCommandPath    string
+	sender              *base.SenderWithMutex
+	webhook             *base.WebhookRunner
+	socketMode          *SocketModeConnection
+	slashCommandHandler func(cmd SlashCommand)
 }
 
 func NewAdapter(config Config, logger *slog.Logger, opts ...base.AdapterOption) *Adapter {
@@ -34,11 +36,12 @@ func NewAdapter(config Config, logger *slog.Logger, opts ...base.AdapterOption)
 	}
 
 	a := &Adapter{
-		config:          config,
-		eventPath:       "/events",
-		interactivePath: "/interactive",
-		sender:          base.NewSenderWithMutex(),
-		webhook:         base.NewWebhookRunner(logger),
+		config:           config,
+		eventPath:        "/events",
+		interactivePath:  "/interactive",
+		slashCommandPath: "/slack",
+		sender:           base.NewSenderWithMutex(),
+		webhook:          base.NewWebhookRunner(logger),
 	}
 
 	// Initialize Socket Mode if configured
@@ -61,6 +64,7 @@ func NewAdapter(config Config, logger *slog.Logger, opts ...base.AdapterOption)
 	// Slack recommends using both Socket Mode and HTTP webhook together
 	handlers[a.eventPath] = a.handleEvent
 	handlers[a.interactivePath] = a.handleInteractive
+	handlers[a.slashCommandPath] = a.handleSlashCommand
 
 	// Build HTTP handler map
 	for path, handler := range handlers {
@@ -108,6 +112,16 @@ func (a *Adapter) defaultSender(ctx context.Context, sessionID string, msg *base
 		}
 	}
 
+	// Send reactions if present
+	if msg.RichContent != nil && len(msg.RichContent.Reactions) > 0 {
+		for _, reaction := range msg.RichContent.Reactions {
+			reaction.Channel = channelID
+			if err := a.AddReaction(ctx, reaction); err != nil {
+				a.Logger().Error("Failed to add reaction", "error", err, "reaction", reaction.Name)
+			}
+		}
+	}
+
 	// Send media/attachments if present
 	if msg.RichContent != nil && len(msg.RichContent.Attachments) > 0 {
 		for _, attachment := range msg.RichContent.Attachments {
@@ -300,6 +314,18 @@ func (a *Adapter) handleEventCallback(ctx context.Context, eventData json.RawMes
 		return
 	}
 
+	// Check user permission
+	if !a.config.IsUserAllowed(msgEvent.User) {
+		a.Logger().Debug("User blocked", "user_id", msgEvent.User)
+		return
+	}
+
+	// Check channel permission
+	if !a.config.ShouldProcessChannel(msgEvent.ChannelType, msgEvent.Channel) {
+		a.Logger().Debug("Channel blocked by policy", "channel_type", msgEvent.ChannelType, "channel_id", msgEvent.Channel)
+		return
+	}
+
 	sessionID := a.GetOrCreateSession(msgEvent.Channel+":"+msgEvent.User, msgEvent.User)
 
 	msg := &base.ChatMessage{
@@ -530,3 +556,104 @@ func (a *Adapter) sendToChannelOnce(ctx context.Context, channelID, text, thread
 	a.Logger().Debug("Message sent successfully", "channel", channelID)
 	return nil
 }
+
+// AddReaction adds a reaction to a message
+func (a *Adapter) AddReaction(ctx context.Context, reaction base.Reaction) error {
+	if a.config.BotToken == "" {
+		return fmt.Errorf("slack bot token not configured")
+	}
+
+	if reaction.Channel == "" || reaction.Timestamp == "" {
+		return fmt.Errorf("channel and timestamp are required for reaction")
+	}
+
+	payload := map[string]any{
+		"channel": reaction.Channel,
+		"name":    reaction.Name,
+		"ts":      reaction.Timestamp,
+	}
+
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return fmt.Errorf("marshal payload: %w", err)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "POST", "https://slack.com/api/reactions.add", bytes.NewReader(body))
+	if err != nil {
+		return fmt.Errorf("create request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", "Bearer "+a.config.BotToken)
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("send request: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode >= 400 {
+		respBody, _ := io.ReadAll(resp.Body)
+		return fmt.Errorf("reaction add failed: %d %s", resp.StatusCode, string(respBody))
+	}
+
+	var slackResp struct {
+		OK    bool   `json:"ok"`
+		Error string `json:"error,omitempty"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&slackResp); err != nil {
+		return fmt.Errorf("parse response: %w", err)
+	}
+
+	if !slackResp.OK {
+		return fmt.Errorf("slack API error: %s", slackResp.Error)
+	}
+
+	a.Logger().Debug("Reaction added", "emoji", reaction.Name, "channel", reaction.Channel)
+	return nil
+}
+
+// SlashCommand represents a Slack slash command
+type SlashCommand struct {
+	Command     string
+	Text        string
+	UserID      string
+	ChannelID   string
+	ResponseURL string
+}
+
+// SetSlashCommandHandler sets the handler for slash commands
+func (a *Adapter) SetSlashCommandHandler(fn func(cmd SlashCommand)) {
+	a.slashCommandHandler = fn
+}
+
+// handleSlashCommand processes incoming slash commands
+func (a *Adapter) handleSlashCommand(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		w.WriteHeader(http.StatusMethodNotAllowed)
+		return
+	}
+
+	if err := r.ParseForm(); err != nil {
+		a.Logger().Error("Parse slash command form failed", "error", err)
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+
+	cmd := SlashCommand{
+		Command:     r.FormValue("command"),
+		Text:        r.FormValue("text"),
+		UserID:      r.FormValue("user_id"),
+		ChannelID:   r.FormValue("channel_id"),
+		ResponseURL: r.FormValue("response_url"),
+	}
+
+	a.Logger().Debug("Slash command received", "command", cmd.Command, "text", cmd.Text, "user", cmd.UserID)
+
+	// Acknowledge immediately
+	w.WriteHeader(http.StatusOK)
+
+	// Process in background if handler is set
+	if a.slashCommandHandler != nil {
+		go a.slashCommandHandler(cmd)
+	}
+}
diff --git a/chatapps/slack/config.go b/chatapps/slack/config.go
index f0831cd0..6c96c49b 100644
--- a/chatapps/slack/config.go
+++ b/chatapps/slack/config.go
@@ -1,6 +1,10 @@
 package slack
 
-import "fmt"
+import (
+	"fmt"
+	"regexp"
+	"strings"
+)
 
 type Config struct {
 	BotToken      string
@@ -11,13 +15,41 @@ type Config struct {
 	Mode string
 	// ServerAddr: HTTP server address (e.g., ":8080")
 	ServerAddr string
+
+	// Permission Policy for Direct Messages
+	// "allow" - Allow all DMs (default)
+	// "pairing" - Only allow when user is paired
+	// "block" - Block all DMs
+	DMPolicy string
+
+	// Permission Policy for Group Messages
+	// "allow" - Allow all group messages (default)
+	// "mention" - Only allow when bot is mentioned
+	// "block" - Block all group messages
+	GroupPolicy string
+
+	// AllowedUsers: List of user IDs who can interact with the bot (whitelist)
+	AllowedUsers []string
+	// BlockedUsers: List of user IDs who cannot interact with the bot (blacklist)
+	BlockedUsers []string
 }
 
+// Token format patterns
+var (
+	botTokenRegex      = regexp.MustCompile(`^xoxb-[0-9]+-[0-9]+-[a-zA-Z0-9]+$`)
+	appTokenRegex      = regexp.MustCompile(`^xapp-[0-9]+-[0-9]+-[a-zA-Z0-9]+$`)
+	signingSecretRegex = regexp.MustCompile(`^[a-zA-Z0-9]+$`)
+)
+
 // Validate checks the configuration based on the selected mode
 func (c *Config) Validate() error {
+	// Bot token is always required
 	if c.BotToken == "" {
 		return fmt.Errorf("bot token is required")
 	}
+	if !botTokenRegex.MatchString(c.BotToken) {
+		return fmt.Errorf("invalid bot token format: expected xoxb-*-*-*")
+	}
 
 	switch c.Mode {
 	case "", "http":
@@ -25,15 +57,31 @@ func (c *Config) Validate() error {
 		if c.SigningSecret == "" {
 			return fmt.Errorf("signing secret is required for HTTP mode")
 		}
+		if len(c.SigningSecret) < 32 {
+			return fmt.Errorf("signing secret too short: minimum 32 characters")
+		}
+		if !signingSecretRegex.MatchString(c.SigningSecret) {
+			return fmt.Errorf("invalid signing secret format: must be alphanumeric")
+		}
 	case "socket":
 		// Socket Mode requires AppToken
 		if c.AppToken == "" {
 			return fmt.Errorf("app token is required for Socket mode")
 		}
+		if !appTokenRegex.MatchString(c.AppToken) {
+			return fmt.Errorf("invalid app token format: expected xapp-*-*-*")
+		}
 	default:
 		return fmt.Errorf("invalid mode: %s (use 'http' or 'socket')", c.Mode)
 	}
 
+	// Validate ServerAddr if provided
+	if c.ServerAddr != "" {
+		if !strings.HasPrefix(c.ServerAddr, ":") && !strings.Contains(c.ServerAddr, ":") {
+			return fmt.Errorf("invalid server address format: use :8080 or host:port")
+		}
+	}
+
 	return nil
 }
 
@@ -41,3 +89,54 @@ func (c *Config) Validate() error {
 func (c *Config) IsSocketMode() bool {
 	return c.Mode == "socket"
 }
+
+// IsUserAllowed checks if a user is allowed to interact with the bot
+func (c *Config) IsUserAllowed(userID string) bool {
+	// Check blocked list first
+	for _, blocked := range c.BlockedUsers {
+		if blocked == userID {
+			return false
+		}
+	}
+
+	// If allowlist is set, check it
+	if len(c.AllowedUsers) > 0 {
+		for _, allowed := range c.AllowedUsers {
+			if allowed == userID {
+				return true
+			}
+		}
+		return false
+	}
+
+	// No allowlist, user is allowed
+	return true
+}
+
+// ShouldProcessChannel checks if messages from a channel should be processed
+// channelType: "dm" or "channel" or "group"
+func (c *Config) ShouldProcessChannel(channelType, channelID string) bool {
+	switch channelType {
+	case "dm":
+		switch c.DMPolicy {
+		case "block":
+			return false
+		case "pairing":
+			// TODO: Check if user is paired
+			return true
+		default: // "allow"
+			return true
+		}
+	case "channel", "group":
+		switch c.GroupPolicy {
+		case "block":
+			return false
+		case "mention":
+			// TODO: Check if bot was mentioned
+			return true
+		default: // "allow"
+			return true
+		}
+	}
+	return true
+}