feat: add channels_me tool

Add a new MCP tool to list channels the calling user is a member of,
using the users.conversations API. Follows the same pattern as
usergroups_me vs usergroups_list.

Unlike channels_list which returns all workspace channels, channels_me
returns only channels the user has joined — useful on large workspaces
where channels_list returns thousands of results.

Supports channel_types, sort (by popularity), limit, and cursor
parameters.

docs/03-configuration-and-usage.md

@@ -261,7 +261,7 @@ docker-compose up -d
 | Argument                    | Required ? | Description                                                                                                                                                                                                         |
 |-----------------------------|------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | `--transport` or `-t`       | Yes        | Select transport for the MCP Server, possible values are: `stdio`, `sse`                                                                                                                                            |
-| `--enabled-tools` or `-e`   | No         | Comma-separated list of tools to register. If not set, all tools are registered. Runtime permissions (e.g., `SLACK_MCP_ADD_MESSAGE_TOOL`) are still enforced. Available tools: `conversations_history`, `conversations_replies`, `conversations_add_message`, `reactions_add`, `reactions_remove`, `attachment_get_data`, `conversations_search_messages`, `conversations_join`, `conversations_leave`, `conversations_unreads`, `conversations_mark`, `channels_list`, `usergroups_list`, `usergroups_me`, `usergroups_create`, `usergroups_update`, `usergroups_users_update`, `users_search`. |
+| `--enabled-tools` or `-e`   | No         | Comma-separated list of tools to register. If not set, all tools are registered. Runtime permissions (e.g., `SLACK_MCP_ADD_MESSAGE_TOOL`) are still enforced. Available tools: `conversations_history`, `conversations_replies`, `conversations_add_message`, `reactions_add`, `reactions_remove`, `attachment_get_data`, `conversations_search_messages`, `conversations_join`, `conversations_leave`, `conversations_unreads`, `conversations_mark`, `channels_list`, `channels_me`, `usergroups_list`, `usergroups_me`, `usergroups_create`, `usergroups_update`, `usergroups_users_update`, `users_search`. |
 
 ### Environment Variables
 
@@ -287,7 +287,7 @@ docker-compose up -d
 | `SLACK_MCP_CACHE_TTL`             | No        | `24h`                     | Cache time-to-live. Supports duration format (`24h`, `30m`) or seconds (`3600`). Set to `0` to disable TTL (cache forever). When the cache expires, stale data is served immediately while a background refresh fetches fresh data.                                                       |
 | `SLACK_MCP_MIN_REFRESH_INTERVAL`  | No        | `30s`                     | Minimum interval between forced cache refreshes. Prevents API abuse from repeated force-refresh requests. Supports duration format (`30s`, `1m`) or seconds (`60`). Set to `0` to disable rate limiting.                                                                                  |
 | `SLACK_MCP_LOG_LEVEL`             | No        | `info`                    | Log-level for stdout or stderr. Valid values are: `debug`, `info`, `warn`, `error`, `panic` and `fatal`                                                                                                                                                                                   |
-| `SLACK_MCP_ENABLED_TOOLS`         | No        | `nil`                     | Comma-separated list of tools to register. If empty, all read-only tools and usergroups tools are registered; write tools (`conversations_add_message`, `reactions_add`, `reactions_remove`, `attachment_get_data`) require their specific env var to be set OR must be explicitly listed here. When a write tool is listed here, it's enabled without channel restrictions. Available tools: `conversations_history`, `conversations_replies`, `conversations_add_message`, `reactions_add`, `reactions_remove`, `attachment_get_data`, `conversations_search_messages`, `conversations_join`, `conversations_leave`, `conversations_unreads`, `conversations_mark`, `channels_list`, `usergroups_list`, `usergroups_me`, `usergroups_create`, `usergroups_update`, `usergroups_users_update`, `users_search`. |
+| `SLACK_MCP_ENABLED_TOOLS`         | No        | `nil`                     | Comma-separated list of tools to register. If empty, all read-only tools and usergroups tools are registered; write tools (`conversations_add_message`, `reactions_add`, `reactions_remove`, `attachment_get_data`) require their specific env var to be set OR must be explicitly listed here. When a write tool is listed here, it's enabled without channel restrictions. Available tools: `conversations_history`, `conversations_replies`, `conversations_add_message`, `reactions_add`, `reactions_remove`, `attachment_get_data`, `conversations_search_messages`, `conversations_join`, `conversations_leave`, `conversations_unreads`, `conversations_mark`, `channels_list`, `channels_me`, `usergroups_list`, `usergroups_me`, `usergroups_create`, `usergroups_update`, `usergroups_users_update`, `users_search`. |
 
 ### Tool Registration and Permissions
 

pkg/handler/channels.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/gocarina/gocsv"
 	"github.com/korotovsky/slack-mcp-server/pkg/provider"
+	"github.com/slack-go/slack"
 	"github.com/korotovsky/slack-mcp-server/pkg/server/auth"
 	"github.com/korotovsky/slack-mcp-server/pkg/text"
 	"github.com/mark3labs/mcp-go/mcp"
@@ -233,6 +234,94 @@ func (ch *ChannelsHandler) ChannelsHandler(ctx context.Context, request mcp.Call
 	return mcp.NewToolResultText(string(csvBytes)), nil
 }
 
+func (ch *ChannelsHandler) ChannelsMeHandler(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) {
+	ch.logger.Debug("ChannelsMeHandler called")
+
+	sortType := request.GetString("sort", "popularity")
+	types := request.GetString("channel_types", "public_channel,private_channel")
+	cursor := request.GetString("cursor", "")
+	limit := request.GetInt("limit", 0)
+
+	if limit == 0 {
+		limit = 100
+	}
+	if limit > 999 {
+		limit = 999
+	}
+
+	channelTypes := []string{}
+	for _, t := range strings.Split(types, ",") {
+		t = strings.TrimSpace(t)
+		if ch.validTypes[t] {
+			channelTypes = append(channelTypes, t)
+		}
+	}
+	if len(channelTypes) == 0 {
+		channelTypes = []string{provider.PubChanType, provider.PrivateChanType}
+	}
+
+	// Fetch channels the user is a member of via users.conversations API.
+	usersMap := ch.apiProvider.ProvideUsersMap().Users
+	var allChannels []provider.Channel
+	var apiCursor string
+	for {
+		params := &slack.GetConversationsForUserParameters{
+			Types:           channelTypes,
+			Limit:           200,
+			Cursor:          apiCursor,
+			ExcludeArchived: true,
+		}
+		channels, nextCursor, err := ch.apiProvider.Slack().GetConversationsForUserContext(ctx, params)
+		if err != nil {
+			ch.logger.Error("Failed to fetch user conversations", zap.Error(err))
+			return nil, fmt.Errorf("failed to fetch your channels: %v", err)
+		}
+
+		for _, c := range channels {
+			allChannels = append(allChannels, provider.MapChannelFromSlack(c, usersMap))
+		}
+
+		if nextCursor == "" {
+			break
+		}
+		apiCursor = nextCursor
+	}
+
+	ch.logger.Debug("Fetched member channels", zap.Int("count", len(allChannels)))
+
+	// Paginate results
+	paged, nextcur := paginateChannels(allChannels, cursor, limit)
+
+	var channelList []Channel
+	for _, channel := range paged {
+		channelList = append(channelList, Channel{
+			ID:          channel.ID,
+			Name:        channel.Name,
+			Topic:       channel.Topic,
+			Purpose:     channel.Purpose,
+			MemberCount: channel.MemberCount,
+		})
+	}
+
+	switch sortType {
+	case "popularity":
+		sort.Slice(channelList, func(i, j int) bool {
+			return channelList[i].MemberCount > channelList[j].MemberCount
+		})
+	}
+
+	if len(channelList) > 0 && nextcur != "" {
+		channelList[len(channelList)-1].Cursor = nextcur
+	}
+
+	csvBytes, err := gocsv.MarshalBytes(&channelList)
+	if err != nil {
+		return nil, err
+	}
+
+	return mcp.NewToolResultText(string(csvBytes)), nil
+}
+
 func filterChannelsByTypes(channels map[string]provider.Channel, types []string) []provider.Channel {
 	logger := zap.L()
 

pkg/provider/api.go

@@ -1478,3 +1478,14 @@ func mapChannel(
 		Members:     members,
 	}
 }
+
+// MapChannelFromSlack converts a slack.Channel to our internal Channel type.
+func MapChannelFromSlack(c slack.Channel, usersMap map[string]slack.User) Channel {
+	return mapChannel(
+		c.ID, c.Name, c.NameNormalized,
+		c.Topic.Value, c.Purpose.Value,
+		c.User, c.Members, c.NumMembers,
+		c.IsIM, c.IsMpIM, c.IsPrivate, c.IsExtShared,
+		usersMap,
+	)
+}

pkg/server/server.go

@@ -37,6 +37,7 @@ const (
 	ToolConversationsLeave          = "conversations_leave"
 	ToolConversationsJoin           = "conversations_join"
 	ToolChannelsList                = "channels_list"
+	ToolChannelsMe                  = "channels_me"
 	ToolUsergroupsList              = "usergroups_list"
 	ToolUsergroupsMe                = "usergroups_me"
 	ToolUsergroupsCreate            = "usergroups_create"
@@ -61,6 +62,7 @@ var ValidToolNames = []string{
 	ToolConversationsLeave,
 	ToolConversationsJoin,
 	ToolChannelsList,
+	ToolChannelsMe,
 	ToolUsergroupsList,
 	ToolUsergroupsMe,
 	ToolUsergroupsCreate,
@@ -418,6 +420,27 @@ func NewMCPServer(provider *provider.ApiProvider, logger *zap.Logger, enabledToo
 		), channelsHandler.ChannelsHandler)
 	}
 
+	if shouldAddTool(ToolChannelsMe, enabledTools, "") {
+		s.AddTool(mcp.NewTool(ToolChannelsMe,
+			mcp.WithDescription("List channels you are a member of. Unlike channels_list which returns all workspace channels, this returns only channels you have joined. Useful on large workspaces where channels_list returns thousands of results."),
+			mcp.WithTitleAnnotation("My Channels"),
+			mcp.WithReadOnlyHintAnnotation(true),
+			mcp.WithString("channel_types",
+				mcp.Description("Comma-separated channel types. Allowed values: 'mpim', 'im', 'public_channel', 'private_channel'. Default: 'public_channel,private_channel'."),
+			),
+			mcp.WithString("sort",
+				mcp.Description("Type of sorting. Allowed values: 'popularity' (default) - sort by member count."),
+			),
+			mcp.WithNumber("limit",
+				mcp.DefaultNumber(100),
+				mcp.Description("Maximum number of items to return (1-999)."),
+			),
+			mcp.WithString("cursor",
+				mcp.Description("Cursor for pagination."),
+			),
+		), channelsHandler.ChannelsMeHandler)
+	}
+
 	// User groups tools
 	if shouldAddTool(ToolUsergroupsList, enabledTools, "") {
 		s.AddTool(mcp.NewTool(ToolUsergroupsList,

pkg/server/server_test.go

@@ -106,6 +106,7 @@ func TestValidToolNames(t *testing.T) {
 			ToolConversationsLeave:          true,
 			ToolConversationsJoin:           true,
 			ToolChannelsList:                true,
+			ToolChannelsMe:                  true,
 			ToolUsergroupsList:              true,
 			ToolUsergroupsMe:                true,
 			ToolUsergroupsCreate:            true,
@@ -137,6 +138,7 @@ func TestValidToolNames(t *testing.T) {
 		assert.Equal(t, "conversations_leave", ToolConversationsLeave)
 		assert.Equal(t, "conversations_join", ToolConversationsJoin)
 		assert.Equal(t, "channels_list", ToolChannelsList)
+		assert.Equal(t, "channels_me", ToolChannelsMe)
 		assert.Equal(t, "usergroups_list", ToolUsergroupsList)
 		assert.Equal(t, "usergroups_me", ToolUsergroupsMe)
 		assert.Equal(t, "usergroups_create", ToolUsergroupsCreate)