feat: add channels support

packages/cli/src/config/config.ts

@@ -98,6 +98,7 @@ export interface CliArgs {
   rawOutput: boolean | undefined;
   acceptRawOutputRisk: boolean | undefined;
   isCommand: boolean | undefined;
+  channels: string[] | undefined;
 }
 
 /**
@@ -299,6 +300,12 @@ export async function parseArguments(
         .option('accept-raw-output-risk', {
           type: 'boolean',
           description: 'Suppress the security warning when using --raw-output.',
+        })
+        .option('channels', {
+          type: 'string',
+          array: true,
+          description: 'Enable channel message delivery from named MCP servers',
+          coerce: coerceCommaSeparated,
         }),
     )
     // Register MCP subcommands
@@ -930,6 +937,7 @@ export async function loadCliConfig(
       };
     },
     enableConseca: settings.security?.enableConseca,
+    channels: argv.channels,
   });
 }
 

packages/cli/src/gemini.test.tsx

@@ -513,6 +513,7 @@ describe('gemini.tsx main function kitty protocol', () => {
       rawOutput: undefined,
       acceptRawOutputRisk: undefined,
       isCommand: undefined,
+      channels: undefined,
     });
 
     await act(async () => {

packages/cli/src/gemini.tsx

@@ -259,6 +259,13 @@ export async function main() {
     });
   }
 
+  if (argv.channels && argv.channels.length > 0) {
+    coreEvents.emitFeedback(
+      'info',
+      `Channels enabled: ${argv.channels.join(', ')}`,
+    );
+  }
+
   // Check for invalid input combinations early to prevent crashes
   if (argv.promptInteractive && !process.stdin.isTTY) {
     writeToStderr(

packages/cli/src/ui/AppContainer.tsx

@@ -67,6 +67,7 @@ import {
   refreshServerHierarchicalMemory,
   flattenMemory,
   type MemoryChangedPayload,
+  type ChannelMessagePayload,
   writeToStdout,
   disableMouseEvents,
   enterAlternateScreen,
@@ -1220,6 +1221,26 @@ Logging in with Google... Restarting Gemini CLI to continue.
     isMcpReady,
   });
 
+  // Listen for external channel messages from MCP servers declaring
+  // experimental['gemini/channel'] and inject them into the message queue.
+  const channelsEnabled = config.getChannels().length > 0;
+  useEffect(() => {
+    if (!channelsEnabled) return;
+    const handler = (payload: ChannelMessagePayload) => {
+      const meta = payload.metadata ?? {};
+      const user = meta['user'] ?? payload.sender;
+      const chatId = meta['chat_id'] ?? '';
+      const msgId = meta['message_id'] ?? '';
+      const imagePath = meta['image_path'] ?? '';
+      const formatted = `<channel source="${payload.channelName}" chat_id="${chatId}" message_id="${msgId}" user="${user}"${imagePath ? ` image_path="${imagePath}"` : ''}>\n${payload.content}\n</channel>`;
+      addMessage(formatted);
+    };
+    coreEvents.on(CoreEvent.ChannelMessage, handler);
+    return () => {
+      coreEvents.off(CoreEvent.ChannelMessage, handler);
+    };
+  }, [channelsEnabled, addMessage]);
+
   cancelHandlerRef.current = useCallback(
     (shouldRestorePrompt: boolean = true) => {
       const pendingHistoryItems = [

packages/cli/src/ui/components/HistoryItemDisplay.tsx

@@ -30,6 +30,7 @@ import { getMCPServerStatus } from '@google/gemini-cli-core';
 import { ToolsList } from './views/ToolsList.js';
 import { SkillsList } from './views/SkillsList.js';
 import { AgentsStatus } from './views/AgentsStatus.js';
+import { ChannelsList } from './views/ChannelsList.js';
 import { McpStatus } from './views/McpStatus.js';
 import { ChatList } from './views/ChatList.js';
 import { ModelMessage } from './messages/ModelMessage.js';
@@ -227,6 +228,9 @@ export const HistoryItemDisplay: React.FC<HistoryItemDisplayProps> = ({
           terminalWidth={terminalWidth}
         />
       )}
+      {itemForDisplay.type === 'channels_list' && (
+        <ChannelsList channels={itemForDisplay.channels} />
+      )}
       {itemForDisplay.type === 'mcp_status' && (
         <McpStatus {...itemForDisplay} serverStatus={getMCPServerStatus} />
       )}

packages/cli/src/ui/components/views/ChannelsList.test.tsx

@@ -0,0 +1,40 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect } from 'vitest';
+import { ChannelsList } from './ChannelsList.js';
+import { type ChannelInfo } from '../../types.js';
+import { renderWithProviders } from '../../../test-utils/render.js';
+
+const mockChannels: ChannelInfo[] = [
+  {
+    name: 'telegram',
+    displayName: 'Telegram',
+    supportsReply: true,
+  },
+  {
+    name: 'minimal-channel',
+    supportsReply: false,
+  },
+];
+
+describe('<ChannelsList />', () => {
+  it('renders correctly with active channels', async () => {
+    const { lastFrame, waitUntilReady } = await renderWithProviders(
+      <ChannelsList channels={mockChannels} />,
+    );
+    await waitUntilReady();
+    expect(lastFrame()).toMatchSnapshot();
+  });
+
+  it('renders correctly with no active channels', async () => {
+    const { lastFrame, waitUntilReady } = await renderWithProviders(
+      <ChannelsList channels={[]} />,
+    );
+    await waitUntilReady();
+    expect(lastFrame()).toMatchSnapshot();
+  });
+});

packages/cli/src/ui/components/views/ChannelsList.tsx

@@ -0,0 +1,56 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type React from 'react';
+import { Box, Text } from 'ink';
+import { theme } from '../../semantic-colors.js';
+import type { ChannelInfo } from '../../types.js';
+
+interface ChannelsListProps {
+  channels: readonly ChannelInfo[];
+}
+
+export const ChannelsList: React.FC<ChannelsListProps> = ({ channels }) => {
+  if (channels.length === 0) {
+    return (
+      <Box flexDirection="column" marginBottom={1}>
+        <Text color={theme.text.primary}>No active channels.</Text>
+        <Text color="gray">
+          {
+            "MCP servers must declare `experimental['gemini/channel']` in their capabilities to act as channels."
+          }
+        </Text>
+      </Box>
+    );
+  }
+
+  return (
+    <Box flexDirection="column" marginBottom={1}>
+      <Text bold color={theme.text.primary}>
+        Active channels:
+      </Text>
+      <Box height={1} />
+      <Box flexDirection="column">
+        {channels.map((channel) => (
+          <Box key={channel.name} flexDirection="row">
+            <Text color={theme.text.primary}>{'  '}- </Text>
+            <Box flexDirection="column">
+              <Text bold color={theme.text.accent}>
+                {channel.displayName || channel.name} ({channel.name})
+              </Text>
+              <Text color="gray">
+                Direction:{' '}
+                <Text color={channel.supportsReply ? 'green' : 'gray'}>
+                  {channel.supportsReply ? 'two-way' : 'one-way'}
+                </Text>
+              </Text>
+            </Box>
+          </Box>
+        ))}
+      </Box>
+    </Box>
+  );
+};

packages/cli/src/ui/components/views/__snapshots__/ChannelsList.test.tsx.snap

@@ -0,0 +1,17 @@
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
+
+exports[`<ChannelsList /> > renders correctly with active channels 1`] = `
+"Active channels:
+
+  - Telegram (telegram)
+    Direction: two-way
+  - minimal-channel (minimal-channel)
+    Direction: one-way
+"
+`;
+
+exports[`<ChannelsList /> > renders correctly with no active channels 1`] = `
+"No active channels.
+MCP servers must declare \`experimental['gemini/channel']\` in their capabilities to act as channels.
+"
+`;

packages/cli/src/ui/types.ts

@@ -295,6 +295,17 @@ export type AgentDefinitionJson = Pick<
   'name' | 'displayName' | 'description' | 'kind'
 >;
 
+export interface ChannelInfo {
+  name: string;
+  displayName?: string;
+  supportsReply: boolean;
+}
+
+export type HistoryItemChannelsList = HistoryItemBase & {
+  type: 'channels_list';
+  channels: ChannelInfo[];
+};
+
 export type HistoryItemAgentsList = HistoryItemBase & {
   type: 'agents_list';
   agents: AgentDefinitionJson[];
@@ -377,6 +388,7 @@ export type HistoryItemWithoutId =
   | HistoryItemToolsList
   | HistoryItemSkillsList
   | HistoryItemAgentsList
+  | HistoryItemChannelsList
   | HistoryItemMcpStatus
   | HistoryItemChatList
   | HistoryItemThinking
@@ -402,6 +414,7 @@ export enum MessageType {
   TOOLS_LIST = 'tools_list',
   SKILLS_LIST = 'skills_list',
   AGENTS_LIST = 'agents_list',
+  CHANNELS_LIST = 'channels_list',
   MCP_STATUS = 'mcp_status',
   CHAT_LIST = 'chat_list',
   HINT = 'hint',