Telegram channel plugin: inbound notifications not delivered (typing indicator fires but message never arrives)

Description

The Telegram channel plugin (telegram@claude-plugins-official v0.0.1) receives messages from Telegram and sends the "typing" indicator, but the MCP notification (notifications/claude/channel) never arrives in the Claude Code conversation.

Environment

• Claude Code version: 2.1.81 (latest)
• Plugin: telegram@claude-plugins-official v0.0.1
• MCP SDK: @modelcontextprotocol/sdk 1.27.1
• Platform: macOS Darwin 25.3.0
• Runtime: Bun

Steps to reproduce

1. Configure the Telegram plugin: claude --channels plugin:telegram@claude-plugins-official
2. Set up bot token and pair a Telegram user (pairing works fine)
3. Send a message from Telegram to the bot

Expected behavior

The message should appear in the Claude Code conversation as a <channel source="telegram" ...> notification.

Actual behavior

• The bot receives the message (confirmed: getUpdates returns empty = consumed by polling)
• The "typing" indicator fires in Telegram (line 775 of server.ts)
• The mcp.notification() call at line 792 executes (no error logged)
• Nothing arrives in the Claude Code conversation

What works

• Outbound tools work fine: reply, react, edit_message all function correctly (Claude Code → Telegram)
• Bot is valid: getMe returns correctly (@youria_claude_code_bot)
• Access control is correct: sender ID is in allowFrom, gate returns deliver
• No webhook conflict: getWebhookInfo shows no webhook, pending_update_count: 0
• Single instance: no 409 Conflict, only one polling process

Diagnosis

The issue is specifically in the server → client notification direction of the MCP connection. The server capability experimental: { 'claude/channel': {} } is declared at line 349. The notification method notifications/claude/channel is sent at line 792. But Claude Code never processes it.

The MCP stdio transport is connected (confirmed via lsof — unix sockets on fd 0, 1, 2). Tool calls (client → server) work. Notifications (server → client) do not.

🤖 Generated with Claude Code