Python: [Bug]: Telegram samples execute commands addressed to other bots #8802

Description

In a Telegram group, /new@otherbot addresses a different bot. The three Python Telegram samples can nevertheless handle it as this bot's /new command and reset this bot's group conversation. This matters when the bot receives group messages addressed to others, such as when it is a group administrator or privacy mode is disabled.

Steps to reproduce

1. Configure one of the Telegram samples as a bot that receives group messages.
2. Send /new@otherbot to a group containing that bot.
3. Inspect this bot's command path. The parser produces /new, and the sample dispatches that value to its reset handler.

The current main source at 2024d4df4 establishes the path:

Expected behavior: Ignore commands addressed to another bot before command dispatch or model invocation. Continue handling /new and /new@thisbot for this bot.

Actual behavior: /new@otherbot loses its target suffix and follows this bot's /new path. Other commands addressed elsewhere can similarly be handled or fall through to the agent.

The parser output was reproduced directly against the earlier c804f32c9 revision. The same parser and dispatch logic is present in 2024d4df4. The session deletion and history clearing above follow from these source call paths; I have not run the samples in a live Telegram group.

Code Sample

from agent_framework_hosting_telegram import telegram_command

update = {
    "message": {
        "chat": {"id": -123, "type": "supergroup"},
        "from": {"id": 42},
        "text": "/new@otherbot",
    }
}

assert telegram_command(update) == "/new"  # Current behavior on main.

Error Messages / Stack Traces

None. The parser returns a valid-looking command, so the failure is a wrong action rather than an exception.

Package Versions

agent-framework-hosting-telegram 1.0.0a260730 and agent-framework-hosting 1.0.0a260730, from repository source.

Python Version

Python 3.13.2 on Windows for the direct parser reproduction and local tests.

Additional Context

One compatible fix is an optional bot_username parameter for telegram_command, with each sample supplying its own username and returning early for a mismatch. The current behavior when callers omit a username is documented; changing that default would be a separate compatibility decision. I am taking on this fix in #8803 and welcome feedback on the public parameter's shape.

A new target-aware parser test failed against the original c804f32c9 code with TypeError: telegram_command() got an unexpected keyword argument 'bot_username' (1 failed). That pre-fix failure establishes the missing API support; it does not claim a live group-session reset. The proposed fix has passing mocked tests for all three sample paths.

I searched open and closed issues and PRs for telegram, telegram_command, otherbot, and bot-suffixed on 2026-09-28 and found no report or PR for target matching. #6588/#7047 introduced the helper and local samples; #7883 added the Foundry-hosted sample. Those items do not cover this routing defect.