Control AI agents through Telegram—use text or voice messages to create appointments, send emails, or retrieve company data.
This is exactly what makes Telegram so attractive to many businesses. The messenger is installed on almost every smartphone, can be accessed instantly, and can be connected to an AI agent in just a few steps.
As a result, there are countless tutorials and templates showing how to set up Telegram as the user interface for an AI agent within minutes.
However, one crucial security aspect often goes unmentioned: Many of these implementations fail to include adequate access controls.
To interact with an AI agent through Telegram, an n8n workflow is typically created that receives incoming messages, forwards them to an AI agent, and then sends the agent’s response back to the chat.
The agent often has access to systems such as Google Calendar, Gmail, Slack, or other business applications. We have already explained the integration of Google services with n8n in detail. This is precisely where the problem arises.
Telegram bots created through BotFather are publicly accessible by default. Any user who knows the bot’s username or discovers it can send messages to it.
Without additional security mechanisms, the workflow may process these messages in exactly the same way as your own.
By default, a Telegram bot does not distinguish between authorized and unauthorized users.
It receives a message and forwards it to the workflow.
If the AI agent has access to applications such as Gmail, Google Calendar, or other business systems, it initially processes every incoming request in the same way.
Without an additional authentication mechanism, an unknown user could therefore send instructions such as “Show me my emails from the past week” or “Create an appointment for tomorrow at 10 a.m.” to the agent.
This is precisely the security check that is missing from many publicly available tutorials and community templates.
Securing the workflow is technically relatively simple.
After receiving a Telegram message, the workflow should verify whether the Telegram user ID included with the message matches a predefined, authorized user ID.
The message is forwarded to the AI agent only if this verification is successful.
All other requests are rejected immediately.
This ensures that only the approved user can access the agent—even if the bot is publicly discoverable.
Every Telegram user has a unique user ID that cannot be changed. This makes it a reliable identifier and the basis for controlling access within the workflow.
The user ID can be identified using the Telegram bot @userinfobot, for example. After starting the bot, your personal user ID is displayed immediately and can then be added to the workflow as an authorized ID.
The actual security mechanism consists of a simple verification step.
The Telegram Trigger receives an incoming message.
Immediately afterward, a filter checks whether the sender’s user ID matches the previously stored authorized user ID.
The message is forwarded to the AI agent only if both values are identical.
All other requests are rejected immediately.
As a result, it no longer matters whether an unknown user discovers the bot or sends it a message.
In n8n, the verification is implemented directly after the Telegram Trigger using an IF node. This node compares the user ID contained in the incoming message with the previously stored authorized user ID.
If both values match, the message is forwarded to the AI agent. Otherwise, the workflow ends at this point.
The following tutorial shows you step by step how to implement this security measure in your own workflow:
The security risk is not caused by Telegram itself, but by missing access controls within the workflow.
A user ID verification prevents unauthorized users from interacting with the AI agent.
The implementation in n8n is technically simple and can be added directly after the Telegram Trigger.
AI agents should only be granted access to the systems they genuinely need to perform their tasks.
If multiple people use the same AI agent, the access control should be expanded to include centralized management of authorized user IDs and, where necessary, different permission levels.You can find ready-made workflow templates for this in our free n8n-workflows.