Files
lettabot/docs/telegram-setup.md
Cameron 64f12be6cd docs: add api.port config reference + Telegram message splitting note (#206)
- Document api.port/host/corsOrigin in configuration.md (example,
  reference table, and env var mapping)
- Add "Long Messages" section to telegram-setup.md noting the
  automatic 4096-char splitting behavior

Written by Cameron ◯ Letta Code

"The best time to plant a tree was 20 years ago. The second best time is now." - Chinese Proverb
2026-02-08 16:48:32 -08:00

5.3 KiB

Telegram Setup for LettaBot

This guide walks you through setting up Telegram as a channel for LettaBot.

Overview

LettaBot connects to Telegram using the Bot API with long-polling:

  • No public URL required (no webhook needed)
  • Works behind firewalls
  • Automatic reconnection handling

Prerequisites

  • A Telegram account
  • LettaBot installed and configured with at least LETTA_API_KEY

Step 1: Create a Bot with BotFather

  1. Open Telegram and search for @BotFather

  2. Start a chat and send /newbot

  3. Choose a display name for your bot (e.g., LettaBot)

  4. Choose a username ending in bot (e.g., my_letta_bot)

  5. BotFather will respond with your bot token

    Important

    : Copy this token immediately. It looks like 123456789:ABCdefGHIjklMNOpqrsTUVwxyz

Step 2: Configure LettaBot

Run the onboarding wizard and select Telegram:

lettabot onboard

Or add directly to your lettabot.yaml:

channels:
  telegram:
    enabled: true
    token: "123456789:ABCdefGHIjklMNOpqrsTUVwxyz"
    dmPolicy: pairing  # or 'allowlist' or 'open'

Or use environment variables:

export TELEGRAM_BOT_TOKEN="123456789:ABCdefGHIjklMNOpqrsTUVwxyz"
export TELEGRAM_DM_POLICY="pairing"

Step 3: Start LettaBot

lettabot server

You should see:

Registered channel: Telegram
[Telegram] Bot started as @your_bot_username
[Telegram] DM policy: pairing

Step 4: Test the Integration

  1. Open Telegram and search for your bot's username
  2. Click Start or send /start
  3. If using pairing mode, you'll receive a pairing code
  4. Approve the code: lettabot pairing approve telegram ABCD1234
  5. Send a message: Hello!
  6. The bot should respond

Access Control

LettaBot supports three DM policies for Telegram:

Pairing (Default)

dmPolicy: pairing
  • New users receive a pairing code
  • Approve with: lettabot pairing approve telegram <CODE>
  • Most secure for personal use

Allowlist

dmPolicy: allowlist
allowedUsers:
  - 123456789  # Telegram user IDs
  • Only specified users can interact
  • Find your user ID: Message @userinfobot or check the bot logs

Open

dmPolicy: open
  • Anyone can message the bot
  • Not recommended for personal bots

Bot Commands

LettaBot responds to these Telegram commands:

Command Description
/start Welcome message and help
/help Show available commands
/status Show current bot status
/heartbeat Trigger a heartbeat (silent)

Features

Voice Messages

Send a voice message to have it transcribed and processed:

  1. Requires OPENAI_API_KEY for transcription
  2. The bot transcribes and responds to the content
  3. Configure in lettabot.yaml:
    transcription:
      provider: openai
      apiKey: sk-...  # Optional: uses OPENAI_API_KEY env var
    

Attachments

The bot can receive and process:

  • Photos
  • Documents
  • Videos
  • Audio files
  • Stickers
  • Animations (GIFs)

Attachments are downloaded to /tmp/lettabot/attachments/telegram/ and the agent can view images using its Read tool.

Long Messages

Telegram limits messages to 4096 characters. LettaBot automatically splits longer responses into multiple messages at paragraph or line boundaries, so no content is lost.

Reactions

LettaBot can react to messages using the lettabot-react CLI:

# React to the most recent message
lettabot-react add --emoji "eyes"

# React to a specific message
lettabot-react add --emoji "thumbsup" --channel telegram --chat 123456789 --message 42

Telegram supports a limited set of reaction emojis. Common ones: thumbsup, heart, fire, eyes, clap, tada

Troubleshooting

Bot not responding

  1. Check the token: Make sure you copied the full token from BotFather
  2. Check pairing: If using pairing mode, approve new users with lettabot pairing list telegram
  3. Check logs: Look for errors in the console output

"Unauthorized" error

Your bot token is invalid:

  1. Go back to @BotFather
  2. Send /mybots and select your bot
  3. Click API Token to see the current token
  4. If needed, use Revoke current token to generate a new one

Bot responds slowly

This is normal - the bot needs to:

  1. Receive your message
  2. Send it to the Letta agent
  3. Wait for the agent to respond
  4. Send the response back

First responses may take longer as the agent "wakes up".

Voice messages not working

  1. Make sure OPENAI_API_KEY is set
  2. Check the logs for transcription errors
  3. Verify your OpenAI account has API access

Rate limiting

If the bot stops responding temporarily, Telegram may be rate-limiting requests. Wait a few minutes and try again.

Security Notes

  • Bot tokens should be kept secret - never commit them to git
  • Use dmPolicy: pairing or allowlist in production
  • The bot can only see messages sent directly to it
  • Group functionality is not currently supported

Cross-Channel Memory

Since LettaBot uses a single agent across all channels:

  • Messages you send on Telegram continue the same conversation as Slack/Discord
  • The agent remembers context from all channels
  • You can start a conversation on Telegram and continue it on another channel

Next Steps