Telegram Bot API: Security, Privacy, and Identity

Purpose

Use this skill whenever the bot handles secrets, personal data, or trust decisions.

Core concerns

• bot token secrecy
• webhook authenticity
• privacy mode behavior
• Telegram login signature validation
• Mini App init-data validation
• Telegram Passport handling
• data minimization and retention

Developer guidance

1. Treat the bot token as root access.
2. Validate webhook requests with a secret_token header and HTTPS.
3. Understand privacy mode before designing group behavior.
4. Verify all Telegram-provided auth payloads server-side.
5. Limit storage of PII and document why you keep it.

Privacy mode implications

• Privacy mode changes which group messages reach the bot.
• It improves privacy and reduces processing load.
• Step-by-step flows in groups should rely on explicit commands, replies, or force-reply patterns.

Identity-sensitive flows

• Web login and Mini App auth are different validation problems.
• Passport data is sensitive and should be isolated operationally.
• Mentions by numeric user ID have context-specific limits.

Common mistakes

• Logging tokens or raw auth payloads.
• Trusting Web App or login data without signature checks.
• Building group features that require messages privacy mode blocks.
• Treating Telegram IDs, usernames, and business chat identifiers as interchangeable.

Read next

• 02-getting-updates
• 14-mini-apps-and-attachment-menu
• 15-web-login-and-deep-linking