🔗 Delta Chat Username & Short Link Bot (deltachat_username)

A Delta Chat bot and FastAPI web service for registering custom usernames and generating short invite links (https://deltachat.id/<username>) that redirect (via HTTP 307 Temporary Redirect) to standard Delta Chat invite URLs (https://i.delta.chat/#...).

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✨ Features

• 👤 Custom Usernames: Claim a short username (/username myname) for your personal profile or group chat.
• 🔐 Visual Cryptographic Verification: Anti-impersonation verification displaying 10-group formatted PGP fingerprints, 5x5 symmetric Unicode block Identicons, and 5-emoji visual badges.
• 🖼️ Social OpenGraph & Twitter Cards: Smart crawler detection serving rich metadata and cached dynamic PNG cards (1200x630) on Telegram, Discord, Twitter, WhatsApp, etc.
• 📇 Web Profile Cards & Avatars: Dynamic endpoints (/{username}/og.png, /{username}/avatar.svg, and /{username}/card) for visual badges, QR codes, and web verification.
• ⚡️ Group Chat Auto-Binding: Use /username myname directly inside any group chat — the bot instantly generates the group's invite URL without manual link pasting.
• 🔀 HTTP 307 Temporary Redirect: Guarantees browsers and proxies always fetch the newest invite link without aggressive caching.
• 🌐 Web Landing Page: Beautiful dark-mode glassmorphism interface on GET / displaying bot description, QR code, and interactive command hints.
• 🛡️ Secure Administration: Authenticate ownership via /initadmin with cryptographic fingerprint verification.
• 📡 Multi-Transport & Statistics: Track sent/received relay stats and configure backup transports.

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🚀 Quick Start & Deployment

1. Build Container

Clone repository and navigate to deltachat_username:

cd deltachat_username
cp .env.example .env
docker compose build

2. Initialize Delta Chat Account

Initialize the bot's account in Delta Chat CLI (deltabot-cli):

# Option A: Automatic setup on a Chatmail server (e.g. chatmail.uk or nine.testrun.org)
docker compose run --rm username_bot python bot.py init usernamebot@chatmail.uk

# Option B: Standard email account with password
docker compose run --rm username_bot python bot.py init usernamebot@yourdomain.com "your_password"

3. (Optional) Pre-configure Admin Email / Fingerprint

docker compose run --rm username_bot python set_admin.py --email admin@yourdomain.com

4. Launch Bot Daemon

docker compose up -d

5. Claim Administrative Ownership

Send /initadmin to the bot in a private message in Delta Chat to complete admin identity verification.

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🤖 Bot Commands

Command	Scope	Description
/username	All	Check your current chat's registered username and short link.
/username <name>	All	Look up short link for any registered username.
/link <name> <url>	Private	Bind custom username & invite link (replaces old username if present).
/link <name>	Group	Auto-generate group invite link and bind username.
/unlink	All	Unlink registered username from current chat.
/unlink <name>	Admin	Force-unlink a registered username.
/help	All	Show command help and bot info.
/donate	All	Support bot development.
/initadmin	Admin	Claim administrative ownership.
/url <url>	Admin	Set base domain URL (https://deltachat.id).
/inviteurl <url>	Admin	Set custom invite base URL/mirror (https://i.gluek.info/#).
/stats	Admin	Show registered usernames and database stats.
/transports	Admin	List configured mail relays and statistics.
/addtransport <uri/creds>	Admin (Private)	Add a backup mail transport relay.
/rmtransport <addr>	Admin	Remove a configured mail transport.

Relay selection and failover are handled by the Delta Chat core (2.61+): it sends via the newest relay first and falls back to the next one if a relay is unreachable. /transports lists relays in that order. The former /setprimary and /resilient commands are deprecated and only reply with this explanation.

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Target-Specific Commands in Group Chats

In group chats where multiple bots are present, you can address this bot specifically to prevent other bots from responding. Append the @username (or @user, @usernamebot) suffix to any command, for example:

• /help@username
• /stats@username

A plain /help sent in a group chat is answered in a private 1:1 chat with the sender, so several bots don't flood the group with help texts. Use /help@username to show the help in the group itself.

🌐 Caddy Configuration

Add to your /etc/caddy/Caddyfile:

deltachat.id, d.gluek.info {
    reverse_proxy 127.0.0.1:8080
}

www.deltachat.id {
    redir https://deltachat.id{uri} permanent
}

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🧪 Running Unit Tests

python3 -m unittest discover -s tests -p "test_*.py" -v

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❤️ Support & Development

If you find this bot useful, consider supporting its development:

• ⭐ Star this repository or bookmark it!
  • Git Repository: mrgluek/deltachat_username
  • Forgejo Mirror: gluek/deltachat_username
• Donations:
  • ☕️ Ko-fi (world cards, PayPal)
  • 🚀 Tribute (Russian cards, SBP)
  • Or use the /donate command in Delta Chat.