Developing for ANetBBS

Want to write a door, a web feature, a theme, or hook into messaging?
You're in the right place.

The ten door types

ANetBBS runs door games via ten distinct backends:

1. DOS doors (DOSBox-staging) — TradeWars, LORD-DOS, Usurper
2. DOS doors (dosemu2, virtual COM1, no FOSSIL) — an alternative to
   DOSBox-staging for DOS games that need it specifically
3. Native Linux doors — any executable, stdio piped
4. Synchronet .js doors — real jsexec if installed, otherwise
   our built-in Node + Synchronet API shim (~270 functions)
5. Mystic Pascal .mps/.mpx — bundled Mystic 1.12 A48 runtime
6. Mystic Python .py — fake mystic_bbs module
7. rlogin out-dial — DoorParty / A-Net Online / Synchronet xtrn
8. Telnet out-dial — TWGS and other telnet-only remotes, no
   pre-auth handshake
9. Built-in web games — Flask-routed mini-games
10. In-browser DOS games — EmulatorJS + dosbox_pure, runs entirely
    client-side, no telnet/SSH client needed

See docs/17-development.md for the
deep-dive: drop file formats, token substitution table, working code
examples for each type.

Extending the web app

The web side is Flask + SQLAlchemy + SocketIO. Adding a new
feature is roughly:

1. Create a blueprint in anetbbs/web/myfeature.py
2. Register it in anetbbs/web_app.py
3. Add templates in anetbbs/templates/myfeature/
4. (Optional) Add a nav-bar link in templates/base.html
5. (Optional) Add a model class (or a new column on an existing one)
   to anetbbs/models.py — see Database below, no migration
   command needed for the common case

The whole pipeline is ~50 lines of code for a working feature blueprint.

Database

anetbbs/models.py is the single source of truth for SQLAlchemy
models. There's no alembic/flask db migrate step in normal use —
web_app.py runs an auto-sweep (_lightweight_migrate()) on every
startup: it walks db.metadata.sorted_tables, and for any column a
model declares that the live table is missing, issues a permissive
ALTER TABLE ADD COLUMN (nullable, no default, so it always succeeds
on SQLite). Add a column, restart anetbbs-web, done. See
Architecture for the same mechanism described from the ops side.
A hand-written migration is still the right call for anything
destructive (renaming/dropping a column, backfilling data) — the
auto-sweep only ever adds.

Themes

Themes are DB rows with CSS variable values, edited visually at
/admin/theme-builder/. Add a new built-in theme by tweaking colors
in the builder, then add the resulting values to the default-theme
seed block in _create_default_data() in anetbbs/web_app.py
(there's no separate seed_data.py — it's all in web_app.py).

Real-time features

Flask-SocketIO is wired up in web_app.py. The Web Terminal and MRC
client are both reference implementations of a feature that spawns a
background eventlet greenthread, pumps bytes between a backend socket
and the browser, and handles reconnect.

Echomail / FidoNet networks

Pollers live in anetbbs/echomail/{binkp,qwk,tic}.py. Adding a new
network type is one new module + one new EchomailNetwork.protocol
discriminator.

Where to ask questions

• Email — a-net-online@proton.me
• Open a GitHub issue at anetonline/anetbbs
• This wiki — anyone with edit rights can expand the
  Development page and create child pages

If you ship something cool, PR it back and we'll bundle it with the
next alpha.

Reference

The authoritative deep-dive is at docs/17-development.md.
This wiki page is the lightweight community-editable companion.