ChatFilter ReForged

A server-side chat filter for NeoForge. It censors or stops swearing in chat and in chat-like commands, sees through the usual disguises, blocks links and spam, and needs nothing installed on the client. Unmodified clients get all of it.

The modern rebuild of ChatFilter, the Bukkit plugin, rewritten from scratch for NeoForge. Most of what was asked for in the old plugin's comments is in it.

Silent by default

A caught word reaches other players as ####, drawn by their own client's chat filter, with a "filtered by the server" hover. The sender sees exactly what they typed and is told nothing, so there is nothing to argue with and nothing to work around. Chat stays signed. Staff with chatfilter.see read the original.

Prefer the classic approach? Every category can instead:

• REPLACE the word for everyone (!@$#, **** or cartoon swearing)
• SHADOW the whole line: a soft-mute where the sender sees it sent and nobody else sees it
• BLOCK it, with "Oi {player}! Mind your language!" if you like
• or just LOG it

Hard to get around

Capitals, accents, leetspeak (sh1t, $h!t), stretched letters (fuuuck), spelled-out letters (f.u.c.k, s h i t), self-censoring (f*ck), full-width and look-alike letters from other alphabets, zero-width characters, and colour codes hidden mid-word. List the plain word once.

Kind to innocent words

Part-word and whole-word lists, so ass catches neither class nor grass. There's an allowlist for the Scunthorpe problem, and regular expressions for anything the lists can't say. /chatfilter test <text> shows exactly what would be caught, by which entry, and what would happen.

Chat that arrives as a command

/msg, /tell, /w, /r, /me, /say, /teammsg, /mail send, /f chat, and anything else you list. Only the message is judged, never the player name, so /msg Assassin hi works.

And the rest

• Links and IP addresses, including example dot com, with an allowlist for your own site and a permission for those who may post them
• Spam: shouting is lowercased, and repeats and floods are stopped
• Strikes that expire one at a time, and a ladder that can alert staff, warn the player, or run any command: mute {player} 10m, kick {player}
• Staff alerts with a per-person toggle, and a console log
• Edit the lists in game: /chatfilter add profanity.words …, saved to the config file
• Keyword replies. It still answers "eleven", and you can switch that off for good.

With SableCraft Standards

With SableCraft Standards 1.11.0 or later installed, ChatFilter also screens everything Standards delivers itself: formatted chat, party and faction channels, /msg, /r, /me and /mail. Each viewer gets their own copy, so the silent mask works there too. Standards is optional. Without it, vanilla chat and commands are filtered just the same.

Permissions

Through NeoForge's permission API, so any permissions mod can grant them.

Configuration

config/chatfilter-common.toml, every option commented. The defaults mask the classic word list silently, block links and floods, quieten shouting, and filter the usual private-message commands. The severe list ships empty: every server's is different, and nobody should get one they didn't choose.

Versions

Minecraft 1.21.11, 26.1, 26.2 and 26.3, one file each. Server-side only. Open source (MIT): GitHub.