FlowChat

Regex-powered chat processor for Minecraft. Replace, filter, toast, auto-respond, and play sounds on chat messages — works on clients and servers across every major platform.

Platforms

Fabric (1.16.5–1.21.4) — client-side mod
Forge (1.7.10–1.21.4) — client-side mod
NeoForge (1.20.4–1.21.4) — client-side mod
Spigot/Paper/Bukkit (1.7.10–1.21.4) — server plugin
BungeeCord — proxy plugin
Velocity — proxy plugin

Features

Regex replacement — Match incoming chat with regex, replace with formatted text
Outgoing message rules — Intercept and rewrite messages you send (command aliases, color prefixing)
Color-aware matching — colorAware: true matches against text with § color codes preserved; replacements support &a, &l, etc.
Toast notifications — Redirect matched messages from chat to overlay display ("toast": true)
Notification styles — "notifyStyle": "actionbar" (default), "toast" (system toast), or "advancement" (achievement popup)
Sound alerts — Play sounds on match: "sound": true (default sound), "sound": "bell" (specific sound), or "sound": "note_pling"
Auto-responses — Send a command/message when a pattern matches: "respond": "/cmd" (single) or "respond": ["/cmd1", "/cmd2"] (multi)
JSON matching — matchJson: true matches against raw JSON chat components instead of displayed text
Value stacking — Aggregate numeric capture groups across rapid messages into running totals (see below)
Tag variables — {username}, {serverip}, {servername}, {time} expanded in replacements
Server filtering — "server": "^mc\.example\.com" restricts a rule to matching servers only
Message cancellation — Set replacement to pleasecancelthismessage to hide a message from chat entirely
Hot-reload — Edit rules file without restarting the game or server
Legacy field support — Old field names (search, toastMe, respondMsg, serversearch, msgsearch, msgreplacement) still work via aliases

Rule Format

{ "incoming": [ { "pattern": "hello", "replacement": "world" }, { "pattern": "alert_me", "toast": true, "sound": "bell", "notifyStyle": "advancement" }, { "pattern": "greet", "respond": ["/say Hi!", "/say Welcome!"] }, { "pattern": "\\$([\\d.]+)", "replacement": "&a$$$1", "colorAware": true }, { "pattern": "\"text\":\"secret\"", "matchJson": true, "replacement": "REDACTED" }, { "pattern": "spam", "replacement": "pleasecancelthismessage" }, { "pattern": "Welcome to (.+)!", "replacement": "Joined $1 as {username} at {time}" }, { "pattern": "restart", "server": "^mc\\.example\\.com", "toast": true, "sound": true } ], "outgoing": [ { "pattern": "/b", "replacement": "/bottle get 64" }, { "pattern": "^[^/].*", "replacement": "&a&l$0", "server": "^mc\\.example\\.com" } ] }

Value Stacking

Aggregates numeric capture groups across rapid successive messages. When a shop sends multiple lines quickly (e.g. selling items in bulk), value stacking collapses them into a running total.

Replacement Tokens

Token Meaning $1, $2, ... Standard regex group references (current match only) $^1, $^2, ... Stacked value for that group (accumulated total) $^i Iteration count (how many messages stacked)

Example

{ "pattern": "^(\\d+) You sold (\\d+) (.*?) for \\$([\\d.]+)\\.$", "replacement": "You sold $^2 $3 for $^4. ($^i)", "toast": true, "valuestack": { "stack_values": [2, 4], "ignore_diffs": [1], "expire_after": 4, "seperate_float_with": "." } } Field Type Description stack_values int[] Required. Capture group indices to accumulate. ignore_diffs int[] Groups that vary between messages but shouldn't create separate cache entries. expire_after int Seconds before the stack resets (default 4). seperate_float_with string Decimal separator in matched text (default ".").