FlameCord overview

FlameCord is a security-focused fork of BungeeCord and Waterfall. It is a proxy JAR, not a Bukkit plugin: it replaces the proxy in front of your network and adds antibot checks, packet validation and an optional host-level firewall. The 2.7.0 label comes from the release commit; the build tree itself reports 26.1-R0.1-SNAPSHOT, so do not look for 2.7.0 as a Maven artifact version.

Identity

Field	Verified value
Project	BungeeCord/Waterfall fork
Release label	2.7.0 (commit 4a1e58e, 16 September 2026)
Build version	26.1-R0.1-SNAPSHOT
Upstream base	Waterfall 26.1-R0.1-SNAPSHOT
Java	Compiled with release 17
License	MIT
Distribution	Proxy JAR; no plugin installation step

Where checks run

FlameCord separates status pings from logins at the handshake. A status request gets its own rate-limit path; a login increments connection counters and enters the login pipeline. The login checks run in a fixed order — reconnect, lockdown, latency, accounts, nickname — and each can disconnect the connection before the player reaches a backend.

Country lookup is offloaded and resumes on the channel event loop rather than blocking it. Limbo verification runs after login success but before LoginEvent: the connection is handed to the limbo filter, login success is sent, and the session either stays in the bot filter or continues to the normal login state depending on the client version.

Packet validation happens before full decode. The decoder rejects frames above 2 MiB and reads the packet ID before constructing the packet; a separate check adds VLS by byte count and packet count, then cancels or kicks at the configured thresholds.

The firewall has two layers. Each remote address accumulates connection, ping, nickname and latency data, and a hit can mark that address as firewalled. Separately, startup can install a host-level ipset and an iptables raw-PREROUTING DROP rule, which is the part that affects the whole machine rather than one proxy process.

Antibot defaults

Key	Default	Effect
antibot.accounts.enabled / .limit	true / 3	Accounts per IP
antibot.latency.enabled / .limit	true / 900	High-latency gate in milliseconds
antibot.ratelimit.connections-per-second	3	Per-IP connection rate
antibot.ratelimit.pings-per-second	8	Per-IP ping rate
antibot.reconnect.enabled / .attempts	true / 2	Reconnect challenge
antibot.firewall.time / .ipset	60 / true	Firewall duration and host ipset use
antibot.packets.vls-to-cancel / .vls-to-kick	25 / 100	Packet VLS thresholds
antibot.country.enabled / .blacklist	true / CN,HK,RU,IN,TH,ID,DZ,VN,IR,PK	Country blocking
antibot.fastchat.enabled / .time	true / 1000	Chat and command flood window
antibot.lockdown.enabled / .period-limit	true / 4	Automatic lockdown policy
antibot.limbo.enabled / .timeout	true / 30	Limbo verification

The defaults are active out of the box, including the country list and the host firewall. Review them before the first production start; see Configure FlameCord for the full operational subset.

Requirements

Requirement	Verified detail
Runtime	Java 17 or newer, matching the release-17 bytecode
Host	Linux with apt, ipset and iptables for the default host firewall
Privileges	Root for the startup firewall commands
Upstream build	Waterfall patches applied through the repo’s scripts
Plugin dependencies	None required to run the proxy

The firewall setup is not optional in the sense of being harmless when it fails. With antibot.firewall.ipset: true, startup runs apt install iptables -y, apt install ipset -y, destroys and recreates the flamecord ipset, and inserts the DROP rule. Commands run through /bin/sh -c, exit codes are ignored, and a spawn failure only logs that the feature requires Linux and root. On a non-apt host, the in-memory firewall state remains but no host rule is installed. The startup sequence also destroys any existing ipset named flamecord.

What is not claimed

• No Minecraft client version range is declared.
• No git tags or published Maven artifact correspond to 2.7.0 in this checkout.
• The exact tested Waterfall upstream commit is not recorded.
• Proxy permission nodes have no default metadata; behavior depends on the permission provider.
• Limbo has version-conditional branches, but the full supported range is not stated.

Nothing here establishes that every antibot check is appropriate for every network. Start with the defaults on a staging proxy, watch what the checks block, then tune.

Next steps

• Install FlameCord for the build and host prerequisites.
• Configure FlameCord for checks, limbo, firewall and modules.yml.
• Read the FlameCord engineering case study for the design tradeoffs.

Verified against FlameCord 4a1e58e (release label 2.7.0, 16 September 2026) on 30 October 2026. Values come from source; no proxy was started and no firewall rule was applied.