Freedom251 › Minecraft Moderation Plugins

ChatSentinel

Paid Self-hosted

What ChatSentinel is

ChatSentinel is a free, open-source moderation plugin for Minecraft Paper servers. It checks messages with a local trie filter, with optional moderation API and large language model review layers. The local filter loads word lists for 28 languages and supports leet-speak normalization and abbreviation expansion. In addition to chat, it can moderate whispers, signs, books, and anvil renames. Flagged content can be blocked or masked, while configurable escalation can warn or mute a player, or alert staff. The two API layers are disabled by default, so a basic setup uses the local filter without API keys. Layer 1 uses an OpenAI-compatible moderation endpoint; Layer 2 supports OpenAI-compatible chat-completions services, including Ollama, LM Studio, vLLM, Azure OpenAI, Together, and Groq. SQLite is the default database, with MySQL and PostgreSQL available as alternatives. If PlaceholderAPI is installed, the plugin can expose moderation scores, mute status, remaining mute time, offense count, and time since last offense as placeholders. The README lists Java 21 or later and a Paper server as requirements. It describes a fail-open pipeline: the local filter stays active if APIs are unreachable, and a configurable timeout determines when messages are allowed through. Recent messages used for LLM context stay in memory and are discarded when the server restarts; moderation logs can be purged by retention window.

Who it suits

ChatSentinel suits administrators of Minecraft Paper servers who want local chat filtering, with optional API or LLM review. It may also fit servers that moderate signs, books, whispers, and anvil renames or use PlaceholderAPI for moderation-related placeholders.

What it does well

Local filtering supports word lists for 28 languages.
Handles leet-speak normalization and abbreviation expansion.
Can moderate chat, whispers, signs, books, and anvil renames.
Optional API layers are off by default and need no keys for local filtering.
Supports SQLite, MySQL, and PostgreSQL storage.
Offers configurable warnings, mutes, blocking, masking, and staff alerts.

What to know first

Requires Java 21 or later and a Paper server.
There is no staff web panel.
API-based moderation layers require configuration to enable.

Getting started

Open the project repository on GitHub.
Run a Minecraft Paper server with Java 21 or later.
Install ChatSentinel for the server.
Use the local filter without API keys, or configure the optional moderation and chat-completions layers.
Choose SQLite or configure MySQL or PostgreSQL if needed.
Install PlaceholderAPI if you want moderation-related placeholders.

Verdict

Choose ChatSentinel if you run a Paper server and want local filtering across several player message surfaces, with optional API review and configurable enforcement. Its self-hosted format and Java and Paper requirements make it a server-admin tool; look elsewhere if you need a staff web panel.

Questions

Does ChatSentinel cost anything?

It is listed as free and open source.

What does ChatSentinel require?

The README lists Java 21 or later and a Paper server as requirements.

Can it work without moderation API keys?

Yes. The API layers are disabled by default, and the local filter works without API keys.

Which databases does it support?

SQLite is the default. MySQL and PostgreSQL are also supported.

Does ChatSentinel integrate with PlaceholderAPI?

Yes, PlaceholderAPI is optional. When installed, it can expose moderation scores, mute status, remaining mute time, offense count, and time since last offense as placeholders.

How can server admins get support?

The README directs users to report issues through the repository’s GitHub Issues page and asks them to include reproduction steps, version details, and relevant redacted logs.

Facts from ChatSentinel's own pages

API compatibility: Layer 1 uses the OpenAI Moderation API by default, while Layer 2 supports OpenAI-compatible chat-completions endpoints including Ollama, LM Studio, vLLM, Azure OpenAI, Together, and Groq. · github.com, 4 Oct 2026
API providers: Layer 1 uses an OpenAI-compatible moderation endpoint; Layer 2 supports OpenAI-compatible chat-completions providers including Ollama, LM Studio, vLLM, Azure OpenAI, Together, and Groq. · github.com, 3 Oct 2026
Database options: SQLite is the default storage backend, with MySQL and PostgreSQL also supported. · github.com, 4 Oct 2026
Data retention: Recent messages used for LLM context are held in memory and discarded when the server restarts; moderation logs can be purged by retention window. · github.com, 3 Oct 2026
Enforcement: Flagged messages can be blocked or masked, and configurable escalation can warn players, mute them, or alert staff. · github.com, 4 Oct 2026
Failure behavior: The documented default is a 3000 ms timeout with fail-open enabled, leaving the local filter active if moderation APIs are unreachable. · github.com, 4 Oct 2026
Integration: If PlaceholderAPI is installed, ChatSentinel registers placeholders for player moderation scores, mute status, remaining mute time, offense count, and time since last offense. · github.com, 4 Oct 2026
Integrations: PlaceholderAPI is an optional integration that exposes player moderation scores, mute status, and offense information as placeholders. · github.com, 3 Oct 2026
Language filtering: The local filter loads word lists for 28 LDNOOBW languages and normalizes leet-speak before scanning. · github.com, 4 Oct 2026
Local operation: Layers 1 and 2 are disabled by default, so the plugin starts with its local filter and does not require API keys for that setup. · github.com, 4 Oct 2026
Moderated content: It can moderate chat, whispers, signs, books, and anvil renames. · github.com, 4 Oct 2026
Moderation pipeline: It checks messages with a local trie filter, a moderation API, and an LLM review layer. · github.com, 4 Oct 2026
Optional APIs: Layers 1 and 2 are disabled by default, and the local filter works without API keys. · github.com, 3 Oct 2026
Other content: The plugin can moderate signs, books, anvil renames, and private messages in addition to chat. · github.com, 3 Oct 2026
Purpose: ChatSentinel is a multi-layered chat moderation plugin for Minecraft Paper servers. · github.com, 4 Oct 2026
Requirements: The README lists Java 21 or later and a Paper server as requirements, and identifies Paper API 1.21.11 in its build dependencies. · github.com, 4 Oct 2026
Storage: SQLite is the default database, with optional MySQL and PostgreSQL backends. · github.com, 3 Oct 2026
Support: The README directs users to report issues through the repository’s GitHub Issues page and asks them to include reproduction steps, version details, and relevant redacted logs. · github.com, 4 Oct 2026
Telemetry: The README says bStats sends anonymous aggregate usage metrics and does not transmit player data, messages, or API keys; it is controlled through the global bStats configuration. · github.com, 4 Oct 2026

Where ChatSentinel stands on Freedom251

Minecraft Moderation Plugins#15 of 19