GraceAC

Please know that THIS plugin page is only the paper STANDALONE anticheat, not the velocity proxy plugin, not the paper companion. I am writing this as of the 28th of Mars 2026, and the modrinth team is sitll reviewing both plugins, be patient with them as they have a huge workload of mods, plugins, packs and etc... to verify.

Grace Anticheat

> Advanced, free anticheat for Java Minecraft servers (1.19+). Built to catch what others miss.

Grace targets ghost cheating and ghost cheating these are the subtle, hard-to-detect cheats that plague competitive servers. Blatant hacking is handled too, but it isn't the focus.

Unlike Watchdog, Sentinel, and Grim, Grace is free. Unlike NCP and other aging open-source anticheats, Grace is built for modern Minecraft with a rules-based detection pipeline and a statistical behavioral analysis layer.

The website is live at https://grace-ac-site.vercel.app/.

---

Architecture

Grace runs as a Paper companion plugin with a Paper companion plugin on the backend server. ``` [Client] → [Grace / Velocity Proxy] → [Paper Server + GraceCompanion] ```

However, this paper plugin standalone runs as follows : ``` [Client] → [Paper Server / Grace Paper (Standalone)] ``` This does not mean this variant of the anticheat is less powerful than the velocity based one, it just acts on another layer with some minimal loss in precision.

---

The proxy intercepts raw packets. The companion feeds server-confirmed truth : hit registration, movement validation, TPS. Together they give Grace a complete picture of player behavior that neither layer could achieve alone.

---

Requirements (for the standalone)

- Java 1.19+ - Java 21+

---

Installation

1 — Backend server

This is the standalone paper plugin installation,

Simply drop the downloaded .jar in /plugins, and you're set!

this plugin downloads like any other, you'll have to launch the server once after download to get the configuration file and graceAC folder.

---

Configuration

```yaml grace: bridge: port: 27016 # make sure this port is open / not blocked by firewall

alerts: ingame-enabled: true # alert staff in-game discord-enabled: false # send alerts to Discord webhook-url: "" # paste your Discord webhook URL here min-level: "HARD_ALERT" # SOFT_ALERT / HARD_ALERT / ACTION

punishment: enabled: true rubber-band-on-hard-alert: true # teleport player back on HARD_ALERT kick-on-action: true # kick on ACTION tier ban-on-action: false # auto-ban (disabled by default) ban-threshold: 3 # ACTION flags before ban kick-message: "Kicked by Grace Anticheat." ban-message: "Banned by Grace Anticheat."

spoof: brand: "vanilla" # spoof server brand to hide Grace from cheat clients enabled: true ```

---

Commands

| Command | Permission | Description | |---|---|---| | `/grace status` | `grace.command` | Engine status, check count, tracked players | | `/grace player <name>` | `grace.command` | Player evidence summary | | `/grace alerts` | `grace.command` | Toggle your personal alert notifications | | `/grace inspect <name>` | `grace.admin` | Full violation history for a player | | `/grace reload` | `grace.admin` | Reload config without restart |

---

Discord Alerts

Grace can send formatted embeds to a Discord channel when a player is flagged.

1. Go to your staff channel → Copy Webhook URL → Copy Webhook URL → Copy Webhook URL → Copy Webhook URL → Copy Webhook URL 2. Paste the URL into `config.yml` under `webhook-url` 3. Set `discord-enabled: true`

---

Open Source

Grace's framework - the API, event pipeline, data model, and companion plugin is open source.

Grace's detection logic - check implementations, model weights, and threshold tuning is closed source. This is intentional. Open detection logic is a bypass roadmap for cheat developers.

---

Status

Beta 0.1.0 - active development. Expect bugs. Thresholds are conservative by default to minimize false positives on first deployment. If Grace is missing cheaters on your server, thresholds can be tuned in config.

Bug reports and feedback welcome via GitHub Issues.

---

Roadmap

- 0.1.0 — ML sidecar (grace-ml) first iteration, behavioral analysis layer, complete checks and advaned setup help for early servers.

this is currently done! Thanks for the support, whoever downloaded Grace <3

- 0.2.0 — Dashboard, per-server threshold tuning, ban history UI