Opaque Chat
Opaque Chat adds encrypted networking to Minecraft chat, so messages between players who share a key are secured end to end while the chat screen keeps its layout.
What it does
Chat traffic is protected with ECDH secp256r1 key exchange and AES-GCM symmetric encryption. Players exchange a key once, and the key is stored in the local config folder and reused between sessions, so only the invited players can read the messages. The mod operates entirely on the client and runs alongside a server that sends standard chat messages, which keeps unencrypted chat working for everyone else.
The features panel is built directly into the vanilla Chat screen rather than as a separate window. Chat cooldowns set per server can be adjusted, and commands use the oc prefix. Opaque Chat works with GUI Integration. Fabric Loader and Fabric API are required, Yet Another Config Lib is required for its settings, and ModMenu is optional but recommended for opening them.
The mod is open source under the GNU General Public License v3.0 only and is published for Fabric and Quilt for 1.21.11. Public links exist for the source code and the issue tracker.
Key features
End-to-end encryption
Messages are secured with ECDH secp256r1 key exchange and AES-GCM symmetric encryption before they leave the client.
Vanilla chat panel
A features panel is drawn directly on the vanilla Chat screen, so no separate window replaces it.
Configurable interface
Colors, layouts and chat cooldowns for each server can be changed through the mod's configuration screen.
Saved session keys
The shared key is saved in the local config folder and reused between sessions, so an invite is needed only once per player.
Oc command prefix
Mod commands are entered with the oc prefix, separating them from ordinary chat messages.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
How it compares
Message Encryption is also a Fabric and Quilt chat encryption mod, client-side only, and it is open source under the GNU Lesser General Public License v3.0 only, for versions 1.20 – 26.3. Coord Chat is a Fabric-only, client-side mod for 1.21.10, open source under the GNU General Public License v3.0 only, with the same license as Opaque Chat. Chat Sync is Fabric-only, client-side and not open source, released under the MIT License for 1.21.10 – 1.21.11.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Opaque Chat | Fabric and Quilt | 1.21.11 | Client-side only | 2026-08-01 |
| Message Encryption | Fabric and Quilt | 1.20 – 26.3 | Client-side only | 2026-10-04 |
| Coord Chat | Fabric | 1.21.10 | Client-side only | 2025-10-27 |
| Chat Sync | Fabric | 1.21.10 – 1.21.11 | Client-side only | 2026-02-19 |
Questions
Which loaders does Opaque Chat support?
Does Opaque Chat need Yet Another Config Lib?
Does a server need to install Opaque Chat?
In the catalog
Opaque Chat is one of 5,392 Social mods on ModsFinder, and one of 4,084 Social mods for Fabric. 19,862 mods support Minecraft 1.21.11.
More from Hyouka-Oshibi
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What the author says
Opaque Chat intercepts incoming and outgoing chat messages prefixed with!oc_. When you invite a player, the mod performs a silent cryptographic handshake (!oc_req and!oc_key) to exchange public keys over the server's public chat. Once a shared secret is established, your messages are encrypted (!oc_msg) before they…
Official listing
- Modrinth page
- modrinth.com/mod/opaque-chat
- Owner
- Hyouka-Oshibi
- Published
- 2026-03-08
- Updated on Modrinth
- 2026-08-01
- Facts verified
- 2026-10-15