CurseForge · Minecraft mod
Echo Protocol
A psychological horror mod where the world remembers, imitates, and slowly replaces the player.
Quick answer
Which Echo Protocol release matches 1.21.2 Fabric?
Echo Protocol 0.5.0-beta.2 for Minecraft 1.21.2–1.21.3 targets 1.21.3, 1.21.2 with Fabric. The project page does not say whether this file belongs on the client, dedicated server, or both. 1 required mod needs a matching file.
Where it goes
Is Echo Protocol required on the client, server, or both?
The project page does not say whether this file belongs on the client, dedicated server, or both.
The source does not explicitly classify this release as client-only or server-only.
What else does Echo Protocol 0.5.0-beta.2 for Minecraft 1.21.2–1.21.3 need?
Echo Protocol 0.5.0-beta.2 for Minecraft 1.21.2–1.21.3 on 1.21.2 Fabric. Every mod below is checked against that same setup.
Install Fabric API first, but 1 required mod has no matching file for this setup. Do not mix loader builds to force a match.
We only count dependency files that match this setup. A file for another loader does not fill the gap.
Before you install it
Add Echo Protocol without breaking your instance.
Built for Echo Protocol 0.5.0-beta.2 for Minecraft 1.21.2–1.21.3 on 1.21.2 Fabric. Pick another file and the loader, install side or required mods may change.
- 01
Stick to this file
Use Echo Protocol 0.5.0-beta.2 for Minecraft 1.21.2–1.21.3. It targets 1.21.3, 1.21.2 with Fabric; another release may have different loader, side or dependency requirements.
- 02
Bring the mods it needs
Install Fabric API first, but 1 required mod has no matching file for this setup. Do not mix loader builds to force a match.
- 03
Put it on the correct side
The project page does not say whether this file belongs on the client, dedicated server, or both.
- 04
Pick the file you checked
Use the “Get this file” button beside Echo Protocol 0.5.0-beta.2 for Minecraft 1.21.2–1.21.3. It opens that exact file at the source.
About this project
What does Echo Protocol add?
Echo Protocol
Echo Protocol is a psychological horror mod for Minecraft that makes the world remember the player.
The mod records short, bounded fragments of player movement and later recreates them as unsettling Echoes. At first, they simply repeat the past. Over time, they begin to make mistakes, copy the present, move independently, and act as though the world belongs to them.
Echo Types
Memory Echo
Replays a previous route from the player's recorded movement history. It does not react or attack and behaves like a distant memory.
Corrupted Echo
Begins by replaying the past, but gradually desynchronizes. It may freeze, turn toward the player, move closer while unobserved, hide, or disappear.
Mimic Echo
Copies the player's current movement with a delay. Its imitation becomes less accurate over time, and rare hostile encounters may occur.
The Original
A rare late-game Echo that no longer copies the player.
The Original remembers familiar locations such as beds, storage areas, crafting spaces, doors, portals, and common idle positions. It moves independently and behaves as though the player is the duplicate.
Features
- Real player skins
- Classic and slim player model support
- Four different Echo types
- Persistent horror progression
- Familiar-location tracking
- Safe server-controlled spawning
- Configurable sounds and visual effects
- Reduced flashing and reduced visual effects options
- English and Russian localization
- Dedicated server support
- Multiplayer privacy
- Advancements and administrator testing commands
Multiplayer Privacy
Private Echoes are server-filtered by default.
When shared Echoes are disabled, unrelated players do not receive the private Echo entity, replay information, particles, sounds, text events, or familiar-location data.
Requirements
- Minecraft Java Edition 1.21.1
- Fabric Loader 0.16.14 or newer
- Fabric API
- Java 21
The mod must be installed on both the client and the server.
Configuration
The configuration file is generated at:
config/echo_protocol.json
Event timing, Echo types, damage, visual effects, sounds, privacy, Stage 3 requirements, and accessibility options can be configured.
Alpha Notice
Echo Protocol is currently in alpha.
The main systems are playable and manually tested, but event balance, configuration defaults, behavior, and save data may change in future versions.
Known Limitations
- Echo movement is scripted rather than using advanced navigation.
- Recorded movement routes are not preserved across server restarts.
- Familiar-location detection uses bounded heuristics.
- The current sound design mostly uses compatible vanilla sound events.
Project description from CurseForge.
Pick your setup
Echo Protocol by Minecraft version and loader
Choose the version and loader you play, then open the matching release.
1.21.8
1 loader build1.21.7
1 loader build1.21.6
1 loader build1.21.5
1 loader build1.21.4
1 loader build1.21.3
1 loader build1.21.2
1 loader build1.21.1
1 loader buildCheck the dependencies, then try the file in a copied instance before changing a world you care about.
Recent files
Echo Protocol versions and loaders
Echo Protocol 0.5.0-beta.2 for Minecraft 1.21.2–1.21.3
echo-protocol-0.5.0-beta.2-mc1.21.2-1.21.3.jar
31 Jul 2026
Looking for an older file? The official CurseForge project page is in Resources.