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 1.21.8 Fabric?
Echo Protocol 0.5.0-beta.2 targets 1.21.6, 1.21.7, 1.21.8 with Fabric. Installation on the client is optional. Installation on the dedicated server is optional. 1 required mod needs a matching file.
Where it goes
Is Echo Protocol required on the client, server, or both?
Installation on the client is optional. Installation on the dedicated server is optional.
The source marks this as usable on both the client and server.
What else does Echo Protocol 0.5.0-beta.2 need?
0.5.0-beta.2 on 1.21.8 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 on 1.21.8 Fabric. Pick another file and the loader, install side or required mods may change.
- 01
Stick to this file
Use 0.5.0-beta.2. It targets 1.21.6, 1.21.7, 1.21.8 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
Installation on the client is optional. Installation on the dedicated server is optional.
- 04
Pick the file you checked
Use the “Get this file” button beside 0.5.0-beta.2. It opens that exact file at the source.
About this project
What does Echo Protocol add?
Echo Protocol
You were never the only thing being recorded.
Echo Protocol is a psychological horror mod for Minecraft Java Edition.
It quietly remembers fragments of your movement, familiar places, habits, sounds, and interactions. Later, those memories return as translucent figures known as Echoes.
At first, they may simply repeat what you did.
Then they begin to change.
Your Memories Are No Longer Reliable
Echoes are not ordinary hostile mobs. They do not wander randomly or behave like traditional monsters.
They are created from you.
They may follow an old route, carry an item you once held, stop where you previously stopped, or repeat a familiar action. Some Echoes remain accurate. Others become corrupted, notice the player, change direction, approach, hide, or
continue beyond the original memory.
The longer you play, the harder it becomes to know which memories are real.
Echo Types
Memory Echo
A translucent replay of a previous movement route. It can reproduce your direction, pose, held item, sprinting, sneaking, and hand movements.
Corrupted Echo
Begins as a normal memory before desynchronizing. It may stop, look directly at you, approach while unobserved, hide, or disappear.
Mimic Echo
Copies your current movement with a delay. Over time, its imitation may become inaccurate, independent, or hostile.
False Memory
Starts with an authentic recording and then performs something that never happened. It may follow the wrong route, hold a different item, repeat a movement, look at the player, or continue beyond the original memory.
Peripheral Echo
Appears briefly at the edge of your vision. If directly observed, it may disappear or reappear once at another nearby location.
Audio Residue
Replays sounds connected to previous doors, containers, workstations, items, and other interactions. Echo Protocol never records real audio or microphones.
The Original
A rare late-game presence connected to your familiar locations, habits, rooms, items, and previous Echo events.
The Original does not behave like a normal mob or boss. It moves deliberately, watches the player, opens spectral doors, interacts with familiar spaces, approaches, retreats, waits, and remembers places that matter to you.
The House Remembers
Version 0.5.0 introduces persistent, bounded memory.
Echo Protocol can learn approximate relationships between familiar rooms and locations without scanning your entire base or inspecting container contents.
The mod may remember:
- Frequently visited rooms
- Doors and entrances
- Beds and storage locations
- Workstations and portals
- Common movement routes
- Repeatedly held items
- Panic Imprints
- Previous Echo encounters
- Significant observed events
These memories remain limited, server-side, and automatically bounded.
Memory Threads
The world can connect separate memories into short generated sequences called Memory Threads.
A thread contains several related events involving a room, route, sound, item, False Memory, Panic Imprint, contradiction, or The Original.
Memory Threads are not traditional quests. They have no visible quest log, fixed campaign, or predictable ending.
They are personal sequences assembled from the way you play.
Contradictory Memories
Some memories can produce two incompatible versions of the same event.
Echo Protocol includes:
- Split Memory
- Repeated Ending
- Wrong Destination
- Memory Arrived First
- Conflicting Item
- Missing Segment
- Conflicting Copies
These contradictions are temporary and non-destructive, but they may make familiar events feel increasingly unreliable.
A World That Reacts
Echoes can visually react to the environment.
They may:
- Open nearby doors while passing through
- Repeat recorded hand movements
- Produce temporary spectral blocks
- Look toward familiar objects
- Stop at beds, doors, storage, and workstations
- Follow remembered local routes
Spectral doors and blocks are visual-only. They restore automatically and do not permanently modify the world.
Adaptive Horror
Echo Protocol observes limited gameplay patterns and adjusts event selection over time.
The Event Director considers:
- Recent Echo events
- Repeated encounters
- Current danger and combat
- Familiar locations
- Active Memory Threads
- Observation behavior
- Memory contamination
- Event cooldowns
- Loaded and safe positions
Quiet sessions remain possible. The mod does not constantly attack the player or rely on continuous jumpscares.
Intensity Presets
Choose how strongly Echo Protocol affects the experience:
- Subtle — slower, quieter, and less direct
- Standard — the intended balanced experience
- Intense — more active threads, contradictions, and confrontations
- Custom — preserves manually configured values
A detailed JSON configuration is available for players and server administrators.
Multiplayer and Privacy
Echo Protocol supports multiplayer and dedicated servers.
By default, personal Echoes are visible only to their target. Servers can optionally enable shared Echoes for nearby players.
Persistent memories, room graphs, Memory Threads, observation profiles, contamination, and personal metadata remain server-side.
Echo Protocol does not record:
- Microphones
- Voice chat
- IP addresses
- Private messages
- Container contents
- Complete persistent movement recordings
- Files outside the Minecraft world and configuration
Requirements
- Minecraft Java Edition 1.21.1
- Fabric Loader 0.16.14 or compatible
- Fabric API 0.116.13+1.21.1
- Java 21
The mod must be installed on both the server and connecting clients.
Installation
- Install Fabric Loader for Minecraft 1.21.1.
- Install Fabric API.
- Place Echo Protocol in your
modsfolder. - Launch the game using Java 21.
- Enter a world and keep playing normally.
The horror develops from your own movement and interactions. Give the world time to remember you.
Beta Notice
0.5.0-beta.2 — The House Remembers is a beta release.
Back up important worlds before installing or updating. The persistent memory format may continue to evolve during the beta period.
The world watched you.
The house remembered you.
Now something else is living inside those memories.
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
0.5.0-beta.2
echo-protocol-0.5.0-beta.2-mc1.21.6-1.21.8.jar
1 Aug 2026
Looking for an older file? The official CurseForge project page is in Resources.