mc-locate
Every Minecraft player has been there: you build an incredible base, explore thousands of blocks, and then lose the world file to a corrupted save or an accidental deletion. The world is gone, but the seed that generated it still exists. Recovering that seed from an existing save is a complex process, but it is now significantly easier thanks to a clever new tool called mc-locate. This add-on works hand-in-hand with a companion command-line interface (CLI) to reverse-engineer the exact seed of your world using only the data your own client can see.
This guide explains everything you need to know about the mc-locate exporter mod, from its core functionality to its installation process. We will cover the supported versions, the specific commands you will use, and how the passive collection mode turns normal gameplay into a seed-recovery operation.
What is the mc-locate Exporter Mod?
The mc-locate mod is a client-side utility designed for Fabric. It does not generate structures or alter gameplay. Instead, it acts as a meticulous data collector. It observes three specific types of in-game information that are mathematically linked to the world seed:
- Nether Bedrock: The unique pattern of bedrock blocks at the top and bottom of the Nether.
- End Pillar Heights: The varying heights of the ten obsidian pillars surrounding the End portal.
- Eye of Ender Bearings: The exact direction an eye of ender travels when thrown.
By collecting these observations, the mod writes them to a structured JSON file. This file is then imported into the main mc-locate CLI application, which performs the heavy mathematical lifting to narrow down and ultimately identify the world seed. The mod is purely observational; it reads blocks and entities that the game server has already sent to your client because you are standing near them. It sends no data to any server, does not forge packets, and never interacts with other players.
Key Features and Design Philosophy
The design of mc-locate prioritizes safety and accuracy. The developer has built in several safeguards to ensure that the data you collect is reliable and that the mod does not interfere with your game or server rules.
Client-Side Only and Server Safe
Every command is processed locally by the Fabric loader. When you type /mclocate ..., it never reaches the server. This means the mod functions on vanilla servers and most multiplayer networks. The only exception is the /mclocate seed command, which reads the integrated server's seed—a feature that only exists in single-player worlds. On multiplayer servers, you will need to use the CLI to crack the seed from your collected data. Remember that seed-cracking may violate server rules, so always check the server's policy before using this tool.
Passive Collection Mode
The intended workflow for mc-locate is to enable passive collection and then simply play the game. The mod automatically logs data as you explore:
- Nether Bedrock: Automatically sampled as chunks load around you when you fly through the Nether.
- End Pillars: Recorded automatically when you enter the End dimension.
- Eye of Ender: Captured the moment you throw one, reading the entity's exact position for precise triangulation.
Passive bedrock collection is off by default to respect your privacy, but you can enable it with a simple command. Pillar and eye capture are on by default. In single-player, passive mode also automatically records the world seed since your client owns it.
Session Persistence
One of the most user-friendly features is the automatic saving of your session. All collected data is continuously written to .minecraft/mc-locate/session-current.json. This means if you crash or forget to export, your afternoon of collecting is not lost. The data is reloaded the next time you launch the game, and you can use /mclocate clear to start fresh.
How to Install mc-locate for Minecraft
Installing the mc-locate mod is straightforward, but it requires the Fabric mod loader. The mod does not support Forge or NeoForge. Follow these steps to get started:
- Install Fabric Loader: Download and run the Fabric installer for your specific Minecraft version. The mod requires Fabric Loader version 0.16 or higher.
- Download Fabric API: You will need the Fabric API jar that matches your Minecraft version. This is a prerequisite for almost all Fabric mods.
- Download the mc-locate Exporter: Navigate to the mod's release page and download the jar file that matches your exact Minecraft version. The file naming convention is
mc-locate-exporter-<mod version>+<mc version>.jar. The Fabric loader will refuse to load a jar built for the wrong version, so you cannot accidentally install an incompatible file. - Place in mods Folder: Move both the Fabric API jar and the mc-locate exporter jar into your
mods/folder. - Launch the Game: Start Minecraft with the Fabric profile. The mod will load and create its configuration files on first run.
If you are looking for a more streamlined way to manage your mods, you might consider using a third-party launcher. For example, the foxygame.net launcher offers a one-click install feature for many popular mods, which can simplify the process of setting up Fabric and dropping in the necessary jars for mc-locate. Its add-on catalog often includes the Fabric API, making it easier to get the prerequisites sorted before you manually add the exporter jar.
Supported Minecraft Versions
The mod is built using a Stonecutter project, which allows the developer to maintain a single codebase and compile it for multiple game versions. A separate jar is built for each supported Minecraft version. As of the latest release, mc-locate supports the following versions:
- 1.21.x Series: This includes versions 1.21 through 1.21.11. Each specific version has its own dedicated jar file.
- 26.x Series: This includes the newer 26.1.x releases and 26.2. The 26.1.x series has a single jar that works for all minor versions (26.1, 26.1.1, 26.1.2), while 26.2 has its own separate jar.
It is crucial to select the jar that corresponds precisely to your game version. The mod's documentation provides a clear table mapping each Minecraft version to its required jar file. The foxygame.net launcher can also help here; its version compatibility checker can alert you if you are trying to run a mod on an unsupported game version, ensuring you always pair the correct mc-locate jar with your client.
Essential Commands and Workflow
Once installed, you control the mod through chat commands prefixed with /mclocate. Here are the most important ones for your seed-recovery workflow:
/mclocate pillars: Reads the ten End pillar heights. This is the most powerful data point, as it narrows the seed space down significantly./mclocate bedrock [radius]: Samples bedrock in a square around you in the Nether. The default radius is 24 blocks, with a maximum of 128./mclocate auto on: Turns on passive collection for bedrock, pillars, and eyes./mclocate status: Shows what your session currently holds and estimates how many seeds are left standing./mclocate export: Writes all collected observations to a timestamped JSON file in.minecraft/mc-locate/./mclocate mark <type>: Records a structure at your current position. This supports 21 different structure types, from villages to ancient cities.
The recommended workflow is to visit the End once to capture the pillar heights, turn on passive mode, and then continue playing normally. As you explore the Nether, the mod quietly logs bedrock patterns. When your status shows you have enough data, you export the file and feed it to the CLI. The CLI uses a "Session & Observations" mode to import the JSON and calculate the seed.
The mod also includes a manual slime chunk marker. This is deliberate: a single slime spawn is not proof of a slime chunk, and a false positive would eliminate the true seed. You must confirm a slime spawning below Y=40 away from a swamp before using /mclocate slime.
Conclusion
mc-locate is a brilliant example of community-driven problem-solving in Minecraft. It transforms the tedious and complex task of seed cracking into a passive, background activity. By collecting precise in-game data and exporting it to a powerful CLI, it gives players a legitimate path to recover lost worlds. While it requires a bit of setup with Fabric, the payoff is immense for anyone who values their long-term worlds. Whether you are a technical player or just someone who lost a beloved save, mc-locate is an essential addition to your toolkit. Just remember to check your server rules before using it in multiplayer, and always download the correct jar for your game version.