Minecraft Java¶

Minecraft Java is the recommended first Swarm Hosts game. It uses TCP, stores worlds and configuration under /data, and supports managed settings, version changes, modpack profiles, imports, backups, player statistics, Server Actions, an optional BlueMap live web map, and bounded helper bots. Linux and Windows 10/11 hosts provide the same management features; Windows requires Docker Desktop in Linux-container mode.

Requirements¶

For a small vanilla server, start with:

• 2 CPU cores;
• 4 GiB Swarm Server memory;
• enough free disk for the selected version, world, logs, and backups; and
• an assigned TCP port reachable directly or through an available relay.

Large view distance, simulation distance, modpacks, farms, and high player counts need more CPU and memory.

Launch¶

1. Choose Minecraft Java.
2. Select a Swarm Host or Swarm Zone.
3. Set CPU and memory limits.
4. Choose the Minecraft version and server type offered by the launch form.
5. Set the server name, server message, player limit, game mode, difficulty, and other Minecraft settings.
6. Keep Authenticate with Mojang enabled for a normal public server.
7. Optionally select Review compatibility to check the non-secret Minecraft settings, game image version, and selected managed content together.
8. Read the Minecraft EULA before launching. The managed server starts with EULA acceptance enabled.
9. Wait for the Minecraft protocol check before inviting players.

The compatibility review is advisory and read-only. It excludes passwords and does not create a server, reserve capacity, stage data, launch, or apply content. Changing a reviewed setting, version, or content selection clears the displayed result; run the review again. If a saved template, managed version, or content revision is no longer current, reload the current choices before reviewing again.

A compatible result describes the inputs checked by that review. Changes made elsewhere may not clear a result already displayed in your browser. Launch is a separate action that revalidates the current inputs, access, and host capacity, and launch or runtime checks can still fail.

The Swarm Server page shows the assigned player endpoint. Share that endpoint, not the container's default port.

Connect¶

In Minecraft Java:

1. choose Multiplayer;
2. choose Add Server or Direct Connection;
3. enter the host and assigned TCP port shown by Swarm Hosts; and
4. join after the Swarm Server reports running and the Minecraft protocol check is healthy.

For direct home hosting, forward the assigned TCP port to the Swarm Host. A managed relay, when offered, provides the public endpoint shown on the Swarm Server.

Minecraft settings¶

Open the Swarm Server, choose Settings, then Minecraft Java Settings. Managed settings include:

Saving managed settings queues a redeploy or restart. Swarm Hosts conditionally updates only the file values you changed. Connected players are disconnected, so announce the maintenance window and keep a recent backup. Saving settings on a stopped server starts it.

Use Safe presets to choose matching memory and player-limit values for common server sizes. A preset does not bypass validation and is disabled when the Swarm Server does not have enough memory for the requested Java heap and runtime overhead.

After initial provisioning, server.properties is authoritative. File Manager edits survive restarts, including keys also offered in the UI. The settings page reads the current file; it does not reuse the previous UI values. If the file changes after you open the page, reload before saving. Runtime options such as Java memory and loader selection remain launch options.

BlueMap live web map¶

BlueMap is an optional interactive 3D and flat browser map. Swarm Hosts installs the newest compatible BlueMap build through Modrinth when the Swarm Server starts. It supports Paper, Purpur, Fabric, Forge, and NeoForge on Minecraft 1.13 or newer. Vanilla and Quilt deployments cannot enable it.

To use it:

1. create a recent backup;
2. open Settings → Minecraft Java Settings;
3. enable BlueMap live web map and review the player privacy settings;
4. save the settings and allow the Swarm Server to restart; and
5. open Live Map from the Swarm Server navigation after its reachability badge reports ready.

The map has a separate assigned TCP endpoint. Swarm Hosts selects the relay map port when a relay route is active and otherwise uses the Swarm Host's public address. Do not share a private backend address. The BlueMap HTTP check is separate from the Minecraft player-protocol check, so a map outage does not make a healthy game server look offline.

The managed defaults provide:

• server-sent tile and marker updates on compatible BlueMap releases;
• regularly updated live player locations and skins;
• hidden spectator, vanished, invisible, and sneaking players;
• configurable underground-player privacy;
• Nether and End maps when those dimensions exist; and
• one background render thread that pauses at 10 online players by default.

The initial render can use significant CPU, storage, and disk I/O on a large or old world. Keep the default render pause for busy servers, watch free disk space, and let the first render run during a quiet period. All BlueMap configuration, web assets, and rendered map data remain under /data, so normal Swarm Hosts backups and migrations preserve them.

The map URL is a public web endpoint; BlueMap does not add Swarm Hosts login protection to it. Anyone who can reach that URL may see the rendered world and any player markers allowed by your settings. Disable live players—or disable BlueMap—when that is not appropriate for the community.

Advanced administrators can use Files & Backups to add BlueMap marker files or compatible server-side addons. Static points, shapes, lines, and HTML marker details are supported by BlueMap itself. These advanced files are customer-managed: Swarm Hosts does not currently expose BlueMap marker editing, full rendering, purge, or reload as Server Actions. Avoid editing the managed privacy, web-server, and performance keys in both the UI and the BlueMap files because the UI values are reconciled at restart.

Enabling BlueMap authorizes its required Minecraft client-resource download under the Minecraft EULA. Anonymous BlueMap metrics are disabled. If the map does not become ready, check Activity & Logs for an incompatible server type/version or a failed optional Modrinth download, then restart when the provider is available. The optional download never blocks Minecraft itself from starting.

Server Actions¶

Open Server Tools on a running Swarm Server. Minecraft's action and helper pages are Actions, Give Item, Saved Kits, and Bots. Action forms stay disabled when RCON is off, the server is stopped, or another Swarm Server operation is queued. Bots have their own eligibility rules described below.

Actions¶

Actions use dedicated forms and generated previews. The available tools are:

• Broadcast message;
• Give XP;
• Teleport player;
• Change game mode;
• Heal and Feed;
• Clear inventory;
• Kick player, Ban player, and Pardon player;
• Whitelist add and Whitelist remove; and
• Set weather, Set time, and Set difficulty.

Higher-impact player and access changes require Swarm Server admin permission and confirmation. Each action record keeps its preview, approval decision, generated commands, and result. RCON is enabled by default for managed Minecraft servers; the browser does not accept raw RCON text.

Swarm Server admins can save named presets over supported built-in templates. Editing a preset does not rewrite older action records.

Give Item¶

Give Item searches the Swarm Server-aware item catalog and known player records. Select players, choose an item and quantity, add a reason when policy requires it, review the generated preview, and queue the action.

The page supports:

• vanilla item search;
• fresh server-reported modded item IDs when the Swarm Server provides them;
• player username and UUID records;
• optional structured display names, lore, enchantments, damage, and unbreakable flags on compatible versions;
• recent and favorite items stored in the browser;
• per-Swarm-Server quantity, player-count, allowlist, blocklist, and reason policies; and
• admin approval for policy-sensitive grants.

Raw item-data blobs, raw commands, and client-supplied command previews are rejected.

Fabric 1.21.11 servers can refresh the catalog from the item registry of the currently running server. The refresh is available only while that exact server type and version are running. If the compatible Fabric API is missing, the managed discovery component cannot start, or the server does not answer in time, Give Item keeps the static vanilla catalog and shows the refresh failure. Minecraft remains online; item discovery never becomes a startup requirement.

After adding, removing, or updating Fabric mods, restart the Swarm Server and refresh the catalog before selecting modded items. Swarm Hosts accepts only a current, complete response tied to that Swarm Server; an older or partial item list is not treated as server verified.

When Offline item delivery is enabled, eligible known players with UUIDs can receive a pending grant when they next join. Queue online and offline targets separately so each path has a clear action record. A full inventory keeps the delivery pending for retry or cancellation.

Saved Kits¶

Saved Kits stores reusable single-item presets or multi-item kits. Each kit has a name, quantities, role limits, and a versioned snapshot. Granting a kit expands it into generated item commands for the selected players.

Editing or deleting a kit does not change an older grant record. That record keeps the exact kit snapshot used when it was queued.

Give Item and Saved Kit grants can run now, run once later, or repeat on a fixed interval. Scheduled actions expose their next run and pause, resume, stop, and cancel controls. The selected offline policy decides whether a missed run fails, retries, or waits for the server.

Bots¶

The Bots page offers bounded helpers for private or test Swarm Servers with Authenticate with Mojang turned off:

• Observer: joins without moving, chatting, building, mining, or fighting.
• Greeter: sends one fixed welcome line per helper.
• Patrol: walks a bounded route near its join position.
• Survival helper: may use safe food and armor from its own inventory.

Bots cannot use Microsoft player accounts, target another server, run slash commands, accept free-form chat or code, open containers, or attack players. Use Stop all bots whenever behavior is unexpected. Do not turn off account authentication on a public server only to use bots.

See Minecraft Helper Bots for profile limits, status meanings, and cleanup steps. See Server Actions for the shared action safety model.

Mods & Content¶

When Server Tools → Mods & Content is available, a Minecraft content profile pins one exact supported Modrinth server-pack revision. Build or select a profile, review compatibility, save the revision, and apply it to the Swarm Server. Saving a profile alone does not change the running server.

For manual mod or plugin files:

1. create a backup;
2. stop the server;
3. upload the files to the location expected by the selected server type;
4. start the server;
5. inspect Activity & Logs; and
6. join once with a real client.

Keep the Minecraft version, loader, server pack, and individual mods compatible. Do not mix files from a working profile with unrelated manual loader changes without a tested recovery point.

Import an existing world¶

Open Server Tools → Import World. Choose a world or full server folder on your computer, then select Upload to swarm host. For a folder already on the Swarm Host, use Advanced/manual swarm-host path and Preview import.

Review the detected world, settings, size, warnings, and errors. When the preview is ready, confirm replacement and choose Import and replace. Swarm Hosts creates a safety backup before replacing the server data. Finish any queued server operation before changing the import state.

After import:

1. wait for the server to become ready;
2. confirm the world name and spawn;
3. verify player data, inventory, dimensions, and important mods;
4. inspect logs for conversion or loader errors; and
5. keep the original source copy until real-client validation is complete.

Player Analytics¶

Open Server Tools → Player Analytics to review player counts, playtime, activity, gameplay totals, and server performance. Search or select a player for an individual report, explore vanilla statistics, or download the player report as CSV.

Gameplay totals come from Minecraft's saved statistics files and can lag behind live activity. Session and returning-player metrics are estimates based on Minecraft's cumulative games-quit counter. The page's Transparent coverage section shows which data sources are available; this dashboard does not collect or show player IP addresses or geolocation.

Files, backups, and versions¶

Use Files & Backups to browse /data, edit text configuration, upload files, create restore points, schedule backups, and restore or migrate a world.

Use Settings → Version Management for a managed Minecraft version change. Keep the safety-backup option enabled. After the server reports ready, verify the running version, inspect logs, and join once. If the version change fails and the recovery point is still available, use the offered rollback action.

Recover a failed or stuck Swarm Server¶

Open the Swarm Server's Help page and use the suggested common fix when one is available. Depending on state and permissions, Swarm Hosts may offer a safe retry, start or restart, unused-image cleanup, agent update, or redacted support report.

Before forcing deletion or restoring data:

1. preserve the visible error and recent log lines;
2. check that the Swarm Host is online and its container runtime is ready;
3. confirm enough disk and memory are available;
4. check backup health; and
5. use the Support Checklist if the safe repair does not resolve the problem.