AutoModpack keeps its files in an automodpack/ folder inside the game directory: the server root for a server, the instance folder for a client. This page writes that folder as ~/automodpack/.
Bootstrap
Bootstrap allows making a very simple user friednly setup for private server, it only requires installing AutoModpack and provide a single file to client, on a first client boot, AutoModpack will install the default selection of a modpack, boot straight into it and keep in sync.
The one-shot client drop-in is ~/automodpack/automodpack-bootstrap.json. Put a copy there, start the game, and AutoModpack imports it and deletes it. AutoModpack must already be installed. The file lives inside automodpack/ because a pack can never write there; the same file name at the instance root is ignored with a warning. If the file includes serverName, the import also creates the entry in the vanilla server list.
/automodpack host bootstrap writes ~/automodpack/automodpack-bootstrap.exported.json. Copy that file to clients as automodpack-bootstrap.json. It is never imported by the instance that wrote it, so running the command on a logical server does not reroute the same instance. An install export contains a provisioning secret, so treat it like a credential.
You edit these
| Path | Role |
|---|---|
server.conf | Server settings |
client.conf | Client settings |
automodpack-bootstrap.json | Client drop-in, imported on launch, then deleted |
automodpack-bootstrap.exported.json | Written by /automodpack host bootstrap, for copying to clients |
host-modpack/<group>/ | Pack files the server itself does not need; the folder name is the group id, and main is the default group |
host-modpack/patch-notes.md | Notes for the next published generation; cleared when it publishes |
host-modpack/waiting-music.ogg | Optional custom waiting track; published into the object store and served like any other pack file |
credentials/certificate.crt | TLS certificate chain |
credentials/private-key.pem | TLS private key, PKCS#8 PEM |
credentials/provisioning-secret | Bootstrap provisioning secret; keep this folder out of support dumps |
credentials/secrets.json | Per-player download secrets; several server processes may share the folder |
recovered/ holds copies you save from the instance timeline. Pack source files belong in host-modpack/, not here.
AutoModpack manages these
Do not edit those manually!
Server runtime: ~/automodpack/server/
| Path | Role |
|---|---|
journal.jsonl | The append-only history of published generations |
current-projection.json | The materialized view of the current generation |
staging/ | In-flight publishes |
data/ | The server's own content store (dedicated servers always keep it here) |
Client runtime: ~/automodpack/client/
| Path | Role |
|---|---|
active/ | The one live projection the game loads from |
history/<modpack-id>/ | The journal mirror for one pack, so pack history works offline |
state-history/ | Instance timeline journal and per-instance tree documents |
overlays/<modpack-id>/ | Player edits that survive generation switches |
generated-copies/, incoming/, backup/ | Update, repair, and loader-copy working state |
selected.json, active-state.json, selections.json, restart-state.json, update-transaction.json, repair.json | Follow pointer (modpackId), installed generation, and in-flight work |
automodpack/helper/, outside client/, is where detached update and repair helpers log their runs.
Content store
Downloaded and hosted bytes live in a content-addressed store, shared across the Minecraft instances of one user:
- Linux:
~/.local/share/automodpack/data, or$XDG_DATA_HOME/automodpack/data - macOS:
~/Library/Application Support/automodpack/data - Windows:
%LOCALAPPDATA%\automodpack\data
A dedicated server keeps its store inside the instance at ~/automodpack/server/data/. A client whose shared root is not writable falls back to its own ~/automodpack/client/data/. Tests and isolated runs can set AUTOMODPACK_DATA_ROOT, or the automodpack.data.root system property; a configured root that cannot be used is an error rather than a silent fallback.
The store contains Git-style objects under objects/, metadata caches, per-pack connection records under packs/<modpack-id>/, and known-hosts.json, the saved certificate pins.
The projection
The selected generation is materialized into the fixed path ~/automodpack/client/active/. Immutable files are hard-linked from the content store where the filesystem allows it, so most packs cost little extra disk space. All editable files keep their live copy in the game directory and use the overlay only after the player changes them.
The game directory receives live copies for files the loader or game must read there, and for every editable file, players included: the standard mods folder gets the AutoModpack loader, loader-required copies, files pinned through pinned-mod-ids, and editable mod jars. Non-editable mods load straight from the projection, so a pack jar only meets the player's mods folder when the pack says the player may touch it. The projection path never changes with generation identity, so switching or restoring a generation rewires one tree instead of juggling one physical tree per pack.
A bad update is also recoverable before the loader sees it: the fix lands in the projection, rather than crashing the game from the standard mods folder.