Install and update instances

An instance is a folder with one modpack’s files. Install and update are the same call, sync.

import modsmith as ms

pack = ms.packs.load("pack.mrpack")
instance = ms.instances.Instance("instances/my-pack")

changes = instance.sync(pack)

The folder is created by the first sync. Modsmith records what it installed in a .modsmith folder inside it.

To add single mods, resource packs or shaders next to the pack, or to start an instance without one, see Add mods and packs. A sync keeps those additions.

Preview changes

diff shows what a sync would do, and changes nothing:

changes = instance.diff(pack)

print("New:", changes.added)
print("Updated:", changes.updated)
print("Removed:", changes.removed)
print("Changed by the player:", changes.conflicts)
print("No longer in the pack:", changes.orphaned)

Player changes are kept

If a player edits a file and the pack also changes it, sync keeps the player’s version and lists the file in changes.conflicts. New files they added are never touched.

To replace their changes instead, ask for it:

instance.sync(pack, overwrite=True)

Tip

Show changes.conflicts to the player and let them choose, rather than passing overwrite=True by default.

What was installed

state = instance.state
if state is not None:
    print(state.pack_name, state.pack_version, state.synced_at)
    print(state.minecraft, state.loader_kind)

state is None if the folder is not an instance yet. pack_name and pack_version are None for an instance made with Instance.create.

Choose what to install

instance.sync(pack, include_optional=True)

Use side="server" to install a server’s files instead of a client’s.

If a sync fails

A failed sync leaves the instance as it was. Run it again, and it continues with the files it already downloaded.

Close the game before you sync. On Windows, a running game locks its mods, so the sync stops and raises modsmith.errors.InstanceError. How sync works has the details.

Delete an instance

instance.delete()

delete removes the whole folder, including the player’s saves. It refuses to delete a folder that Modsmith did not install.