Chest Upgrade Mod

Upgrade your chests in place instead of building new ones. Two ways to do it:

1. Chain upgrade: hover a chest, press the hotkey, it turns into the next tier (same spot, same contents) for a fixed material cost.
2. Hammer replace: select any chest piece on your Hammer (any tier — including going down a tier), aim at an existing chest so it's highlighted, and left-click to place like normal. Instead of trying (and failing, since it collides) to place a new chest next to it, that chest is replaced in place, at the normal build cost for the piece you selected. If the new chest is smaller and some items don't fit, they drop on the ground next to it instead of vanishing.

Both features can be turned on/off independently.

Upgrade chain (feature 1)

How to use

Chain upgrade: look at an eligible chest, press U (default). The hover text shows the key and materials needed, green if you have enough.

Hammer replace: equip the Hammer, select any chest piece in the build menu, aim at an existing chest, left-click (the normal build/place click) — it's swapped for whichever chest you had selected, at that piece's normal build cost. Works for upgrades and downgrades alike, no hotkey needed.

Downgrading (e.g. Black Metal -> Reinforced) drops the OLD chest's own build materials on the ground, since replacing it destroys that value — toggle with RefundOnDowngrade.

If both apply at once (you have a chest selected on the hammer while hovering a chest that could also chain-upgrade), the hover text only shows the hammer-replace hint to avoid clutter — clicking replaces, or switch to an empty spot / unequip the hammer and press the upgrade key instead.

Configuration

After first launch, edit BepInEx/config/yumi.valheim.chestupgrade.cfg:

• UpgradeKey — the key to press (default U)
• ShowHoverText — show/hide the hover hint (default true)
• EnableHotkeyUpgrade — turn the chain upgrade on/off (default true)
• EnableHammerReplace — turn hammer replace on/off (default true)
• WoodToReinforced / ReinforcedToBlackMetal — chain-upgrade material costs, in the format ItemPrefabName:Amount,ItemPrefabName:Amount (hammer replace always uses that piece's own normal build cost instead)

Notes

• Runs client-side. Works fine in singleplayer or when everyone in your group has the mod installed.
• Requires BepInExPack Valheim.
• Hammer replace doesn't block/cancel Valheim's own placement click — it just also runs its own replace logic on that same click. In the normal case (aiming straight at the old chest) the old chest's own collider already stops a real new placement from succeeding there, so only the replace happens. Edge case: if a much smaller chest's ghost somehow validates as placeable while still overlapping the old one, you could in theory get both a replace and a real placement on the same click. If you ever see that happen, let me know and I'll harden it further.
• Hammer replace works even if Valheim shows "invalid placement" for the ghost — it doesn't care about that indicator at all, so a chest still gets replaced (materials charged, upgrade or downgrade) as long as you're aiming at it, blocked-looking ghost or not.
• Downgrading with hammer replace: the old chest's own build materials drop on the ground next to it (since replacing it destroys that value), and if an item in the old chest doesn't fit in the new (smaller) chest's inventory, it drops on the ground too instead of being lost.

Feedback

Found a bug or have a suggestion? Comment on my Steam profile: https://steamcommunity.com/id/Yumileashen/ Please mention the mod name (ChestUpgradeMod) plus your issue or suggestion.