Manage Your Land

Once you own parcels on merca.earth, the real work begins: growing your territory, collecting revenue, and maintaining your portfolio.

Your Land Portfolio

All your parcels appear in the Polygon List sidebar under "Registered Geometry." Each card shows:

• Polygon ID — truncated on-chain identifier, linked to the block explorer.
• Area — total area in square meters or square kilometers.
• Parts and vertices — convex parts count and total vertices. Complex shapes need more parts.
• Price per square kilometer — base price times the parcel's premium multiplier.
• Buyout price — what another user would pay to force-purchase.

Click any parcel in the list or on the map to open the Selected Parcel Panel with options to expand, collect taxes, edit metadata, or remove.

The "Mine" badge marks your parcels. Others show the owner's address and a "Buy Parcel" button.

Tax Obligations

merca.earth uses a Harberger-inspired tax model. When someone registers or buys a parcel, a portion of the payment enters a hierarchy pool:

Destination	Share
Seller (or treasury on first registration)	85%
Protocol treasury	7%
Hierarchy pool	8%

Pool funds flow into tax buckets — time-bucketed escrow records on the parcel's on-chain polygon. These accrue over configurable epoch windows and become claimable by owners of parent-level parcels that geographically contain the taxed parcel.

What happens if you do not collect

Tax buckets have an expiry window. If the parent-level owner does not collect before expiry, anyone can call sweep_expired to return uncollected funds to the treasury. Expired buckets carry no penalty for the child parcel owner — the obligation falls on the parent.

Self-claimable balance

Some tax flows accumulate directly into a self-claimable balance on your parcel — this happens when no eligible parent collector exists. Withdraw this balance any time through "Collect" on the Selected Parcel Panel or "Withdraw All" in the wallet.

Expand Your Parcel

Expansion grows a parcel into adjacent unclaimed space without registering a separate polygon.

How to expand

1. Select your parcel on the map or sidebar.
2. Click Add Slice in the Selected Parcel Panel, or the + button on the sidebar card.
3. Draw the new territory. The shape must attach to your existing parcel boundary — it cannot be disconnected.
4. If the drawn area falls entirely on unclaimed land, the app treats it as an expand_unclaimed operation.
5. Review the preview: new combined shape and cost for the added area.
6. Confirm and sign the transaction.

Pricing

You pay only for the added area: $P = \Delta A \times R$, where $\Delta A$ is the new area and $R$ is the level's base rate. Your parcel's premium multiplier does not change.

Constraints

• The expanded shape must remain a single connected region without holes.
• Total area must stay within the level's min/max limits.
• The new geometry must decompose into valid convex parts under multipart rules.

Rebalance Between Your Parcels

Rebalancing moves area from one of your parcels to another adjacent one you also own. No land cost — you already own both.

How to rebalance

1. Select the receiving parcel (the one to enlarge).
2. Click the R button on the parcel card to enter counterparty-selection mode.
3. Click the adjacent donor parcel you own. The donor must share an edge with the receiver.
4. Draw the slice to transfer from donor to receiver.
5. Review the preview showing updated shapes for both.
6. Confirm the transaction.

Premium behavior

After rebalance, both parcels adopt the higher of the two premiums. This prevents premium arbitrage by reshuffling area between a high-premium and low-premium parcel.

Requirements

• Both parcels must belong to you.
• The parcels must be adjacent (share at least one edge segment).
• Both resulting shapes must remain valid single-region polygons within area limits.

Acquire a Slice from Another Owner

Acquisition takes a piece of a neighboring parcel that belongs to someone else. You pay for the captured area.

How to acquire

1. Select your receiving parcel.
2. Click the A button on the parcel card to enter counterparty-selection mode.
3. Click the adjacent foreign parcel. It must share an edge with yours.
4. Draw the slice to capture.
5. Review the preview. Cost is based on captured area and the donor's current pricing.
6. Confirm and sign. The donor shrinks, yours grows, and the donor's owner receives proceeds via the standard fee split.

Premium behavior

Your receiver's premium stays unchanged. The donor's premium increases proportionally to the fraction of area captured.

Claiming Tax Revenue

If you own a parent-level parcel that geographically contains child-level parcels, you earn tax revenue whenever those children are involved in transactions feeding the hierarchy pool.

How to collect

1. Select your parent-level parcel.
2. The Selected Parcel Panel shows a Taxes section. If collectable buckets exist, the total appears with a "Collect" button.
3. Click Collect. This executes collect_and_withdraw, batching up to 20 buckets, collecting the tax, and transferring SUI to your wallet.

Withdraw All

The Wallet Panel offers "Withdraw All" to aggregate self-claimable tax across all your parcels in a single transaction.

Monitoring your revenue

The parcel detail view shows:

• Child polygon count contained by your parcel.
• Opened tax buckets targeting your level.
• Collectable bucket count and total amount.
• Expired (sweepable) buckets you missed.

Watch expiry windows. Uncollected buckets become sweepable by anyone, returning funds to the treasury.

Removing a Parcel

Click the trash icon on the sidebar card. The on-chain remove function:

1. Cleans up the parcel's PriceState record.
2. Sweeps remaining tax buckets.
3. Removes the polygon from the spatial index.

Removal is irreversible. The land becomes unclaimed and available for anyone to register.

Summary of Operations

Operation	Cost	Requires Adjacent Parcel	Changes Premium
Expand unclaimed	Pay for added area	No (unclaimed space)	No change
Rebalance slice	Free	Yes, your own parcel	Both adopt max premium
Acquire slice	Pay for captured area	Yes, foreign parcel	Donor premium increases
Collect tax	Gas only	N/A	No change
Remove parcel	Gas only	N/A	N/A