The balance model

A register records what each holder owns. In T-REX a position has three parts, held at two kinds of address, and the token presents two views of it. Distinguishing them is what lets one register serve ERC-20 tooling on the reference chain, compliance rules over the whole distribution, and executions on other chains at the same time.

The three parts of a position

Part	Meaning	Movable by its holder on the reference chain
Free	Held on the reference chain, unencumbered.	Yes
Frozen	Held on the reference chain, immobilized by an agent under the asset's controls.	No
Bridged	Owned by the same holder, with its movement delegated to a satellite chain where the holder transacts.	No. It moves on the satellite, and returns through a recall.

All three are owned by the holder. Freezing or bridging a position changes what can be done with it and where. It does not change whose it is.

Two kinds of address

	On the reference chain	On a satellite chain
Holds	Free and frozen tokens	Bridged tokens
Address	The ONCHAINID itself, or a wallet linked to it	A wallet linked to the identity, on that chain
Identified by	An address	An ERC-7930 interoperable address
Recorded in	The standard ERC-20 balances of the token	The bridged ledger of the token

The bridged ledger is separate for a structural reason. balanceOf is defined over the address space of one chain. A position on a non-EVM satellite cannot be expressed as an address of the reference chain. The bridged ledger therefore uses a format that spans every chain the asset reaches: it is keyed by the hash of the wallet's interoperable address, in its canonical encoding, so one wallet has exactly one entry.

The reference chain records bridged positions. It does not hold them in an escrow address. There is no address on the reference chain whose balance is the bridged supply.

Reading a position

Function	On	Returns
balanceOf(address)	Token	Free plus frozen at that address.
freeBalanceOf(address)	Token	Free at that address.
getFrozenTokens(address)	Token	Frozen at that address.
bridgedBalanceOf(wallet)	Token	The position recorded for a satellite wallet.
availableOf(wallet)	Token	What a satellite wallet can still send: its bridged position less what is reserved.
reservedOf(wallet)	Token	What open validations may still draw from a satellite wallet.
positionOf(identity)	ModularCompliance	Everything the identity owns: free, frozen and bridged, over all its addresses and all chains.

Functions that take a satellite wallet take its interoperable address and revert on an encoding that is not canonical.

Two views, by design

• balanceOf is the standard, chain-local view. It answers exactly as every ERC-20 wallet, venue and indexer expects, for what is present on the reference chain. An application that lends against a position reads it, because it reflects what is movable there.

• positionOf is the global view. Rules that depend on the distribution of the asset read it, and so does any action that has to reach a holder's entire position wherever it is active.

Moving tokens between two addresses of the same identity, on one chain or across chains, changes balanceOf and bridged balances. It does not change positionOf, because the owner is the same.

Inside the bridged part

A bridged position is one number per satellite wallet. While a cross-chain movement is in progress, part of it is set aside.

State	Meaning	Still owned by
Available	Bridged and free to be sent on the satellite.	The holder
Reserved	Promised to a validation that has been issued and not yet settled. It cannot be promised to a second validation.	The holder, until the transfer settles
In transit	Burned on one satellite for a transfer to another satellite whose mint is not yet confirmed. No wallet holds it.	The sender, until the transfer settles

The reservation is what prevents a wallet from obtaining two validations against the same tokens. The in-transit hold is what prevents tokens already burned on a satellite from being validated or recalled again while the second half of a movement is in flight. inTransitOf(validationId) returns the amount held for one validation.

Supply

Quantity	Read with	Meaning
Total supply	totalSupply()	The whole issuance of the asset, wherever it is active.
Bridged supply	totalBridged()	The part active on satellites, in-transit amounts included.
In transit	totalInTransit()	The part of the bridged supply that no wallet holds at this moment.
Native supply	totalSupply() - totalBridged()	What the balances on the reference chain add up to.

Two identities always hold:

• totalSupply = the sum of every balanceOf + totalBridged

• totalBridged = the sum of every bridged position + totalInTransit

Only a mint or a burn changes totalSupply.

What each movement does

Movement	Free	Frozen	Bridged	Total supply
Mint	Recipient up			Up
Burn	Holder down	Down, if the burn needs it		Down
Transfer on the reference chain	Sender down, recipient up			Unchanged
Freeze, unfreeze	Down, up	Up, down		Unchanged
Delegation-out	Holder down		Holder's satellite wallet up	Unchanged
Recall	Holder up		Holder's satellite wallet down	Unchanged
Transfer on one satellite			Sender's wallet down, recipient's wallet up	Unchanged
Transfer between two satellites			Sender's wallet down, then in transit, then recipient's wallet up	Unchanged
Transfer from a satellite to the reference chain	Recipient up		Sender's wallet down	Unchanged

Freezes apply to what an address holds on the reference chain. A bridged position is recalled before it can be frozen.

An example

An investor's identity holds 1,000 units of an asset.

Where	Amount
In the ONCHAINID, free	500
In the ONCHAINID, frozen	100
In a linked wallet on the reference chain	150
In a linked wallet on satellite A	250

Read	Returns
balanceOf(identity)	600
freeBalanceOf(identity)	500
getFrozenTokens(identity)	100
balanceOf(wallet)	150
bridgedBalanceOf(walletA)	250
positionOf(identity)	1,000

The investor requests a validation to sell up to 100 units on satellite A. Until it settles, reservedOf(walletA) is 100 and availableOf(walletA) is 150. bridgedBalanceOf(walletA) is still 250 and positionOf(identity) is still 1,000, because nothing has changed hands yet.

For indexers

A delegation-out debits the holder's balance on the reference chain, and the token emits Transfer(holder, 0x0) for it. A recall, or a transfer from a satellite to the reference chain, credits a balance and emits Transfer(0x0, recipient). This keeps every ERC-20 balance indexer correct without special handling.

The cost is on supply: an indexer that derives the supply by summing Transfer events under-reports it by the bridged supply. Read totalSupply(), or reconcile with the events that name these movements.

Event	Movement
DelegatedOut	Free to bridged, same owner
Recalled	Bridged to free, same owner
SettledToNative	A satellite wallet's position to a recipient on the reference chain
BridgedTransfer	One satellite wallet to another
HeldInTransit, ReturnedInTransit	Into and out of the in-transit state
ReservedForValidation, ReleasedFromValidation	A reservation taken and given back