The contracts

Five Soroban contracts, written in Rust. Three of them carry the deal. The other two feed it data.

Contract	What it does
note-token	One instance per class. Holds the notes, the holder registry and the day weights used to split coupons on transfer.
abs-deal	The deal itself: the subscription escrow, the closing, the waterfall, the reserve, the carry.
paying-agent	Receives each class aggregate and pushes stablecoin to every holder.
rate-oracle	Publishes the EURIBOR 1M fixing on chain.
asset-nft	The tokens describing the vehicles, batteries, obligors and the pool.

note-token

A note token has zero decimals, so a note cannot be split. It has no burn function and no mint after issuance is finalized. There is no deposit, no withdrawal, no redeem and no price.

It keeps the list of holders so the paying agent can iterate it, and it keeps an accrual ledger for the coupon split. The ledger is lazy: a transfer freezes the seller's weight for the periods they slept through and starts the buyer's, in constant time, without walking the holder list.

abs-deal

This is the contract the deal lives in. Its states run Funding, Amortizing, Enforced, Matured, with Aborted if the funding window fails.

During funding it escrows subscriptions and refunds cancellations. close() performs the delivery versus payment: proceeds out, notes issued, reserve funded, all in one transaction, with a balance assertion at the end.

After closing, distribute(period, collections) runs the waterfall described in the priority of payments. The authoritative number is the outstanding nominal per note. The note factor is derived from it, never stored independently, so the two can never disagree.

paying-agent

The waterfall hands this contract each class aggregate, interest and principal together. It then pays holders.

push_batch is permissionless: anyone can call it, and it processes up to ten holders per transaction with a cursor so it can be resumed. If a transfer fails, for example because the recipient has no trustline, the amount is recorded as claimable and the holder can take it whenever they want. Per holder, the contract tracks interest and principal received separately.

rate-oracle

Class A pays a floating coupon, so the deal needs the EURIBOR 1M fixing. No third party publishes that fixing on Stellar. Reflector and RedStone publish crypto asset prices, not bank reference rates. So a relay signs the EMMI fixing into this contract, and the waterfall reads it at distribution time with a staleness check.

What the contracts check about themselves

Three invariants hold on chain, and a transaction that would break one fails:

• the deal contract's balance equals the reserve plus the carry
• the paying agent's balance equals the allocations plus the claimables plus the rounding dust
• stablecoin is conserved across a distribution: nothing is created, nothing disappears

Tests

62 tests across the workspace. They cover the arithmetic, not the plumbing: the per note rounding vector from a real prospectus (190.99 per note, 5,000 notes, 954,950.00 paid, 49.39 carried), the reserve release and refill cycle, the enforcement switch, the atomicity of closing, the coupon split on a mid period transfer, and the conservation of stablecoin.

cd contracts && cargo test --workspace

Addresses on the test network

Deal 1, amortizing:

abs-deal	CB3S3NWG7IUKUBAWAAJPFKVMCIMTRJ73GHZX6YZASRMZPVUGYFLCATJ4
Class A note	CBHFKNK7UK6YBVXZUWPOMY6LK44FZJSKWHPF4HJBUBV64KC455IJDROK
Class B note	CDRPAMGBJ6BSRQZE5M56DYCFZW7ODPFVCYLT4AA2OQGIUIDHPCTRBU3O
Class C note	CB3IK7HZQMZZG4GIYOEUPRUEIDUP54MIHXIBYLLAM4QUKHB7H7MYIOQJ
paying-agent	CAXBYHZVHXOP3HQCMXPPVZMDUYEO27CTQQQDMWVNMMGSRCBSJHGIARZW
rate-oracle	CAAOMPQADAW34FU4VUXDUHS6RDF6SVGCTK4S2T2YONIKNQA22IBYA72X

Deal 2, open for subscription:

abs-deal	CBVCKQH6CSGRS5W7SYZAJJ3MH5QUWNX7HKWTSLXK4YHPOSY3YZJ2I7AP
Class A note	CAXW4LVJEJL4A4S7WH5VZOMITJDUXFXIPYDRX7MJF64HLYO6X3JMNZEP
Class B note	CAXTFDN7ATWS4MJALVOLOWWQAAEOAIWGGKQ2N3XSQKEGKKDE6B7V7E6S
Class C note	CCCFVGMXJE2ZM22CP56BPQBO56I5PN5X4IB6Y2RFK2X2E2FNYLL4NEAF
paying-agent	CCD2G6GCWW77RKX3Y4JXUOSNPD7NUAH5Y46SLV64AVACUYR5HZT7E7N4

Settlement is in EURC, issued on Stellar by Circle. The test network contract is CBEO2RDQKBM7S3TYOYKBWAJEC6WMYPCW6JJWX47UCLFMUJI2EUZPJOXW.