The unit: 1 NCU
1 receipt = 1 NCU = one hour on the reference A100 80GB, measured by a fixed benchmark, not a spec sheet. Other cards count by their benchmark result: a faster card burns more NCU per hour, so one receipt lasts fewer minutes on it.
| Card | NCU per hour | 1 NCU lasts |
|---|---|---|
| A100 80GB | 1.0 | ≈ 60 min |
| H100 | 2.3 | ≈ 26 min |
| RTX 4090 | 0.9 | ≈ 67 min |
hours = receipts ÷ NCU per hour of the card
= N × 10,000 ÷ ncuPerHourBps120 NCU on an H100 runs for about 52 hours. On an RTX 4090, about 133 hours.
The rate of an existing card type never changes, so what you bought stays what you bought. New card types are added by the owner through a 7 days timelock.
Quarterly series
Every receipt belongs to a quarterly series, like Series 2026-Q4. Each series is its own ERC-20 token, shared by all providers. One token is one receipt; there are no fractions. Sending a receipt is a plain ERC-20 transfer with no fee and no hooks.
| Phase | When | What works |
|---|---|---|
| Open | 30 days before the quarter → 7 days before its end | List, buy, redeem |
| Closing | last 7 days of the quarter | Redeem; no new sales |
| Ended | after quarter end | Open redemptions close out |
| Finalized | after finalization | Settle in USDG |
Minting and buying
A provider lists N receipts at price P in USDG and locks a listing escrow of 130% of their value. Receipts are minted only when someone buys them, so every receipt in circulation has a known on-chain sale price.
listing escrow = 1.30 × N × P
collateral on a sale = 1.30 × n × max(P, ref)
provider receives = n × P − 1% mint feeIf the series reference price is above the listing price, the difference in collateral is taken from the provider's free collateral; if there is not enough, the purchase reverts. Once a series has a risk price, listing prices must stay within ±20% of it.
Reference price
The reference price (ref) is the average price the series' receipts were sold at, weighted by volume. Only primary sales move it. Secondary trading does not. After listings close, it is fixed for the rest of the quarter.
ref = total USDG paid in primary sales ÷ receipts sold
w_p = min(sold_p ÷ total sold, 40%)
ref = Σ (w_p × average price_p) ÷ Σ w_pRisk price. Collateral checks, flags, liquidations and the listing band use a smoothed risk price. It follows the reference price but moves at most 5% per day, so one large purchase cannot push other providers into liquidation overnight.
The reference price itself sets the redemption fee, the redemption reserve, the missed-start payout and the quarter-end settlement.
Collateral and health
Each provider's collateral is held separately, per series. Part of it is reserved for open redemptions; the rest is free. Health is measured against the free part only.
free = collateral − reserved
CR = free ÷ (outstanding receipts × risk price)| Line | Value | What happens |
|---|---|---|
| Mint | 130% | Every receipt sold is backed by 130% of its value in USDG |
| Maintenance | 115% | Below it, anyone can flag the provider. Flagged providers cannot list or sell |
| Grace | 24 hours | If CR is still below 115% after the grace period, liquidation opens |
| Withdraw | above 130% | Only collateral above 130% can be withdrawn |
Why 115%: it is the receipt's value plus the 15% missed-start penalty. At the top-up line, collateral still covers the worst case on every receipt.
A provider holds $1,820 of collateral against 1,000 receipts sold at $1.40.
Top-up line by price: 1,820 ÷ 1.15 ÷ 1,000 = $1.58 (about 13% above $1.40).
At a risk price of $1.60: CR = 1,820 ÷ 1,600 = 113.75%, below 115%.
Back to 130%: 1.30 × 1,600 − 1,820 = $260 to top up.
Liquidation
Liquidation opens when three things are true: the provider is flagged, the 24 hours grace period has passed, and CR is still below 115%. There is no liquidation once a series has ended.
A liquidator burns K receipts of the series from their own wallet and receives their value at the risk price plus a 5% bonus, from the provider's free collateral. K is capped so the provider is brought back to 130%, not emptied.
liquidator receives = K × risk price × (1 + 5%)
K_max = ceil((1.30 × O × r − free) ÷ ((1.30 − 1 − bonus) × r))If free collateral is at or below 1.05 × outstanding × risk price, every outstanding receipt can be liquidated. If there is not enough left to pay the full amount, the liquidator receives a pro-rata share and decides whether it is worth it.
Redemption
To redeem, you pick a series, a number of receipts, a card and a provider. Your job spec is encrypted to the provider in your browser; only its hash goes on-chain.
receipts burned = N
redemption fee = 1% × N × ref (paid by the holder)
reserve = N × ref × 1.15 (locked from provider collateral)
start by = now + 30 minutes
job length = N ÷ NCU per hour of the cardStart confirmed
The provider starts the job and confirms it on-chain before the deadline. The job then runs for its full length, and a dispute window stays open until 2 hours after it is due to end. If nobody disputes, anyone can release the reserve back to the provider's free collateral afterwards.
Start missed
If the provider does not confirm within 30 minutes, anyone can trigger the payout. The holder gets the whole reserve: the receipts' value plus 15%. No arbiter and no approvals are involved. The redemption fee is not refunded; the 15% penalty is the compensation.
Redemption fee: $9.60.
Job length: about 261 hours.
If the start is missed, the holder receives $960 of value and $144 of penalty: $1,104 in total.
Disputes
A dispute covers two cases: the provider confirmed the start but the job never ran, or the job was stopped early. The holder can open one at any time from the start confirmation until 2 hours after the job is due to end, with a bond of 5% of the receipts' value so that baseless disputes cost something. Evidence is uploaded in the app; it is not written on-chain.
Disputes are resolved by the Tally team multisig in v1.
The arbiter has 7 days to decide (the team aims for 72 hours). The holder receives their share of the reserve and the rest goes back to the provider. If the holder receives anything, the bond is refunded; if not, the bond goes to the provider. If the arbiter does not decide within 7 days, anyone can close the dispute and the holder receives the full reserve and the bond.
The arbiter can only decide open disputes. It cannot move collateral, change parameters or create a dispute.
Quarter end
Receipts that are never redeemed settle in USDG after the quarter ends. Finalization starts once the series has ended and no redemptions are open. Every open redemption can be closed by anyone, so nobody can block finalization.
to settlement pool = min(outstanding × ref, free) per provider
payout per receipt = min(final ref, pool ÷ total supply) rounded downSettling burns your receipts and pays the payout per receipt in USDG. There is no fee and no deadline, and the order in which holders settle does not change the amount.
100 receipts at a final reference price of $1.55: $155 to you.
Fees
| Action | Fee | Who pays |
|---|---|---|
| Mint (primary sale) | 1% | Provider, from sale proceeds |
| Redeem | 1% | Holder, on N × ref |
| Hold | Free | — |
| Send or sell | Free | Plain ERC-20 |
| Settle at quarter end | Free | — |
Fee rates are constants in the contracts and cannot change after deployment. Fees go straight to the treasury.
Worked example: Series 2026-Q4
Two providers, A and B. The card is an H100.
- 1. A sells. 1,000 receipts at $1.40: $1,400 of sales, a $14 mint fee, $1,820 of collateral (130%). ref = $1.40.
- 2. B sells higher. Later, B sells 2,500 receipts at $1.68. ref = (1,400 + 4,200) ÷ 3,500 = $1.60. B's collateral is 130% of $1.68. The risk price catches up with ref over a few days, at most 5% a day.
- 3. A tops up. When the risk price reaches $1.60, A's ratio is 1,820 ÷ 1,600 = 113.75%. A is flagged, tops up $260 and is back at 130%.
- 4. A holder redeems with A. 600 receipts on H100: a $9.60 fee, about 261 hours of compute, a $1,104 reserve. A confirms the start. Nobody disputes, so 2 hours after the job ends the reserve goes back to A's free collateral.
- 5. Quarter end. A has 400 receipts outstanding, so 400 × $1.60 = $640 moves to the settlement pool. Holders of those receipts get $1.60 each, as long as the series has no shortfall.
Risks
Self-purchase can move the reference price
A provider can buy its own receipts to push the reference price. It costs the provider the 1% mint fee, and the purchase money comes back to the provider. Three limiters cap the effect: listing prices must sit within ±20% of the risk price, the risk price moves at most 5% a day, and with three or more providers one provider weighs at most 40% in the reference price. Within those limits the risk remains: a provider willing to pay fees can still shift the price used for redemption fees, missed-start payouts and settlement.
Bad debt is shared equally
If a provider's free collateral runs out while its receipts are still outstanding, other providers' collateral does not cover the gap. The contract does not hide it: at finalization the settlement per receipt is reduced equally for every holder of that series.
Disputes depend on people
Disputes are resolved by the Tally team multisig in v1. The missed-start payout needs no one's approval, but whether a started job really ran is decided by the arbiter.
No external audit
The contracts are open source and verified. They have not been externally audited. Bugs in smart contracts can lose funds.
USDG can be frozen or paused
Collateral, payments and settlement are in USDG. Its issuer can freeze addresses and pause transfers. A frozen provider address, or a paused token, can delay or block payouts, withdrawals and settlement.
Prices move
The market price of a receipt can fall, for example when GPU prices fall. An hour stays an hour, but Tally makes no promise about the future price of a receipt. Read the full risks page before you buy.