Costs and timings

All numbers were measured on Preprod in October 2026. The pool holds tUSDM since 2026-10-07; the earlier runs held ADA. The full tables, with every transaction hash, are in the measurements.

What a payment costs

A private payment of 2 tUSDM costs the agent 1 tUSDM on top of the price, and no ADA.

Item	Amount	Who gets it
Relayer fee	1 tUSDM per payout	The relayer. It pays the Settle transaction fee of about 0.70 ADA and attaches 2 ADA to the payout output from its own wallet
Attached ADA	2 ADA, from the relayer	The one-time address. It pays the second leg’s fee of 0.17 ADA and sends the rest to the seller with the tokens
Protocol fee	0	The pool treasury. The Preprod config sets `settle_fee_bps` to 0

A deposit costs 0.18 ADA of network fee plus 1.39 ADA attached to the deposit output, which the crank keeps as its fee. There is no crank fee in tokens, so a 10 tUSDM deposit is credited as 10 tUSDM. An exit costs 0.65 ADA of network fee plus 1.06 ADA attached to the exit output, which stays in the user’s wallet, and no protocol fee.

In the retired ADA pool the agent paid about 1.2 ADA on top of the price: 1 ADA relayer fee and 0.17 ADA for the second leg, both from the note.

Transactions

Transaction, tUSDM run	CPU steps	Memory units	Size in bytes	Fee in ADA
Deposit, 10 tUSDM	none	none	445	0.175
Insert, one deposit	3.09 billion	0.97 million	983	0.676
ASP update	0.06 billion	0.18 million	599	0.215
Settle, one payout of 2 tUSDM	3.26 billion	1.02 million	1,384	0.700
Second leg, one-time address to the seller	none	none	250	0.168
Insert, one change note	2.90 billion	0.83 million	930	0.644
Ragequit, 7 tUSDM	2.87 billion	0.71 million	1,276	0.649

The ADA pool runs had the same shape: Insert about 3.28 billion steps and 0.71 ADA, Settle about 3.29 billion steps and 0.73 ADA, Ragequit about 2.90 billion steps and 0.68 ADA, and a config update 0.08 billion steps and 0.23 ADA. The limit for one transaction is 10 billion CPU steps and 14 million memory units, so every pool action uses about a third of the CPU budget. A Groth16 verification over BLS12-381 is the bulk of it: the two pairings and the scalar multiplications for the public inputs.

Circuits

Circuit	Constraints	Setup power	Proving time	Proving key
`spend`	16,828	2^15	1.5 to 1.9 s	14 MB
`insert`	62,950	2^16	4.3 to 4.8 s	47 MB
`ragequit`	8,423	2^14	1.0 s	7 MB

Proving times are on an Apple M2 Max with snarkjs 0.7.6, with other work running. An agent needs the spend and ragequit keys, 21 MB together. The crank needs the insert key.

Scripts

Script	Size with parameters, in bytes
`pool`	12,659
`config`	1,794
`asp`	1,254
`deposit`	518
`nft`	499

The pool script holds three verification keys as parameters. It fits one publication transaction, under the limit of 16,384 bytes, and its reference output locks 55.5 ADA. A deployment costs about 245 ADA in total: 160 ADA of role funding, 73.6 ADA locked in the four reference script outputs, 8.9 ADA in the three state outputs, and about 1.5 ADA of fees. The locked ADA comes back when the pool is wound down.

Where the time goes

Preprod makes a block about every 20 seconds, but not always. Every step of the flow waits for a confirmation before the next one starts, and most of a demo is that waiting.

Step	Work before submission	Wait for one confirmation
Deposit	1.8 s to build	28 s
Insert of one deposit	14 s to read, prove, build and submit	34 s
ASP update	6 s to read, build and submit	49 s
Settle	2 s to prove, 7 s to verify, build and submit	28 s
Second leg	under 1 s to build	39 s
Insert of one change note	19 s to read, prove, build and submit	23 s
Ragequit	4 s to prove, 6 s to build	33 s

The demo end to end

Step, in seconds	ADA run 1	ADA run 2	ADA run 3	ADA run 4	ADA run 5	ADA run 6	tUSDM run
Deposit submitted	3.6	2.9	3.0	2.8	3.1	2.9	3.2
Note spendable, from the start	119	164	231	91	195	140	139
First leg confirmed, from the payment request	29	27	30	40	40	35	31
Seller answered HTTP 200, from the payment request	116	110	69	78	83	178	76
Change note spendable, after the seller answered	0	6	55	15	9	0.1	24
Exit confirmed, after the change was spendable	20	75	42	21	23	20	133
Whole demo	255	355	396	206	311	338	372

Three waits make up a payment: the Settle block, the funding check, and the second leg’s block. In a normal run that is 70 to 115 seconds. ADA run 6 took 178 seconds because Preprod made no block for 132 seconds after the Settle, and the tUSDM run’s exit waited 154 seconds for a block. ADA run 5 ran next to two proof-making test suites, so its time to a spendable note says nothing about the code.

A deposit becomes spendable after three blocks in a row: the deposit, the Insert and the ASP update. The crank and the ASP service each poll every 10 seconds and retry an idle step after 20 seconds, so the gap between blocks is mostly the chain.

What would make it faster

Mainnet blocks come at the same rate as Preprod, so mainnet is no faster.
Pre-funded one-time addresses would remove the Settle wait from the request path. The agent would settle ahead of time and pay at once. This is not built.
Batching several change notes per Insert already happens, up to 4 per transaction.
Several payouts per Settle, up to 4, would let one proof fund several one-time addresses at once. The validator allows it. The SDK uses one payout today.
A direct handoff, where the seller takes the pool transaction itself, would save the second leg. The specification keeps it experimental, because facilitators differ on script-funded inputs.

Provider requests

An idle node makes about 1,100 to 1,600 Blockfrost requests an hour and a demo run adds 150 to 200. The free plan’s 50,000 a day covers an idle node and some dozens of runs.