Fees and tariffs

You pay per successful sweep: its gas plus a fee, both in the chain’s native coin, from your gas wallet. There is no subscription. Your exact rates are in your tariff, GET /v1/tariff.

Token sweeps

For a token, you pay the larger of two amounts: the gas of the sweep, or X of what the same sweep would cost the classic way. The fee is the difference:

fee = max(0; X × classic benchmark − gas of the sweep)

• X is your rate on the chain, rate_bps in the tariff: the standard is 70% (7000). BSC has no service fee: there X is 0 and you pay only the gas.
• The classic benchmark is the gas the same sweep takes the classic way: send the deposit address gas, then transfer the token from it. It depends on the chain, the token and the kind of sweep.
• The gas of the sweep is its share of the batch transaction (below).
• Everything is counted in gas and multiplied by the batch’s gas price, so no exchange rate is involved.

If our gas is below X of the classic cost, you pay exactly X of the classic cost. If it is not, you pay only the gas, with no fee. The fee never makes a sweep cost more than the classic way.

Native coin sweeps

The classic way needs no top-up to move ETH or BNB: the deposit address pays the gas with the coin itself, and a plain transfer takes 21,000 gas. So a native coin sweep costs its gas plus a markup M, native_markup_bps, and never more than that plain transfer:

fee = min(M × gas; max(0; 21,000 − gas))

The gas of a sweep

A batch is one transaction, and the chain does not report the gas of each address in it. The batch gas is shared out like this:

• the first sweep of an address carries the cost of setting its delegate, by the table in extra_gas of the tariff;
• the rest is split evenly between all the addresses of the batch.

The shares add up to the gas of the transaction. A sweep that failed on chain bears its share but no fee; a sweep rejected before sending bears nothing. Revocations cost only their gas, with no fee.

Example

Sepolia, X = 70%. A batch of 50 addresses: 10 first sweeps of addresses that held only tokens (first_new) and 40 repeat sweeps.

	Gas of the sweep	Benchmark	70% of it	Fee	You pay
first_new	243,687	237,233	166,063	0	243,687
repeat	18,078	53,633	37,543	19,465	37,543

For the whole batch you pay 3,938,590 gas against 4,517,650 the classic way, 13% less. Each repeat sweep costs 30% less than the classic way.

First sweeps on Sepolia

Sepolia already runs the Glamsterdam gas rules (EIP-8037), under which the first code on an address that holds only tokens costs about as much as the classic first top-up. Such a first sweep carries no fee, but its gas alone can be a few percent above the classic cost, as in the table. The savings come from repeat sweeps of the same addresses.

Check every fee

Each swept sweep, in GET /v1/sweeps/{id} and in its webhook, carries what its fee was computed with:

Field	Meaning
kind	repeat, first or first_new
gas	the sweep’s share of the batch gas
classic_gas	the benchmark
rate_bps	the rate: X, or M for the native coin (7000 = 70%)
gas_cost, fee	gas and fee in wei

The gas price is that of the transaction tx_hash. For a token:

fee = max(0; rate_bps × classic_gas / 10,000 − gas) × gas price

and for the native coin:

fee = min(rate_bps × gas / 10,000; max(0; classic_gas − gas)) × gas price

Where the fees go

Fees accrue on your gas wallet as fees_due in GET /v1/balance, and are withdrawn from it periodically. Until then they stay in reserve and are not spent on gas: available is the balance minus fees_due, what is left for gas. If the gas wallet holds little beyond the fees due, sweeps wait for a top-up.

Your tariff

GET /v1/tariff shows, for each chain:

• rate_bps and rate: X for tokens;
• native_markup_bps and native_markup: M for the native coin;
• classic_gas: the benchmark of each asset, new for an address without an account on the chain and existing for one with an account;
• extra_gas: what a first sweep adds, for the delegation and for creating the account.

Benchmarks are measured per chain and revised when a hard fork changes gas costs. The rates of your account are agreed with us; the testnets charge them in test coins.