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Fees and Gas

When you submit a transaction to Osmosis you pay a gas fee to get it included in a block. This is separate from the swap fees (spread factor + taker fee) that a trade pays to LPs and the protocol, which are already accounted for in a swap quote. This page covers the gas side: the dynamic base fee, estimating gas, and paying fees in tokens other than OSMO.

The dynamic base fee​

Osmosis uses an EIP-1559 style fee market: the minimum gas price adjusts with network congestion rather than being a fixed constant. A transaction whose gas price is below the current base fee is rejected for insufficient fee.

Query the current base fee before setting your gas price:

osmosisd query txfees base-fee
# or over REST:
curl "https://lcd.osmosis.zone/osmosis/txfees/v1beta1/cur_eip_base_fee"
{ "base_fee": "0.030000000000000000" }

Set your --gas-prices at or above this value (in uosmo, or an accepted alternative denom, see below). Because the base fee moves, read it at submission time rather than hardcoding it. Older docs and examples that use 0.0025uosmo predate the dynamic fee market and will be rejected.

Estimating gas​

Set the gas limit from a simulation rather than a fixed number. With osmosisd:

osmosisd tx ... --gas auto --gas-adjustment 1.3 --gas-prices 0.03uosmo

--gas auto simulates the transaction to estimate the gas used, and --gas-adjustment pads that estimate (swaps and multi-hop routes vary, so a 1.2-1.5 pad is typical). Client libraries expose the same simulate-then-pad flow; prefer it over a hardcoded limit, which either wastes fees or risks an out-of-gas failure on a larger route.

The total fee paid is gas_limit * gas_price.

Paying fees in other tokens​

Thanks to fee abstraction, gas does not have to be paid in OSMO. Validators accept a permissionless, governance-managed whitelist of fee tokens, so a transaction can pay gas in many of the assets listed on Osmosis. Accepted non-OSMO fees are converted back to OSMO before distribution to stakers.

To pay in an alternative token, set --gas-prices (or --fees) in that token's denom, for example --gas-prices 0.025ibc/<hash>. The accepted set and each token's minimum price are onchain; query them rather than assuming a token is accepted.

Swap fees are not gas​

Keep the two separate when integrating a swap:

  • Gas fee: paid to include the transaction, sized as above (gas_limit * gas_price).
  • Spread factor + taker fee: charged by the swap itself, already reflected in a quote's amount_out and surfaced as effective_fee. See Swap Integration and The OSMO Token.

Do not double-count: size your token_out_min_amount against the quote's amount_out (which already has swap fees applied), and budget gas separately.