Robinhood Chain gas and fees explained
Robinhood Chain is an Ethereum L2 built on Arbitrum technology, chain id 4663. Gas is paid in ETH, blocks are about 100 ms apart, and a transaction costs a fraction of a cent to a few cents.
Getting ETH onto Robinhood Chain
ETH on Ethereum mainnet, Base or Arbitrum does not count. It has to be bridged to Robinhood Chain first, through the official bridge or a third-party bridge that lists the chain. Holding USDG, NVDA or another tokenised asset does not pay for gas either. The API's insufficient_funds error spells this out because it is the most common first-run problem.
What a trade costs
| Typical gas | At 0.4 gwei | |
|---|---|---|
| Buy on the curve | ~150k | ~0.00006 ETH |
| Buy on Uniswap v4 | ~250k | ~0.0001 ETH |
| One-time approval | ~50-65k | ~0.00003 ETH |
| Swap ETH into a quote asset first | ~200k | ~0.00008 ETH |
What a launch costs
Launching deploys two contracts, so it is heavy: about 4.4 million gas, around 0.002 ETH, plus Pons's 0.0005 ETH launch fee. The API's response includes the exact figures.
Why the wallet needs more than the trade amount
A node reserves gasLimit × maxFeePerGas before running a transaction and refunds what is unused. The API pads the gas limit by 20% and sets the fee ceiling at 1.25× the current base fee, so the reservation is roughly one and a half times what is actually spent. A wallet holding exactly the trade amount plus the expected gas is rejected. The API checks this before you sign, sums the whole batch when there are approvals or swaps in front, and tells you the figure to hold.
A practical rule: keep 0.01 ETH in a trading wallet on top of what you trade with.
Where the fees go
- Gas to the chain.
- Pons's curve fee and creator tax to Pons and the creator, collected by Pons and claimable by the creator - see Claim Creator Fees.
- Uniswap pool fees to the pool, on graduated tokens and on the ETH conversion swaps.
Full list on Fees.