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zeromev API usage guide

The zeromev REST API allows you to get transaction level MEV summary data for the Ethereum blockchain.

Please read the data sources & limitations page before using the API and take note of our terms of service.

access

The endpoint and schema can be found at

Each MEV transaction has an mev_type.

type	description
arb	an arbitrage transaction allowing the extractor to profit from price discrepancies between exchanges.
frontrun	the frontrun transaction in a sandwich. This initiates the attack and moves the price against the victim.
sandwich	a victim transaction in a sandwich. There can be one or more of these per attack.
backrun	this is the backrun in a sandwich, allowing the attacker to close their position and extract a profit.
liquid	refers to a liquidation event in a DeFi lending protocol.
swap	swaps are included to provide volume data for non-MEV transactions.

Although not strictly MEV, swaps are included in the dataset to allow for MEV vs overall swap volume reports.

Please follow these guidelines for best accuracy:

user_swap_volume_usd refers to the estimated volume of swaps less those which were sent only to extract value.
this is usually the correct value to aggregate in reports like the above.
extractor_swap_volume_usd refers to swaps sent by MEV extractors in order to extract MEV and should only be used when this data is specifically required.
swap volumes are limited to those tokens known to zeromev and for which valid exchange rates can be calculated.
this makes it the most appropriate swap volume data for comparison with our MEV data.
the amount of MEV is greatly underestimated at the moment due to both known and unknown limitations with MEV classification and the lack of cross-domain MEV classification and other MEV types.
as such, please be aware that MEV to volume reports will be lower bound and may be somewhat misleading

where there are multiple swaps in a single transaction for different protocols, these are given a generic protocol value of multiple.
frontruns, backruns, and sandwiched types always have one well defined protocol and are not limited in this way.
arbs are detected as single transactions involving multiple swaps and protocols and their protocol column will be set to multiple.

most extractors will balance the backrun of a sandwich attack with the frontrun to extract the maximum possible risk free profit.
we call these balanced sandwiches.
some sandwiches may be (or appear to be) overweight on either the frontrun or the backrun.
we call these unbalanced sandwiches.
the cause of these is an open research area, but examples include:
- the extractor using the sandwich to take a position at a discounted price.
- the extractor engaging in cross-domain MEV, closing out what appears to be an open position on L1 against a CEX or other chain / L2.
- limitations in the MEV detection involving overlapping attacks or attacks co-mingled with arbitrage as in this example.
zeromev calculates sandwiches in a way that aims to compensate for these imbalances.
an imbalance value is provided through the API to provide visibility of when sandwiches have been re-balanced in this way.
a non-zero imbalance value indicates the sandwich was overweight on that side and needed to be re-balanced.
on a backrun transaction, backrun imbalance = (calculated back out - original back out) / calculated back out
on a frontrun transaction, frontrun imbalance = (calculated front in - original front in) / calculated front in

MEV data has been extracted from block number 9216000 and is updated continuously.

Calls are limited to a maximum of 5 per second.