Using Etherscan’s V2 API to Visualize Multichain Bridging

What do wallets do when they move to L2? An illustration using Etherscan’s V2 API to investigate and visualize cross-chain activities.

This post is also published on Medium.

Ethereum’s second layers (L2s) represent a large and still growing ecosystem allowing cheaper, faster transactions — running on rails tuned by Dencun, Pectra and other upgrades. L2s have seen rapid rise in usage in the past year. Coinbase’s Base L2, for example, now processes 10 times as many daily transactions as L1 itself.

There’s a lot of activity, but what are people using L2 for? We can visit great summaries like L2Beat or even Etherscan’s own Blockscan cross-chain dashboard to check recent bridging between L1 and L2s. 

Below is an illustration from Blockscan in early October. Across Protocol’s optimistic multichain bridge is among the most used bridges, and Blockscan allows you to filter by various bridges such as Stargate or Allbridge. 

From this simple table, you can peruse most recent transactions and get a sense of what people seem to be doing across these bridges, mostly sending ERC-20 tokens such as USDC. You can see the very high frequency of these bridgings, with many happening each minute.

We can take a closer look at these cross-chain activities by retrieving the transactions through Etherscan’s V2 API and mapping them into a transaction graph.

What is API V2?

Etherscan’s API is a powerful tool to access account details, contract information, block stats and of course full transaction details. The V2 API provides a simple but useful feature: we can specify a chain identifier number that tells Etherscan which network to use for the data. 

The endpoint URL can now be easily updated for many supported chains, allowing analysts to nimbly jump from chain to chain and download transactions of interest. With V2, you can quickly scan mainnet and second layer networks and integrate information across them.

For example, we can use the V2 API to get the balance of an address across several chains. Simply specify the chainid in the API call, and you can extract information about addresses with the same API usage across many supported chains. You can also do this with contracts, transactions and more.

To use Etherscan API V2 for the question of L2 usage, I selected a major bridging contract to investigate. I chose Across Protocol, because it recently showed increased activity in the above Blockscan table. 

To sample a set of bridging wallets we download the past few weeks of transactions using the Etherscan API for the Across Protocol on L1 (chainid = 1). We can then decode the input for each transaction in Etherscan API payload. 

I chose the transaction type depositV3 (one of Across’s main contract calls) which has a parameter called destinationChainId telling us where the ETH or ERC-20 token is going. It’s neat to see the transactions encoding their ultimate destinations: Arbitrum, Base, BNB Smart Chain, Optimism, and more.

Visualizing L2 usage

After collecting bridge data through Etherscan’s V2 API, the next step is to visualize how users behave once they move from L1 to L2. I analyzed 1,000 addresses from those that recently used the Across bridge’s depositV3 from L1 to a few L2s (late September / early October, 2025). 

For each address, I gathered transactions right before and right after bridging to each chain by specifying startblock, endblock, and chainid in the Etherscan API to capture recent L1 and L2 activity. In the end, I had about 25,000 transactions representing recent L1 and L2 activity for these addresses.

A network diagram is shown below with lines representing transactions going from the source to target address. I used R, jsonlite and igraph to munge and plot the graph.

I chose three chains that got the most activity from Across Protocol: Base, Arbitrum, and BNB Chain. These are represented below as separate systems with their own transactions. The bright spots are the most frequently used addresses or contracts in this data snapshot. 

The result is a galactic transactional space map:

Zooming In: Some Trends on L2

This is activity for recent wallets using Across in September and October of 2025. It’s a visualization of what wallets seem to be doing recently when crossing into the multichain landscape. We see glowing clusters in the visual, where many transactions are meeting, indicating frequent activity at particular addresses.

In the visual you can sometimes see multiple converging “arcs” between two addresses. This indicates multiple transactions between wallets, and it is quickly apparent that many of these are repeated DeFi-related transactions to exchanges. 

Consider an example on Arbitrum: Wallet 0x5c04ed02 engaged in repeated calls to Uniswap contracts. Many wallets like this one jump to an L2 and engage in repeat calls of DeFi-related or token contracts. We can zoom into the visual above and see this example wallet:

When zooming in on Uniswap on Arbitrum, you can see that it serves as a prominent hub of activity. Among the many wallets we analyze here, many of them are interacting with Uniswap, seen as arrows clustered here entering into the V4 router. Many hundreds of transactions from Across, in just this time frame, flow into Uniswap on Arbitrum. 

Zooming into Uniswap’s position on the visual above:

The same can be said for Base: The most active contract in the data sampled here is Uniswap’s V4 as well, with well over 1,000 transactions of recent Across bridgers flowing into the router.

The USDC contract shows very active use across all chains — especially on Base, shown below. The same trend is present in BNB too, but not shown here — Uniswap’s V4 contracts are the most engaged by these recent bridgers by far with over 500 transactions in the addresses analyzed here.

Zooming in and wandering the broader visual above yields other interesting observations. It is not simply DeFi alone that draws activity. L2’s cheaper cost of transaction permits playful gaming. One of the clusters reveals other applications, like this one:

Looking at the code for this contract we see it’s part of a gaming platform on Base. That glowing activity is Base contract 0x72a3d56 and appears to be a coordinating contract for a “CLOAKs battle system.” The Etherscan V2 API helped us to visualize and identify this cluster of activity, and searching for it online yields fun new opportunities that mix DeFi rewards and onchain battles.

Coincidentally, soon after discovering this interesting onchain activity, the CLOAKs app completely closed operations. All that's left is a website with a brief note and a voucher contract on Base:

Conclusion

With the V2 API, we were able to visualize L2 usage as a kind of galactic map of activity. Zooming in on some bright spots yields a clear trend: DeFi dominates, but intriguing new use cases are made possible like onchain gaming and tournaments.

In sum, Etherscan’s V2 API opens up rich data to wander L2 usage. Analysis like this can supplement tabular data such as on Blockscan or L2Beat. 

One thing you can do with Blockscan as well is filter cross-chain transactions by a target wallet to inspect their activity. You can use Etherscan’s API to get the most frequent bridging wallets, then narrow the Blockscan table to these and inspect their usage. V2 API also introduces a new endpoint that lists all bridge transactions for any address, which could easily extend this analysis.

Together, these tools make it easier to investigate the relationship between L1 and L2 activity.

Notes

This is a volunteer guest post by me, Takens Theorem. In my posts, I sometimes own things I mention. If you’d like to support me, feel free to follow me on X or check out prior writing and creative projects.