waitForTransactionReceipt when using MEV Blocker does not wait

[frontier159]

Check existing issues

• [x] I checked there isn't already an issue for the bug I encountered.

Viem Version

2.38.0

Current Behavior

I'm using https://rpc.mevblocker.io (see MEV Blocker) on mainnet in order to get some MeV protection.

Within this:

const txHash = await wclient.writeContract(req);
const receipt = await wclient.waitForTransactionReceipt({
  hash: txHash,
});

As soon as the transaction is signed receipt resolves immediately (too early) and all fields on the receipt are undefined.

I tried retrying with confirmations=2 (if the first attempt is undefined), but this never resolves.

If I manually sleep for 15 seconds and then use:

receipt = await wclient.getTransactionReceipt({
  hash: txHash,
});

Then the receipt is populated ok - but obviously this isn't too useful as the tx may not have mined in that time.

If i update the RPC to be a non-mev protected RPC then it works ok...

Any ideas?

Expected Behavior

No response

Steps To Reproduce

No response

Link to Minimal Reproducible Example

No response

Anything else?

No response

[jxom]

My guess is that the RPC is returning a premature receipt (unexpected). Can you provide a minimal repro?

[frontier159]

My guess is that the RPC is returning a premature receipt (unexpected). Can you provide a minimal repro?

https://github.com/frontier159/viem-mevblocker-repro

Super minimal -- it just approves WETH to the zeroAddress for 0 amount. You can check the console log

NB: I still had to override the RPC url in my wallet (Rabby) on mainnet to https://rpc.mevblocker.io/

[frontier159]

Any thoughts on this @jxom ?

I could replicate using a local fork via anvil too:

anvil --hardfork cancun --fork-url $MAINNET_RPC_URL --fork-block-number 23615817 --block-time 12

And then in https://github.com/frontier159/viem-mevblocker-repro a/ set the config to [mainnet.id]: http("127.0.0.1:8545"), and pnpm run dev b/ import the first anvil test PK (0xac09...) into your browser wallet c/ set your wallet to use that EOA and also override to use the anvil rpc: http://127.0.0.1:8545

After you sign the tx it should log if it couldn't find the tx - I get this

[frontier159]

@jxom I wonder if you have a chance to quickly check / validate this?