blob-lib

Build

Clone this repo.

cd blob-lib nvm use 18 yarn install yarn build

Compiling Contract

To install foundry (which is really a bit of overkill in this situation, because we really just need solc):

cd contracts forge install --no-commit git submodule update --init --recursive ./lib

To compile contracts/src/Blob.sol: From ./contracts:

forge build --evm-version cancun

This creates ./contracts/out/Blob.sol/Blob.json, which the ts tests then read.

To run blob submission smart contract tests:

Start a hardhat network node in one window:

npx hardhat node

(Note: anvil doesn't seem to work with my blob txs)

Then in another window:

export PRIV_KEY=0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80 - this is the default testing private key for anvil and hardhat. yarn test

Notes

It will first send an ordinary eth transfer tx, to demonstrate that this works.

Then it will try to send a blob tx, in keeping with https://viem.sh/docs/guides/blob-transactions. This blob tx will fail with:

InvalidParamsRpcError: Invalid parameters were provided to the RPC method.
Double check you have provided the correct parameters.

and later:

shortMessage: 'RPC Request failed.',
version: '[email protected]',
cause: { code: -32602, message: 'Failed to decode transaction' },

---

Ok, so I had a go at sending the same txs (using the same tests) to a "hardhat network node". Interestingly (confusingly and frustratingly), if you client.sendRawTransaction to a hardhat node, the tx data is formatted differently from when it's sent to a foundry node. That's with the same client configuration chain: foundry. Viem seemingly figures out that it's talking with a hardhat node and reformats the sendRawTransaction request to be in a non-raw, jsonified format. But hardhat can't understand a jsonified blob tx*; it only supports raw (rlp-encoded) blob tx requests formatted with sendRawTransaction - except viem's sendRawTransaction is reformatting the request into json form for a hardhat node (but not for an anvil node)!!! Setting chain: hardhat didn't help, so I kept it at foundry. This foundry setting didn't affect non-blob txs from being successfully processed by the hardhat node.

* Hardhat says this when you feed it a jsonified, non-raw tx: An EIP-4844 (shard blob) call request was received, but Hardhat only supports them via 'eth_sendRawTransaction'. See https://github.com/NomicFoundation/hardhat/issues/5182 (link)

So how to send a raw tx to a hardhat node? Curl! But the size of the blob is way bigger than what curl allows. So I stored the command in a text file raw-tx.json and did:

curl -X POST -H "Content-Type: application/json" --data @raw-tx.json 127.0.0.1:8545

Hooray! The hardhat network node didn't complain - it gave me a tx receipt!

I tried the same with anvil and got: "Failed to decode transaction" - the same error as I've been getting all along from anvil, even if sending via viem.

Note: the nonce for the raw-tx.json is nonce 0 (encoded as 0x80 "nothing here"), so if it fails, you'll need to restart anvil to run it again. Or you could manually modify the nonce: From the start of the raw params string, it's here:

"0x03fa020102f894827a6980...
                       ^^ these two bytes are the nonce
                         `80` means nonce `0`, `01` is nonce `1`. `02` is nonce `2`, etc.

	Viem	Curl
anvil node	❌ InvalidParamsRpcError: Invalid parameters were provided to the RPC method.	❌ InvalidParamsRpcError: Invalid parameters were provided to the RPC method.
hardhat network node	❌ An EIP-4844 (shard blob) call request was received, but Hardhat only supports them via 'eth_sendRawTransaction'. See https://github.com/NomicFoundation/hardhat/issues/5182 but viem isn't sending the tx as raw.	✅

Oooh, it's calling estimate_gas that seems to be killing it. If you specify all gas values (gas limit, max fee per ...) then it seems to work - for hardhat at least!