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Parallel Settlement Submission

Solver7702Delegate lets a solver keep its existing allowlisted EOA and use auxiliary EOAs as additional nonce lanes for settlement submission.

Solvers expecting production volume should set this up early. With one EOA, a pending transaction can block every settlement behind it. Auxiliary EOAs can submit in parallel, while GPv2Settlement still sees the solver EOA as msg.sender.

Reference driver setup​

If you use the reference driver, add submission-accounts to the solver entry in your driver config. This is all most solvers need to configure.

[[solver]]
name = "my-solver"
endpoint = "https://solver.example"
account = "<solver-private-key-or-signer-config>"
max-solutions-to-propose = 6 # solver EOA + 5 auxiliary EOAs
submission-accounts = [
  "<auxiliary-private-key-or-signer-config-1>",
  "<auxiliary-private-key-or-signer-config-2>",
  "<auxiliary-private-key-or-signer-config-3>",
  "<auxiliary-private-key-or-signer-config-4>",
  "<auxiliary-private-key-or-signer-config-5>"
]

The solver account must be able to sign the ERC-7702 authorization. Each submission-accounts entry must also include signing credentials, not only an address.

Fund each auxiliary EOA with the chain's native token so it can pay gas.

At startup, the reference driver deploys Solver7702Delegate at the expected CREATE2 address, or reuses the existing deployment at that address. When the solver EOA is busy, it uses the auxiliary accounts to submit settlements through separate nonce lanes.

What changes when submitting​

When the solver EOA is free, it submits directly to GPv2Settlement. If it already has a pending transaction, an auxiliary EOA can submit to the solver EOA instead. The solver EOA runs Solver7702Delegate, which forwards the call to GPv2Settlement.

The calldata format is packed on purpose. Use abi.encodePacked(bytes20(target), targetCalldata). Do not use abi.encode(target, targetCalldata).

Verification​

First, check that the solver EOA points to the expected delegate:

cast code <solver_eoa> --rpc-url <rpc_url>

For ERC-7702, the code has this form:

0xef0100 || delegate_address

On a block explorer, the solver EOA may not have a normal contract code view. Confirm that its Delegated to banner points to the expected address, then open that address and verify its source as Solver7702Delegate.

See the README's verification steps for details.

More details​

For manual deployment, authorization, revocation, verification, and operational details, use the Solver7702Delegate README.