feat: wallet crate

Creates a new crate, `alphanet-wallet`, that defines a new
RPC namespace, `wallet_`, which specifies the interface for
performing sequencer-sponsored transactions using EIP-7702.

Cargo.toml

@@ -4,6 +4,7 @@ members = [
     "crates/node",
     "crates/precompile",
     "crates/testing",
+    "crates/wallet",
 ]
 default-members = ["bin/alphanet/"]
 resolver = "2"
@@ -56,6 +57,7 @@ strip = false
 # alphanet
 alphanet-node = { path = "crates/node" }
 alphanet-precompile = { path = "crates/precompile" }
+alphanet-wallet = { path = "crates/wallet" }
 
 alloy = { version = "0.4", features = [
     "contract",
@@ -65,6 +67,7 @@ alloy = { version = "0.4", features = [
 ] }
 alloy-network = { version = "0.4" }
 alloy-primitives = { version = "0.8.5" }
+alloy-rpc-types = { version = "0.4" }
 alloy-signer-local = { version = "0.4", features = ["mnemonic"] }
 
 # tokio
@@ -106,10 +109,14 @@ reth-revm = { git = "https://github.com/paradigmxyz/reth.git", rev = "a8a380f",
 reth-tracing = { git = "https://github.com/paradigmxyz/reth.git", rev = "a8a380f" }
 reth-transaction-pool = { git = "https://github.com/paradigmxyz/reth.git", rev = "a8a380f" }
 
+# rpc
+jsonrpsee = "0.24"
+
 # misc
 clap = "4"
 eyre = "0.6.12"
 tracing = "0.1.0"
+serde = "1"
 serde_json = "1"
 once_cell = "1.19"
 

crates/wallet/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "alphanet-wallet"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+authors.workspace = true
+license.workspace = true
+repository.workspace = true
+keywords.workspace = true
+categories.workspace = true
+
+[dependencies]
+alloy-primitives.workspace = true
+alloy-rpc-types.workspace = true
+jsonrpsee = { workspace = true, features = ["server", "macros"] }
+serde = { workspace = true, features = ["derive"] }
+
+[lints]
+workspace = true

crates/wallet/src/lib.rs

@@ -0,0 +1,79 @@
+//! # AlphaNet wallet.
+//!
+//! Implementations of a custom `wallet_` namespace for AlphaNet experiment 1.
+//!
+//! - `wallet_getCapabilities` based on [EIP-5792][eip-5792], with the only capability being
+//!   `delegation`.
+//! - `wallet_sendTransaction` that can perform sequencer-sponsored [EIP-7702][eip-7702] delegations
+//!   and send other sequencer-sponsored transactions on behalf of EOAs with delegated code.
+//!
+//! # Restrictions
+//!
+//! `wallet_sendTransaction` has additional verifications in place to prevent some rudimentary abuse
+//! of the sequencer's funds. For example, transactions cannot contain any `value`.
+//!
+//! [eip-5792]: https://eips.ethereum.org/EIPS/eip-5792
+//! [eip-7702]: https://eips.ethereum.org/EIPS/eip-7702
+
+#![cfg_attr(not(test), warn(unused_crate_dependencies))]
+
+use alloy_primitives::{map::HashMap, Address, ChainId, TxHash};
+use alloy_rpc_types::TransactionRequest;
+use jsonrpsee::{core::RpcResult, proc_macros::rpc};
+use serde::{Deserialize, Serialize};
+
+/// The capability to perform [EIP-7702][eip-7702] delegations, sponsored by the sequencer.
+///
+/// The sequencer will only perform delegations, and act on behalf of delegated accounts, if the
+/// account delegates to one of the addresses specified within this capability.
+///
+/// [eip-7702]: https://eips.ethereum.org/EIPS/eip-7702
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct DelegationCapability {
+    /// A list of valid delegation contracts.
+    pub addresses: Vec<Address>,
+}
+
+/// Wallet capabilities for a specific chain.
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct Capabilities {
+    /// The capability to delegate.
+    pub delegation: DelegationCapability,
+}
+
+/// A map of wallet capabilities per chain ID.
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct WalletCapabilities(pub HashMap<ChainId, Capabilities>);
+
+/// AlphaNet `wallet_` RPC namespace.
+#[cfg_attr(not(test), rpc(server, namespace = "wallet"))]
+#[cfg_attr(test, rpc(server, client, namespace = "wallet"))]
+pub trait AlphaNetWalletApi {
+    /// Get the capabilities of the wallet.
+    ///
+    /// Currently the only capability is [`DelegationCapability`].
+    ///
+    /// See also [EIP-5792][eip-5792].
+    ///
+    /// [eip-5792]: https://eips.ethereum.org/EIPS/eip-5792
+    #[method(name = "getCapabilities")]
+    fn get_capabilities(&self) -> RpcResult<WalletCapabilities>;
+
+    /// Send a sequencer-sponsored transaction.
+    ///
+    /// The transaction will only be processed if:
+    ///
+    /// - The transaction is an [EIP-7702][eip-7702] transaction that delegates to one of the
+    ///   addresses listed in [`DelegationCapability`] (see [`Self::get_capabilities`])
+    /// - The transaction is an [EIP-1559][eip-1559] transaction to an EOA that is currently
+    ///   delegated to one of the addresses above
+    /// - The value in the transaction is exactly 0.
+    ///
+    /// The sequencer will sign the transaction and inject it into the transaction pool, provided it
+    /// is valid. The nonce is managed by the sequencer.
+    ///
+    /// [eip-7702]: https://eips.ethereum.org/EIPS/eip-7702
+    /// [eip-1559]: https://eips.ethereum.org/EIPS/eip-1559
+    #[method(name = "sendTransaction")]
+    fn send_transaction(&self, request: TransactionRequest) -> RpcResult<TxHash>;
+}