feat: rpc_headers in cast and config (#9429)

* feat: specify `rpc_headers` in cast and config

* test

Author: yash-atreya

Cargo.lock

@@ -205,6 +205,7 @@ alloy-transport = { version = "0.6.4", default-features = false }
 alloy-transport-http = { version = "0.6.4", default-features = false }
 alloy-transport-ipc = { version = "0.6.4", default-features = false }
 alloy-transport-ws = { version = "0.6.4", default-features = false }
+alloy-node-bindings = { version = "0.6.4", default-features = false }
 
 ## alloy-core
 alloy-dyn-abi = "0.8.11"

Cargo.toml

@@ -94,6 +94,7 @@ tikv-jemallocator = { workspace = true, optional = true }
 [dev-dependencies]
 anvil.workspace = true
 foundry-test-utils.workspace = true
+alloy-node-bindings.workspace = true
 
 async-trait.workspace = true
 divan.workspace = true

crates/cast/Cargo.toml

@@ -107,11 +107,9 @@ impl RunArgs {
         let compute_units_per_second =
             if self.no_rate_limit { Some(u64::MAX) } else { self.compute_units_per_second };
 
-        let provider = foundry_common::provider::ProviderBuilder::new(
-            &config.get_rpc_url_or_localhost_http()?,
-        )
-        .compute_units_per_second_opt(compute_units_per_second)
-        .build()?;
+        let provider = foundry_cli::utils::get_provider_builder(&config)?
+            .compute_units_per_second_opt(compute_units_per_second)
+            .build()?;
 
         let tx_hash = self.tx_hash.parse().wrap_err("invalid tx hash")?;
         let tx = provider

crates/cast/bin/cmd/run.rs

@@ -48,6 +48,10 @@ pub struct RpcOpts {
     /// Default value: 45
     #[arg(long, env = "ETH_RPC_TIMEOUT")]
     pub rpc_timeout: Option<u64>,
+
+    /// Specify custom headers for RPC requests.
+    #[arg(long, alias = "headers", env = "ETH_RPC_HEADERS", value_delimiter(','))]
+    pub rpc_headers: Option<Vec<String>>,
 }
 
 impl_figment_convert_cast!(RpcOpts);
@@ -95,6 +99,9 @@ impl RpcOpts {
         if let Some(rpc_timeout) = self.rpc_timeout {
             dict.insert("eth_rpc_timeout".into(), rpc_timeout.into());
         }
+        if let Some(headers) = &self.rpc_headers {
+            dict.insert("eth_rpc_headers".into(), headers.clone().into());
+        }
         dict
     }
 }

crates/cli/src/opts/ethereum.rs

@@ -39,6 +39,8 @@ pub const STATIC_FUZZ_SEED: [u8; 32] = [
     0x5d, 0x64, 0x0b, 0x19, 0xad, 0xf0, 0xe3, 0x57, 0xb8, 0xd4, 0xbe, 0x7d, 0x49, 0xee, 0x70, 0xe6,
 ];
 
+const DEFAULT_USER_AGENT: &str = concat!("foundry/", env!("CARGO_PKG_VERSION"));
+
 /// Useful extensions to [`std::path::Path`].
 pub trait FoundryPathExt {
     /// Returns true if the [`Path`] ends with `.t.sol`
@@ -110,6 +112,14 @@ pub fn get_provider_builder(config: &Config) -> Result<ProviderBuilder> {
         builder = builder.timeout(Duration::from_secs(rpc_timeout));
     }
 
+    if let Some(mut rpc_headers) = config.eth_rpc_headers.clone() {
+        if !rpc_headers.iter().any(|h| h.starts_with("User-Agent:")) {
+            rpc_headers.push(format!("User-Agent:{DEFAULT_USER_AGENT}"));
+        }
+
+        builder = builder.headers(rpc_headers);
+    }
+
     Ok(builder)
 }
 

crates/cli/src/utils/mod.rs

@@ -253,6 +253,15 @@ pub struct Config {
     pub eth_rpc_jwt: Option<String>,
     /// Timeout that should be used for any rpc calls
     pub eth_rpc_timeout: Option<u64>,
+    /// Headers that should be used for any rpc calls
+    ///
+    /// # Example
+    ///
+    /// rpc_headers = ["x-custom-header:value", "x-another-header:another-value"]
+    ///
+    /// You can also the ETH_RPC_HEADERS env variable like so:
+    /// `ETH_RPC_HEADERS="x-custom-header:value x-another-header:another-value"`
+    pub eth_rpc_headers: Option<Vec<String>>,
     /// etherscan API key, or alias for an `EtherscanConfig` in `etherscan` table
     pub etherscan_api_key: Option<String>,
     /// Multiple etherscan api configs and their aliases
@@ -2347,6 +2356,7 @@ impl Default for Config {
             eth_rpc_url: None,
             eth_rpc_jwt: None,
             eth_rpc_timeout: None,
+            eth_rpc_headers: None,
             etherscan_api_key: None,
             verbosity: 0,
             remappings: vec![],

crates/config/src/lib.rs

@@ -109,6 +109,7 @@ forgetest!(can_extract_config_values, |prj, cmd| {
         eth_rpc_url: Some("localhost".to_string()),
         eth_rpc_jwt: None,
         eth_rpc_timeout: None,
+        eth_rpc_headers: None,
         etherscan_api_key: None,
         etherscan: Default::default(),
         verbosity: 4,