add gas pricing rpc methods

src/client/client.rs

@@ -78,6 +78,18 @@ impl Client {
         }
     }
 
+    pub async fn get_gas_price(&self) -> Result<U256> {
+        let payload = self.consensus.get_execution_payload().await?;
+        let base_fee = U256::from_little_endian(&payload.base_fee_per_gas.to_bytes_le());
+        let tip = U256::from(10_u64.pow(9));
+        Ok(base_fee + tip)
+    }
+
+    pub async fn get_priority_fee(&self) -> Result<U256> {
+        let tip = U256::from(10_u64.pow(9));
+        Ok(tip)
+    }
+
     pub fn chain_id(&self) -> u64 {
         self.config.general.chain_id
     }

src/client/rpc.rs

@@ -53,6 +53,10 @@ trait EthRpc {
     async fn estimate_gas(&self, opts: CallOpts) -> Result<String, Error>;
     #[method(name = "chainId")]
     fn chain_id(&self) -> Result<String, Error>;
+    #[method(name = "gasPrice")]
+    async fn gas_price(&self) -> Result<String, Error>;
+    #[method(name = "maxPriorityFeePerGas")]
+    async fn max_priority_fee_per_gas(&self) -> Result<String, Error>;
 }
 
 struct RpcInner {
@@ -130,6 +134,16 @@ impl EthRpcServer for RpcInner {
         let id = self.client.chain_id();
         Ok(u64_to_hex_string(id))
     }
+
+    async fn gas_price(&self) -> Result<String, Error> {
+        let gas_price = convert_err(self.client.get_gas_price().await)?;
+        Ok(gas_price.encode_hex())
+    }
+
+    async fn max_priority_fee_per_gas(&self) -> Result<String, Error> {
+        let tip = convert_err(self.client.get_priority_fee().await)?;
+        Ok(tip.encode_hex())
+    }
 }
 
 async fn start(rpc: RpcInner) -> Result<(HttpServerHandle, SocketAddr)> {

src/consensus/types.rs

@@ -69,7 +69,7 @@ pub struct ExecutionPayload {
     #[serde(deserialize_with = "extra_data_deserialize")]
     extra_data: List<u8, 32>,
     #[serde(deserialize_with = "u256_deserialize")]
-    base_fee_per_gas: U256,
+    pub base_fee_per_gas: U256,
     #[serde(deserialize_with = "bytes32_deserialize")]
     pub block_hash: Bytes32,
     #[serde(deserialize_with = "transactions_deserialize")]