impl 1 task

.gitignore

@@ -0,0 +1 @@
+**/target

sol-json-rpc-1/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "sol-json-rpc-1"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+config = "0.15.11"
+futures = "0.3.31"
+serde = { version = "1.0.219", features = ["derive"] }
+serde_json = "1.0.140"
+solana-client = "2.2.7"
+solana-sdk = "2.2.2"
+tokio = { version = "1.45.0", features = ["macros", "rt-multi-thread"] }

sol-json-rpc-1/config.yaml

@@ -0,0 +1,3 @@
+accounts:
+  - 83astBRguLMdt2h5U1Tpdq5tjFoJ6noeGwaY3mDLVcri
+solana_url: https://api.devnet.solana.com

sol-json-rpc-1/src/main.rs

@@ -0,0 +1,51 @@
+use std::{error::Error, str::FromStr, sync::Arc};
+
+use config::Config;
+use futures::future::join_all;
+use serde::Deserialize;
+use solana_client::nonblocking::rpc_client::RpcClient;
+use solana_sdk::{
+    commitment_config::CommitmentConfig, native_token::LAMPORTS_PER_SOL, pubkey::Pubkey,
+};
+
+#[derive(Deserialize)]
+struct Cfg {
+    accounts: Vec<String>,
+    solana_url: String,
+}
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn Error>> {
+    let config = {
+        let config_parser = Config::builder()
+            .add_source(config::File::with_name("config.yaml"))
+            .build()?;
+
+        config_parser.try_deserialize::<Cfg>()?
+    };
+    let client = Arc::new(RpcClient::new_with_commitment(
+        config.solana_url.clone(),
+        CommitmentConfig::confirmed(),
+    ));
+
+    let mut fetchers = vec![];
+    for account in &config.accounts {
+        let client = client.clone();
+        fetchers.push(async move {
+            let pubkey = Pubkey::from_str(&account)?;
+            let balance = client.get_balance(&pubkey).await?;
+            Ok::<_, Box<dyn Error>>(balance as f64 / LAMPORTS_PER_SOL as f64)
+        });
+    }
+
+    let balances = join_all(fetchers)
+        .await
+        .into_iter()
+        .collect::<Result<Vec<_>, _>>()?;
+
+    for (acc, bal) in config.accounts.iter().zip(balances.iter()) {
+        println!("{acc}: {bal}");
+    }
+
+    Ok(())
+}