feat: implement Solana chain module (#22)

Cargo.toml

@@ -21,6 +21,10 @@ hex = "0.4"
 rand = "0.8"
 async-trait = "0.1"
 url = "2"
-
+solana-client = "2.1.0"
+solana-sdk = "2.1.0"
+spl-token = "6.0.0"
 [dev-dependencies]
 tokio-test = "0.4"
+solana-program-test = "2.1.0"
+solana-test-validator = "2.1.0"

README.md

@@ -65,7 +65,7 @@ async fn main() -> Result<()> {
 
 ## Features
 
-- **Multi-chain** — EVM (Ethereum, Arbitrum, Optimism, Base, Avalanche, Tempo) from one agent. Solana and Cosmos planned.
+- **Multi-chain** — EVM (Ethereum, Arbitrum, Optimism, Base, Avalanche, Tempo) and Solana from one agent. Cosmos planned.
 - **Wallet management** — Generate, import, derive. Sign transactions. Manage multiple wallets.
 - **DEX interaction** — Swap, add/remove liquidity, read pool state. Uniswap V3, Aerodrome, Trader Joe.
 - **MPP payments** — Native support for Machine Payments Protocol. Agent pays for APIs, services, compute.
@@ -84,7 +84,7 @@ async fn main() -> Result<()> {
 | `arka::dex` | 🚧 WIP | DEX swap execution, routing |
 | `arka::mpp` | 🚧 WIP | Machine Payments Protocol client |
 | `arka::oracle` | 🚧 WIP | Price feeds, TWAP |
-| `arka::solana` | 📋 Planned | Solana chain connector |
+| `arka::solana` | ✅ MVP | Solana chain connector |
 | `arka::cosmos` | 📋 Planned | Cosmos chain connector |
 
 ## Quick Start

examples/multi_chain.rs

@@ -34,5 +34,11 @@ async fn main() -> Result<()> {
         );
     }
 
+    // Solana example
+    let solana = arka::chain::solana::SolanaChain::new()?;
+    let sol_keypair = solana_sdk::signature::Keypair::new();
+    let sol_balance = solana.balance(&sol_keypair.pubkey())?;
+    println!("{:12} | balance: {} lamports | gas: native", Chain::Solana, sol_balance);
+
     Ok(())
 }

src/chain/mod.rs

@@ -6,6 +6,8 @@ use std::fmt;
 mod connector;
 pub use connector::ChainConnector;
 
+pub mod solana;
+
 /// Supported blockchain networks.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
 pub enum Chain {
@@ -18,6 +20,7 @@ pub enum Chain {
     Bsc,
     Tempo,
     TempoTestnet,
+    Solana,
 }
 
 impl Chain {
@@ -33,6 +36,7 @@ impl Chain {
             Chain::Bsc => 56,
             Chain::Tempo => 4217,
             Chain::TempoTestnet => 42429,
+            Chain::Solana => 0, // Solana doesn't use EVM chain ID
         }
     }
 
@@ -48,6 +52,7 @@ impl Chain {
             Chain::Bsc => "https://bsc-dataseed.binance.org",
             Chain::Tempo => "https://rpc.tempo.xyz",
             Chain::TempoTestnet => "https://rpc.testnet.tempo.xyz",
+            Chain::Solana => "https://api.mainnet-beta.solana.com",
         }
     }
 
@@ -59,6 +64,7 @@ impl Chain {
             Chain::Polygon => "MATIC",
             Chain::Bsc => "BNB",
             Chain::Tempo | Chain::TempoTestnet => "USDC", // Tempo has no native gas token
+            Chain::Solana => "SOL",
         }
     }
 
@@ -79,6 +85,7 @@ impl Chain {
             Chain::Bsc => "https://bscscan.com",
             Chain::Tempo => "https://explorer.tempo.xyz",
             Chain::TempoTestnet => "https://explorer.testnet.tempo.xyz",
+            Chain::Solana => "https://solscan.io",
         }
     }
 }
@@ -95,6 +102,7 @@ impl fmt::Display for Chain {
             Chain::Bsc => write!(f, "bsc"),
             Chain::Tempo => write!(f, "tempo"),
             Chain::TempoTestnet => write!(f, "tempo-testnet"),
+            Chain::Solana => write!(f, "solana"),
         }
     }
 }

src/chain/solana.rs

@@ -0,0 +1,142 @@
+use solana_client::rpc_client::RpcClient;
+use solana_sdk::{
+    pubkey::Pubkey,
+    signature::{Keypair, Signature, Signer},
+    system_instruction,
+    transaction::Transaction,
+};
+
+use crate::error::{ArkaError, Result};
+use super::Chain;
+
+/// Manages connection and transactions for Solana network.
+pub struct SolanaChain {
+    chain: Chain,
+    rpc_url: String,
+    client: RpcClient,
+}
+
+impl SolanaChain {
+    /// Create a new connector with the default RPC.
+    pub fn new() -> Result<Self> {
+        Self::with_rpc(Chain::Solana.default_rpc())
+    }
+
+    /// Create a new connector with a custom RPC URL.
+    pub fn with_rpc(rpc_url: &str) -> Result<Self> {
+        let client = RpcClient::new(rpc_url.to_string());
+
+        Ok(Self {
+            chain: Chain::Solana,
+            rpc_url: rpc_url.to_string(),
+            client,
+        })
+    }
+
+    /// Get native SOL balance for a pubkey (in lamports).
+    pub fn balance(&self, pubkey: &Pubkey) -> Result<u64> {
+        self.client
+            .get_balance(pubkey)
+            .map_err(|e| ArkaError::Rpc(format!("Failed to get balance: {e}")))
+    }
+
+    /// Transfer SOL from one account to another.
+    pub fn transfer_sol(
+        &self,
+        sender: &Keypair,
+        receiver: &Pubkey,
+        lamports: u64,
+    ) -> Result<Signature> {
+        let ix = system_instruction::transfer(&sender.pubkey(), receiver, lamports);
+        let recent_blockhash = self.client
+            .get_latest_blockhash()
+            .map_err(|e| ArkaError::Rpc(format!("Failed to get blockhash: {e}")))?;
+
+        let tx = Transaction::new_signed_with_payer(
+            &[ix],
+            Some(&sender.pubkey()),
+            &[sender],
+            recent_blockhash,
+        );
+
+        self.client
+            .send_and_confirm_transaction(&tx)
+            .map_err(|e| ArkaError::Rpc(format!("Failed to transfer SOL: {e}")))
+    }
+
+    /// Transfer SPL token.
+    pub fn transfer_spl(
+        &self,
+        sender: &Keypair,
+        source: &Pubkey,
+        destination: &Pubkey,
+        authority: &Keypair,
+        amount: u64,
+    ) -> Result<Signature> {
+        let ix = spl_token::instruction::transfer(
+            &spl_token::id(),
+            source,
+            destination,
+            &authority.pubkey(),
+            &[&authority.pubkey()],
+            amount,
+        )
+        .map_err(|e| ArkaError::Rpc(format!("Failed to create SPL transfer instruction: {e}")))?;
+
+        let recent_blockhash = self.client
+            .get_latest_blockhash()
+            .map_err(|e| ArkaError::Rpc(format!("Failed to get blockhash: {e}")))?;
+
+        let tx = Transaction::new_signed_with_payer(
+            &[ix],
+            Some(&sender.pubkey()),
+            &[sender, authority],
+            recent_blockhash,
+        );
+
+        self.client
+            .send_and_confirm_transaction(&tx)
+            .map_err(|e| ArkaError::Rpc(format!("Failed to transfer SPL token: {e}")))
+    }
+
+    /// Get the chain this connector is for.
+    pub fn chain(&self) -> Chain {
+        self.chain
+    }
+
+    /// Get the RPC URL.
+    pub fn rpc_url(&self) -> &str {
+        &self.rpc_url
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use solana_sdk::signature::Keypair;
+    use solana_test_validator::TestValidatorGenesis;
+
+    #[test]
+    fn test_solana_chain_sol_transfer() {
+        // Start a local test validator
+        let (test_validator, payer) = TestValidatorGenesis::default().start();
+        let rpc_url = test_validator.rpc_url();
+
+        let solana = SolanaChain::with_rpc(&rpc_url).unwrap();
+
+        // Check initial balance
+        let balance = solana.balance(&payer.pubkey()).unwrap();
+        assert!(balance > 0);
+
+        // Generate a new receiver
+        let receiver = Keypair::new();
+
+        // Transfer 1 SOL (1_000_000_000 lamports)
+        let amount = 1_000_000_000;
+        let _sig = solana.transfer_sol(&payer, &receiver.pubkey(), amount).unwrap();
+
+        // Check receiver balance
+        let receiver_balance = solana.balance(&receiver.pubkey()).unwrap();
+        assert_eq!(receiver_balance, amount);
+    }
+}