feat: add stake split instruction support

Add support for creating stake account split transactions to enable
partial stake deactivation. Include parsing transaction signatures.

Ticket: BTC-2955

Author: lcovar

packages/wasm-solana/js/builder.ts

@@ -175,6 +175,19 @@ export interface StakeAuthorizeInstruction {
   authority: string;
 }
 
+/** Split stake account instruction (for partial deactivation) */
+export interface StakeSplitInstruction {
+  type: "stakeSplit";
+  /** Source stake account address (base58) */
+  stake: string;
+  /** Destination stake account (must be uninitialized/created first) (base58) */
+  splitStake: string;
+  /** Stake authority (base58) */
+  authority: string;
+  /** Amount in lamports to split (as string) */
+  lamports: string;
+}
+
 // =============================================================================
 // SPL Token Instructions
 // =============================================================================
@@ -338,6 +351,7 @@ export type Instruction =
   | StakeDeactivateInstruction
   | StakeWithdrawInstruction
   | StakeAuthorizeInstruction
+  | StakeSplitInstruction
   | TokenTransferInstruction
   | CreateAssociatedTokenAccountInstruction
   | CloseAssociatedTokenAccountInstruction

packages/wasm-solana/js/index.ts

@@ -68,10 +68,14 @@ export type {
   StakeDeactivateInstruction,
   StakeWithdrawInstruction,
   StakeAuthorizeInstruction,
+  StakeSplitInstruction,
   // SPL Token
   TokenTransferInstruction,
   CreateAssociatedTokenAccountInstruction,
   CloseAssociatedTokenAccountInstruction,
+  MintToInstruction,
+  BurnInstruction,
+  ApproveInstruction,
   // Jito Stake Pool
   StakePoolDepositSolInstruction,
   StakePoolWithdrawStakeInstruction,

packages/wasm-solana/js/parser.ts

@@ -263,6 +263,9 @@ export interface ParsedTransaction {
 
   /** All account keys (base58 strings) */
   accountKeys: string[];
+
+  /** All signatures (base58 strings). Non-empty signatures indicate signed transaction. */
+  signatures: string[];
 }
 
 // =============================================================================

packages/wasm-solana/src/builder/build.rs

@@ -372,6 +372,32 @@ fn build_instruction(ix: IntentInstruction) -> Result<Instruction, WasmSolanaErr
             ))
         }
 
+        IntentInstruction::StakeSplit {
+            stake,
+            split_stake,
+            authority,
+            lamports,
+        } => {
+            let stake_pubkey: Pubkey = stake.parse().map_err(|_| {
+                WasmSolanaError::new(&format!("Invalid stakeSplit.stake: {}", stake))
+            })?;
+            let split_stake_pubkey: Pubkey = split_stake.parse().map_err(|_| {
+                WasmSolanaError::new(&format!("Invalid stakeSplit.splitStake: {}", split_stake))
+            })?;
+            let authority_pubkey: Pubkey = authority.parse().map_err(|_| {
+                WasmSolanaError::new(&format!("Invalid stakeSplit.authority: {}", authority))
+            })?;
+            let amount: u64 = lamports.parse().map_err(|_| {
+                WasmSolanaError::new(&format!("Invalid stakeSplit.lamports: {}", lamports))
+            })?;
+            Ok(build_stake_split(
+                &stake_pubkey,
+                &split_stake_pubkey,
+                &authority_pubkey,
+                amount,
+            ))
+        }
+
         // ===== SPL Token Program =====
         IntentInstruction::TokenTransfer {
             source,
@@ -859,6 +885,25 @@ fn build_stake_authorize(
     )
 }
 
+/// Build a stake split instruction.
+/// Used for partial stake deactivation - splits lamports from one stake account to another.
+fn build_stake_split(
+    stake: &Pubkey,
+    split_stake: &Pubkey,
+    authority: &Pubkey,
+    lamports: u64,
+) -> Instruction {
+    Instruction::new_with_bincode(
+        program_ids::stake_program(),
+        &StakeInstruction::Split(lamports),
+        vec![
+            AccountMeta::new(*stake, false),       // Source stake account
+            AccountMeta::new(*split_stake, false), // Destination stake account
+            AccountMeta::new_readonly(*authority, true), // Stake authority
+        ],
+    )
+}
+
 // ===== SPL Token Instruction Builders =====
 
 /// Build a TransferChecked instruction for SPL Token.
@@ -1454,4 +1499,28 @@ mod tests {
         );
         verify_tx_structure(&result.unwrap(), 1);
     }
+
+    #[test]
+    fn test_build_stake_split() {
+        let intent = TransactionIntent {
+            fee_payer: "DgT9qyYwYKBRDyDw3EfR12LHQCQjtNrKu2qMsXHuosmB".to_string(),
+            nonce: Nonce::Blockhash {
+                value: "GWaQEymC3Z9SHM2gkh8u12xL1zJPMHPCSVR3pSDpEXE4".to_string(),
+            },
+            instructions: vec![IntentInstruction::StakeSplit {
+                stake: "FKjSjCqByQRwSzZoMXA7bKnDbJe41YgJTHFFzBeC42bH".to_string(),
+                split_stake: "5ZWgXcyqrrNpQHCme5SdC5hCeYb2o3fEJhF7Gok3bTVN".to_string(),
+                authority: "DgT9qyYwYKBRDyDw3EfR12LHQCQjtNrKu2qMsXHuosmB".to_string(),
+                lamports: "500000000".to_string(), // 0.5 SOL
+            }],
+        };
+
+        let result = build_transaction(intent);
+        assert!(
+            result.is_ok(),
+            "Failed to build stake split: {:?}",
+            result
+        );
+        verify_tx_structure(&result.unwrap(), 1);
+    }
 }

packages/wasm-solana/src/builder/types.rs

@@ -153,6 +153,19 @@ pub enum Instruction {
         authority: String,
     },
 
+    /// Split stake account (used for partial deactivation)
+    StakeSplit {
+        /// Source stake account address
+        stake: String,
+        /// Destination stake account (must be uninitialized/created first)
+        #[serde(rename = "splitStake")]
+        split_stake: String,
+        /// Stake authority
+        authority: String,
+        /// Amount in lamports to split (as string)
+        lamports: String,
+    },
+
     // ===== SPL Token Instructions =====
     /// Transfer tokens (uses TransferChecked for safety)
     TokenTransfer {

packages/wasm-solana/src/parser.rs

@@ -35,6 +35,9 @@ pub struct ParsedTransaction {
 
     /// All account keys (base58 strings).
     pub account_keys: Vec<String>,
+
+    /// All signatures (base58 strings). Non-empty signatures indicate signed transaction.
+    pub signatures: Vec<String>,
 }
 
 /// Durable nonce information for nonce-based transactions.
@@ -64,7 +67,8 @@ impl TryIntoJsValue for ParsedTransaction {
             "nonce" => self.nonce,
             "durableNonce" => self.durable_nonce,
             "instructionsData" => self.instructions_data,
-            "accountKeys" => self.account_keys
+            "accountKeys" => self.account_keys,
+            "signatures" => self.signatures
         )
     }
 }
@@ -139,13 +143,17 @@ pub fn parse_transaction(bytes: &[u8]) -> Result<ParsedTransaction, String> {
     // (which is the nonce value from the nonce account)
     let nonce = message.recent_blockhash.to_string();
 
+    // Extract signatures as base58 strings
+    let signatures: Vec<String> = tx.signatures.iter().map(|s| s.to_string()).collect();
+
     Ok(ParsedTransaction {
         fee_payer,
         num_signatures: message.header.num_required_signatures,
         nonce,
         durable_nonce,
         instructions_data,
         account_keys,
+        signatures,
     })
 }
 

packages/wasm-solana/test/transaction.ts

@@ -166,10 +166,7 @@ describe("Transaction", () => {
 
       // Try to add a signature with wrong length
       const badSignature = new Uint8Array(32);
-      assert.throws(
-        () => tx.addSignature(feePayer, badSignature),
-        /Invalid signature length/
-      );
+      assert.throws(() => tx.addSignature(feePayer, badSignature), /Invalid signature length/);
     });
 
     it("should throw for non-signer pubkey", () => {
@@ -179,7 +176,7 @@ describe("Transaction", () => {
       // Try to add signature for non-signer (System program)
       assert.throws(
         () => tx.addSignature("11111111111111111111111111111111", signature),
-        /not a required signer/
+        /not a required signer/,
       );
     });