thlorenz · August 28, 2025 08:52 · Aug 28, 2025
diff --git a/Cargo.toml b/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "feepayer"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+solana-instruction = "3.0.0"
+solana-pubkey = "3.0.0"
+solana-sanitize = "3.0.1"
+solana-transaction = { version = "3.0.1", features = ["blake3"] }
diff --git a/main.rs b/main.rs
@@ -0,0 +1,62 @@
+use std::collections::HashSet;
+
+use solana_sanitize::Sanitize;
+
+use solana_instruction::{AccountMeta, Instruction};
+use solana_pubkey::Pubkey;
+use solana_transaction::{sanitized::SanitizedTransaction, Transaction};
+
+fn sanitize_ixs(ixs: &[Instruction], payer: Option<Pubkey>, label: &str) -> Transaction {
+    let tx = Transaction::new_with_payer(ixs, payer.as_ref());
+    let res = tx.sanitize();
+    eprintln!("{label:18}: {res:?}");
+    tx
+}
+
+fn main() {
+    let program = Pubkey::default();
+    let payer = Pubkey::new_unique();
+
+    // No accounts
+    let ix = Instruction::new_with_bytes(program, &[], vec![]);
+    sanitize_ixs(&[ix], None, "Empty Accounts");
+
+    // Readonly Payer
+    let payer_meta = AccountMeta::new_readonly(payer, false);
+    let ix = Instruction::new_with_bytes(program, &[], vec![payer_meta]);
+    sanitize_ixs(&[ix], None, "Readonly");
+
+    // Readonly signing payer
+    let payer_meta = AccountMeta::new_readonly(payer, true);
+    let ix = Instruction::new_with_bytes(program, &[], vec![payer_meta]);
+    sanitize_ixs(&[ix], None, "Readonly signing");
+
+    // Writable Payer
+    let payer_meta = AccountMeta::new(payer, false);
+    let ix = Instruction::new_with_bytes(program, &[], vec![payer_meta]);
+    sanitize_ixs(&[ix], None, "Writable");
+
+    // Writable signing payer
+    let payer_meta = AccountMeta::new(payer, true);
+    let ix = Instruction::new_with_bytes(program, &[], vec![payer_meta]);
+    let tx = sanitize_ixs(&[ix], None, "Writable signing");
+    let sanitized = SanitizedTransaction::try_from_legacy_transaction(tx.clone(), &HashSet::new());
+    eprintln!("                 : {sanitized:#?}");
+
+    // Explicit payer
+    let ix = Instruction::new_with_bytes(program, &[], vec![]);
+    let tx = sanitize_ixs(&[ix], Some(payer), "Explicit payer");
+    let sanitized = SanitizedTransaction::try_from_legacy_transaction(tx.clone(), &HashSet::new());
+    eprintln!("                 : {sanitized:#?}");
+
+    // Explicit payer used as readonly in ix
+    let payer_meta = AccountMeta::new_readonly(payer, false);
+    let ix = Instruction::new_with_bytes(program, &[], vec![payer_meta]);
+    let tx = sanitize_ixs(
+        &[ix],
+        Some(payer),
+        "Explicit payer included as readonly not signing",
+    );
+    let sanitized = SanitizedTransaction::try_from_legacy_transaction(tx.clone(), &HashSet::new());
+    eprintln!("                 : {sanitized:#?}");
+}