Feat/fl actions improvements

[k0beLeenders]

SDK: Titan Swap Provider + Transaction Optimization

Summary

Adds Titan as a swap provider alongside Jupiter, implements transaction size and account lock validation, and enhances error handling in flashloan operations.

Version: 2.2.0-beta.0 (published under @beta tag)

---

🎯 Key Features

1. Titan Swap Provider

• Vendored WebSocket client at src/vendor/titan/ (no external npm dependency)
  • client.ts: WebSocket connection with msgpack encoding
  • types.ts: Protocol types (cherry-picked from @titanexchange/sdk-ts)
  • helpers.ts: Deserialization and route selection utilities
• Fee account validation: Checks ATA existence, strips fees if missing
• Consistent API: Refactored to match Jupiter's quoteParams structure

New Files:

src/vendor/titan/
├── client.ts (369 lines)
├── types.ts (192 lines)
├── helpers.ts (146 lines)
└── index.ts

src/services/account/utils/
└── titan.utils.ts (421 lines)

2. Transaction Size Optimization

Added validation for Solana's transaction limits.

New Helper:

// src/services/transaction/helpers/tx-size.ts
export function getTotalAccountKeys(tx: VersionedTransaction | Transaction): number {
  // Counts static + LUT-resolved accounts
}

New Utility:

// src/services/account/utils/flashloan-size.utils.ts (704 lines)
export async function computeFlashloanSwapConstraints({
  program,
  marginfiAccount,
  bankMap,
  // ...
}): Promise<{
  sizeConstraint: number;
  maxSwapWritableAccounts: number;
  maxSwapTotalAccounts: number;
}>

Applied to all flashloan actions:

• src/services/account/actions/loop.ts
• src/services/account/actions/repay.ts
• src/services/account/actions/swap-collateral.ts
• src/services/account/actions/swap-debt.ts

Each action now validates before simulation:

const txSize = getTxSize(flashloanTx);
const writableKeys = getWritableAccountKeys(flashloanTx);
const totalKeys = getTotalAccountKeys(flashloanTx);

if (txSize > MAX_TX_SIZE || writableKeys > MAX_WRITABLE_ACCOUNTS || totalKeys > MAX_ACCOUNT_LOCKS) {
  throw TransactionBuildingError.swapSizeExceeded*(txSize, writableKeys, provider);
}

3. Enhanced Error Handling

• Fixed error passthrough: TransactionBuildingError now properly propagates through swap provider fallback loops
• Swap provider routing: Automatic fallback from Titan → Jupiter with typed errors
• New error types: 15+ typed error constructors for different failure scenarios

Provider Fallback:

// src/services/account/utils/swap.utils.ts
for (const { provider, apiConfig } of attempts) {
  try {
    const fn = getSwapProviderFn({ attemptProvider: provider, ... });
    return await fn(apiConfig);
  } catch (err) {
    if (err instanceof TransactionBuildingError) throw err; // Proper passthrough
    lastError = err;
  }
}

🔗 Related

• Web App PR: Companion changes for Titan HTTP proxy and error handling
• Version: 2.2.0-beta.0 published under @beta tag (does not affect latest)

[borcherd]

This is a comment claude made, i dont really understand but maybe you do. just want to flag

[borcherd]

accountInfo === null LUTs are silently filtered out. If Titan returns a LUT address that doesn't resolve (RPC slot lag, wrong cluster, stale address), the swap IXs still reference accounts that were supposed to come from that LUT — the V0 compiler then either promotes them to static keys (→ misleading "tx size exceeded" error), or the TX fails on-chain with Invalid account index. Suggest throwing with the list of missing LUT pubkeys so the provider router's catch falls through to Jupiter cleanly instead of handing a broken IX set to makeFlashLoanTx.