sol-trade-sdk/docs/LOW_LATENCY_BOTS.md

Low-Latency Bot Integration Checklist

Before subscription, initialize and warm SolanaTrade, RPC and SWQoS clients, a background blockhash cache or durable nonce pool, known ATAs, and ALTs. Restore signature/instruction deduplication and position state before accepting events.

The event hot path should be limited to:

filter -> deduplicate -> reject stale event -> map post-trade state -> Simple*Params -> sign -> submit

Do not initialize clients, synchronously fetch a blockhash, query balances, or search for pools in this path. An RPC fallback is valid for incomplete shred data but is no longer a purely low-latency path.

Trade intent

Goal	Parameter
Exact spend with minimum-output protection	BuyAmount::ExactInput
Fill-priority sniping/arbitrage with maximum-cost protection	BuyAmount::WithMaxInput
Exact token output with maximum-input protection	BuyAmount::ExactOutput
Sell an exact token amount	SellAmount::ExactInput

WithMaxInput still enforces slippage. Never use min_out = 0 as routine error handling. Exact-output support is protocol- and pool-direction-specific. PumpSwap exposes exact output through its on-chain buy instruction, but its sell instruction accepts exact base input plus minimum quote output; the SDK rejects SellAmount::ExactOutput when that direction would require sell.

Use post-trade event reserves. Preserve PumpFun quote mint, creator/vault, token program, cashback, and mayhem fields. PumpSwap event integrations should use from_trade_with_fee_basis_points. Refresh delayed sells because the triggering trade and your own buy both change pool state. Durable nonce extends transaction validity, not quote validity.

For BuySlippageBelowMinBaseAmountOut, discard the old transaction, obtain newer reserves and fee rates, enforce a quote-age limit, and rebuild only within a bounded retry policy. After a submit timeout or ambiguous relay error, reconcile the signature and position before retrying. A retry policy may rebuild quotes automatically only when the previous transaction is known not to have been submitted.

Reference examples:

• fnzero-examples/pumpfun_grpc_sniper
• fnzero-examples/pumpfun_shredstream_sniper
• examples/pumpswap_trading