This example consumes PumpSwap events through solana-streamer-sdk and builds one follow-up buy from the event's post-trade reserves and dynamic fee rates. The trading client and blockhash cache are initialized before subscription, so the event hot path does not synchronously fetch a blockhash.

Run

cp .env.example .env
# Edit .env, then load it into the current shell:
set -a; source .env; set +a
export PRIVATE_KEY=your_base58_private_key
export RPC_URL=https://your-rpc.example
cargo run --release --package pumpswap_trading

GRPC_ENDPOINT and GRPC_AUTH_TOKEN are optional. TARGET_MINT or TARGET_POOL is required; when both are set, both must match. MAX_EVENT_AGE_MS defaults to 1000. The binary reads environment variables but does not load .env itself, so source the file first when using it.

Trade semantics

The buy uses BuyAmount::WithMaxInput, which applies slippage to maximum quote cost and is appropriate when fill priority matters.
Buy parameters use post-trade reserves and LP/protocol/creator fee bps from the event.
The example records the pre-buy balance and sells only the confirmed balance increase. It refreshes pool state and blockhash before selling.
Use BuyAmount::ExactInput when the quote spend must be exact. That mode protects minimum output and can fail more often in an active pool.

Production bots should also add durable signature deduplication, a position state machine, SWQoS configuration, and bounded requoting. Do not solve slippage errors by setting min_out to zero.