Production trading operations

This guide applies to automated execution, quoting, portfolio automation, and other long-running trading systems. Strategy selection and profitability are outside the SDK's scope.

Fail closed

If book continuity, account state, or mutation outcome is uncertain, stop creating orders. Keep the dead-man switch armed and reconcile before resuming.

Health model

Dependency	Healthy evidence	Response when unhealthy
Catalogs	`wait_for_catalogs()` completed; symbol and scale resolve	Do not encode or submit
Managed book	Recent update, bid below ask, no refresh in progress	Pause book-dependent writes
Private orders	Recent event or successful bounded reconciliation	Reconcile before replacing
Balances	Recent `balances.list(...)` snapshot	Stop the affected side
Dead-man switch	Last `armed` response has safe time remaining	Stop new orders immediately
Event queue	No `Error::QueueOverflow`	Replace subscription and resnapshot

Track book age/sequence, refresh and reconnect counts, owned open orders, reserved and available balance, mutation latency, rejected batch items, unknown outcomes, dead-man expiry margin, and reconciliation duration. Generic queues hold 1000 items; the managed book queue holds 200.

Deployment and shutdown

Start with writes disabled.
Hydrate catalogs and validate configured symbols.
Start managed public feeds and private order/balance streams.
Reconcile open orders owned by this process prefix.
Arm orders.cancel_all_after for 10 to 120 seconds.
Enable writes only when all dependencies are healthy.

For shutdown: disable new orders, cancel owned IDs, confirm they disappear from orders.list_open, then close streams. Do not disarm the dead-man switch until cleanup is confirmed. Avoid account-wide cancellation as ownership cleanup; filter process-owned client IDs first. Treat ERROR_CODE_ORDER_ALREADY_TERMINAL and ERROR_CODE_ORDER_UNKNOWN from those targeted cancels as idempotent success and propagate every other error.

Troubleshooting

Post-only rejection: Refresh the book and calculate a new catalog-aligned price
Insufficient balance: Refresh balances; reduce or disable the affected order flow
Stale/one-sided book: Pause writes until a valid snapshot
mutation_outcome_unknown(): Query known client/request IDs before retrying
Missing fills: Use wait_for_order_trades_complete
Error::QueueOverflow: Replace the subscription, snapshot, and reconcile
Dead-man refresh failure: Stop writes and continue cleanup/reconciliation
Authentication failure: Stop; treat as configuration/policy, not transient transport

Create status accepted is admission, not working state. Batch RPC success does not mean every item was accepted.

Testing ladder

Unit-test strategy math, rounding, limits, and reprice thresholds.
Test how your code handles invalid input and malformed outcomes.
Run public testnet books, trades, and candles.
Run authenticated reads on a dedicated account.
Gate mutations behind an explicit flag with unique IDs and targeted cleanup.
Run bounded scheduled test cycles and assert final open-order state.

Every mutation test needs a strict notional cap, total timeout, guaranteed targeted cleanup, and a final list_open assertion.

Upgrade checklist

The SDK is pre-1.0 and a minor release may break the API, so pin an exact version (polyester-sdk = "=0.12.0"). Review request, default, status, and stream changes in the changelog, run your tests, run public reads, execute one gated create-cancel-reconcile cycle, deploy one instance first, then roll out gradually.

Recipes

Authentication Configure Ed25519 API keys, Account ID, and env-based wiring for bots. Market data Read candles, public trades, order books, and market overview, no credentials required. Trading Place, modify, cancel, and batch spot orders; use triggers with the Rust SDK. Streaming Subscribe with observable errors, handshake-before-return, fail-closed overflow, and private Account ID requirements. Accounts & balances Funding vs trading balances, held amounts, subaccounts, policies, and transfer history. Deposits & withdrawals Deposit addresses, trading withdraws, internal transfers, and funding flows. Server-side usage Long-running bots, process lifecycle, catalogs, and configuration tips. Error handling Classify errors with is_retryable and mutation_outcome_unknown, then retry with stable identities.