openpit is an embeddable pre-trade risk SDK for integrating policy-driven
risk checks into trading systems.
For an overview and links to all resources, see the project website openpit.dev. For full project documentation, see the repository README. For conceptual and architectural pages, see the project wiki.
Before the 1.0 release OpenPit follows a relaxed Semantic Versioning:
PATCHreleases carry bug fixes and small internal corrections.MINORreleases may introduce new features and may also change the public interface.
Breaking API changes can appear in minor releases before 1.0. Pick
version constraints that tolerate API evolution during the pre-stable
phase.
Visit the crate page on crates.io and the API documentation on docs.rs.
Run the following Cargo command in your project directory:
cargo add openpitThe engine evaluates an order through a deterministic pre-trade pipeline:
start_pre_trade(order)runs lightweight start-stage policiesPreTradeRequest::execute()runs main-stage policiesPreTradeReservation::commit()applies reserved state- dropping
PreTradeReservationrolls state back automatically apply_execution_report(report)updates post-trade policy state
Start-stage policies aggregate rejects from all registered policies. Main-stage policies aggregate rejects and roll back registered mutations in reverse order when any reject is produced.
Built-in policies:
SpotFundsPolicy- per-account solvency gate over spendable fundsOrderValidationPolicy- structural integrity checks on every orderRateLimitPolicy- throttle order flow per broker, asset, or accountOrderSizeLimitPolicy- fat-finger caps on quantity and notionalPnlBoundsKillSwitchPolicy- halt an account when realized P&L breaches bounds
The primary integration model is to write project-specific policies against the public Rust policy API: Custom Rust policies.
Two types of rejections are supported: a full kill switch for the account and a rejection of only the current request. Kill switches are intended for algorithmic trading where automatic order submission must be halted until the situation is analyzed.
Canonical contract: Threading Contract.
Custom policies that need internal state across calls use the built-in Storage abstraction. The synchronization policy - no-sync, full-sync, or caller-sharded for per-key parallelism - is selected once at engine construction and applied transparently. Policy code never names a lock primitive; misuse is prevented at compile time.
- The SDK never spawns OS threads. Every public method runs on the OS thread that invoked it.
FullSynchandles permit concurrent invocation, including calls for the same account.LocalSyncis single-threaded. The pure-RustAccountSynchandle isSend + !Syncand therefore forbids concurrent entry.FullSyncsynchronizes individual storage accesses, not whole pipelines. Same-account calls can interleave between accesses; operation-level atomicity is provided only where an API explicitly promises it.- Sequential calls to public methods on a movable handle may run on different OS threads. Handles, contexts, and callbacks are not OS-thread-pinned.
Reject.user_data/Order.user_data/ExecutionReport.user_data/AccountAdjustment.user_dataare opaque caller tokens. The SDK never inspects, dereferences, or frees them. Lifetime, thread-safety, and meaning are entirely caller-managed.
use std::time::Duration;
use openpit::{
FinancialImpact, ExecutionReportOperation, OrderOperation,
WithFinancialImpact, WithExecutionReportOperation,
};
use openpit::param::{
AccountId, Asset, Fee, Pnl, Price, Quantity, Side, TradeAmount, Volume,
};
use openpit::pretrade::policies::{
OrderSizeAssetBarrier, OrderSizeBrokerBarrier, OrderSizeLimit, OrderSizeLimitPolicy,
OrderSizeLimitSettings, OrderValidationPolicy,
PnlBoundsBrokerBarrier, PnlBoundsKillSwitchPolicy, PnlBoundsKillSwitchSettings,
RateLimit, RateLimitBrokerBarrier, RateLimitPolicy, RateLimitSettings,
};
use openpit::storage::NoLocking;
use openpit::{Engine, Instrument};
# fn main() -> Result<(), Box<dyn std::error::Error>> {
let usd = Asset::new("USD")?;
// 1. Build the engine builder.
type Report = WithExecutionReportOperation<WithFinancialImpact<()>>;
let builder = Engine::builder::<OrderOperation, Report, ()>().no_sync();
// 2. Configure policies.
let pnl_policy = PnlBoundsKillSwitchPolicy::new(
PnlBoundsKillSwitchSettings::new(
[PnlBoundsBrokerBarrier {
settlement_asset: usd.clone(),
lower_bound: Some(Pnl::from_str("-1000")?),
upper_bound: None,
}],
[],
)?,
builder.storage_builder(),
);
let rate_limit_policy = RateLimitPolicy::new(
RateLimitSettings::new(
Some(RateLimitBrokerBarrier {
limit: RateLimit {
max_orders: 100,
window: Duration::from_secs(1),
},
}),
[],
[],
[],
)?,
builder.storage_builder(),
);
// 3. Build the engine (one time at the platform initialization).
let engine = builder
.pre_trade(OrderValidationPolicy::new())
.pre_trade(pnl_policy)
.pre_trade(rate_limit_policy)
.pre_trade(OrderSizeLimitPolicy::<NoLocking>::new(
OrderSizeLimitSettings::new(
Some(OrderSizeBrokerBarrier {
limit: OrderSizeLimit {
max_quantity: Quantity::from_str("500")?,
max_notional: Volume::from_str("100000")?,
},
}),
[OrderSizeAssetBarrier {
limit: OrderSizeLimit {
max_quantity: Quantity::from_str("500")?,
max_notional: Volume::from_str("100000")?,
},
settlement_asset: usd.clone(),
}],
[],
)?,
))
.build()?;
// 3. Check an order.
let order = OrderOperation {
instrument: Instrument::new(
Asset::new("AAPL")?,
usd.clone(),
),
account_id: AccountId::from_u64(99224416),
side: Side::Buy,
trade_amount: TradeAmount::Quantity(
Quantity::from_f64(100.0)?,
),
price: Some(Price::from_str("185")?),
};
let request = engine.start_pre_trade(order)?;
// 4. Quick, lightweight checks, such as fat-finger scope or enabled killswitch,
// were performed during pre-trade request creation. The system state has not
// yet changed, except in cases where each request, even rejected ones, must be
// considered (for example, to prevent frequent transfers). Before the
// heavy-duty checks, other work on the request can be performed simply by
// holding the request object.
// 5. Real pre-trade and risk control.
let mut reservation = request.execute()?;
// Optional shortcut for the same two-stage flow:
// let reservation = engine.execute_pre_trade(order)?;
// 6. If the request is successfully sent to the venue, it must be committed.
// The rollback must be called otherwise to revert all performed reservations.
reservation.commit();
// 7. The order goes to the venue and returns with an execution report.
let report = WithExecutionReportOperation {
inner: WithFinancialImpact {
inner: (),
financial_impact: FinancialImpact {
pnl: Pnl::from_str("-50")?,
fee: Fee::from_str("3.4")?,
},
},
operation: ExecutionReportOperation {
instrument: Instrument::new(
Asset::new("AAPL")?,
usd,
),
account_id: AccountId::from_u64(99224416),
side: Side::Buy,
},
};
let result = engine.apply_execution_report(&report);
for outcome in &result.account_pnls {
eprintln!("account P&L outcome for {}", outcome.account_id);
}
for outcome in &result.account_adjustments {
eprintln!(
"account adjustment from group {}",
outcome.policy_group_id.value()
);
}
// 8. After each execution report is applied, the system may report that it has
// been determined in advance that all subsequent requests will be rejected if
// the account status does not change.
assert!(result.account_blocks.is_empty());
# Ok(())
# }Rejects from start_pre_trade(order) and PreTradeRequest::execute() are
returned as
Err(Reject) and Result<PreTradeReservation, Vec<Reject>>.
Each Reject contains:
policy: policy namecode: stable machine-readable code (for exampleRejectCode::OrderQtyExceedsLimit)reason: short human-readable reject type (for example"order quantity exceeded")details: concrete case details (for example"requested 11, max allowed: 10")scope:RejectScope::OrderorRejectScope::Accountuser_data: opaque caller-defined pointer payload (nullby default)
RejectCode values are standardized and stable across Rust, Python, and C FFI.