{"record":{"id":"65ec51309bcd577d","repo":"nautechsystems/nautilus_trader","slug":"cannot-modify-order-in-place-no-parameters-differ","errorCode":null,"errorMessage":"Cannot modify order in place: no parameters differ from current values","messagePattern":"Cannot modify order in place: no parameters differ from current values","errorType":"validation","errorClass":null,"httpStatus":null,"severity":"warning","filePath":"crates/trading/src/algorithm/mod.rs","lineNumber":1043,"sourceCode":"                \"Cannot modify order in place: {} orders do not have a LIMIT price\",\n                order.order_type()\n            );\n        }\n\n        if trigger_price.is_some() && order.trigger_price().is_none() {\n            anyhow::bail!(\n                \"Cannot modify order in place: {} orders do not have a STOP trigger price\",\n                order.order_type()\n            );\n        }\n\n        // Check if any value would actually change\n        let qty_changing = quantity.is_some_and(|q| q != order.quantity());\n        let price_changing = price.is_some() && price != order.price();\n        let trigger_changing = trigger_price.is_some() && trigger_price != order.trigger_price();\n\n        if !qty_changing && !price_changing && !trigger_changing {\n            anyhow::bail!(\"Cannot modify order in place: no parameters differ from current values\");\n        }\n\n        let core = ExecutionAlgorithmNative::exec_algorithm_core_mut(self);\n        let ts_now = core.clock_mut().timestamp_ns();\n\n        let updated = OrderUpdated::new(\n            order.trader_id(),\n            order.strategy_id(),\n            order.instrument_id(),\n            order.client_order_id(),\n            quantity.unwrap_or_else(|| order.quantity()),\n            UUID4::new(),\n            ts_now,\n            ts_now,\n            false, // reconciliation\n            order.venue_order_id(),\n            order.account_id(),\n            price,","sourceCodeStart":1025,"sourceCodeEnd":1061,"githubUrl":"https://github.com/nautechsystems/nautilus_trader/blob/18893faf8b356be3320add8de2f861b0b647cf06/crates/trading/src/algorithm/mod.rs#L1025-L1061","documentation":"modify_order_in_place requires at least one supplied parameter (quantity, price, or trigger price) to actually differ from the order's current value. If nothing would change, the call bails to avoid emitting a pointless OrderUpdated event.","triggerScenarios":"Calling modify_order_in_place with values identical to the order's current quantity/price/trigger_price, e.g. recomputing the same slice quantity in a TWAP/VWAP loop.","commonSituations":"Algorithm re-invoked with cached/computed values that haven't changed; rounding producing the same quantity; a retry after a previous successful modification.","solutions":["Compare the new values against order.quantity()/price()/trigger_price() before calling, and skip the call when equal","Track whether parameters actually changed in the calling algorithm and only modify on change","Handle the no-op case as a benign condition rather than retrying the call"],"exampleFix":"// before\nalgo.modify_order_in_place(&mut order, Some(qty), None, None)?;\n// after\nif qty != order.quantity() {\n    algo.modify_order_in_place(&mut order, Some(qty), None, None)?;\n}","handlingStrategy":"validation","validationCode":"let changed = quantity.is_some_and(|q| q != order.quantity()) || price.is_some() && price != order.price() || trigger_price.is_some() && trigger_price != order.trigger_price();","typeGuard":null,"tryCatchPattern":"if let Err(e) = algo.modify_order_in_place(&mut order, q, p, t) { if !e.to_string().contains(\"no parameters differ\") { return Err(e); } /* treat as no-op */ }","preventionTips":["Compare new values against current order values before modifying","Treat identical-value modifications as benign no-ops in calling code"],"tags":["rust","orders","no-op"],"backgroundTag":"invalid-state-transition","analyzedSha":"18893faf8b356be3320add8de2f861b0b647cf06","analyzedAt":"2026-09-08T20:49:34.690Z","contentChangedAt":"2026-09-08T20:49:34.690Z","schemaVersion":2},"datasetVersion":"2026-09-14T05:17:10.506Z"}