Add a condition card to the strategy. Returns a card_id and canonical name. If the condition type is known, use builder_discover(action='get', ref="<type>") for its direct schema. If it is unfamiliar or the task spans conditions, value refs, configuration, workflows, or recipes, start with builder_discover(action="facets"), narrow with exact list filters, then get a returned ref.

Multi-timeframe — set resolution inside an lhs/rhs value ref:

{"type": "compare",
 "lhs": {"type": "indicator", "indicator": "ema", "period": 14, "resolution": "4h"},
 "op": ">", "rhs": 50}

Cross-instrument market gate — e.g. only long when SPY is in an uptrend:

{"type": "regime_filter", "direction": "uptrend",
 "indicator": "price_vs_ma", "slow_period": 200, "symbol": "SPY"}

Cross-sectional (multi-sleeve / basket strategies only — single-symbol strategies reject these at compile time). Each compares this sleeve's value against portfolio siblings on the current bar.

Top-decile momentum (rank in the upper 10% of the universe):

{"type": "rank",
 "source": {"type": "indicator", "indicator": "roc", "period": 20},
 "op": ">", "value": 0.9}

Pairs-trade leg (long this sleeve when its close < QQQ's close):

{"type": "sibling_compare",
 "source": {"type": "price", "field": "close"},
 "op": "<", "symbol": "QQQ",
 "sibling_source": {"type": "price", "field": "close"}}