fix(strategy_v2): accept positional key/value in DiscoveryContext.set_metadata (#209)

Signed-off-by: Sai Asish Y <say.apm35@gmail.com>

Author: Sai Asish Y

backend_api_python/app/services/ai_generation_contracts.py

@@ -32,7 +32,7 @@
 - Read run-supplied values only inside executable handlers or scheduled callbacks with `context.params.get("name", same_default)`. The discovery context used by `initialize(context)` has no `params`; never read `context.params` in `initialize`.
 - Parameters may control signal periods, thresholds, target weights, stops, take profit, trailing protection, cooldowns, and bounded layer counts.
 - Do not disguise universe, symbol, market type, frequency, leverage permission, initial capital, date range, commission, or slippage as ordinary strategy parameters.
-- Use `context.set_metadata(...)` in `initialize` for stable descriptive metadata such as direction mode and strategy family. Metadata is not a substitute for executable risk logic.
+- Use `context.set_metadata(...)` in `initialize` for stable descriptive metadata such as direction mode and strategy family, passing keyword arguments such as `context.set_metadata(direction_mode="long_only", strategy_family="trend")`. Metadata is not a substitute for executable risk logic.
 
 ## Data and factors
 - Historical-bar signatures are exact: `get_history(count, frequency=None, field=None, security_list=None)` and `data.history(symbols, count, fields=None)`.

backend_api_python/app/services/strategy_v2/contract.py

@@ -6,7 +6,7 @@
 import hashlib
 from dataclasses import dataclass
 from types import SimpleNamespace
-from typing import Any, Callable, Iterable
+from typing import Any, Callable, Iterable, Mapping
 
 from app.utils.safe_exec import build_safe_builtins, safe_exec_with_validation
 from app.services.factors import FactorError, get_factor
@@ -150,7 +150,15 @@ def allow_leverage(self, max_leverage: object = 1) -> None:
         self.leverage_allowed = value > 1.0
         self.max_leverage = value
 
-    def set_metadata(self, **values: Any) -> None:
+    def set_metadata(self, *args: Any, **values: Any) -> None:
+        if len(args) == 1 and isinstance(args[0], Mapping):
+            self.metadata.update(args[0])
+        elif len(args) == 2:
+            self.metadata[str(args[0])] = args[1]
+        elif args:
+            raise TypeError(
+                "set_metadata expects keyword arguments, a single key/value pair, or a mapping"
+            )
         self.metadata.update(values)
 
 

backend_api_python/tests/test_strategy_v2_contract.py

@@ -405,6 +405,23 @@ def handle_data(context, data):
     assert manifest.metadata()["directionMode"] == "both"
 
 
+def test_set_metadata_accepts_positional_key_value_pair():
+    code = """
+def initialize(context):
+    context.set_universe(["Crypto:BTC/USDT@okx:swap"])
+    context.subscribe(frequency="1h")
+    context.set_metadata("direction_mode", "long_only")
+    context.set_metadata({"strategy_family": "trend"})
+
+def handle_data(context, data):
+    pass
+"""
+    manifest = compile_strategy_v2(code).manifest
+
+    assert manifest.direction_mode == "long_only"
+    assert manifest.metadata()["directionMode"] == "long_only"
+
+
 @pytest.mark.parametrize(
     "strategy_body,expected",
     [