refactor(dataflows): read company identity and settlement prices through the data layer

- the Yahoo vendor owns get_company_profile and get_closes; agent_utils and the graph no longer import yfinance
- a test keeps vendor libraries inside dataflows

tests/test_graph_end_to_end.py

@@ -20,7 +20,7 @@ from pydantic import Field
 from tradingagents.agents import schemas
 from tradingagents.agents.analysts import sentiment_analyst
 from tradingagents.agents.utils import agent_utils
-from tradingagents.dataflows import interface, market_data_validator
+from tradingagents.dataflows import interface, market_data_validator, y_finance
 from tradingagents.default_config import DEFAULT_CONFIG
 from tradingagents.graph import trading_graph
 
@@ -106,7 +106,7 @@ def offline(monkeypatch, tmp_path):
                         lambda *a, **k: called.add("ohlcv") or prices.copy())
     monkeypatch.setattr(sentiment_analyst, "fetch_stocktwits_messages", lambda *a, **k: "no posts")
     monkeypatch.setattr(sentiment_analyst, "fetch_reddit_posts", lambda *a, **k: "no posts")
-    monkeypatch.setattr(agent_utils.yf, "Ticker", lambda s: type("T", (), {"info": {"longName": "NVIDIA"}})())
+    monkeypatch.setattr(y_finance.yf, "Ticker", lambda s: type("T", (), {"info": {"longName": "NVIDIA"}})())
     agent_utils.resolve_instrument_identity.cache_clear()
     return called
 

tests/test_instrument_identity.py

@@ -21,7 +21,7 @@ class ResolveInstrumentIdentityTests(unittest.TestCase):
         resolve_instrument_identity.cache_clear()
 
     def test_resolves_company_metadata_from_yfinance(self):
-        with patch("tradingagents.agents.utils.agent_utils.yf.Ticker") as mock:
+        with patch("tradingagents.dataflows.y_finance.yf.Ticker") as mock:
             mock.return_value.info = {
                 "longName": "TOTO LTD.",
                 "shortName": "TOTO",
@@ -38,26 +38,26 @@ class ResolveInstrumentIdentityTests(unittest.TestCase):
         self.assertEqual(identity["exchange"], "PNK")
 
     def test_falls_back_to_short_name(self):
-        with patch("tradingagents.agents.utils.agent_utils.yf.Ticker") as mock:
+        with patch("tradingagents.dataflows.y_finance.yf.Ticker") as mock:
             mock.return_value.info = {"shortName": "TOTO", "sector": "Industrials"}
             identity = resolve_instrument_identity("TOTDY")
         self.assertEqual(identity["company_name"], "TOTO")
 
     def test_skips_placeholder_values(self):
-        with patch("tradingagents.agents.utils.agent_utils.yf.Ticker") as mock:
+        with patch("tradingagents.dataflows.y_finance.yf.Ticker") as mock:
             mock.return_value.info = {"longName": "  ", "sector": "None", "industry": "n/a"}
             identity = resolve_instrument_identity("TOTDY")
         self.assertEqual(identity, {})
 
     def test_fails_open_on_exception(self):
         with patch(
-            "tradingagents.agents.utils.agent_utils.yf.Ticker",
+            "tradingagents.dataflows.y_finance.yf.Ticker",
             side_effect=RuntimeError("rate limited"),
         ):
             self.assertEqual(resolve_instrument_identity("TOTDY"), {})
 
     def test_result_is_cached(self):
-        with patch("tradingagents.agents.utils.agent_utils.yf.Ticker") as mock:
+        with patch("tradingagents.dataflows.y_finance.yf.Ticker") as mock:
             mock.return_value.info = {"longName": "TOTO LTD."}
             first = resolve_instrument_identity("TOTDY")
             second = resolve_instrument_identity("TOTDY")
@@ -104,7 +104,7 @@ class GetInstrumentContextFromStateTests(unittest.TestCase):
 
     def test_fallback_is_network_free_ticker_only(self):
         # No instrument_context and no yfinance call — must not hit the network.
-        with patch("tradingagents.agents.utils.agent_utils.yf.Ticker") as mock:
+        with patch("tradingagents.dataflows.y_finance.yf.Ticker") as mock:
             context = get_instrument_context_from_state(
                 {"company_of_interest": "NVDA", "asset_type": "stock"}
             )

tests/test_layering.py

@@ -0,0 +1,35 @@
+"""Only the data layer imports vendor libraries.
+
+Vendor calls belong in dataflows, where failures are raised as VendorError
+subclasses; a call made elsewhere can report an outage as a fact about the market.
+"""
+
+import ast
+from pathlib import Path
+
+import pytest
+
+ROOT = Path(__file__).resolve().parents[1]
+VENDOR_LIBRARIES = {"yfinance"}
+
+
+def _imports(path: Path) -> set[str]:
+    names = set()
+    for node in ast.walk(ast.parse(path.read_text(encoding="utf-8"))):
+        if isinstance(node, ast.Import):
+            names |= {a.name.split(".")[0] for a in node.names}
+        elif isinstance(node, ast.ImportFrom) and node.module and not node.level:
+            names.add(node.module.split(".")[0])
+    return names
+
+
+@pytest.mark.unit
+def test_vendor_libraries_are_imported_only_by_the_data_layer():
+    data_layer = ROOT / "tradingagents" / "dataflows"
+    offenders = sorted(
+        str(path.relative_to(ROOT))
+        for package in ("tradingagents", "cli")
+        for path in (ROOT / package).rglob("*.py")
+        if data_layer not in path.parents and _imports(path) & VENDOR_LIBRARIES
+    )
+    assert offenders == []

tests/test_memory_log.py

@@ -1043,7 +1043,7 @@ def test_a_longer_window_asks_for_enough_price_history(monkeypatch):
             days = pd.bdate_range(start, end)
             return pd.DataFrame({"Close": range(len(days))}, index=days)
 
-    monkeypatch.setattr("tradingagents.graph.trading_graph.yf.Ticker", _Ticker)
+    monkeypatch.setattr("tradingagents.dataflows.y_finance.yf.Ticker", _Ticker)
 
     raw, alpha, days, resolved = graph._fetch_returns("NVDA", "2026-06-01", 21, benchmark="SPY")
 

tests/test_symbol_normalization_paths.py

@@ -8,8 +8,8 @@ hit the right instrument instead of failing/mismatching.
 import pandas as pd
 
 import tradingagents.agents.utils.agent_utils as au
+import tradingagents.dataflows.y_finance as y_finance
 import tradingagents.dataflows.yfinance_news as ynews
-import tradingagents.graph.trading_graph as tg
 from tradingagents.graph.trading_graph import TradingAgentsGraph
 
 
@@ -24,7 +24,7 @@ def test_identity_lookup_normalizes_symbol(monkeypatch):
         def info(self):
             return {"longName": "Gold Futures", "quoteType": "FUTURE"}
 
-    monkeypatch.setattr(au.yf, "Ticker", FakeTicker)
+    monkeypatch.setattr(y_finance.yf, "Ticker", FakeTicker)
     au.resolve_instrument_identity.cache_clear()
 
     identity = au.resolve_instrument_identity("XAUUSD")
@@ -45,7 +45,7 @@ def test_fetch_returns_normalizes_symbol(monkeypatch):
             idx = pd.date_range(start="2025-01-02", periods=len(prices), freq="D")
             return pd.DataFrame({"Close": prices}, index=idx)
 
-    monkeypatch.setattr(tg.yf, "Ticker", FakeTicker)
+    monkeypatch.setattr(y_finance.yf, "Ticker", FakeTicker)
 
     # _fetch_returns does not use ``self``; call unbound to avoid building the graph.
     raw, alpha, days, resolved = TradingAgentsGraph._fetch_returns(

tradingagents/agents/utils/agent_utils.py

@@ -3,7 +3,6 @@ import logging
 from collections.abc import Mapping
 from typing import Any
 
-import yfinance as yf
 from langchain_core.messages import HumanMessage, RemoveMessage
 
 # Import tools from separate utility files
@@ -23,6 +22,7 @@ from tradingagents.agents.utils.news_data_tools import (
 )
 from tradingagents.agents.utils.prediction_markets_tools import get_prediction_markets
 from tradingagents.agents.utils.technical_indicators_tools import get_indicators
+from tradingagents.dataflows.y_finance import get_company_profile
 
 # Public surface: the data tools are imported here so agents and the graph
 # import them from one place, plus the instrument/language helpers defined below.
@@ -106,13 +106,11 @@ def resolve_instrument_identity(ticker: str) -> dict:
     ticker-only context rather than failing before analysis starts. Cached so
     the lookup happens at most once per ticker per process.
 
-    The symbol is normalized first (e.g. ``XAUUSD`` -> ``GC=F``) so identity
-    resolves for the same instrument the price path actually fetches (#983).
+    Identity resolves for the same instrument the price path fetches
+    (``XAUUSD`` -> ``GC=F``, #983).
     """
-    from tradingagents.dataflows.symbol_utils import normalize_symbol
-
     try:
-        info = yf.Ticker(normalize_symbol(ticker)).info or {}
+        info = get_company_profile(ticker)
     except Exception as exc:  # noqa: BLE001 — fail open, never block the run
         logger.debug("Could not resolve instrument identity for %s: %s", ticker, exc)
         return {}

tradingagents/dataflows/y_finance.py

@@ -519,3 +519,22 @@ def get_insider_transactions(
 
     except Exception as e:
         raise NoMarketDataError(ticker, canonical, f"insider transactions unavailable: {e}") from e
+
+
+def get_company_profile(ticker: str) -> dict:
+    """Yahoo's current profile for ``ticker``: name, sector, industry and the like."""
+    canonical = normalize_symbol(ticker)
+    try:
+        return yf_retry(lambda: yf.Ticker(canonical).info) or {}
+    except Exception as e:
+        raise NoMarketDataError(ticker, canonical, f"profile unavailable: {e}") from e
+
+
+def get_closes(symbol: str, start_date: str, end_date: str) -> pd.Series:
+    """Daily closes from ``start_date`` up to, not including, ``end_date``."""
+    canonical = normalize_symbol(symbol)
+    try:
+        history = yf_retry(lambda: yf.Ticker(canonical).history(start=start_date, end=end_date))
+    except Exception as e:
+        raise NoMarketDataError(symbol, canonical, f"prices unavailable: {e}") from e
+    return history["Close"] if "Close" in history else pd.Series(dtype=float)

tradingagents/graph/trading_graph.py

@@ -8,7 +8,6 @@ from datetime import datetime, timedelta
 from pathlib import Path
 from typing import Any
 
-import yfinance as yf
 from langgraph.prebuilt import ToolNode
 
 # Import the abstract tool methods from agent_utils
@@ -31,6 +30,7 @@ from tradingagents.agents.utils.agent_utils import (
 from tradingagents.agents.utils.memory import TradingMemoryLog
 from tradingagents.dataflows.config import run_config, set_config
 from tradingagents.dataflows.utils import get_current_date, safe_ticker_component
+from tradingagents.dataflows.y_finance import get_closes
 from tradingagents.default_config import DEFAULT_CONFIG
 from tradingagents.llm_clients import create_llm_client
 from tradingagents.reporting import write_report_tree
@@ -302,8 +302,6 @@ class TradingAgentsGraph:
         the full holding window has not traded (#1169), or the symbol is delisted
         or unreachable.
         """
-        from tradingagents.dataflows.symbol_utils import normalize_symbol
-
         try:
             start = datetime.strptime(trade_date, "%Y-%m-%d")
             # holding_days counts trading days, so ask for the calendar span they
@@ -311,11 +309,9 @@ class TradingAgentsGraph:
             end = start + timedelta(days=round(holding_days * 7 / 5) + 7)
             end_str = end.strftime("%Y-%m-%d")
 
-            # Normalize so the realized-return lookup hits the same instrument
-            # the analysis priced (e.g. XAUUSD -> GC=F) (#984). The benchmark is
-            # already a canonical Yahoo symbol from ``_resolve_benchmark``.
-            stock = yf.Ticker(normalize_symbol(ticker)).history(start=trade_date, end=end_str)
-            bench = yf.Ticker(benchmark).history(start=trade_date, end=end_str)
+            # Closes for the instrument the analysis priced (XAUUSD -> GC=F, #984).
+            stock = get_closes(ticker, trade_date, end_str)
+            bench = get_closes(benchmark, trade_date, end_str)
 
             # Require the full holding window in both series. A rerun before it
             # has traded leaves the entry pending to retry next run, rather than
@@ -323,14 +319,8 @@ class TradingAgentsGraph:
             if len(stock) <= holding_days or len(bench) <= holding_days:
                 return None, None, None, None
 
-            raw = float(
-                (stock["Close"].iloc[holding_days] - stock["Close"].iloc[0])
-                / stock["Close"].iloc[0]
-            )
-            bench_ret = float(
-                (bench["Close"].iloc[holding_days] - bench["Close"].iloc[0])
-                / bench["Close"].iloc[0]
-            )
+            raw = float((stock.iloc[holding_days] - stock.iloc[0]) / stock.iloc[0])
+            bench_ret = float((bench.iloc[holding_days] - bench.iloc[0]) / bench.iloc[0])
             alpha = raw - bench_ret
             # The date of the last price bar used is when this outcome became
             # known — the point-in-time cutoff for injecting the lesson (#1251).