fix(dataflows): report a vendor failure as a vendor failure

- yfinance returned its errors as text, which the router counted as an answer, so the chain stopped and the text reached the analyst
- an empty result is checked against the vendor being reachable, so an outage is not reported as a company with no data
- a chain where every vendor is unavailable says so instead of ending the run

tests/test_undated_tools_as_of.py

@@ -149,3 +149,80 @@ def test_an_indicator_that_could_not_be_read_is_not_shown_as_a_blank_value():
                            side_effect=RuntimeError("cache parse failed")), \
             pytest.raises(VendorError):
         y_finance.get_stockstats_indicator("AAPL", "rsi", "2026-05-08")
+
+
+@pytest.mark.unit
+@pytest.mark.parametrize("func, args", [
+    # A past date withholds the live profile before any request, so the
+    # fundamentals case is exercised on the date it does fetch.
+    ("get_fundamentals", ("AAPL", None)),
+    ("get_balance_sheet", ("AAPL", "annual", "2026-09-01")),
+    ("get_cashflow", ("AAPL", "annual", "2026-09-01")),
+    ("get_income_statement", ("AAPL", "annual", "2026-09-01")),
+    ("get_insider_transactions", ("AAPL", "2026-09-01")),
+])
+def test_a_yfinance_failure_is_a_vendor_error_not_a_report(func, args):
+    """Returning the failure as text makes the router count it as an answer, so
+    the chain stops and the analyst reads the error message as if it were data.
+    yfinance serves the default path, so this is the one that matters most."""
+    from tradingagents.dataflows import y_finance
+    from tradingagents.dataflows.errors import VendorError
+
+    with mock.patch.object(y_finance.yf, "Ticker", side_effect=RuntimeError("yahoo hiccup")), \
+            pytest.raises(VendorError):
+        getattr(y_finance, func)(*args)
+
+
+@pytest.mark.unit
+@pytest.mark.parametrize("func, args", [
+    ("get_news_yfinance", ("AAPL", "2026-08-25", "2026-09-01")),
+    ("get_global_news_yfinance", ("2026-09-01", 7, 5)),
+])
+def test_a_yfinance_news_failure_is_a_vendor_error_not_a_report(func, args):
+    from tradingagents.dataflows import yfinance_news
+    from tradingagents.dataflows.errors import VendorError
+
+    target = "Ticker" if "global" not in func else "Search"
+    with mock.patch.object(yfinance_news.yf, target, side_effect=RuntimeError("yahoo hiccup")), \
+            pytest.raises(VendorError):
+        getattr(yfinance_news, func)(*args)
+
+
+@pytest.mark.unit
+def test_an_unreachable_vendor_is_not_reported_as_a_missing_symbol(monkeypatch):
+    """yfinance returns an empty frame when it cannot reach Yahoo, with no
+    exception. Reporting that as "no data for AAPL" tells the analyst the
+    company has no balance sheet, when the truth is we could not ask."""
+    import pandas as pd
+
+    from tradingagents.dataflows import y_finance
+    from tradingagents.dataflows.errors import NoMarketDataError, VendorRateLimitError
+
+    empty = mock.Mock(quarterly_balance_sheet=pd.DataFrame(), balance_sheet=pd.DataFrame())
+    monkeypatch.setattr(y_finance.yf, "Ticker", lambda s: empty)
+
+    monkeypatch.setattr(y_finance, "vendor_reachable", lambda url: False)
+    with pytest.raises(VendorRateLimitError, match="unreachable"):
+        y_finance.get_balance_sheet("AAPL", "annual", "2026-09-01")
+
+    monkeypatch.setattr(y_finance, "vendor_reachable", lambda url: True)
+    with pytest.raises(NoMarketDataError):
+        y_finance.get_balance_sheet("AAPL", "annual", "2026-09-01")
+
+
+@pytest.mark.unit
+def test_every_vendor_unavailable_says_so_rather_than_crashing(monkeypatch):
+    """A throttled or unreachable chain used to raise RuntimeError('No available
+    vendor'), which ends the run, and never said the vendor was the problem."""
+    from tradingagents.dataflows import interface
+    from tradingagents.dataflows.errors import VendorRateLimitError
+
+    def _down(*a, **k):
+        raise VendorRateLimitError("Yahoo Finance is unreachable")
+
+    monkeypatch.setitem(interface.VENDOR_METHODS["get_balance_sheet"], "yfinance", _down)
+
+    out = interface.route_to_vendor("get_balance_sheet", "AAPL", "annual", "2026-09-01")
+
+    assert "unavailable" in out.lower() and "unreachable" in out.lower()
+    assert "delisted" not in out.lower()  # not a claim about the symbol

tradingagents/dataflows/interface.py

@@ -202,6 +202,7 @@ def route_to_vendor(method: str, *args, **kwargs):
         vendor_chain = all_available_vendors
 
     last_no_data: NoMarketDataError | None = None
+    last_unavailable: VendorRateLimitError | None = None
     first_error: Exception | None = None
     for vendor in vendor_chain:
         vendor_impl = VENDOR_METHODS[method][vendor]
@@ -209,8 +210,11 @@ def route_to_vendor(method: str, *args, **kwargs):
 
         try:
             return impl_func(*args, **kwargs)
-        except VendorRateLimitError:
+        except VendorRateLimitError as e:
-            logger.warning("Vendor %r rate-limited for %s; trying next vendor.", vendor, method)
+            logger.warning("Vendor %r unavailable for %s: %s; trying next vendor.", vendor, method, e)
+            # Kept so an all-unavailable chain can say the vendor was the
+            # problem, rather than reporting nothing about the symbol.
+            last_unavailable = e
             continue
         except VendorNotConfiguredError as e:
             logger.warning("Vendor %r not configured for %s; trying next vendor.", vendor, method)
@@ -259,6 +263,15 @@ def route_to_vendor(method: str, *args, **kwargs):
     # first real error (e.g. the primary vendor's network failure). Optional
     # enrichment categories degrade to a sentinel instead, so flavour data can't
     # abort the run.
+    # Every vendor was throttled or unreachable: that is a fact about the
+    # vendors, not about the instrument, and it must not end the run.
+    if last_unavailable is not None:
+        return (
+            f"DATA_UNAVAILABLE: no configured vendor could serve {method} right now "
+            f"({last_unavailable}). This says nothing about the instrument; report the "
+            f"data as unavailable and do not estimate or fabricate values."
+        )
+
     if first_error is not None:
         if category in OPTIONAL_CATEGORIES:
             logger.warning("Optional %s unavailable for %s: %s", category, method, first_error)

tradingagents/dataflows/utils.py

@@ -62,3 +62,16 @@ def get_scrubbed(url: str, *, params: dict, timeout: float, secret: str, passthr
     except requests.RequestException as exc:
         error = type(exc)(str(exc).replace(secret, "***")) if secret else exc
     raise error
+
+
+def vendor_reachable(url: str, timeout: float = 5.0) -> bool:
+    """Whether the vendor answers at all, for telling silence from an outage.
+
+    A client that returns an empty result instead of raising leaves those two
+    cases indistinguishable. Called only when a result is empty.
+    """
+    try:
+        requests.head(url, timeout=timeout, allow_redirects=True)
+        return True
+    except requests.RequestException:
+        return False

tradingagents/dataflows/y_finance.py

@@ -7,6 +7,7 @@ import yfinance as yf
 from dateutil.relativedelta import relativedelta
 
 from .date_window import withhold_live_profile
+from .errors import VendorError, VendorRateLimitError
 from .stockstats_utils import (
     StockstatsUtils,
     _assert_ohlcv_not_stale,
@@ -15,6 +16,9 @@ from .stockstats_utils import (
     yf_retry,
 )
 from .symbol_utils import NoMarketDataError, normalize_symbol
+from .utils import vendor_reachable
+
+_YAHOO_HOST = "https://query2.finance.yahoo.com"
 
 logger = logging.getLogger(__name__)
 
@@ -189,7 +193,7 @@ def get_stock_stats_indicators_window(
         for date_str, value in date_values:
             ind_string += f"{date_str}: {value}\n"
 
-    except NoMarketDataError:
+    except VendorError:
         raise  # Unknown/delisted symbol — let the router emit the sentinel
     except Exception as e:
         logger.warning("Bulk stockstats fetch failed, falling back per-day: %s", e)
@@ -264,7 +268,7 @@ def get_stockstats_indicator(
             indicator,
             curr_date,
         )
-    except NoMarketDataError:
+    except VendorError:
         raise  # Unknown/delisted symbol — let the router emit the sentinel
     except Exception as e:
         # An empty string renders as "2026-05-08: " in the indicator table, which
@@ -300,7 +304,7 @@ def get_fundamentals(
         info = yf_retry(lambda: ticker_obj.info)
 
         if not info:
-            raise NoMarketDataError(ticker, canonical, "no fundamentals returned")
+            _raise_for_empty(ticker, canonical, "fundamentals")
 
         fields = [
             ("Name", info.get("longName")),
@@ -347,10 +351,10 @@ def get_fundamentals(
 
         return header + "\n".join(lines)
 
-    except NoMarketDataError:
+    except VendorError:
         raise
     except Exception as e:
-        return f"Error retrieving fundamentals for {ticker}: {str(e)}"
+        raise NoMarketDataError(ticker, canonical, f"fundamentals unavailable: {e}") from e
 
 
 def get_balance_sheet(
@@ -371,7 +375,7 @@ def get_balance_sheet(
         data = filter_financials_by_date(data, curr_date)
 
         if data.empty:
-            raise NoMarketDataError(ticker, canonical, "no balance sheet data")
+            _raise_for_empty(ticker, canonical, "balance sheet data")
 
         # Convert to CSV string for consistency with other functions
         csv_string = data.to_csv()
@@ -383,10 +387,10 @@ def get_balance_sheet(
 
         return header + csv_string
 
-    except NoMarketDataError:
+    except VendorError:
         raise
     except Exception as e:
-        return f"Error retrieving balance sheet for {ticker}: {str(e)}"
+        raise NoMarketDataError(ticker, canonical, f"balance sheet unavailable: {e}") from e
 
 
 def get_cashflow(
@@ -407,7 +411,7 @@ def get_cashflow(
         data = filter_financials_by_date(data, curr_date)
 
         if data.empty:
-            raise NoMarketDataError(ticker, canonical, "no cash flow data")
+            _raise_for_empty(ticker, canonical, "cash flow data")
 
         # Convert to CSV string for consistency with other functions
         csv_string = data.to_csv()
@@ -419,10 +423,10 @@ def get_cashflow(
 
         return header + csv_string
 
-    except NoMarketDataError:
+    except VendorError:
         raise
     except Exception as e:
-        return f"Error retrieving cash flow for {ticker}: {str(e)}"
+        raise NoMarketDataError(ticker, canonical, f"cash flow unavailable: {e}") from e
 
 
 def get_income_statement(
@@ -443,7 +447,7 @@ def get_income_statement(
         data = filter_financials_by_date(data, curr_date)
 
         if data.empty:
-            raise NoMarketDataError(ticker, canonical, "no income statement data")
+            _raise_for_empty(ticker, canonical, "income statement data")
 
         # Convert to CSV string for consistency with other functions
         csv_string = data.to_csv()
@@ -455,10 +459,10 @@ def get_income_statement(
 
         return header + csv_string
 
-    except NoMarketDataError:
+    except VendorError:
         raise
     except Exception as e:
-        return f"Error retrieving income statement for {ticker}: {str(e)}"
+        raise NoMarketDataError(ticker, canonical, f"income statement unavailable: {e}") from e
 
 
 # Rows are dated by the transaction, which is when the insider traded, not when
@@ -483,6 +487,17 @@ _PERIOD_END_VINTAGE = (
 )
 
 
+def _raise_for_empty(ticker: str, canonical: str, what: str) -> None:
+    """Report an empty result as an absence, or as an outage if Yahoo is down.
+
+    yfinance returns an empty frame for a failed request rather than raising, so
+    without this an outage reads as "this company reports no {what}".
+    """
+    if not vendor_reachable(_YAHOO_HOST):
+        raise VendorRateLimitError(f"Yahoo Finance is unreachable; no {what} was retrieved")
+    raise NoMarketDataError(ticker, canonical, f"no {what}")
+
+
 def get_insider_transactions(
     ticker: Annotated[str, "ticker symbol of the company"],
     curr_date: Annotated[str | None, "only transactions on or before this date, yyyy-mm-dd"] = None,
@@ -519,4 +534,4 @@ def get_insider_transactions(
         return header + csv_string
 
     except Exception as e:
-        return f"Error retrieving insider transactions for {ticker}: {str(e)}"
+        raise NoMarketDataError(ticker, canonical, f"insider transactions unavailable: {e}") from e

tradingagents/dataflows/yfinance_news.py

@@ -8,6 +8,7 @@ from dateutil.relativedelta import relativedelta
 
 from .config import get_config
 from .date_window import coverage_gap, in_window
+from .errors import NoMarketDataError
 from .stockstats_utils import yf_retry
 from .symbol_utils import normalize_symbol
 
@@ -118,7 +119,7 @@ def get_news_yfinance(
         return f"## {ticker}{resolved} News, from {start_date} to {end_date}:\n\n{news_str}"
 
     except Exception as e:
-        return f"Error fetching news for {ticker}: {str(e)}"
+        raise NoMarketDataError(ticker, ticker, f"news unavailable: {e}") from e
 
 
 def get_global_news_yfinance(
@@ -196,4 +197,4 @@ def get_global_news_yfinance(
         return f"## Global Market News, from {start_date} to {curr_date}:\n\n{news_str}"
 
     except Exception as e:
-        return f"Error fetching global news: {str(e)}"
+        raise NoMarketDataError("global news", "global news", f"unavailable: {e}") from e