fix(router): report a vendor chain with an unavailable vendor as unavailable, not as no data

- a vendor that throttled or failed the request never said whether it has the symbol, so another vendor's "no data" no longer speaks for the chain

tests/test_vendor_errors.py

@@ -94,6 +94,26 @@ class RouterHandlesBaseTypesTests(unittest.TestCase):
         ), self.assertRaises(AlphaVantageNotConfiguredError):
             router.route_to_vendor("get_stock_data", "AAPL", "2026-01-01", "2026-01-10")
 
+    def test_an_unavailable_vendor_keeps_absence_from_being_claimed(self):
+        # The throttled vendor's coverage was never learned, so "no usable data
+        # from any configured vendor" would be a claim nobody checked.
+        def throttled(*a, **k):
+            raise VendorUnavailableError("Yahoo HTTP 429")
+
+        def timed_out(*a, **k):
+            raise TimeoutError("read timed out")    # a vendor that does not type its failures
+
+        def not_covered(*a, **k):
+            raise NoMarketDataError("AAPL", "AAPL", "not covered")
+
+        for chain in ({"yfinance": throttled, "alpha_vantage": not_covered},
+                      {"yfinance": not_covered, "alpha_vantage": throttled},
+                      {"alpha_vantage": timed_out, "yfinance": not_covered}):
+            set_config({"data_vendors": {"core_stock_apis": ",".join(chain)}})
+            with mock.patch.dict(router.VENDOR_METHODS, {"get_stock_data": chain}, clear=False):
+                out = router.route_to_vendor("get_stock_data", "AAPL", "2026-01-01", "2026-01-10")
+            self.assertTrue(out.startswith("DATA_UNAVAILABLE"), out)
+
 
 if __name__ == "__main__":
     unittest.main()

tests/test_vendor_routing.py

@@ -72,13 +72,14 @@ class VendorRoutingTests(unittest.TestCase):
         self.assertEqual(result, "AV_DATA")
 
     def test_primary_error_is_logged_not_masked(self):
-        # #989: primary errors + fallback no-data -> NO_DATA, but the failure
-        # must be visible in logs (broken primary not hidden).
+        # #989: a broken primary is not hidden behind a fallback's verdict. It
+        # never said whether it has the symbol, so the answer is unavailable,
+        # and the failure is in the logs.
         set_config({"data_vendors": {"core_stock_apis": "yfinance,alpha_vantage"}})
         with self._route({"yfinance": _raises(ValueError("boom")), "alpha_vantage": _no_data}), \
                 self.assertLogs("tradingagents.dataflows.router", level="WARNING") as cm:
             result = router.route_to_vendor("get_stock_data", "AAPL", "2026-01-01", "2026-01-10")
-        self.assertIn("NO_DATA_AVAILABLE", result)
+        self.assertTrue(result.startswith("DATA_UNAVAILABLE"), result)
         joined = "\n".join(cm.output)
         self.assertIn("boom", joined)            # the real error surfaced in logs
         self.assertIn("yfinance", joined)

tradingagents/dataflows/router.py

@@ -173,7 +173,7 @@ def get_vendor(category: str, method: str = None) -> str:
     return config.get("data_vendors", {}).get(category, "default")
 
 
-def vendor_unavailable(method: str, error: VendorUnavailableError) -> str:
+def vendor_unavailable(method: str, error: Exception) -> str:
     """What a call returns when every vendor was throttled or unreachable."""
     return (
         f"DATA_UNAVAILABLE: no configured vendor could serve {method} right now "
@@ -211,6 +211,7 @@ def route_to_vendor(method: str, *args, **kwargs):
 
     last_no_data: NoMarketDataError | None = None
     last_unavailable: VendorUnavailableError | None = None
+    failed: Exception | None = None     # a vendor that raised something untyped
     first_error: Exception | None = None
     for vendor in vendor_chain:
         vendor_impl = VENDOR_METHODS[method][vendor]
@@ -239,9 +240,19 @@ def route_to_vendor(method: str, *args, **kwargs):
             logger.warning("Vendor %r failed for %s: %s", vendor, method, e)
             if first_error is None:
                 first_error = e
+            failed = e
             continue
 
-    # If any vendor reported "no data", the symbol is genuinely unavailable.
+    # A vendor that throttled or failed the request never said whether it has
+    # the symbol, so no other vendor's "no data" can speak for the whole chain:
+    # report the vendors as the problem, not the instrument. It must not end
+    # the run either.
+    if last_unavailable is not None:
+        return vendor_unavailable(method, last_unavailable)
+    if failed is not None and last_no_data is not None:
+        return vendor_unavailable(method, failed)
+
+    # Every vendor that answered reported "no data": the symbol is genuinely unavailable.
     # Return one explicit, instructive sentinel rather than a vendor-specific
     # empty string, so the agent reports "unavailable" instead of inventing a
     # value. This takes precedence over incidental fallback errors.
@@ -271,11 +282,6 @@ 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 vendor_unavailable(method, last_unavailable)
-
     if first_error is not None:
         if category in OPTIONAL_CATEGORIES:
             logger.warning("Optional %s unavailable for %s: %s", category, method, first_error)