fix(graph): resolve instrument identity to stop wrong-company hallucination

Agents had no ground-truth ticker→company mapping, so the market analyst
could pattern-match a price chart to the wrong company (e.g. TOTDY read as
"TotalEnergies"), and every downstream agent inherited the bad framing.

Resolve identity once at run start via a cached, fail-open yfinance lookup
and inject company/sector/exchange into the shared instrument context that
all twelve agents consume, with an explicit do-not-substitute instruction.
Resolution runs on both the propagate() and CLI entry points.

Also replaces the bare "Continue" message-clear placeholder, which some
OpenAI-compatible providers interpreted as the user task, with a
context-anchored placeholder carrying the resolved identity and date.

#814 #888

tests/test_instrument_identity.py

@@ -0,0 +1,170 @@
+"""Tests for deterministic instrument-identity resolution (#814) and the
+context-anchored message placeholder (#888)."""
+
+import unittest
+from unittest.mock import patch
+
+import pytest
+from langchain_core.messages import AIMessage, HumanMessage, RemoveMessage
+
+from tradingagents.agents.utils.agent_utils import (
+    build_instrument_context,
+    create_msg_delete,
+    get_instrument_context_from_state,
+    resolve_instrument_identity,
+)
+
+
+@pytest.mark.unit
+class ResolveInstrumentIdentityTests(unittest.TestCase):
+    def setUp(self):
+        resolve_instrument_identity.cache_clear()
+
+    def test_resolves_company_metadata_from_yfinance(self):
+        with patch("tradingagents.agents.utils.agent_utils.yf.Ticker") as mock:
+            mock.return_value.info = {
+                "longName": "TOTO LTD.",
+                "shortName": "TOTO",
+                "sector": "Industrials",
+                "industry": "Building Products & Equipment",
+                "exchange": "PNK",
+                "quoteType": "EQUITY",
+            }
+            identity = resolve_instrument_identity("totdy")
+        mock.assert_called_once_with("TOTDY")
+        self.assertEqual(identity["company_name"], "TOTO LTD.")
+        self.assertEqual(identity["sector"], "Industrials")
+        self.assertEqual(identity["industry"], "Building Products & Equipment")
+        self.assertEqual(identity["exchange"], "PNK")
+
+    def test_falls_back_to_short_name(self):
+        with patch("tradingagents.agents.utils.agent_utils.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:
+            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",
+            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:
+            mock.return_value.info = {"longName": "TOTO LTD."}
+            first = resolve_instrument_identity("TOTDY")
+            second = resolve_instrument_identity("TOTDY")
+        mock.assert_called_once()  # second call served from cache
+        self.assertEqual(first, second)
+
+
+@pytest.mark.unit
+class BuildInstrumentContextTests(unittest.TestCase):
+    def test_mentions_exact_symbol_without_identity(self):
+        context = build_instrument_context("7203.T")
+        self.assertIn("7203.T", context)
+        self.assertIn("exchange suffix", context)
+        self.assertNotIn("Resolved identity", context)
+
+    def test_injects_resolved_identity(self):
+        context = build_instrument_context(
+            "TOTDY", "stock",
+            {
+                "company_name": "TOTO LTD.",
+                "sector": "Industrials",
+                "industry": "Building Products & Equipment",
+                "exchange": "PNK",
+            },
+        )
+        self.assertIn("Company: TOTO LTD.", context)
+        self.assertIn("Industrials / Building Products & Equipment", context)
+        self.assertIn("Exchange: PNK", context)
+        self.assertIn("Do not substitute a different company", context)
+
+    def test_crypto_uses_name_label_and_keeps_hint(self):
+        context = build_instrument_context(
+            "BTC-USD", "crypto", {"company_name": "Bitcoin USD"}
+        )
+        self.assertIn("Name: Bitcoin USD", context)
+        self.assertIn("crypto asset rather than a company", context)
+
+
+@pytest.mark.unit
+class GetInstrumentContextFromStateTests(unittest.TestCase):
+    def test_prefers_precomputed_context(self):
+        state = {"company_of_interest": "TOTDY", "instrument_context": "PRECOMPUTED"}
+        self.assertEqual(get_instrument_context_from_state(state), "PRECOMPUTED")
+
+    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:
+            context = get_instrument_context_from_state(
+                {"company_of_interest": "NVDA", "asset_type": "stock"}
+            )
+        mock.assert_not_called()
+        self.assertIn("NVDA", context)
+
+    def test_fallback_respects_asset_type(self):
+        context = get_instrument_context_from_state(
+            {"company_of_interest": "BTC-USD", "asset_type": "crypto"}
+        )
+        self.assertIn("crypto asset", context)
+
+
+@pytest.mark.unit
+class ContextAnchoredPlaceholderTests(unittest.TestCase):
+    """#888 — the message-clear placeholder must not be a bare 'Continue'."""
+
+    def _run(self, state_extra):
+        state = {
+            "messages": [
+                HumanMessage(content="old", id="h1"),
+                AIMessage(content="reply", id="a1"),
+            ],
+            **state_extra,
+        }
+        return create_msg_delete()(state)
+
+    def test_placeholder_is_not_bare_continue(self):
+        result = self._run(
+            {"company_of_interest": "EC", "asset_type": "stock", "trade_date": "2026-05-28"}
+        )
+        placeholder = result["messages"][-1]
+        self.assertIsInstance(placeholder, HumanMessage)
+        self.assertNotEqual(placeholder.content.strip(), "Continue")
+
+    def test_placeholder_carries_resolved_identity(self):
+        result = self._run(
+            {
+                "company_of_interest": "EC",
+                "instrument_context": "The instrument to analyze is `EC`. Resolved identity: Company: Ecopetrol.",
+                "trade_date": "2026-05-28",
+            }
+        )
+        content = result["messages"][-1].content
+        self.assertIn("Ecopetrol", content)
+        self.assertIn("2026-05-28", content)
+
+    def test_old_messages_are_removed(self):
+        result = self._run({"company_of_interest": "EC", "trade_date": "2026-05-28"})
+        removals = [m for m in result["messages"] if isinstance(m, RemoveMessage)]
+        humans = [m for m in result["messages"] if isinstance(m, HumanMessage)]
+        self.assertEqual(len(removals), 2)
+        self.assertEqual(len(humans), 1)
+
+    def test_safe_defaults_when_state_minimal(self):
+        result = create_msg_delete()({"messages": [], "company_of_interest": "EC"})
+        placeholder = result["messages"][-1]
+        self.assertNotEqual(placeholder.content.strip(), "Continue")
+        self.assertIn("EC", placeholder.content)
+
+
+if __name__ == "__main__":
+    unittest.main()