fix(executor): surface the CLI stream error instead of the swallowed-stderr placeholder

When the `claude` CLI errors mid-stream, claude-agent-sdk throws a bare
`Exception("Command failed with exit code 1 …")` whose only text is the
useless `Check stderr output for details` placeholder — but the *actual*
failure reason (model 404, rate limit, auth) arrived a moment earlier as a
stream-json `ResultMessage(is_error=True)` carrying `result` text and
`api_error_status`. That was thrown away.

`_run_query` now captures `ResultMessage(is_error=True)` detail (and, as a
fallback, the trailing AssistantMessage text) and re-attaches it to the
raised exception as `_molecule_stream_detail`. `_format_process_error`
surfaces it as `cli_stream_error=…` and, when present, skips the
`_probe_claude_cli_error` re-probe (#160) — the probe can't replay the
failing `--model`/`--system-prompt` argv, so it may even succeed and
mislead. The probe stays as the last resort when there's nothing to salvage.

Regression context: the 2026-05-10 dev-team incident — six lead workspaces
404ing on every turn (`--model claude-code` → `api_error_status=404`,
"There's an issue with the selected model (claude-code)"), invisible for an
hour because the CLI wrote nothing to stderr and this text was discarded.
See internal#226 follow-up #5.

Tests: tests/test_executor_error_detail.py — 6 cases (format surfaces the
salvaged detail; format still probes when there's nothing salvaged; salvaged
detail takes precedence over the probe; _run_query annotates from
ResultMessage(is_error); _run_query falls back to assistant text; clean
success path unaffected). `pytest tests/` → 87 passed.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

adapter.py

@@ -278,6 +278,26 @@ def _load_providers(config_path: str) -> tuple:
     return tuple(parsed)
 
 
+# Aliases for `MODEL_PROVIDER` env values that should map to a registry
+# provider name. The persona env files use shorter / friendlier slugs
+# than the registry's canonical names — without this alias map a value
+# like ``MODEL_PROVIDER=claude-code`` would fall through to YAML-based
+# resolution and (when the YAML doesn't pin a provider) hit the
+# model-prefix matcher with the operator-picked MODEL, mis-routing a
+# lead workspace through MiniMax even though its CLAUDE_CODE_OAUTH_TOKEN
+# was clearly meant to be used.
+#
+# Maintain this list in sync with the persona env file convention:
+#   - ``claude-code``  → ``anthropic-oauth`` (Claude Code subscription path)
+#   - ``anthropic``    → ``anthropic-api``  (direct Anthropic API key)
+# Provider names already in the registry alias to themselves implicitly
+# (the ``in registry`` check catches them before this map is consulted).
+_PROVIDER_SLUG_ALIASES = {
+    "claude-code": "anthropic-oauth",
+    "anthropic": "anthropic-api",
+}
+
+
 def _resolve_model_and_provider_from_env(
     yaml_model: str,
     yaml_provider: str,
@@ -331,8 +351,20 @@ def _resolve_model_and_provider_from_env(
     # (provider name) vs. the legacy convention (model id). Persona-
     # convention wins when the value matches a registered provider; we
     # fall back to legacy interpretation only when it doesn't.
+    #
+    # First, apply the alias map so persona-friendly slugs like
+    # ``claude-code`` resolve to the canonical registry name
+    # ``anthropic-oauth``. Without this, a lead workspace's
+    # ``MODEL_PROVIDER=claude-code`` env would fall through to the model-
+    # prefix matcher, see ``MODEL=MiniMax-M2.7`` and mis-route to MiniMax
+    # even though the operator's intent (and the OAuth token they set)
+    # was the OAuth subscription path.
+    env_provider_resolved = _PROVIDER_SLUG_ALIASES.get(
+        env_provider.lower(), env_provider,
+    ) if env_provider else ""
     env_provider_is_slug = (
-        bool(env_provider) and env_provider.lower() in provider_names_lower
+        bool(env_provider_resolved)
+        and env_provider_resolved.lower() in provider_names_lower
     )
 
     # Picked model resolution
@@ -345,12 +377,30 @@ def _resolve_model_and_provider_from_env(
     else:
         picked_model = yaml_model or ""
 
-    # Explicit provider resolution — env wins when it's a registered slug,
-    # otherwise fall back to YAML.
+    # Explicit provider resolution — env wins when it's a registered slug
+    # (after alias mapping), otherwise fall back to YAML.
+    #
+    # YAML aliasing: the molecule-runtime wheel (config.py) auto-derives
+    # ``runtime_config.provider`` from the YAML/default model slug — the
+    # default model ``anthropic:claude-opus-4-7`` yields ``anthropic`` as
+    # the inferred provider. Without applying the alias map here, that
+    # auto-derived ``anthropic`` slug fails registry lookup and the
+    # adapter raises ValueError ("provider='anthropic' but it is not in
+    # the providers registry"), wedging the workspace at boot. The alias
+    # map already handles this for the env-var path above; mirror the
+    # same treatment for the YAML path so the runtime-wheel default
+    # produces a registered provider name in both cases. Caught
+    # 2026-05-09 on staging-cplead-2 — every workspace booted with
+    # ``configuration_status=not_configured`` because the YAML provider
+    # ``anthropic`` was passed through verbatim instead of being aliased
+    # to ``anthropic-api``.
     if env_provider_is_slug:
-        explicit_provider = env_provider
+        explicit_provider = env_provider_resolved
+    elif yaml_provider:
+        yp_lower = yaml_provider.lower()
+        explicit_provider = _PROVIDER_SLUG_ALIASES.get(yp_lower, yaml_provider)
     else:
-        explicit_provider = yaml_provider or None
+        explicit_provider = None
 
     return picked_model, explicit_provider
 

claude_sdk_executor.py

@@ -377,21 +377,37 @@ def _format_process_error(exc: BaseException) -> str:
     ``_probe_claude_cli_error`` so the operator sees the real failure
     reason (e.g. ``You've hit your limit · resets Apr 17``) instead of
     chasing ghosts in the workspace logs.
+
+    internal#226: prefer ``exc._molecule_stream_detail`` — the failure
+    reason ``_run_query`` salvaged from the CLI's stream-json
+    ``ResultMessage(is_error=True)`` (model 404, api_error_status, etc.)
+    before the SDK threw it away. That's the *exact* error for *this*
+    invocation; the ``_probe_claude_cli_error`` re-probe is a last resort
+    (it can't replay the failing ``--model``/``--system-prompt`` argv, so
+    it may even succeed and mislead — which is exactly what happened with
+    ``--model claude-code`` on 2026-05-10).
     """
     parts = [f"{type(exc).__name__}: {exc}"]
     exit_code = getattr(exc, "exit_code", None)
     if exit_code is not None:
         parts.append(f"exit_code={exit_code}")
+    stream_detail = getattr(exc, "_molecule_stream_detail", None)
+    if stream_detail:
+        trimmed = stream_detail[:_PROCESS_ERROR_STDERR_MAX_CHARS]
+        if len(stream_detail) > _PROCESS_ERROR_STDERR_MAX_CHARS:
+            trimmed += f"... [{len(stream_detail) - _PROCESS_ERROR_STDERR_MAX_CHARS} more chars truncated]"
+        parts.append(f"cli_stream_error={trimmed!r}")
     stderr = getattr(exc, "stderr", None)
     if stderr:
         trimmed = stderr[:_PROCESS_ERROR_STDERR_MAX_CHARS]
         if len(stderr) > _PROCESS_ERROR_STDERR_MAX_CHARS:
             trimmed += f"... [{len(stderr) - _PROCESS_ERROR_STDERR_MAX_CHARS} more chars truncated]"
         parts.append(f"stderr={trimmed!r}")
-    elif exit_code is None and _SWALLOWED_STDERR_MARKER in str(exc):
-        # #160: generic exception with the swallowed-stderr placeholder.
-        # Probe the CLI directly — this is the only way to surface the real
-        # error when the SDK lost it in translation.
+    elif exit_code is None and not stream_detail and _SWALLOWED_STDERR_MARKER in str(exc):
+        # #160: generic exception with the swallowed-stderr placeholder AND no
+        # stream detail to fall back on — probe the CLI directly as a last
+        # resort. (If _run_query salvaged a stream detail we already have the
+        # real error; the probe is unreliable since it can't replay the argv.)
         probed = _probe_claude_cli_error()
         if probed:
             parts.append(f"probed_cli_error={probed!r}")
@@ -586,6 +602,12 @@ class ClaudeSDKExecutor(AgentExecutor):
         assistant_chunks: list[str] = []
         result_text: str | None = None
         session_id: str | None = None
+        # Captured from a ResultMessage(is_error=True) — the CLI's stream-json
+        # carries the *actual* failure reason (model 404, rate limit, auth) in
+        # the result text + api_error_status BEFORE the SDK throws a bare
+        # "Command failed with exit code 1" that loses it. Stashed so the
+        # except arm below can re-attach it (see _format_process_error).
+        stream_error_detail: str | None = None
         self._active_stream = sdk.query(prompt=prompt, options=options)
         try:
             async for message in self._active_stream:
@@ -606,6 +628,34 @@ class ClaudeSDKExecutor(AgentExecutor):
                     if sid:
                         session_id = sid
                     result_text = getattr(message, "result", None)
+                    if getattr(message, "is_error", False):
+                        api_status = getattr(message, "api_error_status", None)
+                        stream_error_detail = (
+                            (f"api_error_status={api_status} " if api_status else "")
+                            + f"result={result_text!r}"
+                        )
+        except BaseException as exc:  # noqa: BLE001 — re-raised; we only annotate
+            # The claude-agent-sdk raises a bare Exception / ProcessError when
+            # the CLI subprocess errors mid-stream — but the actionable detail
+            # (model not found, rate limit, auth) arrived earlier as a
+            # ResultMessage(is_error) / synthetic AssistantMessage and is about
+            # to be discarded. Re-attach it so _format_process_error surfaces
+            # it instead of the useless "Check stderr output for details"
+            # placeholder. (The 2026-05-10 dev-team incident: `--model
+            # claude-code` → api_error_status=404, "There's an issue with the
+            # selected model (claude-code)" — invisible for an hour because
+            # the CLI wrote nothing to stderr and this text was thrown away.)
+            detail = stream_error_detail
+            if not detail:
+                last_assistant = "".join(assistant_chunks).strip()
+                if last_assistant:
+                    detail = last_assistant[:_PROCESS_ERROR_STDERR_MAX_CHARS]
+            if detail and getattr(exc, "_molecule_stream_detail", None) is None:
+                try:
+                    exc._molecule_stream_detail = detail  # type: ignore[attr-defined]
+                except Exception:  # pragma: no cover — exotic frozen exception
+                    pass
+            raise
         finally:
             self._active_stream = None
         text = result_text if result_text is not None else "".join(assistant_chunks)

tests/test_env_model_provider_dispatch.py

@@ -73,10 +73,11 @@ def test_persona_env_minimax_resolves_correctly(monkeypatch):
 
 def test_persona_env_lead_claude_code_resolves_correctly(monkeypatch):
     """Lead persona env (MODEL=opus, MODEL_PROVIDER=claude-code) —
-    ``claude-code`` isn't a registered provider name (registry uses
-    ``anthropic-oauth``), so it falls back to legacy interpretation
-    and yields no explicit provider, letting the model-based
-    fall-through to providers[0]=anthropic-oauth do the right thing."""
+    ``claude-code`` is the persona-friendly alias for the canonical
+    ``anthropic-oauth`` registry name. Must resolve via the alias map
+    so the lead boots through the OAuth subscription path even when
+    MODEL is a non-Anthropic model id (e.g. an operator who picked
+    MiniMax in canvas but whose persona env still pins claude-code)."""
     _clear_env(monkeypatch)
     monkeypatch.setenv("MODEL", "opus")
     monkeypatch.setenv("MODEL_PROVIDER", "claude-code")
@@ -84,10 +85,38 @@ def test_persona_env_lead_claude_code_resolves_correctly(monkeypatch):
         yaml_model="", yaml_provider="", providers=_REGISTRY,
     )
     assert model == "opus"
-    # claude-code is not a registered slug, so this falls back —
-    # provider is None and the caller will model-resolve to
-    # anthropic-oauth via the alias match on "opus".
-    assert provider is None
+    # claude-code → anthropic-oauth via the alias map
+    assert provider == "anthropic-oauth"
+
+
+def test_persona_env_lead_with_minimax_model_routes_via_oauth(monkeypatch):
+    """Lead workspace whose persona pins MODEL_PROVIDER=claude-code but
+    whose YAML/canvas selection happens to be a MiniMax model still
+    routes via OAuth — the persona's provider pin wins over the
+    model-prefix matcher. Without the alias map, the fall-through
+    mis-routed leads to MiniMax even when their CLAUDE_CODE_OAUTH_TOKEN
+    was set."""
+    _clear_env(monkeypatch)
+    monkeypatch.setenv("MODEL", "MiniMax-M2.7")
+    monkeypatch.setenv("MODEL_PROVIDER", "claude-code")
+    model, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="", providers=_REGISTRY,
+    )
+    assert model == "MiniMax-M2.7"
+    assert provider == "anthropic-oauth"
+
+
+def test_anthropic_alias_resolves_to_anthropic_api(monkeypatch):
+    """``MODEL_PROVIDER=anthropic`` alias → ``anthropic-api`` (direct
+    Anthropic API key path)."""
+    _clear_env(monkeypatch)
+    monkeypatch.setenv("MODEL", "claude-opus-4-7")
+    monkeypatch.setenv("MODEL_PROVIDER", "anthropic")
+    model, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="", providers=_REGISTRY,
+    )
+    assert model == "claude-opus-4-7"
+    assert provider == "anthropic-api"
 
 
 def test_persona_env_glm_resolves_correctly(monkeypatch):
@@ -184,6 +213,54 @@ def test_no_env_no_yaml_returns_empty(monkeypatch):
     assert provider is None
 
 
+def test_yaml_provider_anthropic_is_aliased_to_anthropic_api(monkeypatch):
+    """Regression for 2026-05-09 staging-cplead-2 incident: every
+    workspace booted ``configuration_status=not_configured`` because the
+    molecule-runtime wheel auto-derives ``runtime_config.provider =
+    "anthropic"`` from the default model slug ``anthropic:claude-opus-4-7``.
+    The adapter received ``yaml_provider="anthropic"`` from the wheel and
+    rejected it with ``ValueError: provider='anthropic' but it is not in
+    the providers registry`` — but ``anthropic`` is already in
+    ``_PROVIDER_SLUG_ALIASES`` for the env-var path. Mirror the alias map
+    on the YAML path so the wheel default produces a registered provider
+    name."""
+    _clear_env(monkeypatch)
+    _, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="anthropic", providers=_REGISTRY,
+    )
+    assert provider == "anthropic-api", (
+        f"yaml_provider='anthropic' must resolve through the alias map to "
+        f"'anthropic-api'; got {provider!r}. Without this aliasing the "
+        f"wheel-default workspace boot wedges at adapter.setup()."
+    )
+
+
+def test_yaml_provider_claude_code_is_aliased_to_anthropic_oauth(monkeypatch):
+    """Symmetric coverage: persona-friendly ``claude-code`` slug from the
+    YAML ``provider:`` field must alias to ``anthropic-oauth``, the same
+    way the env-var path resolves it. Lead workspaces that pin the OAuth
+    path in YAML (instead of via env) must not wedge."""
+    _clear_env(monkeypatch)
+    _, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="claude-code", providers=_REGISTRY,
+    )
+    assert provider == "anthropic-oauth"
+
+
+def test_yaml_provider_unknown_passes_through_for_actionable_error(monkeypatch):
+    """An unaliased, unknown YAML provider (e.g. ``yaml_provider="mystery"``)
+    must NOT be silently swapped to providers[0] — it must reach
+    ``_resolve_provider`` so the adapter raises the actionable
+    ``Known providers: ...`` error message. The alias map is a
+    convenience for the two persona-convention slugs only; everything
+    else must keep its original semantics."""
+    _clear_env(monkeypatch)
+    _, provider = _resolve_model_and_provider_from_env(
+        yaml_model="", yaml_provider="mystery", providers=_REGISTRY,
+    )
+    assert provider == "mystery"
+
+
 # ------------------------------------------------------------------
 # Whitespace / empty-value defensive cases
 # ------------------------------------------------------------------

tests/test_executor_error_detail.py

@@ -0,0 +1,221 @@
+"""Pin the CLI-stream-error surfacing in _run_query + _format_process_error.
+
+When the `claude` CLI errors mid-stream, the claude-agent-sdk throws a bare
+``Exception("Command failed with exit code 1 …")`` whose only text is the
+useless ``Check stderr output for details`` placeholder — but the *actual*
+failure reason (model 404, rate limit, auth) arrived a moment earlier as a
+stream-json ``ResultMessage(is_error=True)`` carrying ``result`` text and
+``api_error_status``. ``_run_query`` salvages that onto the exception
+(``_molecule_stream_detail``); ``_format_process_error`` surfaces it.
+
+Regression context: the 2026-05-10 dev-team incident — six lead workspaces
+404ing on every turn (``--model claude-code`` → ``api_error_status=404``,
+"There's an issue with the selected model (claude-code)"), invisible for an
+hour because the CLI wrote nothing to stderr and that text was thrown away.
+See internal#226.
+
+Stub pattern mirrors test_runtime_wedge_mirror.py — same _ensure_module /
+_ensure_attr / _load_executor helpers so a real-package install on a
+workstation still wins over the stubs.
+"""
+
+import os
+import sys
+import types
+from unittest.mock import MagicMock
+
+import pytest
+
+
+# ---- Stubs (mirror test_runtime_wedge_mirror.py) ----
+
+
+def _ensure_module(dotted: str) -> types.ModuleType:
+    if dotted not in sys.modules:
+        sys.modules[dotted] = types.ModuleType(dotted)
+    return sys.modules[dotted]
+
+
+def _ensure_attr(mod: types.ModuleType, name: str, value: object) -> None:
+    if not hasattr(mod, name):
+        setattr(mod, name, value)
+
+
+def _install_executor_stubs():
+    sdk = _ensure_module("claude_agent_sdk")
+    _ensure_attr(sdk, "ClaudeAgentOptions", MagicMock(name="ClaudeAgentOptions"))
+    _ensure_attr(sdk, "AssistantMessage", type("AssistantMessage", (), {}))
+    _ensure_attr(sdk, "TextBlock", type("TextBlock", (), {}))
+    _ensure_attr(sdk, "ResultMessage", type("ResultMessage", (), {}))
+    _ensure_attr(sdk, "query", MagicMock(name="query"))
+
+    _ensure_module("a2a")
+    _ensure_module("a2a.server")
+    a2a_exec = _ensure_module("a2a.server.agent_execution")
+    _ensure_attr(a2a_exec, "AgentExecutor", type("AgentExecutor", (), {}))
+    _ensure_attr(a2a_exec, "RequestContext", type("RequestContext", (), {}))
+    a2a_events = _ensure_module("a2a.server.events")
+    _ensure_attr(a2a_events, "EventQueue", type("EventQueue", (), {}))
+    a2a_helpers = _ensure_module("a2a.helpers")
+    _ensure_attr(a2a_helpers, "new_text_message", lambda *_a, **_kw: None)
+
+    _ensure_module("molecule_runtime")
+    rw = _ensure_module("molecule_runtime.runtime_wedge")
+    _ensure_attr(rw, "mark_wedged", lambda *_a, **_kw: None)
+    _ensure_attr(rw, "clear_wedge", lambda *_a, **_kw: None)
+    helpers = _ensure_module("molecule_runtime.executor_helpers")
+    for name in (
+        "auto_push_hook", "brief_summary", "collect_outbound_files", "commit_memory",
+        "extract_attached_files", "extract_message_text", "get_a2a_instructions",
+        "get_hma_instructions", "read_delegation_results", "recall_memories",
+        "set_current_task",
+    ):
+        _ensure_attr(helpers, name, lambda *_a, **_kw: ("" if "instr" in name or "summary" in name else None))
+    _ensure_attr(helpers, "collect_outbound_files", lambda *_a, **_kw: [])
+    _ensure_attr(helpers, "extract_attached_files", lambda *_a, **_kw: [])
+    _ensure_attr(helpers, "get_mcp_server_path", lambda *_a, **_kw: "/dev/null")
+    _ensure_attr(helpers, "get_system_prompt", lambda *_a, **_kw: "")
+    _ensure_attr(helpers, "sanitize_agent_error", lambda e: str(e))
+    _ensure_attr(helpers, "CONFIG_MOUNT", "/configs")
+    _ensure_attr(helpers, "WORKSPACE_MOUNT", "/workspace")
+    _ensure_attr(helpers, "MEMORY_CONTENT_MAX_CHARS", 10000)
+
+
+def _load_executor():
+    _install_executor_stubs()
+    parent_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+    if parent_dir not in sys.path:
+        sys.path.insert(0, parent_dir)
+    sys.modules.pop("claude_sdk_executor", None)
+    import claude_sdk_executor  # noqa: WPS433
+    return claude_sdk_executor
+
+
+def _async_stream(messages, raise_at_end=None):
+    """Build a fake `sdk.query(...)` return value: an async iterator that
+    yields ``messages`` then (optionally) raises — exactly the shape the
+    claude-agent-sdk produces when the CLI errors after emitting a
+    ResultMessage(is_error)."""
+    class _Stream:
+        def __aiter__(self):
+            return self
+
+        def __init__(self):
+            self._it = iter(messages)
+
+        async def __anext__(self):
+            try:
+                return next(self._it)
+            except StopIteration:
+                if raise_at_end is not None:
+                    raise raise_at_end
+                raise StopAsyncIteration
+
+    return _Stream()
+
+
+# ─── _format_process_error: surface the salvaged stream detail ───────────
+
+
+def test_format_process_error_surfaces_molecule_stream_detail():
+    mod = _load_executor()
+    exc = Exception("Command failed with exit code 1 — Check stderr output for details")
+    exc._molecule_stream_detail = (
+        'api_error_status=404 result="There\'s an issue with the selected '
+        'model (claude-code). It may not exist or you may not have access."'
+    )
+    out = mod._format_process_error(exc)
+    assert "cli_stream_error=" in out
+    assert "api_error_status=404" in out
+    assert "claude-code" in out
+    # When we already salvaged the real error, don't ALSO re-probe the CLI
+    # (the probe can't replay the failing --model argv and may mislead).
+    assert "probed_cli_error" not in out
+
+
+def test_format_process_error_still_probes_when_no_stream_detail(monkeypatch):
+    """The #160 fallback (probe the CLI when only the swallowed-stderr
+    placeholder is present) still fires when _run_query had nothing to
+    salvage."""
+    mod = _load_executor()
+    monkeypatch.setattr(mod, "_probe_claude_cli_error", lambda: "You've hit your limit · resets Apr 17")
+    exc = Exception("Command failed with exit code 1 — Check stderr output for details")
+    out = mod._format_process_error(exc)
+    assert "probed_cli_error=" in out
+    assert "hit your limit" in out
+
+
+def test_format_process_error_stream_detail_takes_precedence_over_probe(monkeypatch):
+    mod = _load_executor()
+    probe = MagicMock(name="_probe_claude_cli_error", return_value="<should not be called>")
+    monkeypatch.setattr(mod, "_probe_claude_cli_error", probe)
+    exc = Exception("Command failed with exit code 1 — Check stderr output for details")
+    exc._molecule_stream_detail = "api_error_status=429 result='rate limited'"
+    out = mod._format_process_error(exc)
+    assert "cli_stream_error=" in out
+    probe.assert_not_called()
+
+
+# ─── _run_query: salvage the detail onto the raised exception ────────────
+
+
+@pytest.mark.asyncio
+async def test_run_query_annotates_exception_from_is_error_result_message():
+    mod = _load_executor()
+    sdk = sys.modules["claude_agent_sdk"]
+
+    rm = sdk.ResultMessage()
+    rm.session_id = "sess-1"
+    rm.result = "There's an issue with the selected model (claude-code)."
+    rm.is_error = True
+    rm.api_error_status = 404
+
+    boom = Exception("Command failed with exit code 1 (exit code: 1)\nCheck stderr output for details")
+    sdk.query = MagicMock(return_value=_async_stream([rm], raise_at_end=boom))
+
+    ex = mod.ClaudeSDKExecutor(system_prompt="", config_path="/tmp", heartbeat=None, model="opus")
+    with pytest.raises(Exception) as ei:
+        await ex._run_query("hi", options=MagicMock())
+    detail = getattr(ei.value, "_molecule_stream_detail", None)
+    assert detail is not None
+    assert "api_error_status=404" in detail
+    assert "claude-code" in detail
+    # And it threads through the formatter the executor's error path uses.
+    assert "cli_stream_error=" in mod._format_process_error(ei.value)
+
+
+@pytest.mark.asyncio
+async def test_run_query_falls_back_to_assistant_text_when_no_error_result():
+    mod = _load_executor()
+    sdk = sys.modules["claude_agent_sdk"]
+
+    tb = sdk.TextBlock()
+    tb.text = "helpful pre-crash context from the model"
+    am = sdk.AssistantMessage()
+    am.content = [tb]
+
+    boom = Exception("Command failed with exit code 1 — Check stderr output for details")
+    sdk.query = MagicMock(return_value=_async_stream([am], raise_at_end=boom))
+
+    ex = mod.ClaudeSDKExecutor(system_prompt="", config_path="/tmp", heartbeat=None, model="opus")
+    with pytest.raises(Exception) as ei:
+        await ex._run_query("hi", options=MagicMock())
+    assert getattr(ei.value, "_molecule_stream_detail", None) == "helpful pre-crash context from the model"
+
+
+@pytest.mark.asyncio
+async def test_run_query_clean_success_unaffected():
+    """No exception → no annotation, normal QueryResult."""
+    mod = _load_executor()
+    sdk = sys.modules["claude_agent_sdk"]
+
+    rm = sdk.ResultMessage()
+    rm.session_id = "sess-ok"
+    rm.result = "done"
+    rm.is_error = False
+    sdk.query = MagicMock(return_value=_async_stream([rm]))
+
+    ex = mod.ClaudeSDKExecutor(system_prompt="", config_path="/tmp", heartbeat=None, model="opus")
+    res = await ex._run_query("hi", options=MagicMock())
+    assert res.text == "done"
+    assert res.session_id == "sess-ok"