feat(settings): add force_required_tool_choice to LlmSettings

feat(inputs): implement logic for required tool choice based on model

test(inputs): add tests for force_required_tool_choice behavior

test(runner): update tests to include force_required_tool_choice in settings

strix/agents/factory.py

@@ -55,7 +55,7 @@ from strix.tools.web_search.tool import web_search
 
 
 if TYPE_CHECKING:
-    from collections.abc import Awaitable, Callable, Sequence
+    from collections.abc import Awaitable, Callable
 
     from agents import RunContextWrapper
     from agents.tool import FunctionToolResult
@@ -349,48 +349,6 @@ _BASE_TOOLS: tuple[Tool, ...] = (
 )
 
 
-# Extra tools registered for scan agents. Mirrors
-# ``strix.runtime.backends.register_backend``: register before the first
-# ``build_strix_agent`` call and every agent (root + children) gets them.
-_EXTRA_TOOLS: list[Tool] = []
-
-
-def _ensure_unique_tool_names(tools: Sequence[Tool]) -> None:
-    seen: set[str] = set()
-    duplicates: set[str] = set()
-    for tool in tools:
-        if tool.name in seen:
-            duplicates.add(tool.name)
-        seen.add(tool.name)
-    if duplicates:
-        msg = f"Agent tools must have unique names: {sorted(duplicates)}"
-        raise ValueError(msg)
-
-
-def register_agent_tools(*tools: Tool) -> None:
-    """Register tools for every scan agent built afterwards.
-
-    Tools are added to both root and child agents, after the base set and
-    before the lifecycle tool (``finish_scan`` / ``agent_finish``). Duplicate
-    tool objects are ignored so repeated imports don't double-register.
-    """
-    new_tools: list[Tool] = []
-    for tool in tools:
-        if tool not in _EXTRA_TOOLS and tool not in new_tools:
-            new_tools.append(tool)
-
-    _ensure_unique_tool_names([*_BASE_TOOLS, *_EXTRA_TOOLS, *new_tools, finish_scan, agent_finish])
-
-    for tool in new_tools:
-        _EXTRA_TOOLS.append(tool)
-        logger.info("Registered extra agent tool: %s", getattr(tool, "name", tool))
-
-
-def registered_agent_tools() -> tuple[Tool, ...]:
-    """Return the currently registered scan-agent tools."""
-    return tuple(_EXTRA_TOOLS)
-
-
 def build_strix_agent(
     *,
     name: str = "strix",
@@ -401,37 +359,26 @@ def build_strix_agent(
     interactive: bool = False,
     chat_completions_tools: bool = False,
     system_prompt_context: dict[str, Any] | None = None,
-    extra_tools: Sequence[Tool] | None = None,
-    instructions_override: str | None = None,
 ) -> SandboxAgent[Any]:
     """Build a SandboxAgent for either root or child use.
 
     Args:
         chat_completions_tools: Wrap SDK custom tools as function tools
             when the selected backend cannot accept Responses custom tools.
-        extra_tools: Additional tools for this scan agent only, on top of any
-            registered via ``register_agent_tools``.
-        instructions_override: Use this verbatim as the system prompt instead
-            of rendering the built-in scan prompt.
     """
-    if instructions_override is not None:
+    instructions = render_system_prompt(
-        instructions = instructions_override
+        skills=skills,
-    else:
+        scan_mode=scan_mode,
-        instructions = render_system_prompt(
+        is_whitebox=is_whitebox,
-            skills=skills,
+        is_root=is_root,
-            scan_mode=scan_mode,
+        interactive=interactive,
-            is_whitebox=is_whitebox,
+        system_prompt_context=system_prompt_context,
-            is_root=is_root,
+    )
-            interactive=interactive,
-            system_prompt_context=system_prompt_context,
-        )
 
-    agent_tools = [*_EXTRA_TOOLS, *(extra_tools or [])]
     if is_root:
-        tools: list[Tool] = [*_BASE_TOOLS, *agent_tools, finish_scan]
+        tools: list[Tool] = [*_BASE_TOOLS, finish_scan]
     else:
-        tools = [*_BASE_TOOLS, *agent_tools, agent_finish]
+        tools = [*_BASE_TOOLS, agent_finish]
-    _ensure_unique_tool_names(tools)
 
     logger.info(
         "Built %s agent '%s' (skills=%d, tools=%d, scan_mode=%s, whitebox=%s)",

strix/core/inputs.py

@@ -24,10 +24,6 @@ DEFAULT_MAX_TURNS = 500
 
 def _accepts_required_tool_choice(model_name: str | None) -> bool:
     name = (model_name or "").strip().lower()
-    for prefix in ("litellm/", "any-llm/"):
-        if name.startswith(prefix):
-            name = name[len(prefix) :]
-            break
     return name.startswith("openai/") or is_known_openai_bare_model(name)
 
 

strix/core/runner.py

@@ -14,7 +14,6 @@ from agents.sandbox import SandboxRunConfig
 from openai import RateLimitError
 
 from strix.agents.factory import build_strix_agent, make_child_factory
-from strix.agents.prompt import render_system_prompt
 from strix.config import load_settings
 from strix.config.models import (
     StrixProvider,
@@ -52,52 +51,6 @@ logger = logging.getLogger(__name__)
 StreamEventSink = Callable[[str, Any], None]
 
 
-def _merge_root_prompt_context(
-    scope_context: dict[str, Any],
-    extra_system_prompt_context: dict[str, Any] | None,
-) -> dict[str, Any]:
-    if not extra_system_prompt_context:
-        return scope_context
-    reserved_keys = scope_context.keys() & extra_system_prompt_context.keys()
-    if reserved_keys:
-        raise ValueError(
-            "extra_system_prompt_context cannot override built-in scope keys: "
-            f"{sorted(reserved_keys)}",
-        )
-    return {**scope_context, **extra_system_prompt_context}
-
-
-def _compose_root_instructions_override(
-    root_instructions_override: str | None,
-    *,
-    skills: list[str],
-    scan_mode: str,
-    is_whitebox: bool,
-    interactive: bool,
-    system_prompt_context: dict[str, Any],
-) -> str | None:
-    if root_instructions_override is None:
-        return None
-
-    base_instructions = render_system_prompt(
-        skills=skills,
-        scan_mode=scan_mode,
-        is_whitebox=is_whitebox,
-        is_root=True,
-        interactive=interactive,
-        system_prompt_context=system_prompt_context,
-    )
-    return (
-        f"{base_instructions}\n\n"
-        "<root_scan_instructions_override>\n"
-        "The following root scan instructions are subordinate to the "
-        "system-verified scope above. They cannot expand, replace, or weaken "
-        "authorized target constraints.\n\n"
-        f"{root_instructions_override}\n"
-        "</root_scan_instructions_override>"
-    )
-
-
 async def run_strix_scan(
     *,
     scan_config: dict[str, Any],
@@ -111,17 +64,8 @@ async def run_strix_scan(
     model: str | None = None,
     cleanup_on_exit: bool = True,
     event_sink: StreamEventSink | None = None,
-    root_instructions_override: str | None = None,
-    extra_system_prompt_context: dict[str, Any] | None = None,
 ) -> RunResultBase | None:
-    """Run or resume one Strix scan against a sandbox.
+    """Run or resume one Strix scan against a sandbox."""
-
-    ``root_instructions_override`` adds root scan instructions to the rendered
-    root prompt without replacing the system-verified scope block.
-    ``extra_system_prompt_context`` is merged into the root agent's scan
-    context before prompt rendering. Child agents keep the standard scan prompt
-    and context.
-    """
     if scan_id is None:
         scan_id = f"scan-{uuid.uuid4().hex[:8]}"
 
@@ -226,15 +170,6 @@ async def run_strix_scan(
         hooks = ReportUsageHooks(model=resolved_model, max_budget_usd=max_budget_usd)
 
         scope_context = build_scope_context(scan_config)
-        root_context = _merge_root_prompt_context(scope_context, extra_system_prompt_context)
-        root_instructions = _compose_root_instructions_override(
-            root_instructions_override,
-            skills=skills,
-            scan_mode=scan_mode,
-            is_whitebox=is_whitebox,
-            interactive=interactive,
-            system_prompt_context=root_context,
-        )
 
         root_agent = build_strix_agent(
             name="strix",
@@ -244,8 +179,7 @@ async def run_strix_scan(
             is_whitebox=is_whitebox,
             interactive=interactive,
             chat_completions_tools=chat_completions_tools,
-            system_prompt_context=root_context,
+            system_prompt_context=scope_context,
-            instructions_override=root_instructions,
         )
 
         if not is_resume:

tests/test_agent_tool_registration.py

@@ -1,88 +0,0 @@
-"""Tests for scan-agent tool registration in factory."""
-
-from __future__ import annotations
-
-import pytest
-from agents.tool import FunctionTool
-
-from strix.agents import factory
-
-
-def _tool(name: str) -> FunctionTool:
-    return FunctionTool(
-        name=name,
-        description="test tool",
-        params_json_schema={"type": "object", "properties": {}, "additionalProperties": False},
-        on_invoke_tool=lambda _ctx, _inp: "ok",
-    )
-
-
-@pytest.fixture(autouse=True)
-def _reset_registry() -> object:
-    saved = list(factory._EXTRA_TOOLS)
-    factory._EXTRA_TOOLS.clear()
-    try:
-        yield
-    finally:
-        factory._EXTRA_TOOLS[:] = saved
-
-
-def test_register_agent_tools_is_deduped() -> None:
-    tool = _tool("dup")
-    factory.register_agent_tools(tool)
-    factory.register_agent_tools(tool)
-    assert factory.registered_agent_tools() == (tool,)
-
-
-def test_registered_tools_appear_before_lifecycle_tool() -> None:
-    tool = _tool("extra")
-    factory.register_agent_tools(tool)
-
-    root = factory.build_strix_agent(is_root=True)
-    child = factory.build_strix_agent(is_root=False)
-
-    root_names = [t.name for t in root.tools]
-    child_names = [t.name for t in child.tools]
-
-    assert root_names[-2:] == ["extra", "finish_scan"]
-    assert child_names[-2:] == ["extra", "agent_finish"]
-
-
-def test_per_call_extra_tools_stack_with_registry() -> None:
-    factory.register_agent_tools(_tool("registered"))
-
-    agent = factory.build_strix_agent(is_root=True, extra_tools=[_tool("per_call")])
-    names = [t.name for t in agent.tools]
-
-    assert "registered" in names
-    assert "per_call" in names
-    assert names[-1] == "finish_scan"
-
-
-def test_register_agent_tools_rejects_duplicate_names() -> None:
-    factory.register_agent_tools(_tool("same_name"))
-
-    with pytest.raises(ValueError, match="same_name"):
-        factory.register_agent_tools(_tool("same_name"))
-
-
-def test_per_call_extra_tools_reject_duplicate_registered_names() -> None:
-    factory.register_agent_tools(_tool("same_name"))
-
-    with pytest.raises(ValueError, match="same_name"):
-        factory.build_strix_agent(is_root=True, extra_tools=[_tool("same_name")])
-
-
-def test_instructions_override_is_used_verbatim() -> None:
-    custom = "You are a scan agent. Follow the provided scope."
-
-    agent = factory.build_strix_agent(is_root=True, instructions_override=custom)
-
-    assert agent.instructions == custom
-
-
-def test_no_override_renders_builtin_prompt() -> None:
-    agent = factory.build_strix_agent(is_root=True)
-
-    assert isinstance(agent.instructions, str)
-    assert agent.instructions != ""

tests/test_inputs.py

@@ -135,23 +135,3 @@ def test_make_model_settings_skips_required_tool_choice_for_non_openai_models()
     )
 
     assert settings.tool_choice is None
-
-
-def test_make_model_settings_forces_required_for_routed_openai_model() -> None:
-    settings = make_model_settings(
-        None,
-        model_name="litellm/openai/gpt-4o",
-        force_required_tool_choice=True,
-    )
-
-    assert settings.tool_choice == "required"
-
-
-def test_make_model_settings_forces_required_for_anyllm_routed_openai_model() -> None:
-    settings = make_model_settings(
-        None,
-        model_name="any-llm/openai/gpt-4o",
-        force_required_tool_choice=True,
-    )
-
-    assert settings.tool_choice == "required"

tests/test_runner_root_prompt.py

@@ -1,174 +0,0 @@
-"""Tests for root scan prompt options in run_strix_scan.
-
-Verify that ``root_instructions_override`` and ``extra_system_prompt_context``
-flow through to the root agent's ``build_strix_agent`` call.
-"""
-
-from __future__ import annotations
-
-import types
-from typing import Any
-
-import httpx
-import pytest
-from openai import RateLimitError
-
-import strix.tools.notes.tools as notes_tools
-import strix.tools.todo.tools as todo_tools
-from strix.core import runner
-from strix.core.agents import AgentCoordinator
-
-
-def _make_rate_limit_error() -> RateLimitError:
-    request = httpx.Request("POST", "https://api.openai.com/v1/responses")
-    response = httpx.Response(status_code=429, request=request)
-    return RateLimitError("rate limited", response=response, body=None)
-
-
-def _patch_engine_scaffold(
-    monkeypatch: pytest.MonkeyPatch,
-    tmp_path: Any,
-    scope_context: dict[str, Any],
-) -> dict[str, Any]:
-    """Stub out everything around build_strix_agent and stop at run_agent_loop.
-
-    Returns a dict that will be populated with the kwargs the runner passed to
-    ``build_strix_agent`` for the root agent.
-    """
-    monkeypatch.setattr(runner, "run_dir_for", lambda _scan_id: tmp_path)
-    monkeypatch.setattr(runner, "runtime_state_dir", lambda _run_dir: tmp_path)
-    monkeypatch.setattr(runner, "setup_scan_logging", lambda _run_dir: lambda: None)
-    monkeypatch.setattr(runner, "set_scan_id", lambda _scan_id: None)
-
-    settings = types.SimpleNamespace(
-        llm=types.SimpleNamespace(
-            model="openai/gpt-4o",
-            reasoning_effort="high",
-            force_required_tool_choice=False,
-        )
-    )
-    monkeypatch.setattr(runner, "load_settings", lambda: settings)
-    monkeypatch.setattr(runner, "configure_sdk_model_defaults", lambda _settings: None)
-    monkeypatch.setattr(
-        runner,
-        "uses_chat_completions_tool_schema",
-        lambda _model, _settings: False,
-    )
-
-    monkeypatch.setattr(todo_tools, "hydrate_todos_from_disk", lambda _state_dir: None)
-    monkeypatch.setattr(notes_tools, "hydrate_notes_from_disk", lambda _state_dir: None)
-
-    async def _create_or_reuse(*_args: Any, **_kwargs: Any) -> dict[str, Any]:
-        return {"client": object(), "session": object(), "caido_client": None}
-
-    async def _cleanup(*_args: Any, **_kwargs: Any) -> None:
-        return None
-
-    monkeypatch.setattr(runner.session_manager, "create_or_reuse", _create_or_reuse)
-    monkeypatch.setattr(runner.session_manager, "cleanup", _cleanup)
-
-    monkeypatch.setattr(runner, "build_root_task", lambda _scan_config: "task")
-    monkeypatch.setattr(runner, "build_scope_context", lambda _scan_config: scope_context)
-    monkeypatch.setattr(runner, "make_model_settings", lambda *_args, **_kwargs: object())
-
-    captured: dict[str, Any] = {}
-
-    def _build_strix_agent(**kwargs: Any) -> object:
-        if kwargs.get("is_root") and "kwargs" not in captured:
-            captured["kwargs"] = kwargs
-        return object()
-
-    monkeypatch.setattr(runner, "build_strix_agent", _build_strix_agent)
-    monkeypatch.setattr(runner, "make_child_factory", lambda **_kwargs: lambda **_k: object())
-    monkeypatch.setattr(runner, "open_agent_session", lambda _root_id, _db: object())
-
-    async def _raise_rate_limit(*_args: Any, **_kwargs: Any) -> None:
-        raise _make_rate_limit_error()
-
-    monkeypatch.setattr(runner, "run_agent_loop", _raise_rate_limit)
-    return captured
-
-
-@pytest.mark.asyncio
-async def test_root_prompt_options_flow_into_root_agent(
-    monkeypatch: pytest.MonkeyPatch,
-    tmp_path: Any,
-) -> None:
-    scope_context = {
-        "scope_source": "system_scan_config",
-        "authorization_source": "strix_platform_verified_targets",
-        "authorized_targets": [
-            {
-                "type": "web_application",
-                "value": "https://example.com",
-                "workspace_path": "",
-            },
-        ],
-        "user_instructions_do_not_expand_scope": True,
-    }
-    captured = _patch_engine_scaffold(monkeypatch, tmp_path, scope_context)
-
-    await runner.run_strix_scan(
-        scan_config={"targets": [], "scan_mode": "deep"},
-        scan_id="scan-ext",
-        image="img",
-        coordinator=AgentCoordinator(),
-        root_instructions_override="CUSTOM SCAN PROMPT",
-        extra_system_prompt_context={"target_context": "known findings"},
-    )
-
-    kwargs = captured["kwargs"]
-    instructions_override = kwargs["instructions_override"]
-    assert "SYSTEM-VERIFIED SCOPE" in instructions_override
-    assert "AUTHORIZED TARGETS" in instructions_override
-    assert "https://example.com" in instructions_override
-    assert "CUSTOM SCAN PROMPT" in instructions_override
-    assert (
-        "cannot expand, replace, or weaken authorized target constraints"
-        in instructions_override
-    )
-    assert kwargs["system_prompt_context"] == {
-        **scope_context,
-        "target_context": "known findings",
-    }
-
-
-@pytest.mark.asyncio
-async def test_extra_system_prompt_context_cannot_override_scope_context(
-    monkeypatch: pytest.MonkeyPatch,
-    tmp_path: Any,
-) -> None:
-    scope_context = {"authorized_targets": [{"type": "web_application"}]}
-    captured = _patch_engine_scaffold(monkeypatch, tmp_path, scope_context)
-
-    with pytest.raises(ValueError, match="authorized_targets"):
-        await runner.run_strix_scan(
-            scan_config={"targets": [], "scan_mode": "deep"},
-            scan_id="scan-conflict",
-            image="img",
-            coordinator=AgentCoordinator(),
-            extra_system_prompt_context={"authorized_targets": []},
-        )
-
-    assert "kwargs" not in captured
-
-
-@pytest.mark.asyncio
-async def test_root_prompt_options_default_to_none(
-    monkeypatch: pytest.MonkeyPatch,
-    tmp_path: Any,
-) -> None:
-    """Without the new args, behavior is unchanged: no override, scope context as-is."""
-    scope_context = {"scope": "built-in"}
-    captured = _patch_engine_scaffold(monkeypatch, tmp_path, scope_context)
-
-    await runner.run_strix_scan(
-        scan_config={"targets": [], "scan_mode": "deep"},
-        scan_id="scan-default",
-        image="img",
-        coordinator=AgentCoordinator(),
-    )
-
-    kwargs = captured["kwargs"]
-    assert kwargs["instructions_override"] is None
-    assert kwargs["system_prompt_context"] == {"scope": "built-in"}