diff --git a/docs/advanced/configuration.mdx b/docs/advanced/configuration.mdx
index f1542b75..5dbfb9b4 100644
--- a/docs/advanced/configuration.mdx
+++ b/docs/advanced/configuration.mdx
@@ -31,6 +31,11 @@ Configure Strix using environment variables or a config file.
Request timeout in seconds for LLM calls.
+
+ Optional maximum output tokens for each agent LLM request. Leave unset to use
+ the provider/model default.
+
+
Maximum number of retries for LLM API calls on transient failures.
diff --git a/strix/config/settings.py b/strix/config/settings.py
index 42a2c97e..cfe156e8 100644
--- a/strix/config/settings.py
+++ b/strix/config/settings.py
@@ -56,6 +56,7 @@ class LlmSettings(BaseSettings):
default=False,
alias="LLM_DISABLE_STREAMING",
)
+ max_tokens: int | None = Field(default=None, gt=0, alias="STRIX_LLM_MAX_TOKENS")
timeout: int = Field(default=300, alias="LLM_TIMEOUT")
stream_idle_timeout: int = Field(default=300, ge=0, alias="LLM_STREAM_IDLE_TIMEOUT")
max_tool_calls_per_turn: int = Field(
diff --git a/strix/core/inputs.py b/strix/core/inputs.py
index ea72abb7..54b21182 100644
--- a/strix/core/inputs.py
+++ b/strix/core/inputs.py
@@ -235,12 +235,14 @@ def make_model_settings(
prompt_cache: bool = True,
extra_headers: dict[str, str] | None = None,
has_tools: bool = True,
+ max_tokens: int | None = None,
) -> ModelSettings:
headers = _request_headers(model_name, extra_headers)
model_settings = ModelSettings(
parallel_tool_calls=False if has_tools else None,
retry=DEFAULT_MODEL_RETRY,
include_usage=True,
+ max_tokens=max_tokens,
extra_args=request_timeout_extra_args(request_timeout),
extra_headers=headers,
)
diff --git a/strix/core/runner.py b/strix/core/runner.py
index b4afdfaf..22ea4ea5 100644
--- a/strix/core/runner.py
+++ b/strix/core/runner.py
@@ -267,6 +267,7 @@ async def run_strix_scan(
request_timeout=settings.llm.timeout,
prompt_cache=settings.llm.prompt_cache,
extra_headers=settings.llm.extra_headers,
+ max_tokens=settings.llm.max_tokens,
)
run_config = RunConfig(
model=resolved_model,
diff --git a/tests/test_config_loader.py b/tests/test_config_loader.py
index e83ab119..e0d324f4 100644
--- a/tests/test_config_loader.py
+++ b/tests/test_config_loader.py
@@ -10,7 +10,7 @@ from pydantic import AliasChoices, Field, ValidationError
from pydantic.fields import FieldInfo
from strix.config import loader
-from strix.config.settings import ContextSettings
+from strix.config.settings import ContextSettings, LlmSettings
if TYPE_CHECKING:
@@ -28,6 +28,7 @@ _LLM_ENV_KEYS = [
"OLLAMA_API_BASE",
"STRIX_REASONING_EFFORT",
"STRIX_FORCE_REQUIRED_TOOL_CHOICE",
+ "STRIX_LLM_MAX_TOKENS",
"LLM_TIMEOUT",
"PERPLEXITY_API_KEY",
# RuntimeSettings
@@ -129,6 +130,10 @@ def test_tool_output_max_bytes_accepts_floor() -> None:
assert ContextSettings(STRIX_TOOL_OUTPUT_MAX_BYTES=1024).tool_output_max_bytes == 1024
+def test_llm_max_tokens_env_alias() -> None:
+ assert LlmSettings(STRIX_LLM_MAX_TOKENS=12_000).max_tokens == 12_000
+
+
# --------------------------------------------------------------------------- #
# _aliases_for
# --------------------------------------------------------------------------- #
diff --git a/tests/test_inputs.py b/tests/test_inputs.py
index 2ff9a603..03e1231d 100644
--- a/tests/test_inputs.py
+++ b/tests/test_inputs.py
@@ -320,6 +320,16 @@ def test_make_model_settings_sets_request_timeout() -> None:
assert settings.extra_args["timeout"] == 300.0
+def test_make_model_settings_sets_configured_token_budget() -> None:
+ settings = make_model_settings(
+ "none",
+ model_name="gpt-4o",
+ max_tokens=12_000,
+ )
+
+ assert settings.max_tokens == 12_000
+
+
def test_make_model_settings_omits_timeout_when_unset() -> None:
settings = make_model_settings("none", model_name="gpt-4o")
diff --git a/tests/test_runner_rate_limit.py b/tests/test_runner_rate_limit.py
index 3110ae2c..ae73b85f 100644
--- a/tests/test_runner_rate_limit.py
+++ b/tests/test_runner_rate_limit.py
@@ -42,6 +42,7 @@ async def test_persistent_rate_limit_stops_gracefully(
timeout=300,
prompt_cache=True,
extra_headers=None,
+ max_tokens=None,
),
runtime=types.SimpleNamespace(max_context_images=3),
)
diff --git a/tests/test_runner_root_prompt.py b/tests/test_runner_root_prompt.py
index 2c346203..60d9e206 100644
--- a/tests/test_runner_root_prompt.py
+++ b/tests/test_runner_root_prompt.py
@@ -50,6 +50,7 @@ def _patch_engine_scaffold(
timeout=300,
prompt_cache=True,
extra_headers=None,
+ max_tokens=12_000,
),
runtime=types.SimpleNamespace(max_context_images=3),
)
@@ -75,10 +76,15 @@ def _patch_engine_scaffold(
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: ModelSettings())
captured: dict[str, Any] = {}
+ def _make_model_settings(*_args: Any, **kwargs: Any) -> ModelSettings:
+ captured["model_settings_kwargs"] = kwargs
+ return ModelSettings()
+
+ monkeypatch.setattr(runner, "make_model_settings", _make_model_settings)
+
def _build_strix_agent(**kwargs: Any) -> object:
if kwargs.get("is_root") and "kwargs" not in captured:
captured["kwargs"] = kwargs
@@ -196,3 +202,20 @@ async def test_unknown_tool_calls_are_returned_to_the_model(
)
assert captured["run_config"].tool_not_found_behavior == "return_error_to_model"
+
+
+@pytest.mark.asyncio
+async def test_llm_max_tokens_flows_into_model_settings(
+ monkeypatch: pytest.MonkeyPatch,
+ tmp_path: Any,
+) -> None:
+ captured = _patch_engine_scaffold(monkeypatch, tmp_path, {"scope": "built-in"})
+
+ await runner.run_strix_scan(
+ scan_config={"targets": [], "scan_mode": "deep"},
+ scan_id="scan-token-budget",
+ image="img",
+ coordinator=AgentCoordinator(),
+ )
+
+ assert captured["model_settings_kwargs"]["max_tokens"] == 12_000