Add mmath500:en, fix inspect backend for multilingual tasks

src/lighteval/main_inspect.py

@@ -37,6 +37,7 @@
 from typer import Argument, Option
 from typing_extensions import Annotated
 
+from lighteval.cli_args import load_tasks_multilingual as load_tasks_multilingual_arg
 from lighteval.models.abstract_model import InspectAIModelConfig
 from lighteval.tasks.lighteval_task import LightevalTaskConfig
 
@@ -432,10 +433,11 @@ def eval(  # noqa C901
             rich_help_panel=HELP_PANEL_NAME_4,
         ),
     ] = False,
+    load_tasks_multilingual: load_tasks_multilingual_arg.type = load_tasks_multilingual_arg.default,
 ):
     from lighteval.tasks.registry import Registry
 
-    registry = Registry(tasks=tasks, custom_tasks=None, load_multilingual=False)
+    registry = Registry(tasks=tasks, custom_tasks=custom_tasks, load_multilingual=load_tasks_multilingual)
     task_configs = registry.task_to_configs
     inspect_ai_tasks = []
 

src/lighteval/tasks/multilingual/tasks/mmath500.py

@@ -6,12 +6,13 @@
 LumiOpen/MATH-500_mt
 
 abstract:
-Multilingual translations of the MATH-500 benchmark, a subset of 500 problems
-from the MATH benchmark that OpenAI created in their Let's Verify Step by Step
-paper. Currently contains Finnish translations produced with Claude Opus 4.5.
+Multilingual MATH-500 benchmark, a subset of 500 problems from the MATH
+benchmark that OpenAI created in their Let's Verify Step by Step paper.
+Contains the original English problems and Finnish translations produced
+with Claude Opus 4.5. Supports configurable scorer model via env vars.
 
 languages:
-finnish
+english, finnish
 
 tags:
 math, reasoning, multilingual
@@ -33,6 +34,12 @@
 
 
 MATH_QUERY_TEMPLATES = {
+    "en": """
+Solve the following problem. The final line of your response MUST be of the following format:
+"ANSWER: $ANSWER" (without quotes) where $ANSWER is the final answer. Think step by step before answering.
+
+{prompt}
+""".strip(),
     "fi": """
 Ratkaise seuraava tehtävä. Vastauksesi viimeisen rivin TÄYTYY olla seuraavassa muodossa:
 "ANSWER: $ANSWER" (ilman lainausmerkkejä), jossa $ANSWER on lopullinen vastaus. Ajattele vaiheittain ennen vastaamista.
@@ -84,6 +91,25 @@ def record_to_sample(record):
     return Sample(input=query, target=target)
 
 
+mmath500_en = LightevalTaskConfig(
+    name="mmath500:en",
+    prompt_function=_mmath500_prompt_fn("en"),
+    hf_repo="HuggingFaceH4/MATH-500",
+    hf_subset="default",
+    hf_avail_splits=["test"],
+    evaluation_splits=["test"],
+    few_shots_split=None,
+    few_shots_select=None,
+    generation_size=32768,
+    metrics=[
+        Metrics.pass_at_k_math(sample_params={"k": 1, "n": 1}),
+    ],
+    version=1,
+    sample_fields=record_to_sample,
+    solver=[prompt_template(MATH_QUERY_TEMPLATES["en"]), generate(cache=True)],
+    scorer=model_graded_fact(model=_get_scorer_model()),
+)
+
 mmath500_fi = LightevalTaskConfig(
     name="mmath500:fi",
     prompt_function=_mmath500_prompt_fn("fi"),
@@ -104,5 +130,6 @@ def record_to_sample(record):
 )
 
 TASKS_TABLE = [
+    mmath500_en,
     mmath500_fi,
 ]

src/lighteval/tasks/tasks/math_500.py

@@ -22,7 +22,17 @@
 true
 """
 
+import os
+import warnings
+
+warnings.warn(
+    "math_500 is deprecated, use mmath500:en instead (supports configurable scorer model)",
+    DeprecationWarning,
+    stacklevel=2,
+)
+
 from inspect_ai.dataset import Sample
+from inspect_ai.model import GenerateConfig, get_model
 from inspect_ai.scorer import model_graded_fact
 from inspect_ai.solver import generate, prompt_template
 
@@ -31,6 +41,21 @@
 from lighteval.tasks.requests import Doc
 
 
+def _get_scorer_model():
+    base_url = os.environ.get("SCORER_MODEL_BASE_URL")
+    if base_url:
+        model_name = os.environ.get("SCORER_MODEL_PATH", "Qwen/Qwen3.5-9B")
+        return get_model(
+            f"openai-api/scorer/{model_name}",
+            config=GenerateConfig(
+                extra_body={"chat_template_kwargs": {"enable_thinking": False}},
+            ),
+            base_url=base_url,
+            api_key=os.environ.get("VLLM_API_KEY", "inspectai"),
+        )
+    return None
+
+
 MATH_QUERY_TEMPLATE = """
 Solve the following problem. The final line of your response MUST be of the following format:
 "ANSWER: $ANSWER" (without quotes) where $ANSWER is the final answer. Think step by step before answering.
@@ -71,7 +96,7 @@ def record_to_sample(record):
     version=2,
     sample_fields=record_to_sample,
     solver=[prompt_template(MATH_QUERY_TEMPLATE), generate(cache=True)],
-    scorer=model_graded_fact(),
+    scorer=model_graded_fact(model=_get_scorer_model()),
 )
 
 TASKS_TABLE = [