diff --git a/pyproject.toml b/pyproject.toml
index 1d30bb29f..e2468d852 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -74,6 +74,9 @@ postgres = [
 gpu = [
     "nvidia-ml-py>=12.560",
 ]
+hard-reasoning = [
+    "np-hard-reasoning @ git+https://github.com/allenai/np-hard-reasoning.git@fa8bbb2a5554e34a7ce051b71e9357e44dbabd0f",
+]
 clients = [
     "openai~=2.21.0",
 ]
diff --git a/src/olmo_eval/common/constants/models.py b/src/olmo_eval/common/constants/models.py
index 60eef6c45..6d76f95d3 100644
--- a/src/olmo_eval/common/constants/models.py
+++ b/src/olmo_eval/common/constants/models.py
@@ -44,6 +44,20 @@ def get_model_presets() -> dict[str, ProviderConfig]:
             revision="stage2-step47684",
             kwargs={"gpu_memory_utilization": 0.7, "add_bos_token": False},
         ),
+        "olmo-3-7b-instruct": ProviderConfig(
+            kind=ProviderKind.VLLM,
+            model="allenai/Olmo-3-7B-Instruct",
+        ),
+        "olmo-3.1-32b-instruct": ProviderConfig(
+            kind=ProviderKind.VLLM,
+            model="allenai/Olmo-3.1-32B-Instruct",
+            kwargs={"tensor_parallel_size": 2},
+        ),
+        "olmo-3.1-32b-think": ProviderConfig(
+            kind=ProviderKind.VLLM,
+            model="allenai/Olmo-3.1-32B-Think",
+            kwargs={"tensor_parallel_size": 2},
+        ),
         "olmo-2-7b": ProviderConfig(
             kind=ProviderKind.VLLM,
             model="allenai/OLMo-2-1124-7B",
@@ -58,6 +72,16 @@ def get_model_presets() -> dict[str, ProviderConfig]:
             kind=ProviderKind.VLLM,
             model="Qwen/Qwen2.5-7B",
         ),
+        "qwen3-32b": ProviderConfig(
+            kind=ProviderKind.VLLM,
+            model="Qwen/Qwen3-32B",
+            kwargs={"tensor_parallel_size": 2},
+        ),
+        "gemma-3-27b-it": ProviderConfig(
+            kind=ProviderKind.VLLM,
+            model="google/gemma-3-27b-it",
+            kwargs={"tensor_parallel_size": 2},
+        ),
         "qwen3-coder-30b": ProviderConfig(
             kind=ProviderKind.VLLM_SERVER,
             model="Qwen/Qwen3-Coder-30B-A3B-Instruct",
@@ -78,6 +102,21 @@ def get_model_presets() -> dict[str, ProviderConfig]:
             model="deepseek-ai/DeepSeek-R1-Distill-Llama-8B",
             max_model_len=32768,
         ),
+        "deepseek-r1-0528-qwen3-8b": ProviderConfig(
+            kind=ProviderKind.VLLM,
+            model="deepseek-ai/DeepSeek-R1-0528-Qwen3-8B",
+            max_model_len=32768,
+        ),
+        "gpt-oss-20b": ProviderConfig(
+            kind=ProviderKind.VLLM,
+            model="openai/gpt-oss-20b",
+        ),
+        "deepseek-r1-distill-qwen-32b": ProviderConfig(
+            kind=ProviderKind.VLLM,
+            model="deepseek-ai/DeepSeek-R1-Distill-Qwen-32B",
+            max_model_len=32768,
+            kwargs={"tensor_parallel_size": 2, "enforce_eager": True},
+        ),
         "mistral-7b": ProviderConfig(
             kind=ProviderKind.VLLM,
             model="mistralai/Mistral-7B-v0.3",
diff --git a/src/olmo_eval/evals/tasks/hard_reasoning.py b/src/olmo_eval/evals/tasks/hard_reasoning.py
new file mode 100644
index 000000000..7293adfcf
--- /dev/null
+++ b/src/olmo_eval/evals/tasks/hard_reasoning.py
@@ -0,0 +1,223 @@
+"""HardReasoning evaluation tasks.
+
+Logic puzzles and reasoning tasks that require multi-step constraint satisfaction.
+
+Dataset: allenai/hard-reasoning
+
+Usage:
+    olmo-eval run -m my-model -t hard_reasoning_bringing_toys
+    olmo-eval run -m my-model -t hard_reasoning_bringing_toys:chat
+"""
+
+from __future__ import annotations
+
+import json
+import sys
+from collections.abc import Iterator
+from dataclasses import dataclass
+from typing import Any
+
+from olmo_eval.common.formatters import ChatFormatter
+from olmo_eval.common.metrics import AccuracyMetric
+from olmo_eval.common.scorers import Scorer
+from olmo_eval.common.types import Instance, LMOutput, LMRequest, RequestType, SamplingParams, Split
+from olmo_eval.evals.tasks.common import Task, register, register_variant
+
+HARD_REASONING_TASKS: tuple[str, ...] = (
+    "bringing_toys",
+    "classroom_assignment",
+    "dinner_party",
+    "expense_splitting",
+    "printing_jobs",
+    "secret_santa",
+    "social_gathering",
+    "wedding_planning",
+    "wedding_supplies",
+)
+
+
+def _extract_last_complete_json(s: str) -> dict | None:
+    """Extract the last complete JSON object from a string."""
+    stack: list[int] = []
+    last_json_start: int | None = None
+    last_json_str: str | None = None
+    for i, char in enumerate(s):
+        if char == "{":
+            stack.append(i)
+            if last_json_start is None:
+                last_json_start = i
+        elif char == "}":
+            if stack:
+                stack.pop()
+                if not stack:
+                    last_json_str = s[last_json_start : i + 1]
+                    last_json_start = None
+    if last_json_str:
+        try:
+            return json.loads(last_json_str.replace("\n", ""))
+        except json.JSONDecodeError:
+            pass
+    return None
+
+
+@dataclass(frozen=True, slots=True)
+class HardReasoningParsedScorer(Scorer):
+    """Score 1.0 if the model output was parsed as valid JSON, else 0.0."""
+
+    name: str = "parsed"
+
+    def score(self, instance: Instance, output: LMOutput) -> float:
+        if output.extracted_answer is None:
+            return 0.0
+        try:
+            json.loads(output.extracted_answer)
+            return 1.0
+        except (json.JSONDecodeError, TypeError):
+            return 0.0
+
+
+@dataclass(frozen=True, slots=True)
+class HardReasoningScorer(Scorer):
+    """Score using the np_hard_reasoning check() function."""
+
+    name: str = "hard_reasoning_check"
+
+    def score(self, instance: Instance, output: LMOutput) -> float:
+        from np_hard_reasoning.scenarios.registry import SCENARIO_REGISTRY
+
+        if output.extracted_answer is None:
+            return 0.0
+        subset = instance.metadata.get("subset", "")
+        scenario_cls = SCENARIO_REGISTRY.get(subset)
+        if scenario_cls is None:
+            return 0.0
+        try:
+            scenario = scenario_cls.load_from_json(instance.metadata["scenario_data"])
+            return 1.0 if scenario.check_json(str(output.extracted_answer)) else 0.0
+        except Exception:
+            return 0.0
+
+
+class HardReasoningBase(Task):
+    """Base class for HardReasoning logic puzzle tasks.
+
+    Each subtask loads from a specific subset of the allenai/hard-reasoning dataset,
+    where files are organized as {subset}/dev_t1.jsonl and {subset}/test_t1.jsonl.
+    """
+
+    subset: str = "bringing_toys"
+    dependencies = [
+        "git+https://github.com/allenai/np-hard-reasoning.git@fa8bbb2a5554e34a7ce051b71e9357e44dbabd0f",
+        "z3-solver",
+        "networkx",
+    ]
+    sampling_params = SamplingParams(
+        max_tokens=4096,
+        temperature=0.0,
+        stop_sequences=("\n\n",),
+    )
+    metrics = (
+        AccuracyMetric(scorer=HardReasoningScorer),
+        AccuracyMetric(name="parse_rate", scorer=HardReasoningParsedScorer),
+    )
+
+    @property
+    def instances(self) -> Iterator[Instance]:
+        if self._instances_cache is None:
+            self._instances_cache = list(self._load_hard_reasoning_split(self.config.split))
+        yield from self._instances_cache
+
+    def _load_hard_reasoning_split(self, split: str) -> Iterator[Instance]:
+        """Load instances from a specific split of the hard-reasoning dataset."""
+        import json
+        import os
+
+        from huggingface_hub import hf_hub_download
+
+        file_name = "dev_t1.jsonl" if split == "validation" else "test_t1.jsonl"
+        local_path = hf_hub_download(
+            repo_id="allenai/hard-reasoning",
+            filename=f"{self.subset}/{file_name}",
+            repo_type="dataset",
+            token=os.environ.get("HF_TOKEN"),
+        )
+        with open(local_path) as f:
+            for index, line in enumerate(f):
+                doc = json.loads(line)
+                instance = self.process_doc(doc, index)
+                if instance is not None:
+                    yield instance
+
+    def process_doc(self, doc: dict[str, Any], index: int = 0) -> Instance | None:
+        return Instance(
+            question=doc["prompt"],
+            metadata={
+                "id": doc.get("id", index),
+                "scenario_data": doc["instance"],
+                "subset": self.subset,
+            },
+        )
+
+    def format_request(self, instance: Instance) -> LMRequest:
+        if self.config.formatter is not None:
+            return self.config.formatter.format(instance, self.get_fewshot())
+        return LMRequest(
+            request_type=RequestType.COMPLETION,
+            prompt=instance.question,
+        )
+
+    def extract_answer(self, output: LMOutput) -> str | None:
+        """Extract the last complete JSON object from the model's response."""
+        json_obj = _extract_last_complete_json(output.text)
+        if json_obj is not None:
+            return json.dumps(json_obj)
+        return output.text.strip() or None
+
+    def _build_fewshot(self) -> list[Instance]:
+        """Build few-shot examples from the dev split."""
+        import random
+
+        if self.config.num_fewshot == 0:
+            return []
+        all_instances = list(self._load_hard_reasoning_split("validation"))
+        if not all_instances:
+            return []
+        rng = random.Random(self.config.fewshot_seed)
+        return rng.sample(all_instances, min(self.config.num_fewshot, len(all_instances)))
+
+
+# =============================================================================
+# Task Registration
+# =============================================================================
+
+for _subset in HARD_REASONING_TASKS:
+    _task_name = f"hard_reasoning_{_subset}"
+    _class_name = f"HardReasoning_{_subset.title().replace('_', '')}"
+    _cls = type(
+        _class_name,
+        (HardReasoningBase,),
+        {
+            "subset": _subset,
+            "__module__": __name__,
+            "__qualname__": _class_name,
+        },
+    )
+    setattr(sys.modules[__name__], _class_name, _cls)
+    register(_task_name)(_cls)
+    register_variant(
+        _task_name,
+        "chat",
+        formatter=ChatFormatter(),
+        sampling_params=SamplingParams(max_tokens=32768, temperature=0.0),
+    )
+    register_variant(
+        _task_name,
+        "dev",
+        split=Split.VALIDATION,
+    )
+
+
+__all__ = [
+    "HARD_REASONING_TASKS",
+    "HardReasoningBase",
+]
diff --git a/src/olmo_eval/inference/providers/vllm.py b/src/olmo_eval/inference/providers/vllm.py
index eb64447a4..14d570942 100644
--- a/src/olmo_eval/inference/providers/vllm.py
+++ b/src/olmo_eval/inference/providers/vllm.py
@@ -216,6 +216,19 @@ def _build_sampling_params(self, params: SamplingParams) -> Any:
 
         return VLLMSamplingParams(**kwargs)
 
+    def _format_prompt(self, request: LMRequest) -> str:
+        """Convert a request to a prompt string, applying chat template for CHAT requests."""
+        from olmo_eval.common.types import RequestType
+
+        if request.request_type == RequestType.CHAT and request.messages:
+            tokenizer = self.llm.get_tokenizer()
+            return tokenizer.apply_chat_template(
+                list(request.messages),
+                tokenize=False,
+                add_generation_prompt=True,
+            )
+        return request.prompt
+
     def generate(
         self,
         requests: list[LMRequest],
@@ -224,7 +237,7 @@ def generate(
         params = self._default_sampling_params(sampling_params)
         vllm_params = self._build_sampling_params(params)
 
-        prompt_strs = [req.prompt for req in requests]
+        prompt_strs = [self._format_prompt(req) for req in requests]
 
         if is_debug_requests():
             for i, prompt in enumerate(prompt_strs):
diff --git a/tests/evals/tasks/test_hard_reasoning.py b/tests/evals/tasks/test_hard_reasoning.py
new file mode 100644
index 000000000..ecfd7b499
--- /dev/null
+++ b/tests/evals/tasks/test_hard_reasoning.py
@@ -0,0 +1,30 @@
+"""Tests for HardReasoning task logic."""
+
+from olmo_eval.evals.tasks.hard_reasoning import _extract_last_complete_json
+
+
+class TestExtractLastCompleteJson:
+    def test_simple_json(self):
+        assert _extract_last_complete_json('{"a": 1}') == {"a": 1}
+
+    def test_json_after_text(self):
+        assert _extract_last_complete_json('Some text {"key": "value"}') == {"key": "value"}
+
+    def test_returns_last_json(self):
+        result = _extract_last_complete_json('{"first": 1} some text {"second": 2}')
+        assert result == {"second": 2}
+
+    def test_nested_json(self):
+        assert _extract_last_complete_json('{"outer": {"inner": 42}}') == {"outer": {"inner": 42}}
+
+    def test_json_with_newlines(self):
+        assert _extract_last_complete_json('{"a":\n1}') == {"a": 1}
+
+    def test_no_json_returns_none(self):
+        assert _extract_last_complete_json("no json here") is None
+
+    def test_incomplete_json_returns_none(self):
+        assert _extract_last_complete_json('{"incomplete": ') is None
+
+    def test_empty_string_returns_none(self):
+        assert _extract_last_complete_json("") is None