AffineFoundation
diff --git a/‎liveweb_arena/core/task_registry.py‎
Lines changed: 8 additions & 0 deletions b/‎liveweb_arena/core/task_registry.py‎
Lines changed: 8 additions & 0 deletions
diff --git a/‎liveweb_arena/plugins/openlibrary/openlibrary.py‎
Lines changed: 2 additions & 1 deletion b/‎liveweb_arena/plugins/openlibrary/openlibrary.py‎
Lines changed: 2 additions & 1 deletion
diff --git a/‎liveweb_arena/plugins/openlibrary/templates/__init__.py‎
Lines changed: 6 additions & 0 deletions b/‎liveweb_arena/plugins/openlibrary/templates/__init__.py‎
Lines changed: 6 additions & 0 deletions
diff --git a/‎liveweb_arena/plugins/openlibrary/templates/author_comparison.py‎
Lines changed: 256 additions & 0 deletions b/‎liveweb_arena/plugins/openlibrary/templates/author_comparison.py‎
Lines changed: 256 additions & 0 deletions
@@ -153,6 +153,11 @@ class TaskRegistry:
         92: ("arxiv", "arxiv_category_comparison"),
         94: ("arxiv", "arxiv_multi_author_filter"),
         95: ("arxiv", "arxiv_title_length_extrema"),
+
+        # Open Library templates — engagement & comparison
+        96: ("openlibrary", "openlibrary_author_engagement_extrema"),
+        97: ("openlibrary", "openlibrary_author_comparison"),
+        98: ("openlibrary", "openlibrary_reading_stats_filter"),
     }
 
     # Template versions - each version's combinations come AFTER all previous versions
@@ -181,6 +186,9 @@ class TaskRegistry:
         [85, 86, 87, 88],
         # Version 6: ArXiv templates
         [90, 91, 92, 94, 95],
+        # Version 7: Open Library engagement & comparison templates (PR #13)
+        # NOTE: PR #14 (openmeteo IDs 99-101) must use Version 8.
+        [96, 97, 98],
     ]
 
     # Combination registry: list of template ID tuples
 
@@ -60,7 +60,8 @@ async def fetch_api_data(self, url: str) -> Dict[str, Any]:
             sort = parse_qs(parsed.query).get("sort", [None])[0]
             mode = parse_qs(parsed.query).get("mode", [None])[0]
             if query:
-                return await fetch_search_api_data(query, limit=20, sort=sort, mode=mode)
+                # limit=25 to support T96 RESULT_COUNTS up to work_count=25
+                return await fetch_search_api_data(query, limit=25, sort=sort, mode=mode)
             return {}
 
         # Work detail page: /works/OL...W or /works/OL...W/Title
 
@@ -10,10 +10,16 @@
 from .book_comparison import OpenLibraryBookComparisonTemplate
 from .author_editions import OpenLibraryAuthorEditionsTemplate
 from .subject_multi_condition import OpenLibrarySubjectMultiConditionTemplate
+from .author_engagement_extrema import OpenLibraryAuthorEngagementExtremaTemplate
+from .author_comparison import OpenLibraryAuthorComparisonTemplate
+from .reading_stats_filter import OpenLibraryReadingStatsFilterTemplate
 
 __all__ = [
     "OpenLibraryBookStatsTemplate",
     "OpenLibraryBookComparisonTemplate",
     "OpenLibraryAuthorEditionsTemplate",
     "OpenLibrarySubjectMultiConditionTemplate",
+    "OpenLibraryAuthorEngagementExtremaTemplate",
+    "OpenLibraryAuthorComparisonTemplate",
+    "OpenLibraryReadingStatsFilterTemplate",
 ]
@@ -0,0 +1,256 @@
+"""Author comparison template for Open Library - MEDIUM/HARD DIFFICULTY.
+
+RL-friendly design:
+- Requires TWO separate author searches and cross-page comparison
+- Dynamic data: engagement metrics change continuously as users interact
+- Large entity pool: C(81,2)×2 metrics×2 result counts = 12,960 variants
+- Computation required: sum metric across N books for each author, compute difference
+- Numeric answer (absolute difference) avoids 50% random baseline of binary choice
+"""
+
+import random
+from enum import Enum
+from typing import Any, Dict, Optional
+from urllib.parse import quote_plus
+
+from liveweb_arena.core.ground_truth_trigger import (
+    GroundTruthResult,
+    TriggerConfig,
+    UrlPatternTrigger,
+)
+from liveweb_arena.core.gt_collector import GTSourceType
+from liveweb_arena.core.validators.base import (
+    GeneratedQuestion,
+    QuestionTemplate,
+    ValidationResult,
+    register_template,
+)
+from .author_editions import ENGAGEMENT_AUTHOR_POOL
+from .common import find_author_search_entry, get_collected_data, safe_metric_value
+
+
+class AuthorMetric(Enum):
+    """Engagement metrics for cross-author comparison."""
+    WANT_TO_READ = ("want_to_read_count", "total want-to-read count")
+    RATINGS_COUNT = ("ratings_count", "total number of ratings")
+
+
+RESULT_COUNTS = [3, 5]
+
+PATTERNS = [
+    (
+        'On Open Library, search for books by "{author_a}" and "{author_b}", '
+        "both sorted by most editions. What is the absolute difference in "
+        "{metric_label} between the first {n} results for each author? "
+        "Answer with just the number."
+    ),
+    (
+        'Compare "{author_a}" and "{author_b}" on Open Library. For each author, '
+        "look at the top {n} books (sorted by most editions) and sum their "
+        "{metric_label}. What is the absolute difference between the two totals? "
+        "Reply with just a number."
+    ),
+    (
+        'Search Open Library for books by "{author_a}" and by "{author_b}" '
+        "(most editions). Sum the {metric_label} across each author's top {n} "
+        "results. What is the absolute difference? Answer with the number only."
+    ),
+]
+
+
+@register_template("openlibrary_author_comparison")
+class OpenLibraryAuthorComparisonTemplate(QuestionTemplate):
+    """Compare aggregate engagement metrics between two authors' top works.
+
+    MEDIUM/HARD difficulty: requires two separate author searches, summing
+    a metric across top N results for each, then comparing the totals.
+    """
+
+    GT_SOURCE = GTSourceType.PAGE_ONLY
+
+    def __init__(self):
+        super().__init__("openlibrary_author_comparison")
+
+    def generate(self, seed: int, variant: Optional[int] = None) -> GeneratedQuestion:
+        rng = random.Random(seed)
+
+        metrics = list(AuthorMetric)
+        metric = (
+            metrics[variant % len(metrics)]
+            if variant is not None
+            else rng.choice(metrics)
+        )
+
+        (name_a, query_a), (name_b, query_b) = rng.sample(ENGAGEMENT_AUTHOR_POOL, 2)
+
+        # Randomly swap order to prevent position bias
+        if rng.random() > 0.5:
+            name_a, query_a, name_b, query_b = name_b, query_b, name_a, query_a
+
+        count = rng.choice(RESULT_COUNTS)
+        search_query_a = f'author:"{query_a}"'
+        search_query_b = f'author:"{query_b}"'
+
+        pattern = rng.choice(PATTERNS)
+        question_text = pattern.format(
+            author_a=name_a,
+            author_b=name_b,
+            n=count,
+            metric_label=metric.value[1],
+        )
+
+        query_encoded_a = quote_plus(search_query_a)
+        start_url = (
+            f"https://openlibrary.org/search?q={query_encoded_a}&sort=editions"
+        )
+
+        return GeneratedQuestion(
+            question_text=question_text,
+            start_url=start_url,
+            variables={
+                "author_a": name_a,
+                "author_b": name_b,
+                "metric": metric.value[0],
+                "work_count": count,
+            },
+            validation_info={
+                "author_a_name": name_a,
+                "author_a_query": query_a,
+                "search_query_a": search_query_a,
+                "author_b_name": name_b,
+                "author_b_query": query_b,
+                "search_query_b": search_query_b,
+                "sort": "editions",
+                "work_count": count,
+                "metric": metric.value[0],
+                "metric_label": metric.value[1],
+            },
+            template_name=self.name,
+            expected_steps=12,
+        )
+
+    def get_validation_rules(self, validation_info: Dict[str, Any]) -> str:
+        author_a = validation_info.get("author_a_name", "")
+        author_b = validation_info.get("author_b_name", "")
+        count = validation_info.get("work_count", "")
+        metric_label = validation_info.get("metric_label", "")
+        return f"""Task-Specific Rules (Open Library Author Comparison):
+- Compare: "{author_a}" vs "{author_b}"
+- Metric: {metric_label} summed across top {count} results
+- Answer: absolute difference between the two totals (a single number)
+- Score 1.0: Exact difference
+- Score 0.5: Within ±10% of correct difference
+- Score 0.0: Wrong value or no answer"""
+
+    async def get_ground_truth(self, validation_info: Dict[str, Any]) -> GroundTruthResult:
+        collected = get_collected_data()
+        if not collected:
+            return GroundTruthResult.fail("No Open Library data collected")
+
+        author_a_name = validation_info.get("author_a_name")
+        author_b_name = validation_info.get("author_b_name")
+        search_query_a = validation_info.get("search_query_a")
+        search_query_b = validation_info.get("search_query_b")
+        sort = validation_info.get("sort")
+        work_count = validation_info.get("work_count")
+        metric = validation_info.get("metric")
+
+        if (
+            not isinstance(author_a_name, str)
+            or not isinstance(author_b_name, str)
+            or not isinstance(search_query_a, str)
+            or not isinstance(search_query_b, str)
+            or not isinstance(sort, str)
+            or not isinstance(work_count, int)
+            or not isinstance(metric, str)
+        ):
+            return GroundTruthResult.fail("Missing or invalid comparison inputs")
+        if work_count <= 0:
+            return GroundTruthResult.fail(f"Invalid work_count: {work_count}")
+
+        sum_a = self._sum_metric(
+            collected, author_a_name, search_query_a, sort, work_count, metric,
+        )
+        if isinstance(sum_a, GroundTruthResult):
+            return sum_a
+
+        sum_b = self._sum_metric(
+            collected, author_b_name, search_query_b, sort, work_count, metric,
+        )
+        if isinstance(sum_b, GroundTruthResult):
+            return sum_b
+
+        return GroundTruthResult.ok(str(abs(sum_a - sum_b)))
+
+    @staticmethod
+    def _sum_metric(
+        collected: Dict[str, Dict[str, Any]],
+        author_name: str,
+        search_query: str,
+        sort: str,
+        work_count: int,
+        metric: str,
+    ) -> "int | GroundTruthResult":
+        """Sum a metric across an author's top N search results.
+
+        Returns the integer sum on success, or a GroundTruthResult on failure.
+        """
+        data = find_author_search_entry(
+            collected,
+            search_query=search_query,
+            sort=sort,
+        )
+        if data is None:
+            ol_keys = [k for k in collected if k.startswith("ol:")][:5]
+            return GroundTruthResult.not_collected(
+                f"Did not collect search data for author '{author_name}' "
+                f"sorted by '{sort}'. Collected OL keys: {ol_keys}"
+            )
+
+        works_dict = data.get("works")
+        if not isinstance(works_dict, dict):
+            return GroundTruthResult.fail(
+                f"Collected data for '{author_name}' missing works dictionary"
+            )
+        if len(works_dict) < work_count:
+            return GroundTruthResult.fail(
+                f"Only {len(works_dict)} works collected for '{author_name}', "
+                f"need {work_count}"
+            )
+
+        ranked = sorted(works_dict.values(), key=lambda w: w.get("rank", 999))
+        top_n = ranked[:work_count]
+
+        total = 0
+        for work in top_n:
+            try:
+                value = safe_metric_value(work, metric)
+            except ValueError as exc:
+                return GroundTruthResult.fail(str(exc))
+            total += int(value)
+
+        return total
+
+    async def validate_answer(
+        self,
+        answer: str,
+        validation_info: Dict[str, Any],
+    ) -> ValidationResult:
+        return ValidationResult(
+            score=0.0,
+            is_correct=False,
+            expected=None,
+            actual=answer,
+            details="Use LLM validation",
+        )
+
+    def get_ground_truth_trigger(self, validation_info: dict) -> TriggerConfig:
+        trigger = UrlPatternTrigger(domains=["openlibrary.org"])
+        return TriggerConfig(trigger=trigger)
+
+    @classmethod
+    def get_cache_source(cls) -> str:
+        return "openlibrary"
+
+    def get_gt_source(self) -> GTSourceType:
+        return self.GT_SOURCE