diff --git a/skillopt_sleep/multi_skill.py b/skillopt_sleep/multi_skill.py
index 256ce6ab..a4a4bfc1 100644
--- a/skillopt_sleep/multi_skill.py
+++ b/skillopt_sleep/multi_skill.py
@@ -15,7 +15,7 @@
 
 from skillopt_sleep.backend import Backend
 from skillopt_sleep.consolidate import ConsolidationResult, consolidate
-from skillopt_sleep.types import TaskRecord
+from skillopt_sleep.types import SkillGroupReport, TaskRecord
 
 CONSOLIDATED = "consolidated"
 SKIPPED = "skipped"
@@ -39,6 +39,7 @@ class GroupConsolidation:
     status: str
     result: Optional[ConsolidationResult] = None
     reason: str = ""
+    n_tasks: int = 0
 
     @property
     def accepted(self) -> bool:
@@ -78,12 +79,20 @@ def consolidate_groups(
     for group in groups:
         name = (group.skill_name or "").strip()
         if not name:
-            out.setdefault("", GroupConsolidation("", SKIPPED, reason="group has no skill name"))
+            # Carry the task count even though the group is unusable: the row
+            # is meant to be that group's own evidence, and reporting 0 tasks
+            # for a group that had several misstates why it was dropped.
+            out.setdefault("", GroupConsolidation(
+                "", SKIPPED, reason="group has no skill name",
+                n_tasks=len(group.tasks),
+            ))
             continue
         if name in out:
             continue  # first group wins; a repeated name is not a second night
         if not group.tasks:
-            out[name] = GroupConsolidation(name, SKIPPED, reason="no mined tasks for this skill")
+            out[name] = GroupConsolidation(
+                name, SKIPPED, reason="no mined tasks for this skill"
+            )
             continue
         try:
             result = consolidate_fn(
@@ -92,13 +101,49 @@ def consolidate_groups(
             )
         except Exception as exc:  # one group's failure must not abort the night
             out[name] = GroupConsolidation(
-                name, FAILED, reason=f"{type(exc).__name__}: {exc}"[:300]
+                name, FAILED, reason=f"{type(exc).__name__}: {exc}"[:300],
+                n_tasks=len(group.tasks),
             )
             continue
-        out[name] = GroupConsolidation(name, CONSOLIDATED, result=result)
+        out[name] = GroupConsolidation(
+            name, CONSOLIDATED, result=result, n_tasks=len(group.tasks)
+        )
     return out
 
 
+def skill_group_reports(
+    outcomes: Dict[str, GroupConsolidation],
+) -> List[SkillGroupReport]:
+    """Build one report row per entry in ``outcomes``, from its evidence only.
+
+    One row per *outcome*, which is at most one per input group: ``outcomes`` is
+    keyed by skill name, so groups that collapsed onto a shared key upstream
+    have already become a single entry and cannot produce a row each.
+
+    A skipped or failed group reports its reason and keeps zeroed scores rather
+    than inheriting another group's numbers, and an accepted group's row is
+    unaffected by its neighbours' decisions.
+    """
+    rows: List[SkillGroupReport] = []
+    for name, outcome in outcomes.items():
+        row = SkillGroupReport(
+            skill_name=name,
+            status=outcome.status,
+            reason=outcome.reason,
+            n_tasks=outcome.n_tasks,
+        )
+        result = outcome.result
+        if result is not None:
+            row.accepted = result.accepted
+            row.gate_action = result.gate_action
+            row.baseline_score = result.baseline_score
+            row.candidate_score = result.candidate_score
+            row.n_applied_edits = len(result.applied_edits)
+            row.n_rejected_edits = len(result.rejected_edits)
+        rows.append(row)
+    return rows
+
+
 def accepted_group_skills(outcomes: Dict[str, GroupConsolidation]) -> Dict[str, str]:
     """Skill name -> new document, for groups whose gate accepted an update."""
     return {
diff --git a/skillopt_sleep/types.py b/skillopt_sleep/types.py
index 81577d94..c7ee7175 100644
--- a/skillopt_sleep/types.py
+++ b/skillopt_sleep/types.py
@@ -128,6 +128,30 @@ class EditRecord:
     rationale: str = ""
 
 
+@dataclass
+class SkillGroupReport:
+    """One skill group's own gate evidence for the night.
+
+    Every field describes that group alone: its baseline, its candidate score,
+    its decision, and why. Groups never share rows, so a weak group cannot
+    borrow a strong group's evidence or block its acceptance.
+    """
+
+    skill_name: str
+    status: str = ""                   # consolidated | skipped | failed
+    accepted: bool = False
+    gate_action: str = ""
+    baseline_score: float = 0.0
+    candidate_score: float = 0.0
+    n_tasks: int = 0
+    n_applied_edits: int = 0
+    n_rejected_edits: int = 0
+    reason: str = ""
+
+    def to_dict(self) -> Dict[str, Any]:
+        return asdict(self)
+
+
 @dataclass
 class SleepReport:
     """Everything one night produced — written to staging for review."""
@@ -154,6 +178,10 @@ class SleepReport:
     # list above — without them a night can report no edits while the optimizer
     # actually produced several.
     unmatched_edits: List[EditRecord] = field(default_factory=list)
+    # Per-skill gate rows for a multi-skill night, in first-seen order. Empty on
+    # a single-managed-skill night, so the fields above remain the whole story
+    # for consumers that predate skill groups.
+    skill_groups: List[SkillGroupReport] = field(default_factory=list)
     tokens_used: int = 0
     notes: List[str] = field(default_factory=list)
 
diff --git a/tests/test_sleep_skill_group_report.py b/tests/test_sleep_skill_group_report.py
new file mode 100644
index 00000000..c4618c7c
--- /dev/null
+++ b/tests/test_sleep_skill_group_report.py
@@ -0,0 +1,192 @@
+"""Tests for per-skill-group gate reporting (issue #120).
+
+Pure-stdlib (unittest), deterministic MockBackend, no API key, no network.
+Run:  python -m pytest tests/test_sleep_skill_group_report.py
+"""
+from __future__ import annotations
+
+import unittest
+
+from skillopt_sleep.backend import MockBackend
+from skillopt_sleep.consolidate import ConsolidationResult
+from skillopt_sleep.experiments.personas import researcher_persona
+from skillopt_sleep.memory import set_learned
+from skillopt_sleep.mine import assign_splits
+from skillopt_sleep.multi_skill import (
+    CONSOLIDATED,
+    FAILED,
+    SKIPPED,
+    GroupConsolidation,
+    SkillGroup,
+    consolidate_groups,
+    skill_group_reports,
+)
+from skillopt_sleep.types import EditRecord, SkillGroupReport, SleepReport
+
+
+def _tasks(seed=42):
+    return assign_splits(researcher_persona(), holdout_fraction=0.34, seed=seed)
+
+
+def _result(accepted, action, baseline, candidate, applied=0, rejected=0):
+    return ConsolidationResult(
+        accepted=accepted, gate_action=action, baseline_score=baseline,
+        candidate_score=candidate, new_skill="", new_memory="",
+        applied_edits=[EditRecord("skill", "add", f"rule {i}") for i in range(applied)],
+        rejected_edits=[EditRecord("skill", "add", f"bad {i}") for i in range(rejected)],
+        holdout_baseline=baseline, holdout_candidate=candidate,
+    )
+
+
+class TestSkillGroupReport(unittest.TestCase):
+    def test_row_defaults_are_empty_evidence(self):
+        row = SkillGroupReport(skill_name="example-skill")
+        self.assertEqual(
+            (row.status, row.accepted, row.gate_action, row.baseline_score,
+             row.candidate_score, row.n_tasks, row.n_applied_edits,
+             row.n_rejected_edits, row.reason),
+            ("", False, "", 0.0, 0.0, 0, 0, 0, ""),
+        )
+        self.assertEqual(row.to_dict()["skill_name"], "example-skill")
+
+
+class TestSkillGroupRows(unittest.TestCase):
+    def test_each_group_keeps_its_own_scores_and_decision(self):
+        outcomes = {
+            "strong-skill": GroupConsolidation(
+                "strong-skill", CONSOLIDATED, n_tasks=6,
+                result=_result(True, "accept_new_best", 0.25, 0.75, applied=2),
+            ),
+            "weak-skill": GroupConsolidation(
+                "weak-skill", CONSOLIDATED, n_tasks=3,
+                result=_result(False, "reject", 0.5, 0.1, rejected=1),
+            ),
+        }
+        rows = {r.skill_name: r for r in skill_group_reports(outcomes)}
+        strong, weak = rows["strong-skill"], rows["weak-skill"]
+        self.assertTrue(strong.accepted)
+        self.assertEqual((strong.baseline_score, strong.candidate_score), (0.25, 0.75))
+        self.assertEqual((strong.n_tasks, strong.n_applied_edits), (6, 2))
+        self.assertFalse(weak.accepted)
+        self.assertEqual((weak.baseline_score, weak.candidate_score), (0.5, 0.1))
+        self.assertEqual((weak.n_applied_edits, weak.n_rejected_edits), (0, 1))
+        self.assertEqual(weak.gate_action, "reject")
+
+    def test_rows_follow_first_seen_group_order(self):
+        outcomes = {
+            "b-skill": GroupConsolidation("b-skill", SKIPPED, reason="no mined tasks"),
+            "a-skill": GroupConsolidation("a-skill", SKIPPED, reason="no mined tasks"),
+        }
+        self.assertEqual([r.skill_name for r in skill_group_reports(outcomes)],
+                         ["b-skill", "a-skill"])
+
+    def test_skipped_and_failed_rows_carry_reasons_and_no_borrowed_scores(self):
+        outcomes = {
+            "strong-skill": GroupConsolidation(
+                "strong-skill", CONSOLIDATED, n_tasks=6,
+                result=_result(True, "accept_new_best", 0.25, 0.75, applied=2),
+            ),
+            "empty-skill": GroupConsolidation(
+                "empty-skill", SKIPPED, reason="no mined tasks for this skill"),
+            "broken-skill": GroupConsolidation(
+                "broken-skill", FAILED, reason="RuntimeError: backend exploded", n_tasks=4),
+        }
+        rows = {r.skill_name: r for r in skill_group_reports(outcomes)}
+        for name in ("empty-skill", "broken-skill"):
+            self.assertFalse(rows[name].accepted)
+            self.assertEqual(rows[name].gate_action, "")
+            self.assertEqual((rows[name].baseline_score, rows[name].candidate_score), (0.0, 0.0))
+            self.assertTrue(rows[name].reason)
+        self.assertEqual(rows["broken-skill"].status, FAILED)
+        self.assertEqual(rows["broken-skill"].n_tasks, 4)
+        self.assertTrue(rows["strong-skill"].accepted)
+
+    def test_rows_from_a_real_mixed_night(self):
+        outcomes = consolidate_groups(
+            MockBackend(),
+            [
+                SkillGroup("research-skill", set_learned("", []), _tasks()),
+                SkillGroup("empty-skill", set_learned("", []), []),
+            ],
+            edit_budget=4, gate_metric="mixed", night=1,
+        )
+        rows = skill_group_reports(outcomes)
+        self.assertEqual([r.skill_name for r in rows], ["research-skill", "empty-skill"])
+        research = rows[0]
+        self.assertEqual(research.status, CONSOLIDATED)
+        self.assertTrue(research.accepted)
+        self.assertGreater(research.candidate_score, research.baseline_score)
+        self.assertEqual(research.n_tasks, len(_tasks()))
+        self.assertEqual(rows[1].status, SKIPPED)
+        self.assertFalse(rows[1].accepted)
+
+
+class TestSleepReportCompatibility(unittest.TestCase):
+    def test_single_skill_report_has_no_group_rows(self):
+        report = SleepReport(night=1, project="/repo/example", accepted=True,
+                             gate_action="accept_new_best")
+        self.assertEqual(report.skill_groups, [])
+        self.assertEqual(report.to_dict()["skill_groups"], [])
+
+    def test_legacy_keyword_construction_still_works(self):
+        legacy = {
+            "night": 2, "project": "/repo/example", "n_sessions": 1, "n_tasks": 3,
+            "baseline_score": 0.1, "candidate_score": 0.2, "accepted": True,
+            "gate_action": "accept", "edits": [], "notes": ["ok"],
+        }
+        report = SleepReport(**legacy)
+        self.assertEqual(report.skill_groups, [])
+        self.assertEqual(report.gate_action, "accept")
+
+    def test_group_rows_serialize_beside_the_single_skill_summary(self):
+        report = SleepReport(night=3, project="/repo/example", accepted=True,
+                             gate_action="accept_new_best", candidate_score=0.75)
+        report.skill_groups = skill_group_reports({
+            "research-skill": GroupConsolidation(
+                "research-skill", CONSOLIDATED, n_tasks=6,
+                result=_result(True, "accept_new_best", 0.25, 0.75, applied=2),
+            ),
+        })
+        payload = report.to_dict()
+        # older consumers read the flat summary and ignore the new key
+        self.assertEqual(payload["gate_action"], "accept_new_best")
+        self.assertEqual(payload["candidate_score"], 0.75)
+        self.assertEqual(payload["skill_groups"][0]["skill_name"], "research-skill")
+        self.assertEqual(payload["skill_groups"][0]["n_applied_edits"], 2)
+
+    def test_rows_track_outcomes_not_input_groups(self):
+        # outcomes is keyed by skill name, so groups that collapsed onto a
+        # shared key upstream are already a single entry and cannot each get a
+        # row. Pinned because "one row per group" is the intuitive reading and
+        # it is wrong.
+        groups = [
+            SkillGroup("research-skill", set_learned("", []), _tasks()),
+            SkillGroup("research-skill", set_learned("", []), _tasks()),
+            SkillGroup("", set_learned("", []), _tasks()),
+            SkillGroup("   ", set_learned("", []), _tasks()),
+        ]
+        outcomes = consolidate_groups(MockBackend(), groups, edit_budget=4, night=1)
+        rows = skill_group_reports(outcomes)
+        self.assertEqual(len(outcomes), 2)
+        self.assertEqual(len(rows), len(outcomes))
+        self.assertLess(len(rows), len(groups))
+        self.assertEqual([r.skill_name for r in rows], ["research-skill", ""])
+
+    def test_a_blank_named_group_still_reports_its_task_count(self):
+        # The row is that group's own evidence. Reporting 0 tasks for a group
+        # that had several misstates why it was dropped.
+        tasks = _tasks()
+        self.assertTrue(tasks, "fixture must supply tasks for this to mean anything")
+        outcomes = consolidate_groups(
+            MockBackend(),
+            [SkillGroup("  ", set_learned("", []), tasks)],
+            edit_budget=4, night=1,
+        )
+        row = skill_group_reports(outcomes)[0]
+        self.assertEqual(row.status, SKIPPED)
+        self.assertEqual(row.n_tasks, len(tasks))
+        self.assertIn("no skill name", row.reason)
+
+
+if __name__ == "__main__":
+    unittest.main()