diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2e46ddf..fbc16ed 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,10 @@ All notable changes to this project will be documented in this file.
 - Opt-in `EvaluationCache` reuses grid evaluations by typed configuration, replicate namespace/id, model/scorer revision, fidelity, objective and annotation definitions; includes provenance, bypass, invalidation and conflicting-evidence checks (#154).
 - `preference_sweep()` reports ranking/selection stability, regret, feasible Pareto alternatives, raw-unit practical equivalence and optional paired uncertainty under explicit normalization and preference assumptions, with exportable per-design summaries (#155).
 
+### Fixed
+
+- Queued, retried and imported adaptive evaluations now join NSGA-II generations and process constraints when completed; interrupted imports resume idempotently. The adaptive extra now requires Optuna >=4.5 for its public generation API (#164).
+
 ## [0.3.0] — 2026-10-02
 
 ### Added
diff --git a/docs/api/session.md b/docs/api/session.md
index 5bbfb27..64edd93 100644
--- a/docs/api/session.md
+++ b/docs/api/session.md
@@ -36,6 +36,9 @@ Use `session.enqueue(config)` to evaluate a known complete configuration before
 sampling new ones. Every call queues a distinct evaluation. Queued configurations
 are visible through `trials("waiting")`; `ask()` supplies their evaluation ids.
 Continuous bounds, log factors and categorical/discrete levels are validated.
+Queued, retried and imported trials join the sampler population when completed;
+constraints are processed through the same tell lifecycle as sampled trials.
+The adaptive extra requires Optuna 4.5 or newer for public generation assignment.
 
 To import completed observations, give both sessions the same explicit
 `revision="simulator-v2-scorer-v1-data-v3-fidelity-high"` and matching factor,
@@ -51,7 +54,9 @@ Imports preserve raw means, standard errors, replicate counts and evaluation
 provenance. They create completed trials without calling a simulator. Repeating
 an import skips known evaluation identities, including after reopening and
 through intermediate sessions; conflicting results for an existing identity
-are refused. All rows are validated before any are imported. Serialize imports
+are refused. All rows are validated before any are imported. Interrupted imports
+resume their pending completion on the next identical import without adding
+another trial. Serialize imports
 into a destination session. A bare grid table lacks a verifiable session schema
 and cannot be imported automatically. The revision is the caller's assertion of
 matching simulator, scorer, data, randomness and fidelity, not evidence inferred
diff --git a/pyproject.toml b/pyproject.toml
index b1bafa1..36ebe0e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -68,7 +68,7 @@ design = [
   "scipy>=1.10",
 ]
 adaptive = [
-  "optuna>=4.0",
+  "optuna>=4.5",
 ]
 parallel = [
   "joblib>=1.3",
diff --git a/src/trade_study/_warm_start.py b/src/trade_study/_warm_start.py
index 160467a..15bfeb1 100644
--- a/src/trade_study/_warm_start.py
+++ b/src/trade_study/_warm_start.py
@@ -179,7 +179,7 @@ def _fingerprint(trial: optuna.trial.FrozenTrial) -> str:
     return json.dumps(
         {
             "params": trial.params,
-            "values": trial.values,
+            "values": trial.values or trial.user_attrs.get("_import_values"),
             "summary": {
                 k: trial.user_attrs.get(k)
                 for k in ("scores", "n_reps", "standard_error")
diff --git a/src/trade_study/session.py b/src/trade_study/session.py
index 1cba00c..3bdc2d3 100644
--- a/src/trade_study/session.py
+++ b/src/trade_study/session.py
@@ -140,6 +140,7 @@ def __init__(
             seed=seed,
             constraints_func=self._constraint_values if self.constraints else None,
         )
+        self._sampler = sampler
         self._study = _optuna.create_study(
             study_name=study_name,
             storage=self._storage,
@@ -203,7 +204,9 @@ def ask(self, n: int = 1) -> list[tuple[int, dict[str, Any]]]:
         proposals = []
         for _ in range(n):
             trial = self._study.ask()
-            proposals.append((trial.number, self._suggest(trial)))
+            config = self._suggest(trial)
+            self._register_generation(trial.number)
+            proposals.append((trial.number, config))
         return proposals
 
     def tell(
@@ -252,6 +255,7 @@ def tell(
         self._storage.set_trial_user_attr(
             internal, "n_reps", {k: v[2] for k, v in summary.items()}
         )
+        self._register_generation(trial_id)
         self._study.tell(
             trial_id, [summary[o.name][0] * o.weight for o in self.observables]
         )
@@ -265,6 +269,10 @@ def _trial_id(self, trial_id: int) -> int:
             msg = f"Unknown trial id {trial_id}"
             raise ValueError(msg) from error
 
+    def _register_generation(self, trial_id: int) -> None:
+        trial = self._storage.get_trial(self._trial_id(trial_id))
+        self._sampler.get_trial_generation(self._study, trial)
+
     def trials(self, state: str | None = None) -> list[SessionTrial]:
         """Inspect trials in creation order without exposing storage internals.
 
@@ -371,6 +379,7 @@ def retry(
         )
         internal = self._storage.create_new_trial(self._study_id, template)
         child = self._storage.get_trial(internal)
+        self._register_generation(child.number)
         return child.number, dict(child.params)
 
     def enqueue(self, config: dict[str, Any]) -> None:
@@ -412,6 +421,8 @@ def warm_start(self, source: AdaptiveSession | ResultsTable) -> list[int]:
             caller's assertion of matching model, scorer, data and fidelity;
             the library cannot establish that assertion from scores alone.
         """
+        import optuna as _optuna
+
         if self.revision is None:
             msg = "warm_start requires an explicit model/data revision"
             raise ValueError(msg)
@@ -419,12 +430,19 @@ def warm_start(self, source: AdaptiveSession | ResultsTable) -> list[int]:
         templates = _import_trials(
             results, self.factors, self.observables, self.constraints, self._schema
         )
+        trials = self._study.get_trials()
+        unfinished = {
+            t.user_attrs["evaluation_id"]: t.number
+            for t in trials
+            if t.state.name == "RUNNING" and "_import_values" in t.user_attrs
+        }
         existing = {
             t.user_attrs.get(
                 "evaluation_id", f"{self._session_id}:{t.number}"
             ): _fingerprint(t)
-            for t in self._study.get_trials()
+            for t in trials
             if t.state.name == "COMPLETE"
+            or (t.state.name == "RUNNING" and "_import_values" in t.user_attrs)
         }
         pending = []
         for trial in templates:
@@ -433,13 +451,25 @@ def warm_start(self, source: AdaptiveSession | ResultsTable) -> list[int]:
             if identity in existing and existing[identity] != fingerprint:
                 msg = f"Conflicting imported evaluation {identity!r}"
                 raise ValueError(msg)
-            if identity not in existing:
+            if identity not in existing or identity in unfinished:
+                trial.user_attrs["_resume_trial"] = unfinished.pop(identity, None)
                 pending.append(trial)
                 existing[identity] = fingerprint
         imported = []
         for trial in pending:
-            self._study.add_trial(trial)
-            imported.append(self._study.get_trials()[-1].number)
+            number = trial.user_attrs.pop("_resume_trial")
+            if number is None:
+                running = _optuna.trial.create_trial(
+                    state=_optuna.trial.TrialState.RUNNING,
+                    params=trial.params,
+                    distributions=trial.distributions,
+                    user_attrs={**trial.user_attrs, "_import_values": trial.values},
+                )
+                internal = self._storage.create_new_trial(self._study_id, running)
+                number = self._storage.get_trial(internal).number
+            self._register_generation(number)
+            self._study.tell(number, trial.values)
+            imported.append(number)
         return imported
 
     def results(self) -> ResultsTable:
diff --git a/tests/test_warm_start.py b/tests/test_warm_start.py
index 0ae4b4e..6f2a21f 100644
--- a/tests/test_warm_start.py
+++ b/tests/test_warm_start.py
@@ -196,3 +196,86 @@ def test_reopening_validates_schema_and_refuses_legacy_storage(tmp_path: Path) -
         _destination(legacy_path)
     with pytest.raises(ValueError, match="nonempty"):
         AdaptiveSession(_FACTORS, _OBS, revision=" ")
+
+
+def _loaded(path: Path) -> optuna.Study:
+    return optuna.load_study(
+        study_name="trade-study-adaptive",
+        storage=optuna.storages.JournalStorage(
+            optuna.storages.journal.JournalFileBackend(str(path))
+        ),
+    )
+
+
+@pytest.mark.parametrize("mode", ["queued", "retried", "imported"])
+def test_known_parameters_join_the_constrained_population(
+    tmp_path: Path, mode: str
+) -> None:
+    path = tmp_path / "population.journal"
+    session = _destination(path)
+    if mode == "imported":
+        expected = session.warm_start(_source())[0]
+    else:
+        session.enqueue(_CONFIG)
+        ((expected, _config),) = session.ask()
+        if mode == "retried":
+            session.fail(expected, "worker failed")
+            expected, _config = session.retry(expected)
+        session.tell(expected, {"loss": [1, 2], "reward": [2, 4], "aux": [1, 3]})
+    stored = _loaded(path)
+    population = optuna.samplers.NSGAIISampler().get_population(stored, 0)
+    assert [t.number for t in population] == [expected]
+    assert population[0].system_attrs["constraints"] == pytest.approx([-3])
+
+
+def test_imported_population_can_supply_the_next_generation(tmp_path: Path) -> None:
+    source = _destination()
+    for _ in range(50):
+        source.enqueue(_CONFIG)
+        ((trial_id, _config),) = source.ask()
+        source.tell(trial_id, {"loss": [1, 2], "reward": [2, 4], "aux": [1, 3]})
+    path = tmp_path / "parents.journal"
+    destination = _destination(path)
+    destination.warm_start(source)
+    stored = _loaded(path)
+    sampler = optuna.samplers.NSGAIISampler(
+        constraints_func=lambda trial: trial.system_attrs["constraints"],
+    )
+    assert len(sampler.get_population(stored, 0)) == 50
+    assert len(sampler.get_parent_population(stored, 1)) == 50
+    assert all(
+        t.system_attrs["constraints"] == pytest.approx([-3]) for t in stored.trials
+    )
+
+
+def test_interrupted_import_resumes_without_duplicate_trials(
+    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    table = _source().results()
+    path = tmp_path / "interrupted.journal"
+    destination = _destination(path)
+
+    def interrupt(
+        sampler: optuna.samplers.NSGAIISampler,
+        study: optuna.Study,
+        trial: optuna.trial.FrozenTrial,
+    ) -> int:
+        del sampler, study, trial
+        raise KeyboardInterrupt
+
+    with monkeypatch.context() as patch:
+        patch.setattr(optuna.samplers.NSGAIISampler, "get_trial_generation", interrupt)
+        with pytest.raises(KeyboardInterrupt):
+            destination.warm_start(table)
+    reopened = _destination(path)
+    assert len(reopened.trials("pending")) == 1
+    duplicated_input = ResultsTable(
+        table.configs * 2,
+        np.vstack([table.scores, table.scores]),
+        table.observable_names,
+        metadata=table.metadata * 2,
+    )
+    assert reopened.warm_start(duplicated_input) == [0]
+    assert len(reopened.trials()) == 1
+    assert len(reopened.trials("complete")) == 1
+    assert reopened.warm_start(table) == []