diff --git a/docs/docs/in_depth/mloda-api.md b/docs/docs/in_depth/mloda-api.md
index 71daffc2..6f80b964 100644
--- a/docs/docs/in_depth/mloda-api.md
+++ b/docs/docs/in_depth/mloda-api.md
@@ -198,7 +198,7 @@ from mloda.provider import FeatureResolutionError, ResolutionDiagnosis, Resoluti
 - **`ResolutionDiagnosis`** (frozen dataclass): the return value of `diagnose`, never raised. Fields: `records` (`list[ResolutionRecord]`), `complete` (`bool`), `feature_name` (`str | None`), `failed_result` (`EvaluationResult | None`), `message` (`str | None`).
 - **`ResolutionRecord`** (frozen dataclass): one per feature, returned inside `resolution_report()`, `ResolutionDiagnosis.records`, and `FeatureResolutionError.partial_records`; never raised. Fields: `feature_name` (`str`), `requested` (`bool`), `result` (`EvaluationResult`).
 
-`EvaluationResult` is the captured matcher outcome carried by the fields above; it is defined in `mloda.core.prepare.resolution_types`, also importable from `mloda.core.prepare.identify_feature_group`, and is not part of the public `__init__` exports.
+`EvaluationResult` is the captured matcher outcome carried by the fields above; it is defined in `mloda.core.prepare.resolution_types` and is not part of the public `__init__` exports.
 
 ##### get_feature_group_docs
 
diff --git a/mloda/core/api/plugin_docs.py b/mloda/core/api/plugin_docs.py
index 964d7e34..e1d44fc3 100644
--- a/mloda/core/api/plugin_docs.py
+++ b/mloda/core/api/plugin_docs.py
@@ -40,11 +40,9 @@
     dedup_feature_group_subclasses,
     registry_for,
 )
-from mloda.core.prepare.identify_feature_group import (
-    CandidateFrameworks,
-    evaluate_and_render,
-    scope_callout,
-)
+from mloda.core.prepare.identify_feature_group import evaluate_and_render
+from mloda.core.prepare.resolution_failure_renderer import scope_callout
+from mloda.core.prepare.resolution_types import CandidateFrameworks
 
 
 def list_registered(plugin_type: type[Any]) -> list[type[Any]]:
diff --git a/mloda/core/api/request.py b/mloda/core/api/request.py
index 4f3cf37d..cd48a124 100644
--- a/mloda/core/api/request.py
+++ b/mloda/core/api/request.py
@@ -12,6 +12,8 @@
 from mloda.core.prepare.identify_feature_group import (
     ComputeFrameworkPinError,
     FeatureResolutionError,
+)
+from mloda.core.prepare.resolution_types import (
     ResolutionDiagnosis,
     ResolutionRecord,
 )
diff --git a/mloda/core/core/engine.py b/mloda/core/core/engine.py
index 28a52fac..f9f3168b 100644
--- a/mloda/core/core/engine.py
+++ b/mloda/core/core/engine.py
@@ -21,10 +21,10 @@
 from mloda.core.prepare.graph.build_graph import BuildGraph
 from mloda.core.prepare.resolve_graph import ResolveGraph
 from mloda.core.runtime.run import ExecutionOrchestrator
-from mloda.core.prepare.identify_feature_group import (
+from mloda.core.prepare.identify_feature_group import resolve_or_raise
+from mloda.core.prepare.resolution_types import (
     EvaluationResult,
     ResolutionRecord,
-    resolve_or_raise,
 )
 from mloda.core.runtime.flight.runner_flight_server import ParallelRunnerFlightServer
 from mloda.core.abstract_plugins.feature_group import FeatureGroup, format_feature_group_class
diff --git a/mloda/core/prepare/identify_feature_group.py b/mloda/core/prepare/identify_feature_group.py
index 721c0220..0e6df593 100644
--- a/mloda/core/prepare/identify_feature_group.py
+++ b/mloda/core/prepare/identify_feature_group.py
@@ -5,6 +5,8 @@
 from typing import Optional
 
 from mloda.core.prepare.accessible_plugins import FeatureGroupEnvironmentMapping
+
+# Not a re-export facade: every import here is used by this module and ruff F401 fails any added just to re-export.
 from mloda.core.prepare.resolution_types import (
     CandidateFrameworks,
     Elimination,
@@ -12,13 +14,10 @@
     EvaluationResult,
     PARTIAL_RECORDS_CAP,
     RenderFacts,
-    ResolutionDiagnosis,
     ResolutionRecord,
 )
 from mloda.core.prepare.resolution_failure_renderer import (
-    TROUBLESHOOTING_URL,
     render_resolution_failure,
-    scope_callout,
     _prefix_name,
     _supported_feature_names,
 )
@@ -39,27 +38,6 @@
 
 logger = logging.getLogger(__name__)
 
-# Keeps the pre-split import surface of this module intact: the moved names stay importable from here.
-__all__ = [
-    "CandidateFrameworks",
-    "ComputeFrameworkPinError",
-    "Elimination",
-    "EliminationStage",
-    "EvaluationResult",
-    "FeatureResolutionError",
-    "IdentifyFeatureGroupClass",
-    "PARTIAL_RECORDS_CAP",
-    "RenderFacts",
-    "ResolutionDiagnosis",
-    "ResolutionRecord",
-    "TROUBLESHOOTING_URL",
-    "evaluate_and_render",
-    "matches_feature_group_scope",
-    "render_resolution_failure",
-    "resolve_or_raise",
-    "scope_callout",
-]
-
 
 class FeatureResolutionError(ValueError):
     """Typed resolution failure carrying the feature name, the EvaluationResult of its single pass,
diff --git a/mloda/provider/__init__.py b/mloda/provider/__init__.py
index f10d403f..35d13f8b 100644
--- a/mloda/provider/__init__.py
+++ b/mloda/provider/__init__.py
@@ -102,8 +102,8 @@
 
 # Feature resolution debugging
 from mloda.core.api.plugin_docs import resolve_feature
-from mloda.core.prepare.identify_feature_group import (
-    FeatureResolutionError,
+from mloda.core.prepare.identify_feature_group import FeatureResolutionError
+from mloda.core.prepare.resolution_types import (
     ResolutionDiagnosis,
     ResolutionRecord,
 )
diff --git a/mloda/steward/__init__.py b/mloda/steward/__init__.py
index 652b5fd6..b57f9443 100644
--- a/mloda/steward/__init__.py
+++ b/mloda/steward/__init__.py
@@ -33,8 +33,8 @@
 )
 
 # Feature resolution
-from mloda.core.prepare.identify_feature_group import (
-    FeatureResolutionError,
+from mloda.core.prepare.identify_feature_group import FeatureResolutionError
+from mloda.core.prepare.resolution_types import (
     ResolutionDiagnosis,
     ResolutionRecord,
 )
diff --git a/mloda/user/__init__.py b/mloda/user/__init__.py
index 8cfcac52..9d4fef2a 100644
--- a/mloda/user/__init__.py
+++ b/mloda/user/__init__.py
@@ -52,8 +52,8 @@
 )
 
 # Feature resolution
-from mloda.core.prepare.identify_feature_group import (
-    FeatureResolutionError,
+from mloda.core.prepare.identify_feature_group import FeatureResolutionError
+from mloda.core.prepare.resolution_types import (
     ResolutionDiagnosis,
     ResolutionRecord,
 )
diff --git a/tests/test_core/test_api/test_diagnose.py b/tests/test_core/test_api/test_diagnose.py
index d298d804..478772b2 100644
--- a/tests/test_core/test_api/test_diagnose.py
+++ b/tests/test_core/test_api/test_diagnose.py
@@ -1,7 +1,7 @@
 """Failing tests for the non-raising resolution preflight ``mlodaAPI.diagnose()`` (issue #812).
 
 Contract under test:
-  * ``mloda.core.prepare.identify_feature_group.ResolutionDiagnosis`` is a frozen dataclass beside
+  * ``mloda.core.prepare.resolution_types.ResolutionDiagnosis`` is a frozen dataclass beside
     ``ResolutionRecord`` and ``EvaluationResult``, with fields ``records``, ``complete``, ``feature_name``,
     ``failed_result``, ``message`` in that order. It is re-exported from ``mloda.user`` and ``mloda.steward``.
   * ``mlodaAPI.diagnose(...)`` runs the SAME eager planning as ``prepare(...)`` but NEVER raises for a
@@ -26,9 +26,9 @@
 # ``mloda`` mlodaAPI alias imported below.
 import mloda.steward as mloda_steward
 import mloda.user as mloda_user
-from mloda.core.prepare.identify_feature_group import (
+from mloda.core.prepare.identify_feature_group import FeatureResolutionError
+from mloda.core.prepare.resolution_types import (
     EvaluationResult,
-    FeatureResolutionError,
     ResolutionDiagnosis,
     ResolutionRecord,
 )
diff --git a/tests/test_core/test_api/test_resolution_report.py b/tests/test_core/test_api/test_resolution_report.py
index 11dd8fae..e83a3d50 100644
--- a/tests/test_core/test_api/test_resolution_report.py
+++ b/tests/test_core/test_api/test_resolution_report.py
@@ -1,7 +1,7 @@
 """Failing tests for per-feature EvaluationResult capture and ``session.resolution_report()`` (issue #811).
 
 Contract under test:
-  * ``mloda.core.prepare.identify_feature_group.ResolutionRecord`` is a frozen dataclass beside
+  * ``mloda.core.prepare.resolution_types.ResolutionRecord`` is a frozen dataclass beside
     ``EvaluationResult``, with fields ``feature_name: str``, ``requested: bool``, ``result: EvaluationResult``
     in that order. It is re-exported from both ``mloda.user`` and ``mloda.steward``.
   * ``IdentifyFeatureGroupClass.evaluate(...)`` returns the winning ``EvaluationResult`` on a successful
@@ -31,9 +31,9 @@
 import mloda.steward as mloda_steward
 import mloda.user as mloda_user
 from mloda.core.core.engine import Engine
-from mloda.core.prepare.identify_feature_group import (
+from mloda.core.prepare.identify_feature_group import FeatureResolutionError
+from mloda.core.prepare.resolution_types import (
     EvaluationResult,
-    FeatureResolutionError,
     ResolutionRecord,
 )
 from tests.test_core.test_prepare.identify_seam import evaluate_or_raise
diff --git a/tests/test_core/test_core/test_engine_domain_propagation.py b/tests/test_core/test_core/test_engine_domain_propagation.py
index 23d74966..0e8e237f 100644
--- a/tests/test_core/test_core/test_engine_domain_propagation.py
+++ b/tests/test_core/test_core/test_engine_domain_propagation.py
@@ -9,7 +9,7 @@
 
 
 from mloda.core.core.engine import Engine
-from mloda.core.prepare.identify_feature_group import EvaluationResult
+from mloda.core.prepare.resolution_types import EvaluationResult
 from mloda.core.abstract_plugins.components.feature import Feature
 from mloda.core.abstract_plugins.components.feature_collection import Features
 from mloda.core.abstract_plugins.components.feature_name import FeatureName
diff --git a/tests/test_core/test_integration/test_core/test_diagnose_integration.py b/tests/test_core/test_integration/test_core/test_diagnose_integration.py
index 07a5650c..0e1af61e 100644
--- a/tests/test_core/test_integration/test_core/test_diagnose_integration.py
+++ b/tests/test_core/test_integration/test_core/test_diagnose_integration.py
@@ -15,9 +15,9 @@
 
 import pytest
 
-from mloda.core.prepare.identify_feature_group import (
+from mloda.core.prepare.identify_feature_group import FeatureResolutionError
+from mloda.core.prepare.resolution_types import (
     EvaluationResult,
-    FeatureResolutionError,
     ResolutionDiagnosis,
     ResolutionRecord,
 )
diff --git a/tests/test_core/test_integration/test_core/test_resolution_report_integration.py b/tests/test_core/test_integration/test_core/test_resolution_report_integration.py
index a1a47951..a7b0b290 100644
--- a/tests/test_core/test_integration/test_core/test_resolution_report_integration.py
+++ b/tests/test_core/test_integration/test_core/test_resolution_report_integration.py
@@ -12,7 +12,7 @@
 
 from typing import Any
 
-from mloda.core.prepare.identify_feature_group import EvaluationResult
+from mloda.core.prepare.resolution_types import EvaluationResult
 from mloda.provider import DefaultOptionKeys
 from mloda.user import Feature, Options, PluginCollector, ResolutionRecord, mloda, mlodaAPI
 from mloda_plugins.compute_framework.base_implementations.pandas.dataframe import PandasDataFrame
diff --git a/tests/test_core/test_prepare/identify_seam.py b/tests/test_core/test_prepare/identify_seam.py
index 733c12a3..7ea90add 100644
--- a/tests/test_core/test_prepare/identify_seam.py
+++ b/tests/test_core/test_prepare/identify_seam.py
@@ -21,10 +21,8 @@
 from mloda.core.abstract_plugins.compute_framework import ComputeFramework
 from mloda.core.abstract_plugins.feature_group import FeatureGroup
 from mloda.core.prepare.accessible_plugins import FeatureGroupEnvironmentMapping
-from mloda.core.prepare.identify_feature_group import (
-    EvaluationResult,
-    resolve_or_raise,
-)
+from mloda.core.prepare.identify_feature_group import resolve_or_raise
+from mloda.core.prepare.resolution_types import EvaluationResult
 
 
 def evaluate_or_raise(
diff --git a/tests/test_core/test_prepare/test_candidate_elimination_reasons.py b/tests/test_core/test_prepare/test_candidate_elimination_reasons.py
index 56034809..4329a76d 100644
--- a/tests/test_core/test_prepare/test_candidate_elimination_reasons.py
+++ b/tests/test_core/test_prepare/test_candidate_elimination_reasons.py
@@ -31,11 +31,11 @@
 from mloda.core.abstract_plugins.feature_group import FeatureGroup
 from mloda.core.prepare.accessible_plugins import FeatureGroupEnvironmentMapping
 from mloda.core.prepare.identify_feature_group import (
-    Elimination,
     FeatureResolutionError,
     IdentifyFeatureGroupClass,
-    render_resolution_failure,
 )
+from mloda.core.prepare.resolution_failure_renderer import render_resolution_failure
+from mloda.core.prepare.resolution_types import Elimination
 from tests.test_core.test_prepare.identify_seam import evaluate_or_raise, identify_winner
 
 
diff --git a/tests/test_core/test_prepare/test_feature_group_dedup.py b/tests/test_core/test_prepare/test_feature_group_dedup.py
index 45fd841f..8cb2f348 100644
--- a/tests/test_core/test_prepare/test_feature_group_dedup.py
+++ b/tests/test_core/test_prepare/test_feature_group_dedup.py
@@ -36,7 +36,7 @@
     dedup_feature_group_subclasses,
     _safe_class_source_hash,
 )
-from mloda.core.prepare.identify_feature_group import ResolutionDiagnosis
+from mloda.core.prepare.resolution_types import ResolutionDiagnosis
 from mloda_plugins.compute_framework.base_implementations.pandas.dataframe import PandasDataFrame
 
 
diff --git a/tests/test_core/test_prepare/test_feature_resolution_error.py b/tests/test_core/test_prepare/test_feature_resolution_error.py
index d913187b..e64defdc 100644
--- a/tests/test_core/test_prepare/test_feature_resolution_error.py
+++ b/tests/test_core/test_prepare/test_feature_resolution_error.py
@@ -27,8 +27,8 @@
 from mloda.core.prepare.identify_feature_group import (
     FeatureResolutionError,
     IdentifyFeatureGroupClass,
-    render_resolution_failure,
 )
+from mloda.core.prepare.resolution_failure_renderer import render_resolution_failure
 from mloda.user import mlodaAPI
 from tests.test_core.test_prepare.identify_seam import evaluate_or_raise
 
diff --git a/tests/test_core/test_prepare/test_feature_resolution_error_partial_records.py b/tests/test_core/test_prepare/test_feature_resolution_error_partial_records.py
index 00b056da..fcd96bdb 100644
--- a/tests/test_core/test_prepare/test_feature_resolution_error_partial_records.py
+++ b/tests/test_core/test_prepare/test_feature_resolution_error_partial_records.py
@@ -1,7 +1,7 @@
 """Failing tests for the diagnose refactor: FeatureResolutionError carries the partial resolution records.
 
 Contract under test (PR #836):
-  * ``PARTIAL_RECORDS_CAP`` is a module-level int constant (1000) in ``identify_feature_group``.
+  * ``PARTIAL_RECORDS_CAP`` is a module-level int constant (1000) in ``resolution_types``.
   * ``FeatureResolutionError.__init__`` accepts ``partial_records: Sequence[ResolutionRecord] = ()`` and stores
     it as a tuple truncated to the LAST ``PARTIAL_RECORDS_CAP`` entries; ``__reduce__`` round-trips it via pickle.
   * The raising ``mloda.prepare`` path attaches the records resolved before the failure to the error, and
@@ -23,9 +23,9 @@
 
 from mloda.core.api.request import SetupConfigurationError
 from mloda.core.core.engine import Engine
-from mloda.core.prepare.identify_feature_group import (
+from mloda.core.prepare.identify_feature_group import FeatureResolutionError
+from mloda.core.prepare.resolution_types import (
     EvaluationResult,
-    FeatureResolutionError,
     ResolutionRecord,
 )
 from mloda.provider import BaseInputData, ComputeFramework, DataCreator, FeatureGroup, FeatureSet
@@ -114,7 +114,7 @@ class TestPartialRecordsCapConstant:
     """PARTIAL_RECORDS_CAP is a module-level int constant with value 1000."""
 
     def test_partial_records_cap_is_1000(self) -> None:
-        from mloda.core.prepare.identify_feature_group import PARTIAL_RECORDS_CAP
+        from mloda.core.prepare.resolution_types import PARTIAL_RECORDS_CAP
 
         assert isinstance(PARTIAL_RECORDS_CAP, int)
         assert PARTIAL_RECORDS_CAP == 1000
@@ -143,7 +143,7 @@ def test_partial_records_is_stored_as_a_tuple(self) -> None:
         assert error.partial_records == tuple(records)
 
     def test_partial_records_is_truncated_to_the_last_cap_entries(self) -> None:
-        from mloda.core.prepare.identify_feature_group import PARTIAL_RECORDS_CAP
+        from mloda.core.prepare.resolution_types import PARTIAL_RECORDS_CAP
 
         result = _empty_result()
         records = [_record(f"capped_836pr_{index}", result) for index in range(PARTIAL_RECORDS_CAP + 5)]
diff --git a/tests/test_core/test_prepare/test_first_pass_rejection_recording.py b/tests/test_core/test_prepare/test_first_pass_rejection_recording.py
index 8ee99a61..500e8a44 100644
--- a/tests/test_core/test_prepare/test_first_pass_rejection_recording.py
+++ b/tests/test_core/test_prepare/test_first_pass_rejection_recording.py
@@ -33,7 +33,8 @@
 from mloda.core.abstract_plugins.compute_framework import ComputeFramework
 from mloda.core.abstract_plugins.feature_group import FeatureGroup
 from mloda.core.prepare.accessible_plugins import FeatureGroupEnvironmentMapping
-from mloda.core.prepare.identify_feature_group import Elimination, EvaluationResult, FeatureResolutionError
+from mloda.core.prepare.identify_feature_group import FeatureResolutionError
+from mloda.core.prepare.resolution_types import Elimination, EvaluationResult
 from tests.test_core.test_prepare.identify_seam import evaluate_or_raise
 
 
diff --git a/tests/test_core/test_prepare/test_identify_feature_group_error_message.py b/tests/test_core/test_prepare/test_identify_feature_group_error_message.py
index 89e14f46..85b80baf 100644
--- a/tests/test_core/test_prepare/test_identify_feature_group_error_message.py
+++ b/tests/test_core/test_prepare/test_identify_feature_group_error_message.py
@@ -1,8 +1,7 @@
-"""Tests for error message formatting in identify_feature_group.py.
+"""Tests for the resolution failure messages raised when a feature does not resolve to exactly one group.
 
-This test verifies that the multiple-feature-group error message uses the
-formatted candidate output from _render_multiple (naming each class as
-"ClassName (module.path)") instead of raw dict/class representation.
+The formatting lives in mloda/core/prepare/resolution_failure_renderer.py: _render_multiple names each
+candidate as "ClassName (module.path)" instead of a raw dict/class representation.
 """
 
 from typing import Optional
diff --git a/tests/test_core/test_prepare/test_identify_feature_group_evaluation_seam.py b/tests/test_core/test_prepare/test_identify_feature_group_evaluation_seam.py
index 9e61a2cc..9f814f8d 100644
--- a/tests/test_core/test_prepare/test_identify_feature_group_evaluation_seam.py
+++ b/tests/test_core/test_prepare/test_identify_feature_group_evaluation_seam.py
@@ -23,9 +23,9 @@
 from mloda.core.prepare.accessible_plugins import FeatureGroupEnvironmentMapping
 from mloda.core.prepare.identify_feature_group import (
     ComputeFrameworkPinError,
-    EvaluationResult,
     IdentifyFeatureGroupClass,
 )
+from mloda.core.prepare.resolution_types import EvaluationResult
 from mloda_plugins.compute_framework.base_implementations.pandas.dataframe import PandasDataFrame
 from mloda_plugins.compute_framework.base_implementations.python_dict.python_dict_framework import PythonDictFramework
 from tests.test_core.test_prepare.identify_seam import evaluate_or_raise
diff --git a/tests/test_core/test_prepare/test_identify_seam.py b/tests/test_core/test_prepare/test_identify_seam.py
index 2040d665..1aa2ef8f 100644
--- a/tests/test_core/test_prepare/test_identify_seam.py
+++ b/tests/test_core/test_prepare/test_identify_seam.py
@@ -21,11 +21,11 @@
 from mloda.core.abstract_plugins.feature_group import FeatureGroup
 from mloda.core.prepare.accessible_plugins import FeatureGroupEnvironmentMapping
 from mloda.core.prepare.identify_feature_group import (
-    EvaluationResult,
     FeatureResolutionError,
     IdentifyFeatureGroupClass,
-    render_resolution_failure,
 )
+from mloda.core.prepare.resolution_failure_renderer import render_resolution_failure
+from mloda.core.prepare.resolution_types import EvaluationResult
 from tests.test_core.test_prepare.identify_seam import evaluate_or_raise, identify_winner
 
 
diff --git a/tests/test_core/test_prepare/test_required_when_rejection_recording.py b/tests/test_core/test_prepare/test_required_when_rejection_recording.py
index 6841336d..20e55a3b 100644
--- a/tests/test_core/test_prepare/test_required_when_rejection_recording.py
+++ b/tests/test_core/test_prepare/test_required_when_rejection_recording.py
@@ -29,7 +29,8 @@
 from mloda.core.abstract_plugins.compute_framework import ComputeFramework
 from mloda.core.abstract_plugins.feature_group import FeatureGroup
 from mloda.core.prepare.accessible_plugins import FeatureGroupEnvironmentMapping
-from mloda.core.prepare.identify_feature_group import EvaluationResult, FeatureResolutionError
+from mloda.core.prepare.identify_feature_group import FeatureResolutionError
+from mloda.core.prepare.resolution_types import EvaluationResult
 from mloda.provider import PropertySpec
 from tests.test_core.test_prepare.identify_seam import evaluate_or_raise
 
diff --git a/tests/test_core/test_prepare/test_identify_feature_group_failure_renderer.py b/tests/test_core/test_prepare/test_resolution_failure_renderer.py
similarity index 99%
rename from tests/test_core/test_prepare/test_identify_feature_group_failure_renderer.py
rename to tests/test_core/test_prepare/test_resolution_failure_renderer.py
index 1129f3c1..f1a893be 100644
--- a/tests/test_core/test_prepare/test_identify_feature_group_failure_renderer.py
+++ b/tests/test_core/test_prepare/test_resolution_failure_renderer.py
@@ -30,13 +30,13 @@
 from mloda.core.abstract_plugins.feature_group import FeatureGroup
 from mloda.core.api.plugin_docs import resolve_feature
 from mloda.core.prepare.accessible_plugins import FeatureGroupEnvironmentMapping
-from mloda.core.prepare.identify_feature_group import (
+from mloda.core.prepare.identify_feature_group import IdentifyFeatureGroupClass
+from mloda.core.prepare.resolution_failure_renderer import render_resolution_failure
+from mloda.core.prepare.resolution_types import (
     CandidateFrameworks,
     Elimination,
     EvaluationResult,
-    IdentifyFeatureGroupClass,
     RenderFacts,
-    render_resolution_failure,
 )
 
 
diff --git a/tests/test_core/test_prepare/test_resolution_module_split.py b/tests/test_core/test_prepare/test_resolution_module_split.py
index 9c761105..5e389ccb 100644
--- a/tests/test_core/test_prepare/test_resolution_module_split.py
+++ b/tests/test_core/test_prepare/test_resolution_module_split.py
@@ -1,7 +1,8 @@
 """Pins the split of identify_feature_group into resolution_types and resolution_failure_renderer.
 
-Ownership, re-export identity for the public names, and the acyclic direction
-resolution_types <- resolution_failure_renderer <- identify_feature_group.
+Which module owns which name, that the matcher is not a facade (no __all__, no call site importing a
+name it does not own from it), and the acyclic direction resolution_types <- resolution_failure_renderer
+<- identify_feature_group.
 """
 
 from __future__ import annotations
@@ -10,7 +11,7 @@
 import importlib
 import subprocess  # nosec B404
 import sys
-from collections.abc import Iterable, Sequence
+from collections.abc import Sequence
 from pathlib import Path
 from types import ModuleType
 
@@ -45,7 +46,7 @@
     "render_resolution_failure",
 )
 
-# What stays in the matcher module, with its definition, not as a re-export.
+# What stays in the matcher module, with its definition, and the only names a call site may import from it.
 MATCHER_KEPT_NAMES = (
     "matches_feature_group_scope",
     "FeatureResolutionError",
@@ -55,24 +56,12 @@
     "resolve_or_raise",
 )
 
-# Every name a call site imports from the matcher module today; the split must keep all of them importable.
-CALL_SITE_NAMES = (
-    "CandidateFrameworks",
-    "ComputeFrameworkPinError",
-    "Elimination",
-    "EvaluationResult",
-    "FeatureResolutionError",
-    "IdentifyFeatureGroupClass",
-    "PARTIAL_RECORDS_CAP",
-    "RenderFacts",
-    "ResolutionDiagnosis",
-    "ResolutionRecord",
-    "evaluate_and_render",
-    "matches_feature_group_scope",
-    "render_resolution_failure",
-    "resolve_or_raise",
-    "scope_callout",
-)
+# Directories swept for imports of the matcher, relative to the repo root. docs/ is in because the marimo
+# notebooks under docs/docs/examples/ are excluded from both mypy and ruff F401, so nothing else gates them.
+SWEPT_DIRS = ("mloda", "mloda_plugins", "tests", "docs")
+
+# Last segment of MATCHER_MODULE: what the sweep gates on, see the gate comment below.
+MATCHER_BASENAME = MATCHER_MODULE.rsplit(".", 1)[-1]
 
 _SUBPROCESS_TIMEOUT = 8.0
 
@@ -91,12 +80,31 @@ def _prepare_dir() -> Path:
     return Path(matcher_file).parent
 
 
+def _repo_root() -> Path:
+    """Repo root, derived from this file's location at <root>/tests/test_core/test_prepare.
+
+    Deliberately not off _prepare_dir(): under `tox -e installed` the matcher resolves to site-packages,
+    which has no tests tree, so a module-derived root would sweep nothing and still pass. The test file
+    is always in the checkout, whichever import mode is in play.
+    """
+    return Path(__file__).parents[3]
+
+
 def _missing_names(module: ModuleType, names: Sequence[str]) -> list[str]:
     return [name for name in names if not hasattr(module, name)]
 
 
-def _public(names: Iterable[str]) -> list[str]:
-    return [name for name in names if not name.startswith("_")]
+def _foreign_matcher_imports(path: Path, source: str) -> list[str]:
+    """`path:line -> name` for every name imported from the matcher that the matcher does not own."""
+    tree = ast.parse(source, filename=str(path))
+    offenders: list[str] = []
+    for node in ast.walk(tree):  # walk, not tree.body: function-local imports count too
+        if not isinstance(node, ast.ImportFrom) or node.module != MATCHER_MODULE:
+            continue
+        offenders.extend(
+            f"{path}:{node.lineno} -> {alias.name}" for alias in node.names if alias.name not in MATCHER_KEPT_NAMES
+        )
+    return offenders
 
 
 def _imported_modules(path: Path) -> set[str]:
@@ -132,17 +140,6 @@ def test_resolution_failure_renderer_module_defines_its_names() -> None:
     assert missing == [], f"{RENDERER_MODULE} does not define {missing}"
 
 
-def test_public_moved_names_are_reexported_by_identity() -> None:
-    """The matcher must re-export the same objects, not copies, so isinstance and `is` checks keep working."""
-    for module_name, names in ((TYPES_MODULE, TYPES_NAMES), (RENDERER_MODULE, RENDERER_NAMES)):
-        owner = importlib.import_module(module_name)
-        for name in _public(names):
-            assert hasattr(identify_feature_group, name), f"{MATCHER_MODULE} no longer re-exports {name}"
-            assert getattr(identify_feature_group, name) is getattr(owner, name), (
-                f"{MATCHER_MODULE}.{name} is not the same object as {module_name}.{name}"
-            )
-
-
 def test_kept_names_stay_defined_in_the_matcher_module() -> None:
     for name in MATCHER_KEPT_NAMES:
         assert hasattr(identify_feature_group, name), f"{MATCHER_MODULE} no longer defines {name}"
@@ -150,17 +147,38 @@ def test_kept_names_stay_defined_in_the_matcher_module() -> None:
         assert owner == MATCHER_MODULE, f"{name} moved out of {MATCHER_MODULE} to {owner}"
 
 
-def test_call_site_names_remain_importable_from_the_matcher() -> None:
-    matcher = importlib.import_module(MATCHER_MODULE)
-    missing = _missing_names(matcher, CALL_SITE_NAMES)
-    assert missing == [], f"{MATCHER_MODULE} no longer exposes {missing}, so its call sites break"
-    # hasattr alone is blind to __all__, but mypy --strict implies --no-implicit-reexport: the re-export
-    # surface it checks against is __all__, so a name missing there breaks type checking at every call site
-    # even while the runtime attribute is still there.
-    unexported = [name for name in CALL_SITE_NAMES if name not in matcher.__all__]
-    assert unexported == [], (
-        f"{MATCHER_MODULE}.__all__ omits {unexported}; mypy --strict's no-implicit-reexport checks against "
-        f"__all__, so its call sites fail to type-check even though the attributes still exist"
+def test_matcher_declares_no_all() -> None:
+    """A module always exports what it defines, so __all__ here would only re-export imports: the facade is back."""
+    declared = getattr(identify_feature_group, "__all__", None)
+    assert declared is None, f"{MATCHER_MODULE} declares __all__ = {declared}, re-exporting names it does not own"
+
+
+def test_no_call_site_imports_a_foreign_name_from_the_matcher() -> None:
+    """No call site imports a name from the matcher that the matcher does not own.
+
+    Not the main line of defence: `mypy --strict` sweeps the same trees and its no_implicit_reexport
+    rejects every static evasion (aliased imports, module-object attribute access, relative imports).
+    Its one blind spot is what this test exists for: re-adding __all__ to the matcher makes those
+    re-exports legal again for mypy, and the call sites route through the facade unchallenged.
+    """
+    root = _repo_root()
+    offenders: list[str] = []
+    for directory in SWEPT_DIRS:
+        base = root / directory
+        if not base.is_dir():  # a directory may be absent (slim checkout, sdist layout); the rest still gets swept
+            continue
+        for path in sorted(base.rglob("*.py")):
+            source = path.read_text(encoding="utf-8")
+            # Substring gate: parses 27 of 907 files, ~0.15s instead of ~1.5s. A 10x saving well inside the
+            # 10s timeout either way, so drop it freely if it ever gets in the way. Gating on the bare last
+            # segment rather than the dotted path keeps `from a.b . c import X` spellings in scope.
+            if MATCHER_BASENAME not in source:
+                continue
+            offenders.extend(_foreign_matcher_imports(path, source))
+    listed = "\n".join(offenders)
+    assert offenders == [], (
+        f"these imports take a name from {MATCHER_MODULE} that it does not own; import each from "
+        f"{TYPES_MODULE} or {RENDERER_MODULE} instead:\n{listed}"
     )
 
 
diff --git a/tests/test_core/test_prepare/test_resolve_or_raise.py b/tests/test_core/test_prepare/test_resolve_or_raise.py
index 1321f3f4..5fe08dfa 100644
--- a/tests/test_core/test_prepare/test_resolve_or_raise.py
+++ b/tests/test_core/test_prepare/test_resolve_or_raise.py
@@ -40,16 +40,17 @@
 from mloda.core.api.plugin_info import ResolvedFeature
 from mloda.core.prepare.accessible_plugins import FeatureGroupEnvironmentMapping, PreFilterPlugins
 from mloda.core.prepare.identify_feature_group import (
-    PARTIAL_RECORDS_CAP,
     ComputeFrameworkPinError,
-    EvaluationResult,
     FeatureResolutionError,
     IdentifyFeatureGroupClass,
-    ResolutionRecord,
     evaluate_and_render,
-    render_resolution_failure,
     resolve_or_raise,
-    scope_callout,
+)
+from mloda.core.prepare.resolution_failure_renderer import render_resolution_failure, scope_callout
+from mloda.core.prepare.resolution_types import (
+    PARTIAL_RECORDS_CAP,
+    EvaluationResult,
+    ResolutionRecord,
 )
 from tests.test_core.test_prepare.identify_seam import evaluate_or_raise
 
diff --git a/tests/test_core/test_prepare/test_single_pass_exactly_once.py b/tests/test_core/test_prepare/test_single_pass_exactly_once.py
index cf84b384..1800a51d 100644
--- a/tests/test_core/test_prepare/test_single_pass_exactly_once.py
+++ b/tests/test_core/test_prepare/test_single_pass_exactly_once.py
@@ -44,10 +44,8 @@
 from mloda.core.api.plugin_docs import resolve_feature
 from mloda.core.prepare import identify_feature_group
 from mloda.core.prepare.accessible_plugins import FeatureGroupEnvironmentMapping, PreFilterPlugins
-from mloda.core.prepare.identify_feature_group import (
-    IdentifyFeatureGroupClass,
-    render_resolution_failure,
-)
+from mloda.core.prepare.identify_feature_group import IdentifyFeatureGroupClass
+from mloda.core.prepare.resolution_failure_renderer import render_resolution_failure
 from tests.test_core.test_prepare.identify_seam import evaluate_or_raise
 
 
diff --git a/tests/test_core/test_prepare/test_subtype_matching.py b/tests/test_core/test_prepare/test_subtype_matching.py
index edbc0946..c24c4081 100644
--- a/tests/test_core/test_prepare/test_subtype_matching.py
+++ b/tests/test_core/test_prepare/test_subtype_matching.py
@@ -11,7 +11,8 @@
 from mloda.core.abstract_plugins.components.options import Options
 from mloda.core.abstract_plugins.compute_framework import ComputeFramework
 from mloda.core.prepare.accessible_plugins import FeatureGroupEnvironmentMapping
-from mloda.core.prepare.identify_feature_group import CandidateFrameworks, IdentifyFeatureGroupClass
+from mloda.core.prepare.identify_feature_group import IdentifyFeatureGroupClass
+from mloda.core.prepare.resolution_types import CandidateFrameworks
 from mloda.provider import FeatureChainParserMixin, FeatureGroup, SubtypeDeclaration, property_spec
 from tests.test_core.test_prepare.identify_seam import identify_winner
 
diff --git a/tests/test_core/test_resolution_parity/test_environment_build_failure_parity.py b/tests/test_core/test_resolution_parity/test_environment_build_failure_parity.py
index 62a2b1a3..d87084bb 100644
--- a/tests/test_core/test_resolution_parity/test_environment_build_failure_parity.py
+++ b/tests/test_core/test_resolution_parity/test_environment_build_failure_parity.py
@@ -49,7 +49,7 @@
     PreFilterPlugins,
     RedefinitionConflictError,
 )
-from mloda.core.prepare.identify_feature_group import ResolutionDiagnosis
+from mloda.core.prepare.resolution_types import ResolutionDiagnosis
 from mloda_plugins.compute_framework.base_implementations.pandas.dataframe import PandasDataFrame