diff --git a/src/physrisk/api/v1/impact_req_resp.py b/src/physrisk/api/v1/impact_req_resp.py
index 6840fa21..592444ab 100644
--- a/src/physrisk/api/v1/impact_req_resp.py
+++ b/src/physrisk/api/v1/impact_req_resp.py
@@ -35,43 +35,8 @@ class Category(int, Enum):
     REDFLAG = 4
 
 
-class RiskKey(BaseModel):
-    scenario_id: str
-    year: str
-
-
-class RiskMeasureKey(RiskKey):
-    risk_measure_id: str = Field("", description="Identifier of the risk measure.")
-
-
-class AssetsRiskScores(BaseModel):
-    """Risk scores for a set of assets, with risk measures used to calculate the measures.
-    A single score may be derived from multiple risk measures in principle, the measures are identified
-    by the ScoreBasedMeasureDefinition corresponding to the asset.
-    In principle multiple measures may be used to compute the score, hence 'measures_0', 'measures_1' etc,
-    although no example yet.
-    """
-
-    key: RiskKey
-    scores: List[int] = Field(None, description="Identifier for the risk measure.")
-    measures_0: List[float]
-    measures_1: Optional[List[float]]
-
-
-class AssetRiskMeasures(BaseModel):
-    """Risk measures for a set of assets."""
-
-    key: RiskMeasureKey
-    measures: List[float]
-
-
-class AssetScoreModel(BaseModel):
-    asset_model_id: List[str]
-
-
 class RiskMeasureDefinition(BaseModel):
     measure_id: str = Field(None, description="Identifier for the risk measure.")
-    measure_index: int = Field(None, description="Identifier for the risk measure.")
     label: str = Field(
         "<short description of the measure, e.g. fractional loss for 1-in-100 year event.",
         description="Value of the score.",
@@ -103,26 +68,31 @@ def __hash__(self):
         return id(self)
 
 
-class HazardRiskMeasures(BaseModel):
-    """Risk measures for one particular type of hazard"""
-
+class RiskMeasureKey(BaseModel):
     hazard_type: str
-    scores_for_assets: Optional[List[AssetsRiskScores]] = Field(
-        [], description="Risk scores for the set of assets for different scenarios and years."
-    )
-    measures_for_assets: Optional[List[AssetRiskMeasures]] = Field(
-        [], description="Risk measures for the set of assets for different scenarios and years."
-    )
-    score_measure_ids_for_assets: Optional[List[str]] = Field(
-        None, description="Identifiers of the score-based risk measures used for each asset."
-    )
+    scenario_id: str
+    year: str
+    measure_id: str
+
+
+class RiskMeasuresForAssets(BaseModel):
+    key: RiskMeasureKey
+    scores: List[int] = Field(None, description="Identifier for the risk measure.")
+    measures_0: List[float]
+    measures_1: Optional[List[float]]
+
+
+class ScoreBasedRiskMeasureSetDefinition(BaseModel):
+    measure_set_id: str
+    asset_measure_ids_for_hazard: Dict[str, List[str]]
+    score_definitions: Optional[Dict[str, ScoreBasedRiskMeasureDefinition]]
 
 
 class RiskMeasures(BaseModel):
     """Risk measures"""
 
-    hazard_risk_measures: List[HazardRiskMeasures]
-    score_definitions: Optional[Dict[str, ScoreBasedRiskMeasureDefinition]]
+    measures_for_assets: List[RiskMeasuresForAssets]
+    score_based_measure_set_defn: ScoreBasedRiskMeasureSetDefinition
     measures_definitions: Optional[List[RiskMeasureDefinition]]
 
 
diff --git a/src/physrisk/requests.py b/src/physrisk/requests.py
index 1aa31fe5..2a560aa1 100644
--- a/src/physrisk/requests.py
+++ b/src/physrisk/requests.py
@@ -37,11 +37,11 @@
     AssetLevelImpact,
     Assets,
     AssetSingleImpact,
-    AssetsRiskScores,
-    HazardRiskMeasures,
-    RiskKey,
+    RiskMeasureKey,
     RiskMeasures,
+    RiskMeasuresForAssets,
     ScoreBasedRiskMeasureDefinition,
+    ScoreBasedRiskMeasureSetDefinition,
 )
 from .data.image_creator import ImageCreator
 from .data.inventory import EmbeddedInventory, Inventory
@@ -352,15 +352,15 @@ def _create_risk_measures(
         RiskMeasures: Output for writing to JSON.
     """
     hazard_types = all_hazards()
-    hazard_risk_measures = []
+    measure_set_id = "measure_set_1"
+    measures_for_assets: List[RiskMeasuresForAssets] = []
     for hazard_type in hazard_types:
-        # assets_risk_scores contains the hazard scores for each scenario and year
-        assets_risk_scores: List[AssetsRiskScores] = []
-        # if all asset measure IDs are empty
         for scenario_id in scenarios:
             for year in years:
                 # we calculate and tag results for each scenario, year and hazard
-                score_key = RiskKey(scenario_id=scenario_id, year=str(year))
+                score_key = RiskMeasureKey(
+                    hazard_type=hazard_type.__name__, scenario_id=scenario_id, year=str(year), measure_id=measure_set_id
+                )
                 scores = [-1] * len(assets)
                 measures_0 = [float("nan")] * len(assets)
                 for i, asset in enumerate(assets):
@@ -370,20 +370,17 @@ def _create_risk_measures(
                     if measure is not None:
                         scores[i] = measure.score
                         measures_0[i] = measure.measure_0
-                assets_risk_scores.append(
-                    AssetsRiskScores(key=score_key, scores=scores, measures_0=measures_0, measures_1=None)
+                measures_for_assets.append(
+                    RiskMeasuresForAssets(key=score_key, scores=scores, measures_0=measures_0, measures_1=None)
                 )
-        hazard_risk_measures.append(
-            HazardRiskMeasures(
-                hazard_type=hazard_type.__name__,
-                scores_for_assets=assets_risk_scores,
-                measures_for_assets=None,
-                score_measure_ids_for_assets=measure_ids_for_asset[hazard_type],
-            )
-        )
-    return RiskMeasures(
-        hazard_risk_measures=hazard_risk_measures,
+    score_based_measure_set_defn = ScoreBasedRiskMeasureSetDefinition(
+        measure_set_id=measure_set_id,
+        asset_measure_ids_for_hazard={k.__name__: v for k, v in measure_ids_for_asset.items()},
         score_definitions={v: k for (k, v) in definitions.items()},
+    )
+    return RiskMeasures(
+        measures_for_assets=measures_for_assets,
+        score_based_measure_set_defn=score_based_measure_set_defn,
         measures_definitions=None,
     )
 
diff --git a/src/test/risk_models/test_risk_models.py b/src/test/risk_models/test_risk_models.py
index 7ec09aac..be3e1ad5 100644
--- a/src/test/risk_models/test_risk_models.py
+++ b/src/test/risk_models/test_risk_models.py
@@ -5,12 +5,13 @@
 
 import numpy as np
 
+from physrisk.api.v1.impact_req_resp import RiskMeasureKey
 from physrisk.data.pregenerated_hazard_model import ZarrHazardModel
 from physrisk.hazard_models.core_hazards import get_default_source_paths
 from physrisk.kernel.assets import RealEstateAsset
 from physrisk.kernel.calculation import get_default_vulnerability_models
 from physrisk.kernel.hazards import CoastalInundation, RiverineInundation
-from physrisk.kernel.risk import AssetLevelRiskModel
+from physrisk.kernel.risk import AssetLevelRiskModel, MeasureKey
 from physrisk.requests import _create_risk_measures
 from physrisk.risk_models.risk_models import RealEstateToyRiskMeasures
 
@@ -51,7 +52,7 @@ def sp_coastal(scenario, year):
 
         assets = [
             RealEstateAsset(TestData.latitudes[0], TestData.longitudes[0], location="Asia", type="Buildings/Industrial")
-            for i in range(100)
+            for i in range(2)
         ]
 
         model = AssetLevelRiskModel(
@@ -60,9 +61,22 @@ def sp_coastal(scenario, year):
         measure_ids_for_asset, definitions = model.populate_measure_definitions(assets)
         _, measures = model.calculate_risk_measures(assets, prosp_scens=scenarios, years=years)
 
-        risk_measures = _create_risk_measures(measures, measure_ids_for_asset, definitions, assets, scenarios, years)
-
-        #with open("test.json", "w") as f:
-        #    f.write(risk_measures.model_dump_json())
+        # how to get a score using the MeasureKey
+        measure = measures[MeasureKey(assets[0], scenarios[0], years[0], RiverineInundation)]
+        score = measure.score
+        measure_0 = measure.measure_0
 
-        # print(measures[MeasureKey(assets[0], scenarios[0], years[0], RiverineInundation)])
+        # packing up the risk measures, e.g. for JSON transmission:
+        risk_measures = _create_risk_measures(measures, measure_ids_for_asset, definitions, assets, scenarios, years)
+        # we still have a key, but no asset:
+        key = RiskMeasureKey(
+            hazard_type="RiverineInundation",
+            scenario_id=scenarios[0],
+            year=str(years[0]),
+            measure_id=risk_measures.score_based_measure_set_defn.measure_set_id,
+        )
+        item = next(m for m in risk_measures.measures_for_assets if m.key == key)
+        score2 = item.scores[0]
+        measure_0_2 = item.measures_0[0]
+        assert score == score2
+        assert measure_0 == measure_0_2