diff --git a/.changeset/lovely-eels-attend.md b/.changeset/lovely-eels-attend.md
new file mode 100644
index 000000000..7012418ae
--- /dev/null
+++ b/.changeset/lovely-eels-attend.md
@@ -0,0 +1,6 @@
+---
+"@osdk/client": patch
+"@osdk/api": patch
+---
+
+Fix where clause types so we don't accept more than one key in the clauses.
diff --git a/etc/api.report.api.md b/etc/api.report.api.md
index 07f7d95b7..84dcada46 100644
--- a/etc/api.report.api.md
+++ b/etc/api.report.api.md
@@ -961,8 +961,8 @@ export interface VersionBound<V extends VersionString<any, any, any>> {
 // Warning: (ae-forgotten-export) The symbol "FilterFor" needs to be exported by the entry point index.d.ts
 //
 // @public (undocumented)
-export type WhereClause<T extends ObjectOrInterfaceDefinition> = OrWhereClause<T> | AndWhereClause<T> | NotWhereClause<T> | (IsNever<PropertyKeys<T>> extends true ? Record<string, never> : {
-    [P in PropertyKeys<T>]?: FilterFor<CompileTimeMetadata<T>["properties"][P]>;
+export type WhereClause<T extends ObjectOrInterfaceDefinition> = OrWhereClause<T> | AndWhereClause<T> | NotWhereClause<T> | (IsNever<keyof CompileTimeMetadata<T>["properties"]> extends true ? Record<string, never> : {
+    [P in keyof CompileTimeMetadata<T>["properties"]]?: FilterFor<CompileTimeMetadata<T>["properties"][P]>;
 });
 
 // @public (undocumented)
diff --git a/packages/api/src/aggregate/ArrayFilter.ts b/packages/api/src/aggregate/ArrayFilter.ts
new file mode 100644
index 000000000..cbfea2ba9
--- /dev/null
+++ b/packages/api/src/aggregate/ArrayFilter.ts
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2024 Palantir Technologies, Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import type { Just } from "./Just.js";
+
+interface ArrayFilterOptions<T> {
+  "$contains": T;
+  "$isNull": boolean;
+}
+namespace ArrayFilter {
+  export interface $contains<T>
+    extends Just<"$contains", ArrayFilterOptions<T>>
+  {}
+  export interface $isNull<T> extends Just<"$isNull", ArrayFilterOptions<T>> {}
+}
+
+export type ArrayFilter<T> =
+  | ArrayFilter.$contains<T>
+  | ArrayFilter.$isNull<T>;
diff --git a/packages/api/src/aggregate/BaseFilter.ts b/packages/api/src/aggregate/BaseFilter.ts
new file mode 100644
index 000000000..65e5b253b
--- /dev/null
+++ b/packages/api/src/aggregate/BaseFilter.ts
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2024 Palantir Technologies, Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import type { Just } from "./Just.js";
+
+export type BaseFilterOptions<T> = {
+  "$eq": T;
+  "$ne": T;
+  "$isNull": boolean;
+  "$in": ReadonlyArray<T>;
+};
+
+export namespace BaseFilter {
+  export interface $eq<T> extends Just<"$eq", BaseFilterOptions<T>> {}
+  export interface $ne<T> extends Just<"$ne", BaseFilterOptions<T>> {}
+  export interface $in<T> extends Just<"$in", BaseFilterOptions<T>> {}
+  export interface $isNull<T> extends Just<"$isNull", BaseFilterOptions<T>> {}
+}
+
+export type BaseFilter<T> =
+  | BaseFilter.$eq<T>
+  | BaseFilter.$ne<T>
+  | BaseFilter.$in<T>
+  | BaseFilter.$isNull<T>;
+
+/** @internal */
+export type CatchThemAll<T> = CatchThemAllInternal<T, keyof T>;
+
+// extends for union distribution
+/** @internal */
+type CatchThemAllInternal<T, K extends keyof T> = K extends keyof T
+  ? { [k in K]: T[k] }
+  : never;
diff --git a/packages/api/src/aggregate/BooleanFilter.ts b/packages/api/src/aggregate/BooleanFilter.ts
new file mode 100644
index 000000000..57f196fc9
--- /dev/null
+++ b/packages/api/src/aggregate/BooleanFilter.ts
@@ -0,0 +1,38 @@
+/*
+ * Copyright 2024 Palantir Technologies, Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import type { BaseFilterOptions, CatchThemAll } from "./BaseFilter.js";
+import type { Just } from "./Just.js";
+
+interface BooleanFilterOptions extends BaseFilterOptions<boolean> {}
+
+export namespace BooleanFilter {
+  export interface $eq extends Just<"$eq", BooleanFilterOptions> {}
+  export interface $ne extends Just<"$ne", BooleanFilterOptions> {}
+  export interface $isNull extends Just<"$isNull", BooleanFilterOptions> {}
+  export interface $in extends Just<"$in", BooleanFilterOptions> {}
+}
+export type BooleanFilter =
+  | boolean
+  | BooleanFilter.$eq
+  | BooleanFilter.$ne
+  | BooleanFilter.$in
+  | BooleanFilter.$isNull;
+
+/** @internal */
+function _typeCheck() {
+  const b: BooleanFilter = {} as CatchThemAll<BooleanFilterOptions>;
+}
diff --git a/packages/api/src/aggregate/DatetimeFilter.ts b/packages/api/src/aggregate/DatetimeFilter.ts
new file mode 100644
index 000000000..454000871
--- /dev/null
+++ b/packages/api/src/aggregate/DatetimeFilter.ts
@@ -0,0 +1,51 @@
+/*
+ * Copyright 2024 Palantir Technologies, Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import type { BaseFilterOptions, CatchThemAll } from "./BaseFilter.js";
+import type { Just } from "./Just.js";
+
+export interface DatetimeFilterOptions extends BaseFilterOptions<string> {
+  "$gt": string;
+  "$gte": string;
+  "$lt": string;
+  "$lte": string;
+}
+
+export namespace DatetimeFilter {
+  export interface $eq extends Just<"$eq", DatetimeFilterOptions> {}
+  export interface $ne extends Just<"$ne", DatetimeFilterOptions> {}
+  export interface $isNull extends Just<"$isNull", DatetimeFilterOptions> {}
+  export interface $gt extends Just<"$gt", DatetimeFilterOptions> {}
+  export interface $gte extends Just<"$gte", DatetimeFilterOptions> {}
+  export interface $lt extends Just<"$lt", DatetimeFilterOptions> {}
+  export interface $lte extends Just<"$lte", DatetimeFilterOptions> {}
+  export interface $in extends Just<"$in", DatetimeFilterOptions> {}
+}
+export type DatetimeFilter =
+  | string
+  | DatetimeFilter.$eq
+  | DatetimeFilter.$ne
+  | DatetimeFilter.$isNull
+  | DatetimeFilter.$in
+  | DatetimeFilter.$gt
+  | DatetimeFilter.$gte
+  | DatetimeFilter.$lt
+  | DatetimeFilter.$lte;
+
+/** @internal */
+function _typeCheck() {
+  const b: DatetimeFilter = {} as CatchThemAll<DatetimeFilterOptions>;
+}
diff --git a/packages/api/src/aggregate/GeoFilter.ts b/packages/api/src/aggregate/GeoFilter.ts
new file mode 100644
index 000000000..c9cb06d76
--- /dev/null
+++ b/packages/api/src/aggregate/GeoFilter.ts
@@ -0,0 +1,66 @@
+/*
+ * Copyright 2024 Palantir Technologies, Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import type { BBox, Point, Polygon } from "geojson";
+import type { Just } from "./Just.js";
+import type { DistanceUnitMapping } from "./WhereClause.js";
+
+interface GeoFilterOptions {
+  "$within":
+    | {
+      $distance: [number, keyof typeof DistanceUnitMapping];
+      $of: [number, number] | Readonly<Point>;
+      $bbox?: never;
+      $polygon?: never;
+    }
+    | {
+      $bbox: BBox;
+      $distance?: never;
+      $of?: never;
+      $polygon?: never;
+    }
+    | BBox
+    | {
+      $polygon: Polygon["coordinates"];
+      $bbox?: never;
+      $distance?: never;
+      $of?: never;
+    }
+    | Polygon;
+  "$intersects":
+    | {
+      $bbox: BBox;
+      $polygon?: never;
+    }
+    | BBox
+    | {
+      $polygon: Polygon["coordinates"];
+      $bbox?: never;
+    }
+    | Polygon;
+  "$isNull": boolean;
+}
+
+export namespace GeoFilter {
+  export interface $within extends Just<"$within", GeoFilterOptions> {}
+  export interface $intersects extends Just<"$intersects", GeoFilterOptions> {}
+  export interface $isNull extends Just<"$isNull", GeoFilterOptions> {}
+}
+
+export type GeoFilter =
+  | GeoFilter.$within
+  | GeoFilter.$intersects
+  | GeoFilter.$isNull;
diff --git a/packages/api/src/aggregate/Just.ts b/packages/api/src/aggregate/Just.ts
new file mode 100644
index 000000000..73c9118ad
--- /dev/null
+++ b/packages/api/src/aggregate/Just.ts
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2024 Palantir Technologies, Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+export type Just<Z extends keyof V, V> =
+  & {
+    [k in Z]: V[k];
+  }
+  & {
+    [k in keyof V as k extends Z ? never : k]?: never;
+  };
+
+export type NeverThese<V extends string | symbol | number> = {
+  [k in V]?: never;
+};
diff --git a/packages/api/src/aggregate/NumberFilter.ts b/packages/api/src/aggregate/NumberFilter.ts
new file mode 100644
index 000000000..99c1f75f5
--- /dev/null
+++ b/packages/api/src/aggregate/NumberFilter.ts
@@ -0,0 +1,51 @@
+/*
+ * Copyright 2024 Palantir Technologies, Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import type { BaseFilterOptions, CatchThemAll } from "./BaseFilter.js";
+import type { Just } from "./Just.js";
+
+interface NumberFilterOptions extends BaseFilterOptions<number> {
+  "$gt": number;
+  "$gte": number;
+  "$lt": number;
+  "$lte": number;
+}
+
+export namespace NumberFilter {
+  export interface $eq extends Just<"$eq", NumberFilterOptions> {}
+  export interface $ne extends Just<"$ne", NumberFilterOptions> {}
+  export interface $isNull extends Just<"$isNull", NumberFilterOptions> {}
+  export interface $gt extends Just<"$gt", NumberFilterOptions> {}
+  export interface $gte extends Just<"$gte", NumberFilterOptions> {}
+  export interface $lt extends Just<"$lt", NumberFilterOptions> {}
+  export interface $lte extends Just<"$lte", NumberFilterOptions> {}
+  export interface $in extends Just<"$in", NumberFilterOptions> {}
+}
+export type NumberFilter =
+  | number
+  | NumberFilter.$eq
+  | NumberFilter.$ne
+  | NumberFilter.$isNull
+  | NumberFilter.$in
+  | NumberFilter.$gt
+  | NumberFilter.$gte
+  | NumberFilter.$lt
+  | NumberFilter.$lte;
+
+/** @internal */
+function _typeCheck() {
+  const b: NumberFilter = {} as CatchThemAll<NumberFilterOptions>;
+}
diff --git a/packages/api/src/aggregate/StringFilter.ts b/packages/api/src/aggregate/StringFilter.ts
new file mode 100644
index 000000000..7b65d7fa3
--- /dev/null
+++ b/packages/api/src/aggregate/StringFilter.ts
@@ -0,0 +1,65 @@
+/*
+ * Copyright 2024 Palantir Technologies, Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import type { BaseFilterOptions, CatchThemAll } from "./BaseFilter.js";
+import type { Just } from "./Just.js";
+
+interface StringFilterOptions extends BaseFilterOptions<string> {
+  "$startsWith": string;
+  "$containsAllTermsInOrder": string;
+  "$containsAnyTerm": string;
+  "$containsAllTerms": string;
+  "$in": ReadonlyArray<string>;
+}
+
+export namespace StringFilter {
+  export interface $eq extends Just<"$eq", StringFilterOptions> {}
+  export interface $ne extends Just<"$ne", StringFilterOptions> {}
+  export interface $isNull extends Just<"$isNull", StringFilterOptions> {}
+  export interface $startsWith
+    extends Just<"$startsWith", StringFilterOptions>
+  {
+  }
+  export interface $containsAllTermsInOrder
+    extends Just<"$containsAllTermsInOrder", StringFilterOptions>
+  {
+  }
+  export interface $containsAnyTerm
+    extends Just<"$containsAnyTerm", StringFilterOptions>
+  {
+  }
+  export interface $containsAllTerms
+    extends Just<"$containsAllTerms", StringFilterOptions>
+  {
+  }
+  export interface $in extends Just<"$in", StringFilterOptions> {}
+}
+
+export type StringFilter =
+  | string
+  | StringFilter.$eq
+  | StringFilter.$ne
+  | StringFilter.$isNull
+  | StringFilter.$in
+  | StringFilter.$startsWith
+  | StringFilter.$containsAllTermsInOrder
+  | StringFilter.$containsAnyTerm
+  | StringFilter.$containsAllTerms;
+
+/** @internal */
+function _typeCheck() {
+  const b: StringFilter = {} as CatchThemAll<StringFilterOptions>;
+}
diff --git a/packages/api/src/aggregate/WhereClause.ts b/packages/api/src/aggregate/WhereClause.ts
index faf1b656b..92adf0a4a 100644
--- a/packages/api/src/aggregate/WhereClause.ts
+++ b/packages/api/src/aggregate/WhereClause.ts
@@ -24,6 +24,13 @@ import type {
   ObjectMetadata,
 } from "../ontology/ObjectTypeDefinition.js";
 import type { IsNever } from "../OsdkObjectFrom.js";
+import type { ArrayFilter } from "./ArrayFilter.js";
+import type { BaseFilter, BaseFilterOptions } from "./BaseFilter.js";
+import type { BooleanFilter } from "./BooleanFilter.js";
+import type { DatetimeFilter } from "./DatetimeFilter.js";
+import type { GeoFilter } from "./GeoFilter.js";
+import type { NumberFilter } from "./NumberFilter.js";
+import type { StringFilter } from "./StringFilter.js";
 
 export type PossibleWhereClauseFilters =
   | "$gt"
@@ -42,44 +49,6 @@ export type PossibleWhereClauseFilters =
   | "$containsAnyTerm"
   | "$containsAllTerms";
 
-// We need to conditional here to force the union to be distributed
-type MakeFilter<K extends PossibleWhereClauseFilters, V> = K extends string ? {
-    [k in K]: V;
-  }
-  : never;
-
-type BaseFilter<T> =
-  | T
-  | MakeFilter<"$eq" | "$ne", T>
-  | MakeFilter<"$in", ReadonlyArray<T>>
-  | MakeFilter<"$isNull", boolean>;
-
-type StringFilter =
-  | BaseFilter<string>
-  | MakeFilter<
-    | "$startsWith"
-    | "$containsAllTermsInOrder"
-    | "$containsAnyTerm"
-    | "$containsAllTerms",
-    string
-  >;
-type NumberFilter =
-  | BaseFilter<number>
-  | MakeFilter<"$gt" | "$gte" | "$lt" | "$lte", number>;
-
-type DatetimeFilter =
-  | BaseFilter<string>
-  | MakeFilter<"$gt" | "$gte" | "$lt" | "$lte", string>;
-
-type BooleanFilter =
-  | boolean
-  | MakeFilter<"$eq" | "$ne", boolean>
-  | MakeFilter<"$isNull", boolean>;
-
-type ArrayFilter<T> =
-  | MakeFilter<"$contains", T>
-  | MakeFilter<"$isNull", boolean>;
-
 // the value side of this needs to match DistanceUnit from @osdk/internal.foundry but we don't
 // want the dependency
 export const DistanceUnitMapping = {
@@ -153,11 +122,6 @@ export type GeoFilter_Intersects = {
     | Polygon;
 };
 
-export type GeoFilter =
-  | GeoFilter_Within
-  | GeoFilter_Intersects
-  | MakeFilter<"$isNull", boolean>;
-
 type FilterFor<PD extends ObjectMetadata.Property> = PD["multiplicity"] extends
   true
   ? (PD["type"] extends
@@ -169,7 +133,10 @@ type FilterFor<PD extends ObjectMetadata.Property> = PD["multiplicity"] extends
     : PD["type"] extends "geopoint" | "geoshape" ? GeoFilter
     : PD["type"] extends "datetime" | "timestamp" ? DatetimeFilter
     : PD["type"] extends "boolean" ? BooleanFilter
-    : NumberFilter); // FIXME we need to represent all types
+    : PD["type"] extends
+      "double" | "integer" | "long" | "float" | "decimal" | "byte"
+      ? NumberFilter
+    : BaseFilter<string>); // FIXME we need to represent all types
 
 export interface AndWhereClause<
   T extends ObjectOrInterfaceDefinition,
@@ -195,6 +162,10 @@ export type WhereClause<
   | OrWhereClause<T>
   | AndWhereClause<T>
   | NotWhereClause<T>
-  | (IsNever<PropertyKeys<T>> extends true ? Record<string, never> : {
-    [P in PropertyKeys<T>]?: FilterFor<CompileTimeMetadata<T>["properties"][P]>;
-  });
+  | (IsNever<keyof CompileTimeMetadata<T>["properties"]> extends true
+    ? Record<string, never>
+    : {
+      [P in keyof CompileTimeMetadata<T>["properties"]]?: FilterFor<
+        CompileTimeMetadata<T>["properties"][P]
+      >;
+    });
diff --git a/packages/client/src/internal/conversions/modernToLegacyWhereClause.test.ts b/packages/client/src/internal/conversions/modernToLegacyWhereClause.test.ts
index ff0331024..b62632286 100644
--- a/packages/client/src/internal/conversions/modernToLegacyWhereClause.test.ts
+++ b/packages/client/src/internal/conversions/modernToLegacyWhereClause.test.ts
@@ -26,10 +26,18 @@ describe(modernToLegacyWhereClause, () => {
   describe("api namespaces", () => {
     describe("interfaces", () => {
       it("properly converts shortname to fqApiName", () => {
-        const T: ObjectOrInterfaceDefinition = {
+        const T = {
           type: "interface",
           apiName: "a.Foo",
-        };
+          __DefinitionMetadata: {
+            type: "interface",
+            properties: { "prop": { type: "integer" } },
+            apiName: "a.Foo",
+            displayName: "",
+            links: {},
+            rid: "",
+          },
+        } as const satisfies ObjectOrInterfaceDefinition;
 
         const r = modernToLegacyWhereClause({
           prop: 5,
@@ -45,10 +53,22 @@ describe(modernToLegacyWhereClause, () => {
       });
 
       it("properly does not convert when interface has no apiNamespace", () => {
-        const T: ObjectOrInterfaceDefinition = {
+        const T = {
           type: "interface",
           apiName: "Foo",
-        };
+          __DefinitionMetadata: {
+            type: "interface",
+            properties: {
+              "foo": { type: "integer" },
+              "b.prop": { type: "integer" },
+              "prop": { type: "integer" },
+            },
+            apiName: "Foo",
+            displayName: "",
+            links: {},
+            rid: "",
+          },
+        } as const satisfies ObjectOrInterfaceDefinition;
 
         const r = modernToLegacyWhereClause({
           "b.prop": 5,
@@ -75,10 +95,22 @@ describe(modernToLegacyWhereClause, () => {
       });
 
       it("gracefully handles redundant apiNamespace in property", () => {
-        const T: ObjectOrInterfaceDefinition = {
+        const T = {
           type: "interface",
           apiName: "a.Foo",
-        };
+          __DefinitionMetadata: {
+            type: "interface",
+            properties: {
+              "a.foo": { type: "integer" },
+              "b.prop": { type: "integer" },
+              "prop": { type: "integer" },
+            },
+            apiName: "a.Foo",
+            displayName: "",
+            links: {},
+            rid: "",
+          },
+        } as const satisfies ObjectOrInterfaceDefinition;
 
         const r = modernToLegacyWhereClause({
           "b.prop": 5,
@@ -105,10 +137,22 @@ describe(modernToLegacyWhereClause, () => {
       });
 
       it("properly does not convert different apiNamespaces", () => {
-        const T: ObjectOrInterfaceDefinition = {
+        const T = {
           type: "interface",
           apiName: "a.Foo",
-        };
+          __DefinitionMetadata: {
+            type: "interface",
+            properties: {
+              "a.foo": { type: "integer" },
+              "b.prop": { type: "integer" },
+              "prop": { type: "integer" },
+            },
+            apiName: "a.Foo",
+            displayName: "",
+            links: {},
+            rid: "",
+          },
+        } as const satisfies ObjectOrInterfaceDefinition;
 
         expect(modernToLegacyWhereClause({
           "b.prop": 5,
@@ -124,18 +168,28 @@ describe(modernToLegacyWhereClause, () => {
 
     describe("objects", () => {
       it("does not convert object short property names to fq", () => {
-        const T: ObjectOrInterfaceDefinition = {
-          type: "object",
+        const T = {
+          type: "interface",
           apiName: "a.Foo",
-        };
-
+          __DefinitionMetadata: {
+            type: "interface",
+            properties: {
+              "a.foo": { type: "integer" },
+              "prop": { type: "integer" },
+            },
+            apiName: "a.Foo",
+            displayName: "",
+            links: {},
+            rid: "",
+          },
+        } as const satisfies ObjectOrInterfaceDefinition;
         const r = modernToLegacyWhereClause({
           prop: 5,
         }, T);
 
         expect(r).toMatchInlineSnapshot(`
           {
-            "field": "prop",
+            "field": "a.prop",
             "type": "eq",
             "value": 5,
           }
diff --git a/packages/client/src/object/fetchPage.test.ts b/packages/client/src/object/fetchPage.test.ts
index 5e8b48e95..8d3b1d656 100644
--- a/packages/client/src/object/fetchPage.test.ts
+++ b/packages/client/src/object/fetchPage.test.ts
@@ -24,7 +24,7 @@ import type {
   SelectArgToKeys,
 } from "@osdk/api";
 import type { FooInterface } from "@osdk/client.test.ontology";
-import { Todo } from "@osdk/client.test.ontology";
+import { Employee, Todo } from "@osdk/client.test.ontology";
 import type { SearchJsonQueryV2 } from "@osdk/internal.foundry.core";
 import { describe, expect, expectTypeOf, it } from "vitest";
 import { createMinimalClient } from "../createMinimalClient.js";
@@ -168,6 +168,52 @@ describe(fetchPage, () => {
     );
   });
 
+  it("where clause keys correctly typed", () => {
+    const client = createMinimalClient(
+      metadata,
+      "https://foo",
+      async () => "",
+    );
+    const objectSet = createObjectSet(Todo, client);
+    const objectSetWithSpecialPropertyTypes = createObjectSet(Employee, client);
+
+    expectTypeOf(objectSet.where).toBeCallableWith({
+      $and: [{ id: { $gt: 2 } }, { id: { $lte: 2 } }],
+    });
+    expectTypeOf(objectSet.where).toBeCallableWith({
+      // @ts-expect-error
+      id: { $gt: 2, $lte: 2 },
+    });
+
+    // We used to default to number filters for other types, like geotimeseries reference and timeseries. These tests will make sure
+    // we don't do that anymore
+    expectTypeOf(objectSetWithSpecialPropertyTypes.where).toBeCallableWith({
+      $and: [
+        { employeeLocation: { $eq: "myLocation" } },
+        {
+          employeeLocation: { $ne: "notMyLocation" },
+        },
+        { employeeLocation: { $isNull: false } },
+        // @ts-expect-error
+        { employeeLocation: { $isNull: false, $eq: "myLocation" } },
+        // @ts-expect-error
+        { employeeLocation: { $gt: 5 } },
+      ],
+    });
+
+    expectTypeOf(objectSetWithSpecialPropertyTypes.where).toBeCallableWith({
+      $and: [
+        { employeeStatus: { $eq: "myStatus" } },
+        {
+          employeeLocation: { $ne: "notMyStatus" },
+        },
+        { employeeLocation: { $isNull: false } },
+        // @ts-expect-error
+        { employeeLocation: { $lte: 5 } },
+      ],
+    });
+  });
+
   describe("includeRid", () => {
     it("properly returns the correct string for includeRid", () => {
       expectTypeOf<Awaited<FetchPageResult<TodoDef, "text", false, "throw">>>()
diff --git a/packages/client/src/objectSet/ObjectSet.test.ts b/packages/client/src/objectSet/ObjectSet.test.ts
index da41347e5..30c5a7ebd 100644
--- a/packages/client/src/objectSet/ObjectSet.test.ts
+++ b/packages/client/src/objectSet/ObjectSet.test.ts
@@ -25,7 +25,7 @@ import type {
   PropertyKeys,
   Result,
 } from "@osdk/api";
-import { isOk } from "@osdk/api";
+import { isOk, WhereClause } from "@osdk/api";
 import {
   $ontologyRid,
   BarInterface,
@@ -44,6 +44,7 @@ import {
 } from "vitest";
 import type {
   ApiNameAsString,
+  IsNever,
   JustProps,
   PropMapToInterface,
   PropMapToObject,
diff --git a/packages/monorepo.cspell/dict.test-words.txt b/packages/monorepo.cspell/dict.test-words.txt
index f0513d32b..b376e1b6a 100644
--- a/packages/monorepo.cspell/dict.test-words.txt
+++ b/packages/monorepo.cspell/dict.test-words.txt
@@ -6,3 +6,4 @@ objectdoesnotexist
 Packag
 querydoesnotexist
 unstubAllEnvs
+geotimeseries