diff --git a/.github/workflows/pull-requests.yml b/.github/workflows/pull-requests.yml
index 31d47ece3..9769c5425 100644
--- a/.github/workflows/pull-requests.yml
+++ b/.github/workflows/pull-requests.yml
@@ -13,10 +13,10 @@ jobs:
     timeout-minutes: 10
     steps:
     - uses: actions/checkout@v6
-    - name: Setup .NET 10
+    - name: Setup .NET
       uses: actions/setup-dotnet@v5
       with:
-        dotnet-version: 10.0.201
+        dotnet-version-file: global.json
     - name: Cache NuGet packages
       uses: actions/cache@v5
       with:
@@ -37,10 +37,10 @@ jobs:
     timeout-minutes: 40
     steps:
     - uses: actions/checkout@v6
-    - name: Setup .NET 10
+    - name: Setup .NET
       uses: actions/setup-dotnet@v5
       with:
-        dotnet-version: 10.0.201
+        dotnet-version-file: global.json
     - name: Cache NuGet packages
       uses: actions/cache@v5
       with:
@@ -63,10 +63,10 @@ jobs:
     timeout-minutes: 40
     steps:
     - uses: actions/checkout@v6
-    - name: Setup .NET 10
+    - name: Setup .NET
       uses: actions/setup-dotnet@v5
       with:
-        dotnet-version: 10.0.201
+        dotnet-version-file: global.json
     - name: Cache NuGet packages
       uses: actions/cache@v5
       with:
diff --git a/.github/workflows/push-master.yml b/.github/workflows/push-master.yml
index bdad12347..64e097f2d 100644
--- a/.github/workflows/push-master.yml
+++ b/.github/workflows/push-master.yml
@@ -17,10 +17,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v6
-    - name: Setup .NET 10
+    - name: Setup .NET
       uses: actions/setup-dotnet@v5
       with:
-        dotnet-version: 10.0.201
+        dotnet-version-file: global.json
     - name: Cache NuGet packages
       uses: actions/cache@v5
       with:
diff --git a/tests/FSharp.Data.Core.Tests/FSharp.Data.Core.Tests.fsproj b/tests/FSharp.Data.Core.Tests/FSharp.Data.Core.Tests.fsproj
index 1341f156a..dc1bf9cd1 100644
--- a/tests/FSharp.Data.Core.Tests/FSharp.Data.Core.Tests.fsproj
+++ b/tests/FSharp.Data.Core.Tests/FSharp.Data.Core.Tests.fsproj
@@ -44,6 +44,7 @@
     <Compile Include="HtmlAttributeExtensions.fs" />
     <Compile Include="HtmlCssSelectors.fs" />
     <Compile Include="HtmlTableCell.fs" />
+    <Compile Include="StructuralInference.fs" />
     <Compile Include="StructuralTypes.fs" />
     <Compile Include="BaseTypesHtmlDocument.fs" />
     <Compile Include="BaseTypesHtmlGenerics.fs" />
diff --git a/tests/FSharp.Data.Core.Tests/StructuralInference.fs b/tests/FSharp.Data.Core.Tests/StructuralInference.fs
new file mode 100644
index 000000000..a9567ebf6
--- /dev/null
+++ b/tests/FSharp.Data.Core.Tests/StructuralInference.fs
@@ -0,0 +1,354 @@
+module FSharp.Data.Tests.StructuralInference
+
+open System
+open System.Globalization
+open NUnit.Framework
+open FsUnit
+open FSharp.Data
+open FSharp.Data.Runtime.StructuralTypes
+open FSharp.Data.Runtime.StructuralInference
+
+// Helpers
+
+let private culture = CultureInfo.InvariantCulture
+let private uomProvider = defaultUnitsOfMeasureProvider
+let private valuesOnly = InferenceMode'.ValuesOnly
+let private noInference = InferenceMode'.NoInference
+
+let private prim typ = InferedType.Primitive(typ, None, false, false)
+let private primOpt typ = InferedType.Primitive(typ, None, true, false)
+
+let private inferStr value =
+    getInferedTypeFromString uomProvider valuesOnly culture value None
+
+// ─── typeTag ────────────────────────────────────────────────────────────────
+
+[<Test>]
+let ``typeTag returns Number for numeric primitives`` () =
+    typeTag (prim typeof<int>) |> should equal InferedTypeTag.Number
+    typeTag (prim typeof<int64>) |> should equal InferedTypeTag.Number
+    typeTag (prim typeof<decimal>) |> should equal InferedTypeTag.Number
+    typeTag (prim typeof<float>) |> should equal InferedTypeTag.Number
+    typeTag (prim typeof<Bit>) |> should equal InferedTypeTag.Number
+    typeTag (prim typeof<Bit0>) |> should equal InferedTypeTag.Number
+    typeTag (prim typeof<Bit1>) |> should equal InferedTypeTag.Number
+
+[<Test>]
+let ``typeTag returns correct tag for other primitive types`` () =
+    typeTag (prim typeof<bool>) |> should equal InferedTypeTag.Boolean
+    typeTag (prim typeof<string>) |> should equal InferedTypeTag.String
+    typeTag (prim typeof<DateTime>) |> should equal InferedTypeTag.DateTime
+    typeTag (prim typeof<DateTimeOffset>) |> should equal InferedTypeTag.DateTime
+    typeTag (prim typeof<TimeSpan>) |> should equal InferedTypeTag.TimeSpan
+    typeTag (prim typeof<Guid>) |> should equal InferedTypeTag.Guid
+
+[<Test>]
+let ``typeTag returns Null for Null and Top`` () =
+    typeTag InferedType.Null |> should equal InferedTypeTag.Null
+    typeTag InferedType.Top |> should equal InferedTypeTag.Null
+
+[<Test>]
+let ``typeTag returns correct tag for record, collection, heterogeneous, json`` () =
+    typeTag (InferedType.Record(Some "Foo", [], false)) |> should equal (InferedTypeTag.Record(Some "Foo"))
+    typeTag (InferedType.Record(None, [], false)) |> should equal (InferedTypeTag.Record None)
+    typeTag (InferedType.Collection([], Map.empty)) |> should equal InferedTypeTag.Collection
+    typeTag (InferedType.Heterogeneous(Map.empty, false)) |> should equal InferedTypeTag.Heterogeneous
+    typeTag (InferedType.Json(prim typeof<string>, false)) |> should equal InferedTypeTag.Json
+
+#if NET6_0_OR_GREATER
+[<Test>]
+let ``typeTag returns DateOnly and TimeOnly on NET6+`` () =
+    typeTag (prim typeof<DateOnly>) |> should equal InferedTypeTag.DateOnly
+    typeTag (prim typeof<TimeOnly>) |> should equal InferedTypeTag.TimeOnly
+#endif
+
+// ─── subtypeInfered: Top and Null ───────────────────────────────────────────
+
+[<Test>]
+let ``subtypeInfered: Top merged with any type returns that type`` () =
+    subtypeInfered false InferedType.Top (prim typeof<int>) |> should equal (prim typeof<int>)
+    subtypeInfered false (prim typeof<string>) InferedType.Top |> should equal (prim typeof<string>)
+    subtypeInfered false InferedType.Top InferedType.Null |> should equal InferedType.Null
+    subtypeInfered false InferedType.Top InferedType.Top |> should equal InferedType.Top
+
+[<Test>]
+let ``subtypeInfered: Null merged with string makes it optional`` () =
+    // string can have empty values so with allowEmptyValues=true, string stays non-optional
+    let result = subtypeInfered true InferedType.Null (prim typeof<string>)
+
+    match result with
+    | InferedType.Primitive(typ, None, false, false) when typ = typeof<string> -> () // stays non-optional
+    | _ -> failwithf "Unexpected result: %A" result
+
+[<Test>]
+let ``subtypeInfered: Null merged with int makes it optional`` () =
+    // int cannot have empty values so it becomes optional regardless of allowEmptyValues
+    let result = subtypeInfered false InferedType.Null (prim typeof<int>)
+
+    match result with
+    | InferedType.Primitive(typ, None, true, false) when typ = typeof<int> -> ()
+    | _ -> failwithf "Unexpected result: %A" result
+
+// ─── subtypeInfered: primitives ─────────────────────────────────────────────
+
+[<Test>]
+let ``subtypeInfered: identical primitives return same primitive`` () =
+    subtypeInfered false (prim typeof<int>) (prim typeof<int>) |> should equal (prim typeof<int>)
+    subtypeInfered false (prim typeof<string>) (prim typeof<string>) |> should equal (prim typeof<string>)
+    subtypeInfered false (prim typeof<bool>) (prim typeof<bool>) |> should equal (prim typeof<bool>)
+
+[<Test>]
+let ``subtypeInfered: numeric widening Bit0 + Bit1 → Bit`` () =
+    let result = subtypeInfered false (prim typeof<Bit0>) (prim typeof<Bit1>)
+
+    match result with
+    | InferedType.Primitive(typ, None, false, false) when typ = typeof<Bit> -> ()
+    | _ -> failwithf "Unexpected result: %A" result
+
+[<Test>]
+let ``subtypeInfered: numeric widening int + int64 → int64`` () =
+    let result = subtypeInfered false (prim typeof<int>) (prim typeof<int64>)
+
+    match result with
+    | InferedType.Primitive(typ, None, false, false) when typ = typeof<int64> -> ()
+    | _ -> failwithf "Unexpected result: %A" result
+
+[<Test>]
+let ``subtypeInfered: numeric widening int + float → float`` () =
+    let result = subtypeInfered false (prim typeof<int>) (prim typeof<float>)
+
+    match result with
+    | InferedType.Primitive(typ, None, false, false) when typ = typeof<float> -> ()
+    | _ -> failwithf "Unexpected result: %A" result
+
+[<Test>]
+let ``subtypeInfered: numeric widening decimal + float → float`` () =
+    let result = subtypeInfered false (prim typeof<decimal>) (prim typeof<float>)
+
+    match result with
+    | InferedType.Primitive(typ, None, false, false) when typ = typeof<float> -> ()
+    | _ -> failwithf "Unexpected result: %A" result
+
+[<Test>]
+let ``subtypeInfered: Bit0 + bool → bool`` () =
+    // bool ⊇ Bit0 (bool has Bit0 in conversion table)
+    let result = subtypeInfered false (prim typeof<Bit0>) (prim typeof<bool>)
+
+    match result with
+    | InferedType.Primitive(typ, None, false, false) when typ = typeof<bool> -> ()
+    | _ -> failwithf "Unexpected result: %A" result
+
+[<Test>]
+let ``subtypeInfered: incompatible types create Heterogeneous`` () =
+    let result = subtypeInfered false (prim typeof<string>) (prim typeof<int>)
+
+    match result with
+    | InferedType.Heterogeneous(map, false) ->
+        map |> Map.containsKey InferedTypeTag.String |> should equal true
+        map |> Map.containsKey InferedTypeTag.Number |> should equal true
+    | _ -> failwithf "Unexpected result: %A" result
+
+[<Test>]
+let ``subtypeInfered: Guid + string creates Heterogeneous`` () =
+    let result = subtypeInfered false (prim typeof<Guid>) (prim typeof<string>)
+
+    match result with
+    | InferedType.Heterogeneous(map, false) ->
+        map |> Map.containsKey InferedTypeTag.Guid |> should equal true
+        map |> Map.containsKey InferedTypeTag.String |> should equal true
+    | _ -> failwithf "Unexpected result: %A" result
+
+[<Test>]
+let ``subtypeInfered: optionality is preserved when merging`` () =
+    // Required int merged with required int → required int
+    subtypeInfered false (prim typeof<int>) (prim typeof<int>) |> should equal (prim typeof<int>)
+
+    // Optional int merged with required int → optional int
+    let result = subtypeInfered false (primOpt typeof<int>) (prim typeof<int>)
+
+    match result with
+    | InferedType.Primitive(typ, None, true, false) when typ = typeof<int> -> ()
+    | _ -> failwithf "Unexpected result: %A" result
+
+// ─── subtypeInfered: records ────────────────────────────────────────────────
+
+[<Test>]
+let ``subtypeInfered: records with same name union their fields`` () =
+    let record1 =
+        InferedType.Record(
+            Some "R",
+            [ { Name = "a"; Type = prim typeof<int> }
+              { Name = "b"; Type = prim typeof<string> } ],
+            false
+        )
+
+    let record2 =
+        InferedType.Record(
+            Some "R",
+            [ { Name = "a"; Type = prim typeof<int> }
+              { Name = "c"; Type = prim typeof<bool> } ],
+            false
+        )
+
+    let result = subtypeInfered false record1 record2
+
+    match result with
+    | InferedType.Record(Some "R", fields, false) ->
+        fields |> List.map (fun f -> f.Name) |> List.sort |> should equal [ "a"; "b"; "c" ]
+        // 'b' is in record1 only → optional in result
+        let bField = fields |> List.find (fun f -> f.Name = "b")
+
+        match bField.Type with
+        | InferedType.Primitive(_, _, true, _) -> () // optional
+        | _ -> failwithf "'b' should be optional, got %A" bField.Type
+    | _ -> failwithf "Unexpected result: %A" result
+
+[<Test>]
+let ``subtypeInfered: records with different names become Heterogeneous`` () =
+    let record1 = InferedType.Record(Some "R1", [], false)
+    let record2 = InferedType.Record(Some "R2", [], false)
+    let result = subtypeInfered false record1 record2
+
+    match result with
+    | InferedType.Heterogeneous _ -> ()
+    | _ -> failwithf "Expected Heterogeneous, got %A" result
+
+// ─── inferCollectionType ────────────────────────────────────────────────────
+
+[<Test>]
+let ``inferCollectionType with single int type gives Collection with Number`` () =
+    let result = inferCollectionType false [ prim typeof<int> ]
+
+    match result with
+    | InferedType.Collection(order, map) ->
+        order |> should contain InferedTypeTag.Number
+        map |> Map.containsKey InferedTypeTag.Number |> should equal true
+    | _ -> failwithf "Unexpected result: %A" result
+
+[<Test>]
+let ``inferCollectionType with mixed numeric types widens to float`` () =
+    let result =
+        inferCollectionType false [ prim typeof<int>; prim typeof<float>; prim typeof<decimal> ]
+
+    match result with
+    | InferedType.Collection(_, map) ->
+        let _, elemType = map |> Map.find InferedTypeTag.Number
+
+        match elemType with
+        | InferedType.Primitive(typ, None, false, false) when typ = typeof<float> -> ()
+        | _ -> failwithf "Expected float element type, got %A" elemType
+    | _ -> failwithf "Unexpected result: %A" result
+
+[<Test>]
+let ``inferCollectionType with multiple items of same type gives Multiple multiplicity`` () =
+    let result =
+        inferCollectionType false [ prim typeof<int>; prim typeof<int>; prim typeof<int> ]
+
+    match result with
+    | InferedType.Collection(_, map) ->
+        let mult, _ = map |> Map.find InferedTypeTag.Number
+        mult |> should equal InferedMultiplicity.Multiple
+    | _ -> failwithf "Unexpected result: %A" result
+
+[<Test>]
+let ``inferCollectionType with single item gives Single multiplicity`` () =
+    let result = inferCollectionType false [ prim typeof<int> ]
+
+    match result with
+    | InferedType.Collection(_, map) ->
+        let mult, _ = map |> Map.find InferedTypeTag.Number
+        mult |> should equal InferedMultiplicity.Single
+    | _ -> failwithf "Unexpected result: %A" result
+
+// ─── getInferedTypeFromString ────────────────────────────────────────────────
+
+[<Test>]
+let ``getInferedTypeFromString: empty string returns Null`` () =
+    inferStr "" |> should equal InferedType.Null
+
+[<Test>]
+let ``getInferedTypeFromString: "0" and "1" infer Bit types`` () =
+    inferStr "0" |> should equal (prim typeof<Bit0>)
+    inferStr "1" |> should equal (prim typeof<Bit1>)
+
+[<Test>]
+let ``getInferedTypeFromString: boolean strings infer bool`` () =
+    inferStr "true" |> should equal (prim typeof<bool>)
+    inferStr "false" |> should equal (prim typeof<bool>)
+    inferStr "True" |> should equal (prim typeof<bool>)
+    inferStr "yes" |> should equal (prim typeof<bool>)
+    inferStr "no" |> should equal (prim typeof<bool>)
+
+[<Test>]
+let ``getInferedTypeFromString: integer strings infer int`` () =
+    inferStr "42" |> should equal (prim typeof<int>)
+    inferStr "-123" |> should equal (prim typeof<int>)
+    inferStr "2147483647" |> should equal (prim typeof<int>) // Int32.MaxValue
+
+[<Test>]
+let ``getInferedTypeFromString: large integer strings infer int64`` () =
+    inferStr "2147483648" |> should equal (prim typeof<int64>) // Int32.MaxValue + 1
+    inferStr "9999999999" |> should equal (prim typeof<int64>)
+
+[<Test>]
+let ``getInferedTypeFromString: decimal strings infer decimal`` () =
+    inferStr "3.14" |> should equal (prim typeof<decimal>)
+    inferStr "-0.5" |> should equal (prim typeof<decimal>)
+
+[<Test>]
+let ``getInferedTypeFromString: unrecognised strings fall back to string`` () =
+    inferStr "hello" |> should equal (prim typeof<string>)
+    inferStr "not-a-number" |> should equal (prim typeof<string>)
+    inferStr "abc123" |> should equal (prim typeof<string>)
+
+[<Test>]
+let ``getInferedTypeFromString: GUID strings infer Guid`` () =
+    inferStr "6F9619FF-8B86-D011-B42D-00C04FC964FF" |> should equal (prim typeof<Guid>)
+
+[<Test>]
+let ``getInferedTypeFromString: NoInference mode always returns string`` () =
+    let inferNoInference value =
+        getInferedTypeFromString uomProvider noInference culture value None
+
+    inferNoInference "42" |> should equal (prim typeof<string>)
+    inferNoInference "true" |> should equal (prim typeof<string>)
+    inferNoInference "3.14" |> should equal (prim typeof<string>)
+
+// ─── InferenceMode' ─────────────────────────────────────────────────────────
+
+[<Test>]
+let ``InferenceMode FromPublicApi BackwardCompatible with legacyInferTypesFromValues=true → ValuesOnly`` () =
+    InferenceMode'.FromPublicApi(InferenceMode.BackwardCompatible, true)
+    |> should equal InferenceMode'.ValuesOnly
+
+[<Test>]
+let ``InferenceMode FromPublicApi BackwardCompatible with legacyInferTypesFromValues=false → NoInference`` () =
+    InferenceMode'.FromPublicApi(InferenceMode.BackwardCompatible, false)
+    |> should equal InferenceMode'.NoInference
+
+[<Test>]
+let ``InferenceMode FromPublicApi explicit modes map correctly`` () =
+    InferenceMode'.FromPublicApi(InferenceMode.NoInference) |> should equal InferenceMode'.NoInference
+    InferenceMode'.FromPublicApi(InferenceMode.ValuesOnly) |> should equal InferenceMode'.ValuesOnly
+
+    InferenceMode'.FromPublicApi(InferenceMode.ValuesAndInlineSchemasHints)
+    |> should equal InferenceMode'.ValuesAndInlineSchemasHints
+
+    InferenceMode'.FromPublicApi(InferenceMode.ValuesAndInlineSchemasOverrides)
+    |> should equal InferenceMode'.ValuesAndInlineSchemasOverrides
+
+// ─── supportsUnitsOfMeasure ──────────────────────────────────────────────────
+
+[<Test>]
+let ``supportsUnitsOfMeasure returns true for numeric types`` () =
+    supportsUnitsOfMeasure typeof<int> |> should equal true
+    supportsUnitsOfMeasure typeof<int64> |> should equal true
+    supportsUnitsOfMeasure typeof<decimal> |> should equal true
+    supportsUnitsOfMeasure typeof<float> |> should equal true
+
+[<Test>]
+let ``supportsUnitsOfMeasure returns false for non-numeric types`` () =
+    supportsUnitsOfMeasure typeof<string> |> should equal false
+    supportsUnitsOfMeasure typeof<bool> |> should equal false
+    supportsUnitsOfMeasure typeof<DateTime> |> should equal false
+    supportsUnitsOfMeasure typeof<Guid> |> should equal false