Reified
Repository F# setup
open Reified
open Reified.Refinements
open Reified.Result
open Reified.Schema.Json

Build Generation

Add the runtime Schema package and the private build-time generator package:

<ItemGroup>
  <PackageReference Include="Reified.Schema" Version="..." />
  <PackageReference Include="Reified.Schema.Contracts.Build" Version="..." PrivateAssets="all" />
</ItemGroup>

Put [<DeriveSchema>] records in ordinary .fs files already listed as <Compile> items. No generator item, target, or manual generated-file <Compile> entry is required. Before CoreCompile, the package:

  1. examines the project's F# compile files in order;
  2. generates a companion for every file containing marked records;
  3. inserts each generated file immediately after its source file; and
  4. lets the F# compiler catch stale field names and incompatible generated code.

By default output is written below obj/, so it should not be committed.

Complete project example

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <Compile Include="Wire.fs" />
    <Compile Include="Program.fs" />
  </ItemGroup>

  <ItemGroup>
    <PackageReference Include="Reified.Schema" Version="..." />
    <PackageReference Include="Reified.Schema.Contracts.Build" Version="..." PrivateAssets="all" />
  </ItemGroup>
</Project>

Wire.fs must use a namespace and place marked records at namespace level:

namespace MyApp.Wire

open Reified.DerivedSchema

[<DeriveSchema>]
type Order = { Sku: string; Quantity: int }

An ordinary dotnet build now generates and compiles the companion schema.

MSBuild properties

Property Default Purpose
ReifiedSchemaGenEnabled true Set to false to skip generation.
ReifiedSchemaNaming camel Default wire naming: camel, snake, or verbatim.
ReifiedSchemaGeneratedFiles Intermediate Intermediate writes under obj; CheckedIn writes sibling .g.fs files.
ReifiedSchemaGenToolPath packaged tool Override the generator task assembly path, mainly for repository development.

Checked-in output

Use checked-in output when generated source must be reviewed or consumed outside the normal build:

<PropertyGroup>
  <ReifiedSchemaGeneratedFiles>CheckedIn</ReifiedSchemaGeneratedFiles>
</PropertyGroup>

The build writes Wire.g.fs beside Wire.fs and still manages F# compile ordering. Do not add the .g.fs file to <Compile> yourself.

Troubleshooting

  • No output: confirm generation is enabled, the source is a <Compile> item, and the record has [<DeriveSchema>].
  • Namespace diagnostic: marked records must be namespace-level declarations; one generated companion has one namespace.
  • Duplicate compile item: remove a manually listed .g.fs; the target inserts it.
  • A stale checked-in file fails compilation: rebuild to regenerate it. This failure is intentional drift detection.