TypedConfig 1.0.0

TypedConfig

TypedConfig is a lightweight F# library for loading configuration into strongly typed records with validation.

It maps environment variables into F# record types, ensuring type safety and clear error reporting.

Features

• Load configuration into F# records using generics
• Built-in parsing for common types (string, int, bool)
• Accumulates validation errors instead of failing fast
• Environment variable source support
• Small API surface with explicit Result-based errors

Requirements

• .NET 10 SDK
• Paket for dependency restore

Example

open TypedConfig

type Config =
    {
        DATABASE_URL: string
        PORT: int
        DEBUG: bool
    }

let result =
    Api.load<Config> ()

If all required environment variables are present and valid, the result is:

Ok {
    DATABASE_URL = "localhost"
    PORT = 5000
    DEBUG = true
}

or

Error [
    MissingVariable "DATABASE_URL"
    InvalidValue ("PORT", "abc", "int")
    UnsupportedType "DateTime"
]

Supported Types

TypedConfig currently supports these record field types:

• string
• int
• bool

Unsupported field types return an UnsupportedType error.

Development

dotnet build
dotnet test

NuGet Packaging and Publishing

Package metadata is defined in TypedConfig/TypedConfig.fsproj for SDK-style packing.

Publishing is automated by GitHub Actions via .github/workflows/nuget-publish.yml.

Release flow:

1. Ensure GitHub secret NUGET_API_KEY is configured in the repository settings.
2. Create and push a version tag in format *.*.* (for example 0.1.0).
3. Workflow restores, builds, tests, packs, and publishes the package to NuGet.org.

Example:

git tag 0.1.0
git push origin 0.1.0

The repository uses Paket files:

• paket.dependencies
• paket.lock
• TypedConfig/paket.references
• TypedConfig.Tests/paket.references

Motivation

TypedConfig helps eliminate boilerplate configuration code and runtime errors caused by missing or invalid values, while keeping the API simple and idiomatic for F# developers.

Status

Early stage. API may change. Planned future extensions include additional sources, optional fields, custom field names, enum parsing, and nested records.