Mijn.Host DNS Updater – ACME Challenge Tool

A minimal, fast .NET console application to create or update a single _acme-challenge TXT record via the Mijn.Host API v2.

Perfect as a dns-01 challenge hook for Let’s Encrypt tools (Certbot, win-acme, acme.sh, Posh-ACME, etc.).

Features

• Pure top-level console app – no DI container, no Host, no Singleton
• API key safely loaded from appsettings.json
• Fully async HttpClient with proper error handling
• Strongly-typed records
• Uses PATCH to add or replace exactly one DNS record
• Tiny binary, zero external runtime dependencies beyond .NET runtime

Usage

MijnHost.exe example.com L5f...your-acme-challenge-token