OpenHolidays API

The service behind the OpenHolidays API. Build with .NET 10.

Technology stack

• PostgreSQL 17+ as database
• ASP.NET as web framework
• Entity Framework Core as ORM layer
• Swagger UI for OpenAPI based documentation

Getting started

The following instructions show you how to set up a development environment on your computer.

Prerequisites

• Set up a local PosgreSQL 17 (or higher) instance.
• Clone or download the repository OpenHolidaysApi.Data.
• Clone or download this repository.
• Open the solution file OpenHolidaysApi.slnx in Visual Studio 2026.

Configure the OpenHolidaysApi CLI

• Switch to the project OpenHolidaysApi.CLI.

• Make a copy of the the appsettings.json file and name it appsettings.Development.json.

• Exchange the content with the following JSON document and adjust the values to your needs. This configures the root folder for the csv data sources (the src folder in your local OpenHolidaysApi.Data repository) and the database connection.

  "Sources": {
    "RootFolderName": "c:\\openholidaysapi.data\\src"
  },
  "Database": {
    "Server": "localhost",
    "Database": "OpenHolidaysApi",
    "Username": "postgres",
    "Password": "qwertz"
  }

Create and populate the database

• Build the OpenHolidaysApi.CLI project.
• Run the OpenHolidaysApi.CLI project with parameter initdb --import. This will create and populate the PostgreSQL database.

Configure the OpenHolidaysApi WebService

• Switch to the OpenHolidaysApi.WebService.

• Make a copy of the the appsettings.json file and name it appsettings.Development.json.

• Exchange the content with the following JSON document and adjust the values to your needs. This configures the database connection.

  "Database": {
    "Server": "localhost",
    "Database": "OpenHolidaysApi",
    "Username": "postgres",
    "Password": "qwertz"
  }

Build and test the API

• Build the OpenHolidaysApi.WebService project.
• Run the OpenHolidaysApi.WebService project and play with the Swagger UI.

Can I help?

Yes, that would be much appreciated. The best way to help is to post a response via the Issue Tracker and/or submit a Pull Request.