Check-in

A simple self-hosted check-in app for saving where you have been or favouriting locations. Something I put together after wanting a way to 'check-in' to places I like, or have simply been, using my phone (or browser, in case I forget to on my phone), without relying on some third party provider.

My aim is to keep the API extremely simple, and unchanging.

This is just a small side project I'm working on when I feel like it. I have purposely kept things simple for now. No need to add complexity until necessary (hence the recent move to HTMX + Razor Pages!).

This project is not vibe-coded (I don't use any AI tools in vscode). I do use an LLM in the browser in the same way I would have previously used web search / StackOverflow.

The logo/favicon was generated by ChatGPT.

Styling ideas/boiler plate for the add popup & header also from ChatGPT, enhanced/polished by me.

Features

• Simple web API to save a longitude, latitude, note and date to a database.
• Map visualisation see your saved locations plotted on a leaflet.js map.
• Dockerized for easy deployment.

Using Check-in

Save a Location

• Endpoint: POST /checkin

• Content-type: application/json

• Body params:

  Field	Type	Description
  lat	double	Latitude in decimal degrees
  long	double	Longitude in decimal degrees
  dateTime	string	Can be any string *
  note	string	Text content of the note

• Example request:

  curl -X POST http://localhost:8080/checkin?apiKey=your_api_key \
      -H "Content-Type: application/json" \
      -d '{
          "lat": 50.17479763660827,
          "long": -5.256169543434019,
          "dateTime": "2025-05-11T14:30+01:00",
          "note": "Cornwall!"
      }'

• Note that 'dateTime' is a text field in SQLite, so it can be whatever you want. I personally opt for ISO8601 as I feel that has all the info I'd ever need.

Visualise Locations on Map

Once the Docker container is running, go to http://localhost:8080/checkin

Check-in in from iOS

Use Shortcuts with the following actions:

• Get current location
• Current Date
• Ask for Text with Note
• Get contents of http://localhost:8080/checkin?apiKey=your_api_key

With the above actions, you then have enough data to send a POST request to the API, which can be done in the 'Get contents of' advanced options.

Place a shortcut on your home screen or in the action centre!

Database

You can find a blank SQLite database here.

Make sure you copy db_empty.db to the right place and update the docker run command / Docker Compose config accordingly.

Docker Usage

Docker Run

docker run \
  -d \
  -p 8080:8080 \
  -v ./checkin_data/db.db:/data/db.db \
  -e Settings__ApiKey="your_api_key" \
  cwndev/checkin:latest

Docker Compose

services:
  checkin:
    image: cwndev/checkin:latest
    container_name: checkin
    restart: always
    environment:
      - Settings__ApiKey=your_api_key
    ports:
      - 8080:8080
    volumes:
      - ./checkin_data/db.db:/data/db.db

Tech Stack

• HTMX
• .NET Razor Pages
• .NET Core 10 Minimal APIs
• TypeScript ES2022 (plain JS)
• SQLite