This FastAPI server exposes an endpoint (the "webapp endpoint") which the lettergun webapp can contact to initiate letter writing.

The FastAPI app validates the webapp's JSON payload, then sends it to the lettergun-handwriting app. If the payload is valid it returns an 200 response.

lettergun-handwriting parses the JSON to create an svg image of the handwritten note. It sends the image to the image endpoint on the API server.

The API server verifies the SVG image against the original JSON payload and if it is valid, used the AxiDraw Python API to plot the SVG image. When the image is complete, it notifies the API server, which notifies the webapp.

• http://127.0.0.1/docs
• http://127.0.0.1/redoc

Use the following command whilst developing to build and run a docker image based on current code:

docker stop container-one && docker rm container-one && docker build -t image-one . && docker run -d --name container-one -p 80:80 image-one

To shell into it and run the tests:

docker exec -it container-one pytest app/

Once the container is running, and assuming you've mapped the ports to 80:80, you can go to http://127.0.0.1/.

You can experiment with API requests by using httpie. Use the command https http://127.0.0.1 to get started.

http post http://127.0.0.1/api/v1/create/ uid=foo message="Dear {name}, Good bye." "variables[0][name]=Joe" "variables[0][product]=tshirt" paper_size=A6 paper_orientation=landscape paper_type=p1

To run the test suite: docker exec -it container-one pytest app/