Local development

1. Start the cloud: aspire run (or dotnet run --project Heavymatica.Cloud.AppHost) from src/cloud. MongoDB, MinIO, the service and the websites’ dev servers start together; the service listens on http://localhost:5180.
2. Point the dev client at the cloud’s DevMojang, since dev clients have no Microsoft session: in src/mod/heavymatica/neoforge/runs/client/config/heavymatica-client.toml (or fabric/runs/...) set devSessionJoinUrl = "http://localhost:5180/dev/mojang".
3. Start the client: ./gradlew :heavymatica:neoforge:runClient or ./gradlew :heavymatica:fabric:runClient from src/mod, then open the library with H in a world. Each loader has its own run folder, heavymatica/<loader>/runs.

Dev client runs always talk to http://localhost:5180, whatever the config file says: released mods default to https://api.heavymatica.com, and the dev run overrides it so it never reaches production by accident. Set HEAVYMATICA_CLOUD_URL to use another local address. The game asks the cloud whether it is open only when the library opens; the local cloud always says open. To test against a cloud that says closed, set access = "ON" in the [cloud] section of the client config.

DevMojang (/dev/mojang) stands in for Mojang’s session server and accepts every join. Its counterpart for the website, /dev/web/sign-in?minecraft=<profile id>&returnTo=/library/, signs a browser in to the account of a Minecraft identity without GitHub, for example http://localhost:5180/dev/web/sign-in?minecraft=<uuid> for the player of HEAVYMATICA_DEV_USER. Open the website afterwards on the cloud’s origin or the website’s dev server; browsers send localhost cookies to every port. Both exist only when the service runs in the Development environment.

The websites’ local setup, including GitHub sign-in, is on Websites. The dev client’s scripting and other aids are on Development aids.