The platform-free core of the CodeAssist SPI: the symbol model, the neutral syntax tree, VirtualFile, and the content digest they are keyed by. Multiplatform, and exposed by every other SPI artifact.

The CodeAssist platform substrate the plugin SPI exposes: extension points, scoped services, the message bus, logging, and the settings model.

The CodeAssist language SPI: the neutral syntax tree, resolution, file types, completion, formatting, folding, and a language's compilation context.

The CodeAssist virtual file system, which the other SPI artifacts expose.

The CodeAssist project model: module types, project templates, facets and their codecs, and file icons.