MPS: Skill for Claude Code

MPS Generator Aspect

Loading companion skills

Companion names in this skill are lazy dependencies: load only those relevant to the current task. If this skill came from an MCP server, use the host's skill loader to resolve the companion's unique discovered entry URI on the same host-assigned originating server. If the host has no server-backed skill loader, stop and report that limitation; do not silently fall back to a filesystem copy. If this skill came from a filesystem catalog, load the named sibling from that same catalog at <skills-root>/<skill-name>/SKILL.md, even if remote skill loaders are also available. Do not invent a tool name or server endpoint.

A generator transforms models written in the source language into models of one or more target languages (usually BaseLanguage or another DSL). It is a separate MPS module — a generator module — owned by the language and driven by templates: target-language code snippets annotated with macros.

Generator architecture (read first)

A generator translates from the problem domain (source language) toward the implementation domain, often as a cascade: each generator lowers the abstraction level by producing its target language, which becomes the next generator's input, until a base language (usually BaseLanguage) is reached and TextGen emits plain text.

A generator definition has a stable part and a variable part:

• the stable part does not change with the model being generated — engines, base classes, helpers. Provide it once in a runtime solution (an MPS Solution the language declares as a runtime module — as MPS-authored source or a bundled JAR), not as a template.
• the variable part is the templates + macros, which react to the input model and choose different output.

Idiomatic generators keep the stable part out of the templates and emit thin code that calls into the runtime solution. Before adding rules, decide how much is stable: see the architecture ladder in references/cookbook.md and the stable-vs-variable split + wiring in references/runtime-solutions.md in the mps-aspect-accessories skill root after loading that companion skill from the same origin (worked example: the Kaja language + its JavaKaja runtime).