MPS

Use when authoring XML documents as MPS root nodes or building XML-generating generator templates with jetbrains.mps.core.xml — covers XmlFile, XmlDocument, prolog (XML declaration, DOCTYPE, processing instructions, comments), elements, attributes, CDATA, entity references, and macro attachment via the smodelAttribute role for templates that emit XML output.

Analyze an MPS language by name — discover concepts, properties, references, children, aspects (editor/constraints/behavior), and metadata. Use when investigating an unfamiliar language, exploring concept structure, or finding sample nodes to use as templates for JSON blueprints.

Entry point for authoring or modifying an MPS language — index of all aspects (structure, editor, constraints, behavior, typesystem, intentions, actions, generator, textgen, accessories, generation plans), the recommended authoring order, cross-aspect call patterns, dependency/rebuild rules, and validation flow. Start here when defining a new language or when you do not know which aspect-specific skill applies.

Investigate inheritance between MPS languages and between concepts — extended languages, superconcepts, implemented interfaces, sub-/assignable concepts, and cross-language specialization. Use when tracing language hierarchies, finding extension points, or checking concept assignability.

Use when designing how multiple MPS languages relate or compose — choosing between language referencing, extension, reuse, and embedding, or deciding where a cross-language dependency should live and how generated code interacts. Covers the 2×2 modularity taxonomy adapted to MPS, a decision procedure, per-kind recipes (references + search scopes; subconcepting + overloaded operations; abstract hooks + adapter languages + separated/interwoven generation; guest + composition languages + type bridges), the annotations escape hatch, and per-kind validation. This is the design tier above the aspect-implementation skills: it picks the strategy, then routes into the relevant mps-aspect-* skills (structure, constraints, typesystem, generator, generation-plan, intentions) and mps-tests. Reach for it before authoring aspects, or whenever one language must see, extend, embed, or adapt another.

Complete JetBrains MPS workflow guide for DSL projects — models, languages, generators, node JSON blueprints, validation, MPS MCP tool usage, and the index of companion skills. Use whenever working in an MPS project, when AGENTS.md says to load the MPS workflow skill, or when you need to pick the right MPS aspect-specific skill.

Use when writing or editing MPS BaseLanguage code that lives inside a model — behavior methods, typesystem rules, checking rules, generator queries, constraints, intentions, scope/canBe callbacks, dataflow builders — and combines the `smodel`, `collections`, and `closures` language extensions. Covers querying nodes (`.descendants<C>`, `.ancestor<C>`, `.children`, `.parent`, `containingRoot`), filtering sequences (`.where`, `.select`, `.translate`, `.ofConcept<C>`), building closures (`{ it => ... }`, `yield`, recursion), creating and mutating nodes (`new node<C>()`, `add new(C)`, `set new(C)`, `replace with new(C)`, `.detach`, `.copy`), property and link access (`SPropertyAccess`, `SLinkAccess`, `SLinkListAccess`), reference operations (`.reference/C : role/`, `.target`), null-safe node equality (`:eq:` / `:ne:`), smodel/Java type casts (`node:C`, `node as C`, `/`, `downcast`), foreach choice, the `command` / `read action` lock wrappers, and JSON blueprints for every shape the Java parser cannot produce.

Add, update, or delete MPS nodes using JSON blueprints — covers the unified blueprint format, staged construction for large subtrees, validation, and reference repair. Use whenever creating, editing, or restructuring nodes in any MPS model (structure, editor, behavior, generator, application code, etc.).

Use when writing or debugging MPS quotations and anti-quotations — "node literals" that create SNode trees inline in behavior, typesystem, intentions, generator, and other model code. Covers heavy quotations (`Quotation`, `<...>`), light quotations (`NodeBuilder`, constructor-style for bootstrapping), and the four anti-quotation varieties: child (`%(...)%`), list (`*(...)*`), reference (`^(...)^`), property (`$(...)$`). Reach for this skill whenever the task involves splicing runtime values into quoted node trees or choosing between heavy and light quotations.

Create and execute IDE run configurations for MPS root nodes via MPS MCP — Java Application for `IMainClass` / `ClassConcept` with `main`, JUnit Tests for `ITestCase`. Use when launching DSL `main`-like roots, plain BaseLanguage `ClassConcept` mains, or MPS test cases from a node; reusing or replacing an existing run config; diagnosing `ClassNotFoundException`, `compileInMPS=false`, or "not runnable through this tool" failures.

Use when writing or modifying tests inside MPS `@tests` models — `NodesTestCase` (typesystem, constraints, scopes, dataflow, generator output), `EditorTestCase` (intentions, actions, keystrokes, side-transforms, completion), `MigrationTestCase` (migration scripts), `BTestCase` (plain JUnit on hand-written Java/Kotlin runtime), inline annotations such as `has error` / `has type` / `ScopesTest`, label-based `node<label>` cross-references, caret markers, and running tests via MCP / in MPS. Reach for this skill whenever the task involves authoring or fixing tests in a `tests`-stereotype model, or interpreting failures from one.

Guidelines for using the IntelliJ Registry API. Use when working with registry keys or feature flags.

Guide for using Structural Search and Replace in IntelliJ. Use when creating or modifying SSR inspections or search patterns.

Use when working with TeamCity CI/CD or when user provides a TeamCity build URL. Use `teamcity` CLI for builds, logs, jobs, queues, agents, and pipelines.