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 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.

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.

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.

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.

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.

Use when authoring or modifying MPS IDE plugins — code that integrates with the MPS / IntelliJ host IDE shell. Covers ActionDeclaration, ActionGroupDeclaration, ToolDeclaration/TabbedToolDeclaration (dockable tool windows), KeymapChangesDeclaration (shortcuts), PreferencesComponentDeclaration (settings pages), EditorTab+Order (concept editor tabs), InterfaceGroup (bootstrap wrappers around external groups), NonDumbAwareActions, IdeaConfigurationXml, ApplicationPluginDeclaration/ProjectPluginDeclaration/StandalonePluginDescriptor (lifecycle hooks). Uses jetbrains.mps.lang.plugin and jetbrains.mps.lang.plugin.standalone. Trigger terms: action group, tool window, menu item, MainMenu, EditorPopup, NodeActions, ModelActions, ModuleActions, ProjectViewPopupMenu, MPS plugin solution, ActionInstance, ModificationStatement, DataKey, MPSCommonDataKeys, MPSDataKeys, dumb-aware, project.tool<...>, project.preferenceComponent<...>, application plugin<...>, project plugin<...>.

Create or refresh project-local DSL skills under `.agents/skills/<dsl-name>-dsl/` for one or more MPS languages after discovering concepts, sandbox examples, JSON blueprints, references, or gotchas.

Use when bundling a new plain Java/Kotlin plugin into MPS distribution archives, debugging packaging/layout issues in `build/mps*.xml`, tracing where per-plugin artefacts end up, or editing `plugins/mps-build/solutions/mpsBuild/models/build.mps` (the source of truth that generates every `build/mps*.xml`). The skill covers the generated Ant pipeline, plugin-to-distribution wiring, and the per-plugin / aggregator / distribution layers.

Use when running or generating MPS Console code, or when writing `jetbrains.mps.lang.smodel.query` queries anywhere in MPS (intentions, behavior, actions, generator queries, plain BaseLanguage). Covers the console command languages (`jetbrains.mps.console.base` / `ideCommands` / `internalCommands` / `scripts`): `BLCommand` / `BLExpression`, the `#print*` / `#show` result printers, IDE commands (`#make` / `#clean` / `#removeGenSources` / `#reloadClasses` / `#stat` / `#showGenPlan` / `#showBrokenRefs`), `#exec` / `forEach` / `refactor` scripts. Covers the smodel query language: `#nodes` / `#references` / `#models` / `#modules` / `#instances` / `#usages`, the `with`-statement scope wrapper, scopes (`project` / `editable` / `global` / `visible` / `modules` / `models` / `custom`) and query parameters (`scope` / `exact` / `r/o+`). Also how to insert, read, recall, and run console commands with `mps_mcp_insert_console_command_from_json`, `mps_mcp_get_current_editor_root_node(source="console")`, `mps_mcp_get_console_history`, `mps_mcp_recall_console_command`, and `mps_mcp_run_console_command`.

Use when authoring or modifying MPS Build Language scripts (`BuildProject` roots) — the declarative DSL that generates Ant `build.xml` to package MPS language plugins, IDEA plugins, plain Java modules, standalone IDE/RCP distributions, module tests, or `run code from solution` tasks. Covers build solution setup, macros, project/external/Java dependencies, MPS module declarations (`BuildMps_Language` / `_Solution` / `_Generator`), groups, layouts, IDEA-plugin declarations, MPS settings, and the workflow language. Trigger terms: `BuildProject`, `BuildMps_*`, `BuildLayout_*`, `jetbrains.mps.build`, `build.mps` solution, `internalBaseDirectory`, `compactBuildScriptFileName`, Ant target generation, `mps_home`, `idea_home`.

Analyze a repository to generate recommended Claude Code settings.json permissions. Use when setting up a new project, auditing existing settings, or determining which read-only bash commands to allow. Detects tech stack, build tools, and monorepo structure.

Structured MPS bugfix workflow driven by a YouTrack issue ID — preflight tool checks, version/branch derivation, parallel-agent problem analysis, solution design, branch creation, implementation, review, and YouTrack updates. Use when the user invokes "/bugfix", asks to "fix a bug", "work on a bug", "investigate an issue", or provides a YouTrack issue ID.

Diagnose and fix Claude in Chrome MCP extension connectivity issues. Use when mcp__claude-in-chrome__* tools fail, return "Browser extension is not connected", or behave erratically.

Author and edit MPS `jetbrains.mps.baseLanguage` (Java) nodes — choose between the Java parser and JSON AST blueprints, map Java syntax to baseLanguage concepts/roles, harvest persistent member references, and validate. Use when writing class/method bodies, fields, expressions, statements, or any Java/BaseLanguage code inside MPS models, especially when BaseLanguage extensions (smodel, closures, collections) are involved.

Use when authoring or debugging MPS typesystem — inference rules (`typeof :==: / :<=: / :>=:`), `SubtypingRule`, `ComparisonRule`, `InequationReplacementRule`, `SubstituteTypeRule`, `WhenConcreteStatement` blocks, `NonTypesystemRule` checking rules, `TypesystemQuickFix`, error/warning/info reports with `messageTarget` highlighting and quick-fix wiring (`helginsIntention`), and shared BaseLanguage helpers in the typesystem model. Reach for this skill whenever the task involves editing `<lang>/languageModels/typesystem.mps`.

Use when authoring or debugging MPS TextGen — concept-to-plain-text serialisation for languages whose final output is text (source files, config, scripts, DDL, XML, markdown). Covers `ConceptTextGenDeclaration` roots, `append` / `indent buffer` / `with indent` statements, text layout areas, context objects (e.g. imports sets), attributes, the base text gen component (`LanguageTextGenDeclaration`), binary `write`, `found error`, and the indentation-buffer model. Reach for this skill whenever the task involves editing `<lang>/languageModels/textGen.mps`.

Define concepts, interface concepts, enumerations, and constrained data types in an MPS language's `structure` aspect. Covers smart-reference detection, alias rules, cardinality, INamedConcept usage, bulk creation, and the full `mps_mcp_alter_structure` / `mps_mcp_query_structure` reference. Use when authoring or modifying a language's structure model.

Use when authoring or debugging MPS migration scripts that upgrade user models after a language definition changes — covers jetbrains.mps.lang.migration (MigrationScript class-based, PureMigrationScript declarative, MoveConcept/MoveContainmentLink/MoveReferenceLink/MoveProperty, ordering via OrderDependency, data exchange via putData/getData, RefactoringLog, ConceptMigrationReference) and jetbrains.mps.lang.script Enhancement Scripts (MigrationScript with MigrationScriptPart_Instance, ExtractInterfaceMigration, FactoryMigrationScriptPart, CommentMigrationScriptPart) — when a model needs version-gated upgrade, concept rename or removal, link or property rename, instance-level transformation, or composition of migration steps.

Use when defining or editing MPS intentions (the Alt+Enter context-action aspect) — adding `IntentionDeclaration` roots, parameterized or surround-with variants, description/isApplicable/execute blocks, child-filter functions, factory-initialized AST splicing, or debugging why an intention is not offered. Lives in the language's `intentions` model and uses `jetbrains.mps.lang.intentions`.