What is mps-aspect-generation-plan?

A JetBrains MPS feature for defining the order in which code generators run. MPS is a tool for creating programming languages, and generators turn models written in those languages into code or other files.

It is for cross-model generation, checkpoints, parallel output branches, and optional additions to a base generation plan.

It makes generator order and synchronization explicit when generators depend on shared models or results.

How JetBrains/MPS configures Claude Code and Codex

About the project

JetBrains MPS is a development environment for creating domain-specific languages, which are programming languages designed for a particular field or task. It provides editors with features such as completion, semantic checks, and type checking, and can generate code in languages including Java and XML.

JetBrains/MPS · 1,656 stars · on GitHub · jetbrains.com

Reuse

Borrowing it

Nothing to install: this file belongs to JetBrains/MPS. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/JetBrains/MPS/master/.agents/skills/mps-aspect-generation-plan/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/JetBrains/MPS

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/jetbrains/mps/mps-aspect-generation-plan.svg)](https://agentmods.dev/skills/jetbrains/mps/mps-aspect-generation-plan)

Your own site

<a href="https://agentmods.dev/skills/jetbrains/mps/mps-aspect-generation-plan"><img src="https://agentmods.dev/badge/skills/jetbrains/mps/mps-aspect-generation-plan.svg" alt="Measured on agentmods" height="20"></a>

Per session 101 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,455 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits

NVIDIA SkillSpector pass 7 Sept 2026

How audits are shown

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00101	$0.01455
Opus 5	$0.00051	$0.00727
Sonnet 5	$0.00020	$0.00291
Haiku 4.5	$0.00010	$0.00145

Measured 8d ago against content hash 50a89c2d392d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

mps-aspect-generation-plan scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.agents/skills/mps-aspect-generation-plan/SKILL.md · 60 lines

How it starts

The opening of the file, as written. The whole thing — 60 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MPS Generation Plans

A generation plan (Plan) is an ordered script that controls which generators run, in what sequence, and with what synchronization points. Without a plan, MPS determines order from mutual generator priorities and dependencies. A plan lets language designers specify that ordering once, in a single place, without requiring all involved languages to know about each other.

Language: jetbrains.mps.lang.generator.plan (id 7ab1a6fa-0a11-4b95-9e48-75f363d6cb00, version 3) Also requires: jetbrains.mps.lang.smodel (for LanguageId / LanguageIdentity nodes)

When to use a generation plan

You need a guaranteed ordering of generators across languages that must not depend on each other.
You are doing cross-model generation and need mapping labels from one model to be available when generating another (requires checkpoints).
You want to fork the generation of certain models into a separate branch (e.g., generate both .java files and XML descriptors from the same input).
You want a conditional contribution added to a base plan without modifying it (PlanContribution).

Critical Directives

Genplan models use the genplan stereotype. File name pattern: <name>@genplan.mps. Pass modelName: "<name>@genplan" to mps_mcp_create_model. See aspect-model-stereotypes.md for all model identifiers. Set doNotGenerate=true (MPS adds this automatically).
Only one DevKit per model may carry a genplan. Assigning multiple genplan-bearing DevKits to the same model is unsupported.
Plan.steps is 1..n. A plan with no steps is invalid.
LanguageEntry.language (LanguageId) and GeneratorModulePointer.module (ModulePointer) are each cardinality 1 — missing them is a validation error.
Checkpoints persist transient state. Cross-phase reference resolution works only when phases share a plan AND a Checkpoint sits between them.
Do not hand-edit serialized .mps genplan files. Use MPS MCP node tools.

Read the full file on GitHub · 60 lines

Files

What ships with it

10 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

8d ago First seen · 60 lines · 101 tokens per session scan A 50a89c2d392d

Subscribe to this mod's changes

mps-aspect-generation-plan is a skill published in the GitHub repository JetBrains/MPS (1,656 stars, last pushed yesterday), licensed Apache-2.0. It adds 101 tokens to every session and 1,455 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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