Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/jetbrains/mps/mps-aspect-dataflownpx skills add JetBrains/MPS --skill mps-aspect-dataflowgit clone --depth 1 https://github.com/JetBrains/MPSWrote 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.
[](https://agentmods.dev/skills/jetbrains/mps/mps-aspect-dataflow)<a href="https://agentmods.dev/skills/jetbrains/mps/mps-aspect-dataflow"><img src="https://agentmods.dev/badge/skills/jetbrains/mps/mps-aspect-dataflow.svg" alt="Measured on agentmods" height="20"></a>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 | $0.00116 | $0.01499 |
| Opus 5 | $0.00058 | $0.00749 |
| Sonnet 5 | $0.00023 | $0.00300 |
| Haiku 4.5 | $0.00012 | $0.00150 |
Grade A, and why
mps-aspect-dataflow 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 4d 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.
How it starts
The opening of the file, as written. The whole thing — 53 lines — stays where its author put it; the contents beside it link to each section on GitHub.
MPS Dataflow Aspect
The dataflow aspect (jetbrains.mps.lang.dataFlow, l:7fa12e9c-b949-4976-b4fa-19accbc320b4) lets a language describe how control and data flow through nodes of a concept. MPS uses that information for reachability analysis, uninitialised-variable checks, and (via IBuilderMode) richer flow analyses such as nullable tracking.
Mental Model
Each DataFlowBuilderDeclaration answers: given a node of concept X, in what order might execution visit its children, and which variables are read or written?
The builder body is a BL StatementList (inside a BuilderBlock). You use normal BL control flow (if, foreach, local variables) to compute which emit instructions to output at runtime. The node implicit parameter (concept NodeParameter) is always in scope — its type is the concept referenced by conceptDeclaration, giving smodel-typed access to children and references.
The MPS dataflow engine builds a control-flow graph from the emitted instructions, then runs analyses (unreachable code, uninitialised variable reads) on that graph. The engine only traces the paths you declare; if no builder exists for a concept, MPS falls back to delegating all children in declaration order.
Critical Directives
code foris delegation, not a call. Never usejumpfor child delegation. UseEmitCodeForStatementto inline a child's own builder at this point.ifjumpsemantics: the jump is taken when the condition is FALSE. Use it aftercode for node.conditionto model branching.- Labels are node references, not string lookups.
EmitLabelStatement.nameis display-only; jumps reference the label node viaLabelPosition.label. Two labels with the same string are still distinct targets. - Always null-guard
0..1children with BLif (node.child != null)before emittingcode for node.child. write nodevswrite node.link: usewrite node(justNodeParameteras the variable expression) when the concept node is the variable being declared. Usewrite node.link(viaSLinkAccess) when the node merely references the variable being written.- Leaf concepts need no builder. The engine treats unbuilt concepts as no-ops, or for ordinary parents delegates to children in declaration order.
- Do not hand-edit serialized
.mpsdataflow files. Use MPS MCP node tools.
What ships with it
6 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.
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.
- 4d ago First seen · 53 lines · 116 tokens per session scan A 2a0d200ccdcc
mps-aspect-dataflow is a skill published in the GitHub repository JetBrains/MPS (1,658 stars, last pushed today), licensed Apache-2.0. It adds 116 tokens to every session and 1,499 once invoked, about $0.0006 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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