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 skills add eclipse-langium/langium-ai --skill langiumgit clone --depth 1 https://github.com/eclipse-langium/langium-aiWrote 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/eclipse-langium/langium-ai/langium)<a href="https://agentmods.dev/skills/eclipse-langium/langium-ai/langium"><img src="https://agentmods.dev/badge/skills/eclipse-langium/langium-ai/langium/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/eclipse-langium/langium-ai/langium"><img src="https://agentmods.dev/badge/skills/eclipse-langium/langium-ai/langium.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00033 | $0.09757 |
| Opus 5.5 | $0.00013 | $0.03903 |
| Sonnet 5.5 | $0.00007 | $0.01951 |
| Haiku 4.5 | $0.00003 | $0.00976 |
Grade A, and why
langium 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 2mo 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 — 1,089 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Langium SKILL.md
A comprehensive guide to understanding how Langium-based projects work — from grammar definition through code generation, runtime parsing, linking, validation, and LSP integration. Reading this document should make an agent fully proficient at navigating, debugging, and extending any Langium DSL project.
Table of Contents
- High-Level Architecture
- The Grammar Language
- Code Generation (Build Time)
- Dependency Injection System
- Lexing
- Parsing: Tokens → CST → AST
- The Document Lifecycle (DocumentState Pipeline)
- Scope Computation
- Scope Provider and Name Resolution
- Linking and Cross-Reference Resolution
- Validation
- Workspace Management
- LSP Integration
- Common Customization Patterns
- End-to-End Runtime Flow
1. High-Level Architecture
Langium is a language engineering framework that takes a .langium grammar file and produces a fully operational TypeScript-based DSL toolkit with LSP support. The architecture has two major phases:
Build time — langium-cli reads .langium grammars and generates:
ast.ts— TypeScript interfaces for every AST node, type guards, and anAstReflectionclassgrammar.ts— The grammar serialized as JSON, lazy-loaded at runtimemodule.ts— A DI module providingGrammar,LanguageMetaData, andAstReflectionservices
Runtime — A service-oriented architecture driven by dependency injection:
- All components (parser, lexer, linker, scope provider, validator, LSP handlers) are registered as services
- Two service layers: shared services (cross-language: workspace, index, document management) and language-specific services (parser, references, validation — one set per language)
- Users customize behavior by providing partial DI modules that override default service factories
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.
- 2mo ago First seen · 1,089 lines · 33 tokens per session scan A 3973f4c92656
langium is a skill published in the GitHub repository eclipse-langium/langium-ai (30 stars, last pushed 14d ago), licensed MIT. It adds 33 tokens to every session and 9,757 once invoked, about $0.0001 per session on Opus 5.5. 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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