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.
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.
curl -O https://raw.githubusercontent.com/JetBrains/MPS/master/.agents/skills/debugging/SKILL.mdgit 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/debugging)<a href="https://agentmods.dev/skills/jetbrains/mps/debugging"><img src="https://agentmods.dev/badge/skills/jetbrains/mps/debugging/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/jetbrains/mps/debugging"><img src="https://agentmods.dev/badge/skills/jetbrains/mps/debugging.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 | $0.00022 | $0.00494 |
| Opus 5.5 | $0.00009 | $0.00198 |
| Sonnet 5.5 | $0.00004 | $0.00099 |
| Haiku 4.5 | $0.00002 | $0.00049 |
Grade A, and why
debugging 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 29d 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.
What it actually says
Debugging
Documentation
- Logger FAQ - Frequently asked questions about logging
- How to Investigate Freezes - Diagnosing IDE freezes
- Exception Analyzing FAQ - Analyzing and categorizing exceptions
Searching idea.log
For a running MPS, get the log location via mps_mcp_list_open_projects (logDirectory) or see .agents/skills/mps-mcp-workflow/references/ide-log.md.
When debugging IntelliJ code, search idea.log using these patterns:
Log Levels:
FINE= debug level (fromLOG.debug { })INFO= info level (fromLOG.info())
Category Format:
#<abbreviated.package.path>.<ClassName>
Example: com.intellij.openapi.wm.impl.status.IdeStatusBarImpl → #c.i.o.w.i.s.IdeStatusBarImpl
Search Examples:
# Debug logs from IdeStatusBarImpl
grep "FINE - #c.i.o.w.i.s.IdeStatusBarImpl" idea.log
# Info logs from IdeStatusBarImpl
grep "INFO - #c.i.o.w.i.s.IdeStatusBarImpl" idea.log
# All logs from a class
grep "#c.i.o.w.i.s.IdeStatusBarImpl" idea.log
End-to-End Behavior
When fixing issues where a user-facing entry point (script, command, API) doesn't behave as expected:
- Trace the full execution chain from entry point to actual executor before making changes
- Identify all layers that handle the relevant behavior - each layer may swallow, transform, or ignore it
- Verify the fix at the entry point the user actually invokes, not just at the layer you modified
- Add debugging output if still unsure - add to all layers to trace the issue
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.
- 29d ago Changed · +2 lines 8ec2c7ed6fcf
- 2mo ago First seen · 47 lines · 22 tokens per session scan A 5e55cb1cdd62
debugging is a skill published in the GitHub repository JetBrains/MPS (1,666 stars, last pushed yesterday), licensed Apache-2.0. It adds 22 tokens to every session and 494 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.
debugging compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| debuggingJetBrains/MPS | Skill | 1.7k | yesterday | Apache-2.0 | A | 22 | Claude Code, Codex |
| langiumeclipse-langium/langium-ai | Skill | 31 | 4d ago | MIT | A | 33 | Claude Code |
| lai-gen-evalseclipse-langium/langium-ai | Skill | 31 | 4d ago | MIT | A | 42 | Claude Code |
| laieclipse-langium/langium-ai | Skill | 31 | 4d ago | MIT | A | 52 | Claude Code |
| lai-gen-descriptoreclipse-langium/langium-ai | Skill | 31 | 4d ago | MIT | A | 49 | Claude Code |
| lai-gen-mcpeclipse-langium/langium-ai | Skill | 31 | 4d ago | MIT | A | 43 | Claude Code |
| lai-gen-language-skilleclipse-langium/langium-ai | Skill | 31 | 4d ago | MIT | A | 33 | Claude Code |