jdb-debugger

jdb-debugger is a skill for Claude Code from brunoborges/jdb-agentic-debugger. It costs 73 tokens per session (2,653 once invoked), scanned B, original, MIT.

A command-line debugger for Java programs using JDB, the Java Development Kit's built-in debugging tool.

In plain words
What is it for?
Use it after compiling Java classes to set breakpoints, step through execution, inspect variables, attach to a Java process, and investigate errors.
Why use it?
It helps inspect a running Java program and locate the code, values, threads, or exceptions causing a problem.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Part of the jdb-debugger plugin — 2 skills, 4 agents shipped together

Good fit Use it after compiling Java classes to set breakpoints, step through execution…

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/brunoborges/jdb-agentic-debugger/jdb-debugger-snapshot-baseline
Install

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.

Any agent
npx skills add brunoborges/jdb-agentic-debugger --skill jdb-debugger-snapshot-baseline
Clone the repo
git clone --depth 1 https://github.com/brunoborges/jdb-agentic-debugger

Made for: Claude Code.

Or install jdb-debugger, the plugin that ships this one along with the rest of its 2 skills, 4 agents.

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.

agentmods badge for jdb-debugger

README.md
[![agentmods](https://agentmods.dev/badge/skills/brunoborges/jdb-agentic-debugger/jdb-debugger-snapshot-baseline.svg)](https://agentmods.dev/skills/brunoborges/jdb-agentic-debugger/jdb-debugger-snapshot-baseline)
Your own site
<a href="https://agentmods.dev/skills/brunoborges/jdb-agentic-debugger/jdb-debugger-snapshot-baseline"><img src="https://agentmods.dev/badge/skills/brunoborges/jdb-agentic-debugger/jdb-debugger-snapshot-baseline.svg" alt="Measured on agentmods" height="20"></a>
Per session 73 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,653 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe.
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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00073 $0.02653
Opus 5 $0.00036 $0.01326
Sonnet 5 $0.00015 $0.00531
Haiku 4.5 $0.00007 $0.00265

Measured 7d ago against content hash 971f83762b65, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade B, and why

jdb-debugger scanned grade B with 1 finding 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 7d ago.

The scan reads SKILL.md. This mod also ships 4 executable files (scripts/jdb-attach.sh, scripts/jdb-breakpoints.sh, scripts/jdb-diagnostics.sh, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Asks for rootmediumPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

sudo apt update && sudo apt install -y default-jdk
skills/jdb-debugger-snapshot-baseline/SKILL.md · 323 lines

How it starts

The opening of the file, as written. The whole thing — 323 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Java Debugger (JDB) Skill

Debug Java applications interactively using the JDK's built-in command-line debugger.

Critical Rules for Agents

  1. NEVER create files in the workspace (no bp.txt, cmds.txt, wrapper scripts, etc.). Use the inline CLI flags (--bp, --cmd, --auto-inspect, --timeout) provided by the skill scripts.
  2. ALWAYS use the skill scripts in scripts/. Never write custom JDB wrapper scripts, FIFO-based launchers, or shell scripts to drive JDB.
  3. Compile first, then debug. Ensure classes are compiled before launching JDB.
  4. On Windows, invoke scripts via WSL: wsl bash scripts/<script>.sh

Platform Support

Windows (WSL Required)

The scripts in this skill are Bash scripts. On Windows, invoke them via WSL:

wsl bash scripts/jdb-launch.sh com.example.MyApp --sourcepath src/main/java

If your compiled classes are on the Windows filesystem, WSL accesses them via /mnt/c/:

wsl bash scripts/jdb-launch.sh com.example.MyApp --classpath /mnt/c/Users/you/project/out

Ensure JDK is installed in WSL:

# Ubuntu/Debian WSL
sudo apt update && sudo apt install -y default-jdk

# Verify
which jdb && jdb -version

Linux / macOS

Scripts run natively. Ensure JDK is installed and jdb is on PATH:

export PATH=$JAVA_HOME/bin:$PATH

Decision Tree

User wants to debug Java app →
  ├─ App is already running with JDWP agent?
  │   ├─ Yes → Attach: scripts/jdb-attach.sh --port <port>
  │   └─ No  → Can you restart with JDWP?
  │       ├─ Yes → Launch with: scripts/jdb-launch.sh <mainclass> [args]
  │       └─ No  → Suggest adding JDWP agent to JVM flags (see below)
  │
  ├─ What does the user need?
  │   ├─ Set breakpoints & step through code → Interactive JDB session
  │   ├─ Collect thread dumps / diagnostics → scripts/jdb-diagnostics.sh
  │   └─ Catch a specific exception → Use `catch` command in JDB
  │
  └─ Done debugging → Detach cleanly with `quit` or Ctrl+C

Read the full file on GitHub · 323 lines

Files

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.

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.

  1. 7d ago First seen · 323 lines · 73 tokens per session scan B 971f83762b65

Subscribe to this mod's changes

jdb-debugger is a skill published in the GitHub repository brunoborges/jdb-agentic-debugger (66 stars, last pushed 19d ago), licensed MIT. It adds 73 tokens to every session and 2,653 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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