Qwen Code is an open-source AI coding agent that runs in a terminal and helps developers work with code through language models. It supports multiple model providers and can also be used through IDEs, desktop software, SDKs, and messaging bots.
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 QwenLM/qwen-code --skill memory-leak-debuggit clone --depth 1 https://github.com/QwenLM/qwen-codeWrote 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/qwenlm/qwen-code/memory-leak-debug)<a href="https://agentmods.dev/skills/qwenlm/qwen-code/memory-leak-debug"><img src="https://agentmods.dev/badge/skills/qwenlm/qwen-code/memory-leak-debug/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/qwenlm/qwen-code/memory-leak-debug"><img src="https://agentmods.dev/badge/skills/qwenlm/qwen-code/memory-leak-debug.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Snyk pass
- 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 | $0.00042 | $0.01324 |
| Opus 5.5 | $0.00017 | $0.00530 |
| Sonnet 5.5 | $0.00008 | $0.00265 |
| Haiku 4.5 | $0.00004 | $0.00132 |
Grade A, and why
memory-leak-debug scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 162 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Memory Leak Debugging
Diagnose memory leaks in the Qwen Code Node.js CLI by capturing heap snapshots
and analyzing retained object sizes via chrome-devtools CLI tooling.
Prerequisites
chrome-devtoolsCLI (fromchrome-devtools-mcppackage). If not found, install with:npm i chrome-devtools-mcp@latest -gafter user confirmation. See https://github.com/ChromeDevTools/chrome-devtools-mcp/blob/main/docs/cli.md- Node.js 22+ (for
--heapsnapshot-signalsupport)
Step 1: Start the CLI with Snapshot Signal
Use tmux so you can interact with the TUI and trigger snapshots from another pane. Use the tmux-real-user-testing helper script:
HELPER=.qwen/skills/tmux-real-user-testing/scripts/tmux-real-user-log.sh
eval "$(bash "$HELPER" start memleak . \
env QWEN_CODE_NO_RELAUNCH=true NODE_OPTIONS=--heapsnapshot-signal=SIGUSR2 \
npm run dev)"
echo "SESSION=$SESSION OUTDIR=$OUTDIR"
The eval exports SESSION and OUTDIR. Note: shell environment does not
persist across separate tool calls — save the session name from the output and
use it explicitly in subsequent commands.
Notes:
npm run devruns from TypeScript source via tsx — no build step needed and changes to core/cli are reflected immediately.QWEN_CODE_NO_RELAUNCH=trueprevents the CLI from spawning a child process, so PID management is simpler.NODE_OPTIONSpropagates the flag through npm → tsx → node.
Get the PID of the actual node process. With npm run dev, there's a process
chain (npm → node scripts/dev.js → tsx → node CLI), so walk the tree to the
innermost node child:
NODE_PID=$(bash .qwen/skills/memory-leak-debug/scripts/find-leaf-node.sh "<session-name>")
To profile the production bundle instead (e.g., verifying tree-shaking):
npm run bundle first, then use
env QWEN_CODE_NO_RELAUNCH=true node --heapsnapshot-signal=SIGUSR2 dist/cli.js
as the command. Since node is the direct pane process, PID discovery is simpler:
NODE_PID=$(tmux list-panes -t "<session-name>" -F '#{pane_pid}')
What ships with it
2 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.
- 1mo ago First seen · 162 lines · 42 tokens per session scan A b1e8fda9850f
memory-leak-debug is a skill published in the GitHub repository QwenLM/qwen-code (28,565 stars, last pushed today), licensed Apache-2.0. It adds 42 tokens to every session and 1,324 once invoked, about $0.0002 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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tdd-test-engineer
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rust-check
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debug
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optimization
Use when improving performance, latency, throughput, memory usage, or general efficiency. Start by defining target metrics, measuring comprehensively, attributing bottlenecks, validating with static analysis, and prioritizing macro-optimizations before micro-optimizations.