sglang: Skill for Claude Code

.agents/skills/clean-startup-log/SKILL.md

clean-startup-log is a skill for Claude Code from sgl-project/sglang. It costs 51 tokens per session (1,306 once invoked), scanned A, original, Apache-2.0.

A workflow for removing unwanted messages from SGLang server startup logs. It compares captured output with an expected clean log and looks for warnings, deprecation messages, third-party prints, and duplicates.

In plain words
What is it for?
Investigating and cleaning noisy startup output when launching SGLang servers, including single-GPU, multi-GPU, mixture-of-experts, and hybrid models.
Why use it?
It makes real startup problems easier to spot by separating useful server information from noise. It also checks different paths, such as multi-GPU and hybrid models.

Skill for Claude Code

Written for Claude Code: disable-model-invocation in frontmatter. Also seen: installed under .agents/ (shared by several agents); $skill-name invocation.

This is sgl-project/sglang's own configuration. It tells Claude Code how to work on sglang itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything sglang configures →

About the project

SGLang is a framework for running inference for large language models and multimodal models, meaning it processes inputs to produce model outputs such as text or other media. It is used to serve and accelerate open AI models and related workloads.

sgl-project/sglang · 38,324 stars · on GitHub · sglang.io

Reuse

Borrowing it

Nothing to install: this file belongs to sgl-project/sglang. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/sgl-project/sglang/main/.agents/skills/clean-startup-log/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/sgl-project/sglang

Made for: Claude Code.

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 clean-startup-log

README.md
[![agentmods](https://agentmods.dev/badge/skills/sgl-project/sglang/clean-startup-log/github.svg)](https://agentmods.dev/skills/sgl-project/sglang/clean-startup-log)
Your own site
<a href="https://agentmods.dev/skills/sgl-project/sglang/clean-startup-log"><img src="https://agentmods.dev/badge/skills/sgl-project/sglang/clean-startup-log/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.

agentmods 80×15 button for clean-startup-log

Your own site · 80×15
<a href="https://agentmods.dev/skills/sgl-project/sglang/clean-startup-log"><img src="https://agentmods.dev/badge/skills/sgl-project/sglang/clean-startup-log.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 51 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,306 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • Snyk pass 7 Sept 2026
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Anti-Refusal · line 282
    Skill instructs the agent to omit warnings, disclaimers, or ethical commentary. Stripping safety caveats hides risk from the user and is a common jailbreak preamble.
    Fix: Remove instructions that suppress warnings, disclaimers, or ethical commentary. Let the agent surface safety-relevant caveats to the user.
How audits are shown
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 $0.00051 $0.01306
Opus 5.5 $0.00020 $0.00522
Sonnet 5.5 $0.00010 $0.00261
Haiku 4.5 $0.00005 $0.00131

Measured 1mo ago against content hash a173099a353e, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

clean-startup-log 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.

.agents/skills/clean-startup-log/SKILL.md · 106 lines

How it starts

The opening of the file, as written. The whole thing — 106 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Audit SGLang Startup Logs

The default outcome is saved logs and a findings report. Apply runtime changes only after the user selects them. A request to edit this skill does not itself launch servers.

Default runs

A bare $clean-startup-log invocation runs these cases sequentially without asking for commands. Explicit commands, models, or TP sizes replace this matrix.

Case / log filename Command
qwen3-8b-tp1.log uv run sglang serve --model-path Qwen/Qwen3-8B
qwen3-8b-tp2.log uv run sglang serve --model-path Qwen/Qwen3-8B --tp 2
gpt-oss-20b-tp1.log uv run sglang serve --model-path openai/gpt-oss-20b

These cover dense, tensor-parallel, and MoE/hybrid sliding-window attention startup. Reuse complete captures from the current audit when code and environment have not changed.

Capture logs

  1. Check the checkout, free GPUs, and ports once. Use the requested command when resources are free; otherwise select free GPUs with CUDA_VISIBLE_DEVICES and an unused --port, recording the adjustments. Leave existing servers alone.
  2. Create a unique directory with mktemp -d /tmp/sglang-startup-audit-XXXXXX. Save raw stdout and stderr together in a separate log for each case, for example with set -o pipefail and COMMAND 2>&1 | tee LOG_PATH. Record commands, GPU IDs, ports, commit, relevant overrides, and readiness status.
  3. Wait for The server is fired up and ready to roll!, then stop that server and its workers before the next case. First runs can spend many minutes downloading weights or compiling FlashInfer kernels; check download/compiler activity before treating a quiet log as a hang. Preserve partial logs for failed or stalled starts and report the last stage. Continue independent cases when possible.
  4. Preserve the user's logging configuration, including NCCL_DEBUG. If NCCL verbosity needs explaining, inspect relevant shell settings, NCCL_CONF_FILE, and /etc/nccl.conf. Do not override intentional diagnostics or recommend NCCL_DEBUG=WARN solely because the output is long. Avoid full environment dumps.

Read the full file on GitHub · 106 lines

Files

What ships with it

1 file 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. 1mo ago Changed · -177 lines · +6 tokens per session a173099a353e
  2. 2mo ago First seen · 283 lines · 45 tokens per session scan A bead524743d1

Subscribe to this mod's changes

clean-startup-log is a skill published in the GitHub repository sgl-project/sglang (38,324 stars, last pushed today), licensed Apache-2.0. It adds 51 tokens to every session and 1,306 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.