audit-langfuse-llm

audit-langfuse-llm is a skill for Claude Code from kensaurus/cursor-kenji. It costs 73 tokens per session (3,964 once invoked), scanned A, original, MIT.

A review of an AI feature’s quality, usage cost, prompts, evaluations, and traces. Traces are records of what the model received, produced, and cost.

In plain words
What is it for?
Use it to inspect Langfuse records, prompt versions, model costs, missing traces, evaluations, grounding, and hallucinations.
Why use it?
It shows whether an AI feature is being monitored, grounded in reliable information, evaluated consistently, or costing more than expected.

Skill for Claude Code

Written for Claude Code: effort in frontmatter.

Part of the cursor-kenji plugin — 132 skills, 63 commands, 6 agents, 1 hook, 3 MCP servers shipped together

Good fit Use it to inspect Langfuse records, prompt versions, model costs, missing traces, evaluations, grounding, and hallucinations.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/kensaurus/cursor-kenji/audit-langfuse-llm
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 kensaurus/cursor-kenji --skill audit-langfuse-llm
Clone the repo
git clone --depth 1 https://github.com/kensaurus/cursor-kenji

Made for: Claude Code.

Or install cursor-kenji, the plugin that ships this one along with the rest of its 132 skills, 63 commands, 6 agents, 1 hook, 3 MCP servers.

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 audit-langfuse-llm

README.md
[![agentmods](https://agentmods.dev/badge/skills/kensaurus/cursor-kenji/audit-langfuse-llm/github.svg)](https://agentmods.dev/skills/kensaurus/cursor-kenji/audit-langfuse-llm)
Your own site
<a href="https://agentmods.dev/skills/kensaurus/cursor-kenji/audit-langfuse-llm"><img src="https://agentmods.dev/badge/skills/kensaurus/cursor-kenji/audit-langfuse-llm/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 audit-langfuse-llm

Your own site · 80×15
<a href="https://agentmods.dev/skills/kensaurus/cursor-kenji/audit-langfuse-llm"><img src="https://agentmods.dev/badge/skills/kensaurus/cursor-kenji/audit-langfuse-llm.svg" alt="Reviewed on agentmods" width="80" 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 3,964 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
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 9 findings, up to medium

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 →

  • medium MCP Rug Pull · line 170
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 188
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 194
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 219
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 236
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 255
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 266
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 298
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 284
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
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 $0.00073 $0.03964
Opus 5.5 $0.00029 $0.01586
Sonnet 5.5 $0.00015 $0.00793
Haiku 4.5 $0.00007 $0.00396

Measured 28d ago against content hash a29fefa66db6, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

audit-langfuse-llm 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 28d 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.

skills/audit-langfuse-llm/SKILL.md · 469 lines

How it starts

The opening of the file, as written. The whole thing — 469 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Langfuse LLM Quality Audit

Degree of freedom: MIXED — Phases 0–1, 4 [HIGH freedom]; Phases 2–3 CLI traces and playwright [LOW freedom — run exactly]. Read protocol-browser-anti-stall before any browser step. Phase 0 first: Phases 2–3 verify the feature map it produces.

How to reason

  1. Observe — quote the trace, prompt version, token/cost, or live output
  2. Interpret — is quality, cost, or the pipeline actually broken?
  3. Classify — missing-trace / prompt / cost / eval / grounding / correct
  4. Severity — pipeline break or untraced prod feature = P0; cost/eval gap = P1

Worked example

Observe: after Playwright chat, langfuse-cli api traces list shows no new row; app/api/chat/route.ts calls openai.chat with no Langfuse wrap. Interpret: the live path is uninstrumented — the static map was wrong. Classify: missing instrumentation (pipeline break). Severity: P0 — prod chat is invisible. Finding: chat | P0 | no trace after live send | wrap the SDK call.

Self-critique before reporting [LOW freedom — do not skip]

  1. Concrete numbers — model + $/call or tokens, not "costs seem high"
  2. Live, not static — trigger the feature; missing post-trigger trace = P0
  3. Severity justified — P0 = pipeline break or untraced user-facing call
  4. Right owner — jailbreak/OWASP → audit-llm-security; token caps → plan-llm-cost-guardrails
  5. Keys stay in env — report host + presence, never secret values

Phase 0: Auto-Detect Langfuse Integration

0a. Find Langfuse Configuration

Search for environment variables and config files (in order):

  1. .env, .env.local, .env.production — look for LANGFUSE_PUBLIC_KEY, LANGFUSE_SECRET_KEY, LANGFUSE_BASE_URL, LANGFUSE_HOST
  2. langfuse.config.ts, langfuse.config.js — dedicated config files
  3. instrumentation.ts / instrumentation.js — Next.js instrumentation with Langfuse
  4. Supabase Edge Functions — Glob("**/supabase/functions/**/index.ts") and search for Langfuse imports

Read the full file on GitHub · 469 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. 28d ago Changed · -13 tokens per session a29fefa66db6
  2. 1mo ago Changed · -7 tokens per session 304c01691838
  3. 1mo ago Changed e734024d75c9
  4. 1mo ago First seen · 469 lines · 93 tokens per session scan A 5f38b593d45e

Subscribe to this mod's changes

audit-langfuse-llm is a skill published in the GitHub repository kensaurus/cursor-kenji (9 stars, last pushed 26d ago), licensed MIT. It adds 73 tokens to every session and 3,964 once invoked, about $0.0003 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 2026-09-03.

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