llm-eval-harness

llm-eval-harness is a skill for Claude Code, Codex from daymade/claude-code-skills. It costs 96 tokens per session (4,537 once invoked), scanned A, original, MIT.

A test suite for checking whether an AI model endpoint works as expected. An endpoint is the network address an application calls to use a model; the tool checks availability, request handling, speed, stability, protocol behaviour, and use-case quality.

In plain words
What is it for?
Comparing model endpoints, checking OpenAI- or Anthropic-compatible services, measuring response performance, and detecting quality regressions.
Why use it?
It exposes problems that vendor claims or a single successful request may miss, such as dropped instructions, unsupported features, slow responses, or failures under load.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions Claude Code.

Good fit Comparing model endpoints, checking OpenAI- or Anthropic-compatible services, measuring response performance, and detecting quality regressions.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/daymade/claude-code-skills/llm-eval-harness
About the project

Claude Code Skills Marketplace is a collection and marketplace of skills, plugins, agents, and instructions that extend Claude Code with specialized development workflows. It is for developers who want to install existing workflows or create, validate, and package their own Claude Code skills.

daymade/claude-code-skills · 1,473 stars · on GitHub

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 daymade/claude-code-skills --skill llm-eval-harness
Clone the repo
git clone --depth 1 https://github.com/daymade/claude-code-skills

Made for: Claude Code, Codex.

Its marketplace also offers this one on its own, as the plugin llm-eval-harness — /plugin install llm-eval-harness after adding the marketplace above.

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 llm-eval-harness

README.md
[![agentmods](https://agentmods.dev/badge/skills/daymade/claude-code-skills/llm-eval-harness/github.svg)](https://agentmods.dev/skills/daymade/claude-code-skills/llm-eval-harness)
Your own site
<a href="https://agentmods.dev/skills/daymade/claude-code-skills/llm-eval-harness"><img src="https://agentmods.dev/badge/skills/daymade/claude-code-skills/llm-eval-harness/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 llm-eval-harness

Your own site · 80×15
<a href="https://agentmods.dev/skills/daymade/claude-code-skills/llm-eval-harness"><img src="https://agentmods.dev/badge/skills/daymade/claude-code-skills/llm-eval-harness.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 96 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,537 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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: 3 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 Data Exfiltration · line 79
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Data Exfiltration · line 83
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Rogue Agent · line 292
    Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.
    Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
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 $0.00096 $0.04537
Opus 5.5 $0.00038 $0.01815
Sonnet 5.5 $0.00019 $0.00907
Haiku 4.5 $0.00010 $0.00454

Measured 24d ago against content hash 23d825018153, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

llm-eval-harness scanned grade A 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 24d ago.

The scan reads SKILL.md. This mod also ships 6 executable files (scripts/availability_probe.py, scripts/concurrency_probe.py, scripts/fidelity_probe.py, …), 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl loop, when onboarding a provider, or debugging "system prompt 不生效" / a tok/s claim —
llm-eval-harness/SKILL.md · 319 lines

How it starts

The opening of the file, as written. The whole thing — 319 lines — stays where its author put it; the contents beside it link to each section on GitHub.

LLM Eval Harness

Overview

Give this skill an endpoint (base_url + model + an API key in an env var) and it measures whether the endpoint actually works and whether the model is fast, stable, protocol-correct, and good enough — instead of trusting the vendor's headline numbers. Six dimensions, usually scattered across ad-hoc scripts that get rewritten (with the same bugs) every time:

Dimension Script Answers
Availability scripts/availability_probe.py which model IDs work here, with 3-state error classification
Request fidelity scripts/fidelity_probe.py do system prompt / tools / history actually REACH the model?
Speed scripts/speed_probe.py TTFT + sustained decode tok/s, thinking-aware
Concurrency / stability scripts/concurrency_probe.py success rate, p50/p90 latency, where it breaks
Protocol compliance scripts/protocol_probe.py does the Anthropic thinking block actually fire when requested, AND does the endpoint accept one already sitting in history on a later turn (N≥10, both are separate checks — see Dimension 3)?
Quality / use-case regression scripts/usecase_runner.py + blind judges does it pass your accumulated cases?

Which dimensions to run

Route from what the user is actually doing:

  • "接入新模型/新网关先测一下" / onboarding a provider → Availability → Fidelity, then speed/concurrency if adoption looks likely
  • "这个 ID 能不能用 / 写个支持列表" → Availability (and read disciplines §9 before writing any "unavailable" verdict)
  • "模型不听 system prompt / agent 行为怪但没报错" → Fidelity (system canary)
  • "快不快 / tok/s 是真的吗" → Speed; "扛不扛得住" → Concurrency
  • "这个兼容端点是真兼容吗" → Protocol + Fidelity's tools/auth checks
  • "这个模型/渠道用着用着就 400 了 / session 断了 / continue 不下去了" (extended-thinking client, multi-turn session) → Protocol --check history-replay specifically — this symptom is the generation check passing while history-replay silently doesn't; don't stop at generation
  • "换模型质量会不会掉" → Quality regression
  • "要给厂商报 bug" → run the relevant probe with --output, then follow references/vendor_evidence_protocol.md
  • "部署闸门 / 常驻监控 / 告警老误报" → references/production_testing_patterns.md

Read the full file on GitHub · 319 lines

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. 24d ago Changed · -8 lines · -167 tokens per session 23d825018153
  2. 1mo ago Changed · -1 lines · +2 tokens per session e03488e53b6c
  3. 1mo ago First seen · 328 lines · 261 tokens per session scan A 9d5d8e75f10d

Subscribe to this mod's changes

llm-eval-harness is a skill published in the GitHub repository daymade/claude-code-skills (1,473 stars, last pushed today), licensed MIT. It adds 96 tokens to every session and 4,537 once invoked, about $0.0004 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

Related

Other skills, from other repositories

cli-eval

Create and run evaluation suites, watch live benchmark progress, view scorecards, compare model performance, and integrate eval runs with CI workflows from the CLI.

diegosouzapw/OmniRoute · 34 tokens

model-merging

Merge multiple fine-tuned models using mergekit to combine capabilities without retraining. Use when creating specialized models by blending domain-specific expertise (math + coding + chat), improving performance beyond single models, or experimenting rapidly with model variants. Covers SLERP, TIES-Merging, DARE, Task…

davila7/claude-code-templates · 73 tokens

dummy-dataset

Generate realistic dummy datasets for testing with customizable columns, constraints, and output formats (CSV, JSON, SQL, Python script). Use when creating test data, building mock datasets, or generating sample data for development and demos.

phuryn/pm-skills · 48 tokens

darwinian-evolver

Evolve prompts/regex/SQL/code with Imbue's evolution loop.

NousResearch/hermes-agent · 22 tokens

bad-case-to-dpo

A guide to turning failed production agent runs into training and evaluation data. It explains how to find the first mistake, create preference examples for DPO (Direct Preference Optimization), and check that a fix does not damage other tasks.

bojieli/ai-agent-book · 168 tokens

validate

Validate Semantica pipelines, extraction quality, graph schemas, and ontology consistency. Returns structured error/warning checklists. Uses PipelineValidator, PipelineBuilder.validatepipeline(), GraphValidator, and OntologyValidator. Sub-commands: pipeline, step, dependencies, extraction, graph, ontology, performance.

semantica-agi/semantica · 0 tokens