ulw-perf

ulw-perf is a skill for Claude Code, Codex from rlaope/oh-my-hermes. It costs 98 tokens per session (1,532 once invoked), scanned A, original, MIT.

A workflow skill for finding the source of slow, expensive, or memory-heavy code through measurements and then testing focused improvements.

In plain words
What is it for?
Use it to establish a baseline, investigate likely hot spots one at a time, make executor-owned changes, and check for regressions.
Why use it?
It prevents performance changes from being based on guesses or unverified claims.

Skill for Claude CodeCodex

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

Good fit Use it to establish a baseline, investigate likely hot spots one at a time, make executor-owned changes, and check for regressions.

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Install with agentmods
npx agentmods add skills/rlaope/oh-my-hermes/ulw-perf
About the project

oh-my-hermes is an operating layer for Hermes Agent that organizes requests into workflows for planning, research, creation, coding handoffs, operations, and project memory. Hermes users run these workflows through the desktop app, CLI, or messenger app, while the catalogue add-ons extend its native capabilities.

rlaope/oh-my-hermes · 1,648 stars · on GitHub · rlaope.github.io

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 rlaope/oh-my-hermes --skill ulw-perf
Clone the repo
git clone --depth 1 https://github.com/rlaope/oh-my-hermes

Made for: Claude Code, Codex.

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 ulw-perf

README.md
[![agentmods](https://agentmods.dev/badge/skills/rlaope/oh-my-hermes/ulw-perf/github.svg)](https://agentmods.dev/skills/rlaope/oh-my-hermes/ulw-perf)
Your own site
<a href="https://agentmods.dev/skills/rlaope/oh-my-hermes/ulw-perf"><img src="https://agentmods.dev/badge/skills/rlaope/oh-my-hermes/ulw-perf/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 ulw-perf

Your own site · 80×15
<a href="https://agentmods.dev/skills/rlaope/oh-my-hermes/ulw-perf"><img src="https://agentmods.dev/badge/skills/rlaope/oh-my-hermes/ulw-perf.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 98 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,532 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 pass 7 Sept 2026
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 $0.00098 $0.01532
Opus 5 $0.00049 $0.00766
Sonnet 5 $0.00020 $0.00306
Haiku 4.5 $0.00010 $0.00153

Measured 3d ago against content hash 765d37fe54e9, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

ulw-perf 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 3d 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/ulw-perf/SKILL.md · 132 lines

How it starts

The opening of the file, as written. The whole thing — 132 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Ultraperf

This is a Hermes-native ultraperf workflow skill.

Why This Exists

ultraperf exists because most performance work starts unlocalized: something is slow, leaking, or expensive and nobody knows where. It forces measurement before edits, one hypothesis at a time, executor-owned changes, and a regression budget, so an optimization loop cannot end in unverified claims.

Do Not Use When

  • Metric, baseline, budget, and benchmark command are already declared for one measurable goal; use performance-goal.
  • The ask is to judge code quality, structure, or correctness rather than measured cost; use code-review.
  • The ask is to score model or agent output quality on a task suite; use agent-evaluation.
  • The request is a settings-only change, one bounded edit that is explicitly low-risk and has a direct owner and verification path, or one already-identified slow query or hotspot fix; handle it directly instead of opening a performance loop.

Examples

Good example:

  • Prompt: $ultraperf checkout feels slow and the worker memory keeps climbing - find where and fix it
  • Expected behavior: Audit the baseline, name the evaluator command, rank hot-path hypotheses, hand the smallest reversible fix to the selected executor, re-measure, and state the budget delta.
  • Why: The problem is real but unlocalized across more than one domain.

Bad example:

  • Prompt: $ultraperf make the recommender p95 under 200ms; baseline 340ms, benchmark is 'make bench'
  • Expected behavior: Route to performance-goal, which owns a declared metric/baseline/budget/benchmark goal.
  • Why: A single declared measurable goal does not need a discovery loop.

Completion Checklist

  • Baseline, workload, environment, and evaluator command are recorded before any edit is proposed.
  • Each accepted fix names the measured hot path, the reversible change, and its owner.
  • Re-measured deltas cite observed evidence; unmeasured steps stay not_observed.
  • The regression budget and the gate that enforces it are stated with the tolerance.

Read the full file on GitHub · 132 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. 3d ago Changed 765d37fe54e9
  2. 5d ago Changed f6407e1317e5
  3. 8d ago First seen · 132 lines · 98 tokens per session scan A 04278f220507

Subscribe to this mod's changes

ulw-perf is a skill published in the GitHub repository rlaope/oh-my-hermes (1,648 stars, last pushed yesterday), licensed MIT. It adds 98 tokens to every session and 1,532 once invoked, about $0.0005 per session on Opus 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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