hhl

hhl is a skill for Claude Code, Codex from unitarylab/quantum-practices. It costs 102 tokens per session (5,957 once invoked), scanned A, original, no licence file.

An implementation of the HHL algorithm, a quantum method for approximately solving linear equations of the form Ax=b when A is Hermitian. It uses quantum phase estimation and statevector simulation, then reconstructs a classical approximate solution.

In plain words
What is it for?
Use it with user-provided Hermitian matrices A and vectors b whose dimension is a power of two, to simulate and inspect an approximate solution.
Why use it?
It lets you experiment with the HHL approach without manually assembling its simulation steps, while making the matrix and vector inputs explicit.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/unitarylab/quantum-practices/hhl
Any agent
npx skills add unitarylab/quantum-practices --skill hhl
Clone the repo
git clone --depth 1 https://github.com/unitarylab/quantum-practices

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 hhl

README.md
[![agentmods](https://agentmods.dev/badge/skills/unitarylab/quantum-practices/hhl.svg)](https://agentmods.dev/skills/unitarylab/quantum-practices/hhl)
Your own site
<a href="https://agentmods.dev/skills/unitarylab/quantum-practices/hhl"><img src="https://agentmods.dev/badge/skills/unitarylab/quantum-practices/hhl.svg" alt="Measured on agentmods" height="20"></a>
Per session 102 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,957 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00102 $0.05957
Opus 5 $0.00051 $0.02978
Sonnet 5 $0.00020 $0.01191
Haiku 4.5 $0.00010 $0.00596

Measured 5d ago against content hash fb1f39a2e054, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

hhl 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 5d ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/algorithm.py, scripts/hhl_implementation.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.

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.

algorithms/linear-systems/hhl/SKILL.md · 335 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

Files

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.

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. 5d ago First seen · 335 lines · 102 tokens per session scan A fb1f39a2e054

Subscribe to this mod's changes

hhl is a skill published in the GitHub repository unitarylab/quantum-practices (18 stars, last pushed 21d ago), with no licence file. It adds 102 tokens to every session and 5,957 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 2026-08-30.