chart-master

chart-master is a skill for Claude Code, Codex from yennanliu/InvestSkill. It costs 36 tokens per session (5,870 once invoked), scanned A, original, MIT.

A chart-making skill for financial data, supporting formats such as Mermaid, plain-text diagrams, and HTML charts. It covers common views including moving averages, candlesticks, volume, RSI, and MACD.

In plain words
What is it for?
It is for creating charts from financial tables, prices, market indicators, and analysis for use in markdown reports.
Why use it?
It helps turn financial numbers into visual reports while requiring current data and clearly marking unavailable or stale market information.

Skill for Claude CodeCodex

Part of the us-stock-analysis plugin — 27 skills shipped together

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/yennanliu/investskill/chart-master
Any agent
npx skills add yennanliu/InvestSkill --skill chart-master
Clone the repo
git clone --depth 1 https://github.com/yennanliu/InvestSkill

Made for: Claude Code, Codex.

Or install us-stock-analysis, the plugin that ships this one along with the rest of its 27 skills.

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 chart-master

README.md
[![agentmods](https://agentmods.dev/badge/skills/yennanliu/investskill/chart-master.svg)](https://agentmods.dev/skills/yennanliu/investskill/chart-master)
Your own site
<a href="https://agentmods.dev/skills/yennanliu/investskill/chart-master"><img src="https://agentmods.dev/badge/skills/yennanliu/investskill/chart-master.svg" alt="Measured on agentmods" height="20"></a>
Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,870 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00036 $0.05870
Opus 5 $0.00018 $0.02935
Sonnet 5 $0.00007 $0.01174
Haiku 4.5 $0.00004 $0.00587

Measured 4d ago against content hash 32c7b577eeaf, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

chart-master 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 4d 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.

plugins/us-stock-analysis/skills/chart-master/SKILL.md · 632 lines

How it starts

The opening of the file, as written. The whole thing — 632 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Chart Master — Financial Visualization Agent

⚠️ Data Verification — Do This Before Any Analysis

Before running any analysis, always retrieve the latest market data for the ticker:

  1. Fetch current price — use web search or ask the user for the live price, 52-week range, and market cap. Never assume a price from training data.
  2. Confirm key figures — recent earnings, revenue, key ratios (P/E, P/S, etc.) as applicable to this skill.
  3. State your data source — note where the numbers came from (e.g., "Google Finance, June 19 2026") at the top of the output.
  4. Flag stale data explicitly — if live data is unavailable, display this warning before proceeding:

⚠️ Live data unavailable. The following analysis uses training-data estimates which may be significantly out of date. Verify all prices and metrics before making any decisions.

Never silently substitute training-data estimates for current prices. When in doubt, ask the user to paste the latest quote.


You are a financial visualization specialist. Given financial data (tables, numbers, analysis output), you produce clean, publication-quality charts optimized for markdown reports.

Platform Detection

Before rendering, identify the target platform and choose the appropriate format:

Platform Primary Format Fallback
Claude Code / Claude.ai Mermaid + HTML/Chart.js ASCII
Gemini CLI / Gemini Mermaid ASCII
Cursor IDE Mermaid ASCII
GitHub Copilot / VS Code Mermaid ASCII
Plain markdown / terminal ASCII Text table
Report export (HTML) HTML/Chart.js Mermaid

Default rule: Always produce Mermaid first. If the user requests "rich", "interactive", or "HTML report", also produce the HTML/Chart.js version. If Mermaid won't render, fall back to ASCII.


Chart Types & When to Use Them

1. Price with Moving Averages — MA Line Chart

Use for: price trend with MA20, MA50, MA200 overlays. Core technical chart for any stock report.

Read the full file on GitHub · 632 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. 4d ago First seen · 632 lines · 36 tokens per session scan A 32c7b577eeaf

Subscribe to this mod's changes

chart-master is a skill published in the GitHub repository yennanliu/InvestSkill (198 stars, last pushed today), licensed MIT. It adds 36 tokens to every session and 5,870 once invoked, about $0.0002 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.