malloy-charts

malloy-charts is a skill for Claude Code, Codex from malloydata/publisher. It costs 57 tokens per session (4,263 once invoked), scanned A, original, MIT.

A guide for choosing charts in Malloy, a data-query language that can display results using charts and tables.

In plain words
What is it for?
Use it when deciding how to display comparisons, trends, relationships, geographic data, routes, summaries, or detailed rows.
Why use it?
It connects the shape of the data—such as categories, dates, numbers, or locations—to a suitable visual format.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it when deciding how to display comparisons, trends, relationships, geographic data, routes, summaries, or detailed rows.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/malloydata/publisher/malloy-charts
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 malloydata/publisher --skill malloy-charts
Clone the repo
git clone --depth 1 https://github.com/malloydata/publisher

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 malloy-charts

README.md
[![agentmods](https://agentmods.dev/badge/skills/malloydata/publisher/malloy-charts/github.svg)](https://agentmods.dev/skills/malloydata/publisher/malloy-charts)
Your own site
<a href="https://agentmods.dev/skills/malloydata/publisher/malloy-charts"><img src="https://agentmods.dev/badge/skills/malloydata/publisher/malloy-charts/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 malloy-charts

Your own site · 80×15
<a href="https://agentmods.dev/skills/malloydata/publisher/malloy-charts"><img src="https://agentmods.dev/badge/skills/malloydata/publisher/malloy-charts.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 57 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,263 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 $0.00057 $0.04263
Opus 5 $0.00028 $0.02132
Sonnet 5 $0.00011 $0.00853
Haiku 4.5 $0.00006 $0.00426

Measured 10d ago against content hash a6fb070efb2a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

malloy-charts 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 10d 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/malloy-charts/SKILL.md · 427 lines

How it starts

The opening of the file, as written. The whole thing — 427 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Chart Selection for Malloy

Malloy uses Vega-Lite under the hood. # tags control visualization. Call search_malloy_docs with topic "rendering" for the full tag reference (or see https://docs.malloydata.dev/documentation/visualizations/overview).

Tool names are written bare here - get_context, execute_query, search_malloy_docs. The exact prefixed name depends on the host surface; match each against the tools you actually have.

Decision Tree: Which Chart?

Data Shape Default Choice
Aggregates only (no group_by) # big_value
1 time column + 1 measure # line_chart
1 category + 1 measure # bar_chart
2 numeric columns # scatter_chart
Geographic (US states) + 1 measure # shape_map
Route data (lat/lon pairs) # segment_map
Multiple perspectives # dashboard with nest:
Nested query to pivot # pivot
Filtered aggregates side-by-side # flatten
Detailed rows Default table (no annotation)
Goal Renderer
Compare categories # bar_chart (sort by value, limit ~15)
Show composition # bar_chart.stack
Trend over time # line_chart
Highlight KPIs # big_value with # label
Correlation # scatter_chart
Compare dimensions # dashboard (nest chart views)
Before/after # transpose or # pivot
Multiple metrics per category Default table, # flatten, or y=['a','b']

Constraints:

  • ONE aggregate per chart view (charts render only the first; use y=['a','b'] for multi-measure)
  • No fixed scale on measure definitions: use # currency not # currency=usd0m
  • One tag per line
  • Alias joined fields in group_by before order_by
  • Define measures in source, not in views

Chart Types

# bar_chart

Data shape: group_by = x-axis, aggregate = y-axis, optional 2nd group_by = series.

# bar_chart
view: by_carrier is { group_by: carrier, aggregate: flight_count, order_by: flight_count desc, limit: 10 }

# bar_chart.stack
view: by_region is { group_by: category, region, aggregate: revenue }

# bar_chart { y=['revenue','cost'] }
view: rev_vs_cost is { group_by: category, aggregate: revenue, cost }

Read the full file on GitHub · 427 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. 10d ago First seen · 427 lines · 57 tokens per session scan A a6fb070efb2a

Subscribe to this mod's changes

malloy-charts is a skill published in the GitHub repository malloydata/publisher (100 stars, last pushed today), licensed MIT. It adds 57 tokens to every session and 4,263 once invoked, about $0.0003 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.

Related

Other skills, from other repositories

reimagine-it-extract

Emit the content signals reimagine-it reads from an HTML file — title, anchors, proper nouns, dates, numbers, emails, links, source hex colors, and the derived palette — as JSON without generating a redesign. Use when the user says /reimagine-it extract, "what does the engine see in this page", "extract the palette"…

Kayforkind/reimagine-it · 133 tokens

reusable-visualization

Build ONE reusable chart visualization component that receives its data and its settings from the host application instead of fetching them, and declares the fields and config options the host exposes to viewers. Use this whenever a single chart component is reused across many different queries rather than built for…

lightdash/lightdash · 102 tokens

lightdash-agent-slack-messaging

Use this skill when writing, designing, or generating Slack messages for Lightdash's in-app analytics agent. Triggers when someone asks to create agent update messages, Slack digests, agent notifications, weekly summaries, daily summaries, or any Slack copy for the Lightdash project agent. Also use when asked to vary…

lightdash/lightdash · 114 tokens

developing-in-lightdash

Use when reading, creating, and editing Lightdash dashboards and charts as JSON, including dashboard layout and chart-type-specific configuration.

lightdash/lightdash · 31 tokens

upgrade-preflight

Checks whether a self-hosted Lightdash upgrade is safe to run, and reads the tooling's answer without over-reading it. Use when upgrading a self-hosted instance, planning a maintenance window, answering "is this upgrade safe", or recovering a failed, hung, parked or lock-stuck migration — covers lightdash…

lightdash/lightdash · 101 tokens

developing-data-apps-locally

Use when editing a locally created or downloaded Lightdash data app — how local editing, building, and uploading work, and what is read-only.

lightdash/lightdash · 38 tokens