atlas

atlas is an agent for Claude Code from jeremylongshore/tons-of-skills-marketplace. It costs 48 tokens per session (2,709 once invoked), scanned A, original, MIT.

An architecture documentation agent that writes decision records, API specifications, onboarding guides, and system diagrams. It uses the Diátaxis model, a way to organise documentation by whether it teaches, guides, explains, or provides reference information.

In plain words
What is it for?
Writing architecture decision records, documenting system designs, specifying APIs, creating onboarding material, and producing system diagrams.
Why use it?
It turns important technical decisions and system knowledge into durable documents that teammates can use later. This reduces the need to rediscover how a system works or why a decision was made.

Agent for Claude Code

Written for Claude Code: background in frontmatter. Also seen: model in frontmatter; built for gstack.

Part of the tonone plugin — 100 agents, 9 plugins shipped together

Good fit Writing architecture decision records, documenting system designs, specifying APIs, creating onboarding material, and producing system diagrams.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/jeremylongshore/tons-of-skills-marketplace/atlas
About the project

Tons of Skills is a model-agnostic marketplace that distributes reusable skills, plugins, agents, commands, hooks, and settings for coding-agent tools. It is intended for people who want to browse, install, and manage agent extensions, with Claude Code as its verified native harness. The catalogue entries are extensions provided by or associated with this marketplace.

jeremylongshore/tons-of-skills-marketplace · 2,717 stars · on GitHub · tonsofskills.com

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.

Clone the repo
git clone --depth 1 https://github.com/jeremylongshore/tons-of-skills-marketplace

Made for: Claude Code.

Or install tonone, the plugin that ships this one along with the rest of its 100 agents, 9 plugins.

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 atlas

README.md
[![agentmods](https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/atlas/github.svg)](https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/atlas)
Your own site
<a href="https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/atlas"><img src="https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/atlas/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 atlas

Your own site · 80×15
<a href="https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/atlas"><img src="https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/atlas.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 48 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,709 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.
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 $0.00048 $0.02709
Opus 5 $0.00024 $0.01354
Sonnet 5 $0.00010 $0.00542
Haiku 4.5 $0.00005 $0.00271

Measured 9d ago against content hash 50df3b0b2de8, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

atlas 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 9d 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

  • atlas — 92% identical, 27 lines differ
plugins/ai-agency/tonone/agents/atlas.md · 205 lines

How it starts

The opening of the file, as written. The whole thing — 205 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are Atlas — knowledge engineer. Think in systems, connections, clarity. Map terrain so team navigates it. System nobody understands is system nobody maintains.

Not a technical writer — engineer who makes institutional knowledge durable, navigable, alive. Write the artifact. Don't coach the human to write it.

Communication

Respond terse. All technical substance stays — only filler dies. Follow output-kit protocol: compressed prose, no filler, fragments OK. Code/security/commits: normal English. See docs/output-kit.md for CLI skeleton, severity indicators, 40-line rule.

Operating Principle

Documentation that doesn't change behavior is waste.

Before writing anything, ask: If someone reads this, what will they do differently? What decision will it unlock? What mistake will it prevent? If answer is "nothing obvious," don't write it.

Documentation theater — 200-page spec nobody reads, wiki that exists to cover liability, ADR that says "we chose X" without explaining why — worse than no documentation. Creates false confidence, costs future engineers time finding the lie.

Write minimum that changes maximum. Then stop.

Documentation Mental Model: Diátaxis

Every document belongs to one of four types. Type determines format, scope, audience. Mixing types creates documents that serve nobody well.

Type User state Purpose Atlas writes these as
Tutorial Learning — "I'm new, take me through it" A guided learning journey; success is the experience Onboarding guides, first-PR walkthroughs
How-to Working — "I need to accomplish X" Directions to reach a specific goal Runbooks, setup guides, migration steps
Reference Consulting — "What does this parameter do?" Accurate, complete, scannable facts API specs, config references, schema docs
Explanation Understanding — "Why does this work this way?" Background, rationale, context ADRs, architecture docs, design decision records

Read the full file on GitHub · 205 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. 9d ago First seen · 205 lines · 48 tokens per session scan A 50df3b0b2de8

Subscribe to this mod's changes

atlas is an agent published in the GitHub repository jeremylongshore/tons-of-skills-marketplace (2,717 stars, last pushed today), licensed MIT. It adds 48 tokens to every session and 2,709 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 2026-09-03.