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create-atomic-agent

create-atomic-agent is a skill for Claude Code from Eigenwise/atomic-agents. It costs 93 tokens per session (1,825 once invoked), scanned A, original, MIT.

A guide for building an Atomic Agents agent: a program that sends structured input to a language model and receives structured output. It covers schemas, prompts, provider clients, configuration, conversation history, and optional context.

In plain words
What is it for?
Use it to create or connect agents such as chat, planner, extractor, classifier, or router agents in an Atomic Agents Python application.
Why use it?
It removes the wiring work involved in connecting an agent's data formats, instructions, language-model provider, and conversation state.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the atomic-agents plugin — 7 skills, 2 agents shipped together

not rated 6.3krepo +5 8d ago A scan SkillSpector: pass 93 tokens original MIT

Good fit Use it to create or connect agents such as chat, planner, extractor, classifier, or router agents in an Atomic Agents Python application.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/eigenwise/atomic-agents/create-atomic-agent
View source ↗ Eigenwise/atomic-agents eigenwise.github.io
About the project

Atomic Agents is a lightweight, modular framework for assembling AI agents and applications from single-purpose components such as agents, tools, and context providers. It is for developers building maintainable agentic AI pipelines with reusable, composable parts and structured outputs. The catalogue entries provide agent skills, instructions, settings, and related development workflows for the framework.

Eigenwise/atomic-agents · 6,319 stars · on GitHub · eigenwise.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 Eigenwise/atomic-agents --skill create-atomic-agent
Clone the repo
git clone --depth 1 https://github.com/Eigenwise/atomic-agents

Made for: Claude Code.

Or install atomic-agents, the plugin that ships this one along with the rest of its 7 skills, 2 agents.

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 create-atomic-agent

README.md
[![agentmods](https://agentmods.dev/badge/skills/eigenwise/atomic-agents/create-atomic-agent/github.svg)](https://agentmods.dev/skills/eigenwise/atomic-agents/create-atomic-agent)
Your own site
<a href="https://agentmods.dev/skills/eigenwise/atomic-agents/create-atomic-agent"><img src="https://agentmods.dev/badge/skills/eigenwise/atomic-agents/create-atomic-agent/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 create-atomic-agent

Your own site · 80×15
<a href="https://agentmods.dev/skills/eigenwise/atomic-agents/create-atomic-agent"><img src="https://agentmods.dev/badge/skills/eigenwise/atomic-agents/create-atomic-agent.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 93 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,825 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 $0.00093 $0.01825
Opus 5.5 $0.00037 $0.00730
Sonnet 5.5 $0.00019 $0.00365
Haiku 4.5 $0.00009 $0.00183

Measured 2mo ago against content hash 278b9aaeeaa0, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

create-atomic-agent 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 2mo 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.

claude-plugin/atomic-agents/skills/create-atomic-agent/SKILL.md · 161 lines

How it starts

The opening of the file, as written. The whole thing — 161 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Create an Atomic Agent

An agent is an LLM-backed transformer from one BaseIOSchema to another. Building one means: design the schemas, write the system prompt, wire the provider client, build the AgentConfig, instantiate AtomicAgent[In, Out].

For deep material (streaming, token counting, hooks, multi-agent memory), the authority is ../framework/references/agents.md plus providers.md, prompts.md, and memory.md. This skill is the action-oriented path: clarify → write → run.

When this fires vs the umbrella framework skill

  • This skill: the user is creating or wiring a specific agent — "add a planner agent", "build a Q&A agent", "make a router that classifies tickets".
  • framework skill: questions about Atomic Agents in general, or the user is doing something other than authoring an agent.

Phase 1 — Clarify

Bundle into one message:

  1. What should the agent do? One sentence. Becomes the persona / background line.
  2. Inputs and outputs. Use BasicChatInputSchema / BasicChatOutputSchema for free-form chat. Use a custom pair for anything structured (extraction, classification, planning, routing). When custom, branch to the create-atomic-schema skill for the schema authoring.
  3. Provider. OpenAI / Anthropic / Groq / Ollama / Gemini / OpenRouter / MiniMax. Default: whatever the project already uses; otherwise OpenAI.
  4. Conversational? Yes → wire a ChatHistory. No (single-shot transformer) → omit it for stateless behavior.
  5. Context providers. Anything to inject into the prompt at runtime (current time, user identity, retrieved docs)? If yes, plan to also use the create-atomic-context-provider skill afterwards.

Skip anything already settled in context.

Phase 2 — Plan

State the plan in one short block:

  • File: <project>/agents/<agent_name>.py (or directly in main.py for a tiny project — see ../framework/references/project-structure.md).
  • Schemas: which pair, where they live.
  • Provider + model + Instructor mode. Default models: OpenAI gpt-5-mini, Anthropic claude-haiku-4-5, Groq llama-3.3-70b-versatile, Ollama llama3.1, Gemini gemini-2.5-flash.
  • SystemPromptGenerator content — three sections: background, steps, output_instructions.
  • History? Hooks? Context providers?

Read the full file on GitHub · 161 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. 2mo ago First seen · 161 lines · 93 tokens per session scan A 278b9aaeeaa0

Subscribe to this mod's changes

create-atomic-agent is a skill published in the GitHub repository Eigenwise/atomic-agents (6,319 stars, last pushed 8d ago), licensed MIT. It adds 93 tokens to every session and 1,825 once invoked, about $0.0004 per session on Opus 5.5. 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.

Building agentsaiartificial-intelligencelarge-language-modellarge-language-modelsllmsopenai
Related

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