---
title: Build with Atomic
description: Extend Atomic with skills, subagents, intercom, workflows, extensions, prompt templates, themes, packages, custom models and providers, and programmatic integrations.
---

# Build with Atomic

Customize an Atomic session or embed it in your own software. Choose a starting point below.

New to Atomic? Start with the [Quickstart](/quickstart). To look up an exact contract, use the [Reference index](/reference).

## Choose the lightest mechanism

Work down this list and stop at the first mechanism that solves your problem.

1. [Prompt templates](/prompt-templates) — reusable prompts that expand from a slash command. No code.
2. [Skills](/skills) — on-demand instructions the agent loads when a task matches. Markdown plus optional scripts.
3. [Subagents](/subagents) — delegate a focused, bounded task to a child agent.
4. [Intercom](/intercom) — coordinate several sessions on one machine.
5. [Workflows](/workflows) — multi-stage, resumable engineering loops with gates and artifacts.
6. [Extensions](/extensions) — TypeScript that adds tools, commands, events, and custom UI when nothing lighter fits.
7. [Atomic packages](/packages) — bundle and distribute the result.

## Change the model layer

- [Custom models](/models) — add model entries for a supported provider API.
- [Custom providers](/custom-provider) — implement a provider API or OAuth flow Atomic does not ship.

## Customization

Use [Themes](/themes) to restyle the terminal with a built-in or custom theme.

## Embed Atomic in your own software

[Programmatic use](/programmatic) compares JSON mode, RPC, and the SDK, and links each one to its protocol or API reference.


- [SDK](/sdk) - embed Atomic in Node.js applications.
- [RPC mode](/rpc) - integrate over stdin/stdout JSONL.
- [JSON event stream mode](/json) - print mode with structured events.
- [TUI components](/tui) - build custom terminal UI for extensions.