Claude Code Agent Development
anthropics/claude-plugins-official
Explains how to write agents for Claude Code plugins: the markdown file with YAML frontmatter, trigger descriptions, model and color settings, and system prompt design.
Delegate work to builtin or custom subagents with single-agent, parallel, forked-context, and intercom-coordinated runs.
Install Subagent
$ npx skills add bastani-inc/atomic --skill subagent -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install bastani-inc/atomic subagent --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/bastani-inc/atomic.git skills-src && mkdir -p .claude/skills && cp -r skills-src/packages/subagents/skills/subagent .claude/skills/subagent && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "subagent" agent skill from https://github.com/bastani-inc/atomic/tree/main/packages/subagents/skills/subagent into .claude/skills/subagent/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "subagent", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/bastani-inc/atomic/tree/main/packages/subagents/skills/subagentType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add bastani-inc/atomic --skill subagent -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install bastani-inc/atomic subagent --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/bastani-inc/atomic.git skills-src && mkdir -p .agents/skills && cp -r skills-src/packages/subagents/skills/subagent .agents/skills/subagent && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "subagent" agent skill from https://github.com/bastani-inc/atomic/tree/main/packages/subagents/skills/subagent into .agents/skills/subagent/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "subagent", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add bastani-inc/atomic --skill subagent -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install bastani-inc/atomic subagent --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/bastani-inc/atomic.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/packages/subagents/skills/subagent .cursor/skills/subagent && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "subagent" agent skill from https://github.com/bastani-inc/atomic/tree/main/packages/subagents/skills/subagent into .cursor/skills/subagent/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "subagent", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/bastani-inc/atomic.git --path packages/subagents/skills/subagent--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add bastani-inc/atomic --skill subagent -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install bastani-inc/atomic subagent --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/bastani-inc/atomic.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/packages/subagents/skills/subagent .gemini/skills/subagent && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "subagent" agent skill from https://github.com/bastani-inc/atomic/tree/main/packages/subagents/skills/subagent into .gemini/skills/subagent/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "subagent", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install bastani-inc/atomic subagentInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add bastani-inc/atomic --skill subagent -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/bastani-inc/atomic.git skills-src && mkdir -p .github/skills && cp -r skills-src/packages/subagents/skills/subagent .github/skills/subagent && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "subagent" agent skill from https://github.com/bastani-inc/atomic/tree/main/packages/subagents/skills/subagent into .github/skills/subagent/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "subagent", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add bastani-inc/atomic --skill subagent -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install bastani-inc/atomic subagent --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/bastani-inc/atomic.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/packages/subagents/skills/subagent .opencode/skills/subagent && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "subagent" agent skill from https://github.com/bastani-inc/atomic/tree/main/packages/subagents/skills/subagent into .opencode/skills/subagent/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "subagent", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
subagent- GitHub stars
- 846
- Token cost
- ~11k tokens
- SKILL.md length
- 5,105 words
- Files
- 1
- Skills in repo
- 15
- Repo updated
- First seen
- Licence
- Custom licence
At a glance
Delegate work to builtin or custom subagents with single-agent, parallel, forked-context, and intercom-coordinated runs.
- Works in 3 steps: project scope → user scope → builtin agents
- Bounded specialist delegation where a single parent agent stays in control while subagents contribute locate
- SKILL.md covers When to Use, Tool, Applying Prompt Techniques and Builtin Agents, plus 10 more sections
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Subagent is an agent skill from bastani-inc/atomic. Delegate work to builtin or custom subagents with single-agent, parallel, forked-context, and intercom-coordinated runs. Use for bounded specialist delegation where a single parent agent stays in control while subagents contribute locate, analyze, pattern-find, research, debug, or simplify passes.
Its SKILL.md is about 11k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Agent Workflows, covering Subagents. It works with Intercom. The repository describes itself as: The verifiable coding agent runtime. Define your coding agent's process in natural language with stages, checks, and approval gates instead of hoping it follows your…
When your agent uses it
- Bounded specialist delegation where a single parent agent stays in control while subagents contribute locate
- Simplify passes
Example prompts
- “/subagent”
Workflow steps
3 steps, taken from the first numbered list in SKILL.md.
- project scope
- user scope
- builtin agents
What it can do on your machine
Read from SKILL.md and the folder at commit 1ec2fe8. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are typescript, json and markdown).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Subagent loads about 11k tokens when it runs. Until then it costs about 77 tokens; SKILL.md has 5,105 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
Its licence (Custom licence) doesn't allow us to republish the file, so here is its outline and opening line. It has 5,105 words (~11,244 tokens).
“This skill is for the main parent orchestrator only. Do not inject or follow it inside spawned child subagents. The parent session owns delegation, orchestration, review fanout, and final writer launches; child subagents should receive concrete role-specific tasks and should…”
- name
- subagent
Files
Just SKILL.md in packages/subagents/skills/subagent of bastani-inc/atomic.
Open the folder on GitHubat commit 1ec2fe8
Compare with similar skills
Subagent next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Subagent this skillbastani-inc/atomic | 846 | — | ~11k | Automated safety check: Pass | Custom licence | |
| Claude Code Agent Developmentanthropics/claude-plugins-official | 38k | 8 repos | ~2.8k | Automated safety check: Pass | Apache-2.0 | |
| Subagent Driven DevelopmentAsvarox/allkaraoke | 261 | 38 repos | ~1.2k | Automated safety check: Pass | None | |
| Dispatching Parallel Agentsultralisp/ultralisp | 258 | 41 repos | ~1.5k | Automated safety check: Pass | None | |
| Paseo Advisor Second Opiniongetpaseo/paseo | 20k | 1 repos | ~756 | Automated safety check: Pass | Custom licence | |
| Task Observerrebelytics/one-skill-to-rule-them-all | 3.2k | 1 repos | ~12k | Automated safety check: Pass | CC-BY-4.0 |
Similar skills
- Official
Subagent Driven Development
Asvarox/allkaraoke
A skill your agent uses when executing implementation plans with independent tasks in the current session
Dispatching Parallel Agents
ultralisp/ultralisp
A skill your agent uses when facing 2+ independent tasks that can be worked on without shared state or sequential dependencies
Paseo Advisor Second Opinion
getpaseo/paseo
Launches one separate agent through Paseo to give a second opinion on the current task, with a self-contained briefing and no permission to edit files.
Task Observer
rebelytics/one-skill-to-rule-them-all
Monitors task execution for skill improvement opportunities.
O2 Review Loop
openobserve/openobserve
Splits a change into planner, coder and independent reviewer roles: you confirm a spec, a subagent implements it, and a separate reviewer checks each round's local WIP commit.
More from bastani-inc/atomic
All 15 skills in this repoHow
bastani-inc/atomic
A skill your agent uses for "how does X work", code walkthroughs before changing something, and placement / ownership / layering questions ("where should this live", "which package owns this", "is…
Liteparse
bastani-inc/atomic
A skill your agent uses whenever a task involves a document file (PDF, DOCX, PPTX, XLSX, or image) and you need to read it or pull text, tables, or specific values out of it — to answer a question…
Bun
bastani-inc/atomic
A skill your agent uses when building, testing, and deploying JavaScript/TypeScript applications.
Feedback
bastani-inc/atomic
Draft, revise and post privacy-scrubbed Atomic bug reports or enhancements through ordinary conversation.
Prek
bastani-inc/atomic
A skill your agent uses when setting up or running hooks with prek in any repository.
TDD
bastani-inc/atomic
Test-driven development with red-green-refactor loop, plus a value gate and audit workflow for tests.
Related
Works with
Categories
Questions about Subagent
What does Subagent do?
Delegate work to builtin or custom subagents with single-agent, parallel, forked-context, and intercom-coordinated runs. Subagent is an agent skill from bastani-inc/atomic. Delegate work to builtin or custom subagents with single-agent, parallel, forked-context, and intercom-coordinated runs.
When should I use Subagent?
Subagent fits situations like: bounded specialist delegation where a single parent agent stays in control while subagents contribute locate; simplify passes.
How do I install Subagent in Claude Code?
Run `npx skills add bastani-inc/atomic --skill subagent -a claude-code`. Or copy the skill folder (packages/subagents/skills/subagent in bastani-inc/atomic) into .claude/skills/subagent in your project. Claude Code loads it when a task matches its description.
How do I install Subagent in Codex?
Run `npx skills add bastani-inc/atomic --skill subagent -a codex`. Or copy the skill folder (packages/subagents/skills/subagent in bastani-inc/atomic) into .agents/skills/subagent in your project. Codex loads it when a task matches its description.
Can I use Subagent in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add bastani-inc/atomic --skill subagent -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/subagent, .gemini/skills/subagent, .github/skills/subagent and .opencode/skills/subagent in your project.
What does Subagent need to run?
SKILL.md names no scripts, command-line tools or credentials: Subagent is instructions for the agent only.
Does Subagent access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Subagent safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Subagent use?
Subagent has a licence file (the repository's licence) that doesn't match a standard licence. Read it on GitHub before reusing the skill.
How many tokens does Subagent use?
About 11k tokens (SKILL.md is roughly 45k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Subagent?
Skills that share tags, products or a category with Subagent: Claude Code Agent Development (anthropics/claude-plugins-official, 38k stars), Subagent Driven Development (Asvarox/allkaraoke, 261 stars), Dispatching Parallel Agents (ultralisp/ultralisp, 258 stars) and Paseo Advisor Second Opinion (getpaseo/paseo, 20k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Subagent?
bastani-inc (a GitHub organization) maintains it in bastani-inc/atomic, which has 846 GitHub stars. The repository holds 15 skills in this directory. The repository was last updated on October 8, 2026.
Source: bastani-inc/atomic on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.