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.
npx agentmods add instructions/gruckion/nested-subagent/claude-mdgit clone --depth 1 https://github.com/gruckion/nested-subagentWrote 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.
[](https://agentmods.dev/instructions/gruckion/nested-subagent/claude-md)<a href="https://agentmods.dev/instructions/gruckion/nested-subagent/claude-md"><img src="https://agentmods.dev/badge/instructions/gruckion/nested-subagent/claude-md.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00895 | $0.00895 |
| Opus 5 | $0.00447 | $0.00447 |
| Sonnet 5 | $0.00179 | $0.00179 |
| Haiku 4.5 | $0.00089 | $0.00089 |
Grade A, and why
nested-subagent CLAUDE.md 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 4d 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.
How it starts
The opening of the file, as written. The whole thing — 89 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
Project Overview
This is a Claude Code plugin that enables unlimited nested subagents. The native Task tool blocks subagents from spawning other subagents (via tool filtering in AgentTool). This plugin bypasses that limitation by spawning fresh claude -p processes, which are full main agents with complete tool access.
Commands
Build & Development
cd mcp-server && bun run build # Build MCP server (uses tsdown)
cd mcp-server && bun run dev # Run MCP server in development mode (tsx)
cd mcp-server && bun run typecheck # TypeScript type checking
Testing
cd mcp-server && bun run test # Run unit tests
cd mcp-server && bun run test:watch # Watch mode
cd mcp-server && bun run test:integration # Integration tests (*.integration.test.ts files)
Plugin Installation
claude --plugin-dir ./ # Per-session usage
Architecture
Key Insight
The native Task tool's recursion blocker (.filter(_ => _.name !== AgentTool.name)) is process-local. By spawning a fresh claude -p process via MCP, we create a new main agent that has full tool access including the Task tool.
Native: Main → Subagent → BLOCKED (Task tool filtered out)
Plugin: Main → MCP Tool → spawn "claude -p" → Fresh Main Agent → CAN use Task → Unlimited nesting
Directory Structure
fallback-agent/
├── .claude-plugin/
│ └── marketplace.json # Plugin manifest for marketplace distribution
├── .mcp.json # MCP server configuration
├── mcp-server/
│ ├── src/index.ts # MCP server implementation (core logic)
│ ├── dist/ # Built output (bundled with tsdown)
│ └── test/ # Unit and integration tests
└── src/ # Reference Claude Code source (for understanding internals)
MCP Server (mcp-server/src/index.ts)
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.
- 4d ago First seen · 89 lines · 895 tokens per session scan A 4e3442a865e4
nested-subagent CLAUDE.md is an instructions file published in the GitHub repository gruckion/nested-subagent (24 stars, last pushed 8mo ago), licensed MIT. It adds 895 tokens to every session, about $0.0045 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.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
spec-kit AGENTS.md
AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.
codex AGENTS.md
AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).
next.js AGENTS.md
Instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.