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/stacklok/brood-box/claude-mdgit clone --depth 1 https://github.com/stacklok/brood-boxWhat 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 | $0.05203 | $0.05203 |
| Opus 5 | $0.02601 | $0.02601 |
| Sonnet 5 | $0.01041 | $0.01041 |
| Haiku 4.5 | $0.00520 | $0.00520 |
Grade A, and why
brood-box 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 2d 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 — 305 lines — stays where its author put it; the contents beside it link to each section on GitHub.
brood-box
CLI tool for running coding agents (Claude Code, Codex, OpenCode) inside hardware-isolated microVMs. Wraps the go-microvm framework with an opinionated CLI.
Module: github.com/stacklok/brood-box
Commands — ALWAYS use task (Taskfile.yaml)
IMPORTANT: ALWAYS use task <target> for building, testing, linting, formatting, and running. NEVER invoke go build, go test, golangci-lint, go fmt, goimports, docker build, or podman build directly — the Taskfile wraps these with the correct flags, ldflags, env vars, and dependency ordering. Running raw commands will produce incorrect builds or miss steps.
task build # Build self-contained bbox with embedded go-microvm runtime
task build-init # Cross-compile bbox-init for guest VM
task build-dev # Alias for task build (Linux)
task build-dev-darwin # Alias for task build (macOS)
task build-dev-system # Build bbox + go-microvm-runner from system libkrun (Linux, requires libkrun-devel)
task build-dev-system-darwin # Build bbox + go-microvm-runner from system libkrun (macOS, requires Homebrew libkrun)
task fetch-runtime # Download pre-built go-microvm runtime from GitHub Release
task fetch-firmware # Optional: prefetch go-microvm firmware
task test # go test -v -race ./...
task test-coverage # Run tests with coverage report
task lint # golangci-lint run ./...
task lint-fix # Auto-fix lint issues
task fmt # go fmt + goimports
task tidy # go mod tidy
task verify # fmt + lint + test
task install # Install bbox to GOPATH/bin
task run # Build and run
task clean # Remove bin/ and coverage files
task image-base # Build base guest image
task image-claude-code # Build claude-code guest image
task image-codex # Build codex guest image
task image-opencode # Build opencode guest image
task image-all # Build all guest images
task image-push # Push all images to GHCR
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.
- 2d ago First seen · 305 lines · 5,203 tokens per session scan A 2d570331a5e0
brood-box CLAUDE.md is an instructions file published in the GitHub repository stacklok/brood-box (64 stars, last pushed 3d ago), licensed Apache-2.0. It adds 5,203 tokens to every session, about $0.0260 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
vmette CLAUDE.md
Instructions for chamuka-inc/vmette, covering vmette — project instructions, checks (run before considering work done), workspace layout, core library — crates/vmette/src/ and daemon — crates/vmette-daemon/src/.
microsandbox AGENTS.md
AGENTS.md instructions for superradcompany/microsandbox, covering agents.md, scope, project map, design principles and backward compatibility review.
agentos CLAUDE.md
Claude Code instructions for rivet-dev/agentos, covering agentos, boundaries, security model, sqlite schema ownership and runtime and registry.
OpenSandbox CLAUDE.md
Claude Code instructions for opensandbox-group/OpenSandbox: See AGENTS.md for all rules, routing, and conventions.
agent-sandbox AGENTS.md
Instructions for kubernetes-sigs/agent-sandbox, covering agents.md, project summary, repository layout, agent skills and build, test, lint.
arcbox CLAUDE.md
Instructions for arcboxlabs/arcbox, covering repository guidelines for coding agents, project overview, performance targets, platform priority and project structure.