Borrowing it
Nothing to install: this file belongs to jayminwest/burrow. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/jayminwest/burrow/main/AGENTS.mdgit clone --depth 1 https://github.com/jayminwest/burrowWrote 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/jayminwest/burrow/agents-md)<a href="https://agentmods.dev/instructions/jayminwest/burrow/agents-md"><img src="https://agentmods.dev/badge/instructions/jayminwest/burrow/agents-md/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.
<a href="https://agentmods.dev/instructions/jayminwest/burrow/agents-md"><img src="https://agentmods.dev/badge/instructions/jayminwest/burrow/agents-md.svg" alt="Reviewed on agentmods" width="80" 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 5.1 | $0.01792 | $0.01792 |
| Opus 5.5 | $0.00717 | $0.00717 |
| Sonnet 5.5 | $0.00358 | $0.00358 |
| Haiku 4.5 | $0.00179 | $0.00179 |
Grade A, and why
burrow AGENTS.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 1mo 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 — 187 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS.md
This file is the canonical entry point for AI coding agents working in
burrow, following the agents.md convention.
Mission
burrow — OS-isolated sandbox runtime for coding agents.
Burrow wraps untrusted agent processes in OS-level sandboxes — bwrap on
Linux, sandbox-exec on macOS — with no Docker and no daemon. Its single
most important guarantee is that a sandboxed agent cannot read or write
outside the filesystem scopes the operator granted it. Sessions and events
persist in SQLite via bun:sqlite.
Burrow is part of the os-eco ecosystem: it
is the substrate sandbox primitive that warren (the cloud control plane)
embeds per run, and it works standalone via the burrow / bw CLI.
SPEC.md is the frozen V1 design record; ROADMAP.md is the punch list of
forward-looking R-NN items.
Commands
All commands run from the repo root. Bun must be on PATH.
bun install # install dependencies
bun test # run all tests
bun test src/foo.test.ts # run a single test file
bun run lint # biome check --error-on-warnings .
bun run lint:fix # biome check --write .
bun run typecheck # tsc --noEmit
bun run check:all # full quality-gate suite (see below)
bun run verify # alias for check:all (agent-facing entry point)
bun run check:coverage # tests + coverage-floor ratchet
The user-facing CLI entry points:
bw --help # CLI top-level help
bw up # start a sandboxed session
Quality gates
bun run check:all (quiet runner, scripts/check-all.ts) runs every gate
CI also enforces, in canonical order:
lint—biome check --error-on-warnings .(warnings fail)typecheck—tsc --noEmitcheck:agents—scripts/validate-agents-md.ts(this file's references)check:dups—bunx jscpd(duplicate-code detector,.jscpd.json)check:deps—knip --dependencies(unused / undeclared deps,knip.json)check:size—scripts/check-file-sizes.ts(line-count ratchet)check:debt—scripts/check-debt-markers.ts(tracker-pinned TODOs)check:coverage—scripts/check-coverage.ts(coverage-floor ratchet)check:ci-parity—scripts/check-ci-parity.ts(CI ⇄ check:all parity)
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.
- 1mo ago First seen · 187 lines · 1,792 tokens per session scan A 041e9ba1086e
burrow AGENTS.md is an instructions file published in the GitHub repository jayminwest/burrow (12 stars, last pushed 2mo ago), licensed MIT. It adds 1,792 tokens to every session, about $0.0072 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.
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).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
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 copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
deepseek-harness AGENTS.md
AGENTS.md instructions for deepseek-ai/deepseek-harness, covering agents.md, pre-stable apis and released session data, repository layout, commands and host sandbox failures.