Borrowing it
Nothing to install: this file belongs to dzhng/duet-agent. 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/dzhng/duet-agent/main/AGENTS.mdgit clone --depth 1 https://github.com/dzhng/duet-agentWrote 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/dzhng/duet-agent/agents-md)<a href="https://agentmods.dev/instructions/dzhng/duet-agent/agents-md"><img src="https://agentmods.dev/badge/instructions/dzhng/duet-agent/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/dzhng/duet-agent/agents-md"><img src="https://agentmods.dev/badge/instructions/dzhng/duet-agent/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 | $0.01540 | $0.01540 |
| Opus 5.5 | $0.00616 | $0.00616 |
| Sonnet 5.5 | $0.00308 | $0.00308 |
| Haiku 4.5 | $0.00154 | $0.00154 |
Grade A, and why
duet-agent 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 6d 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 — 98 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Working in this repo
Read README.md first: what the product is, how the repo fits together, and how to build and check it. Active plans live with their specs, and each one says what to do next. If a folder you're working in has a readme, read it before continuing. The readmes are written for you.
These are the principles. Commands, flags and paths live with the code that owns them: the readmes, the manifests, and each tool's own usage text.
Talking to the user
The user is very technical but doesn't read the code day to day. Pointing at code is fine; introduce a variable, function or module briefly the first time you mention it.
Lead with contracts. When work touches an interface between components (a command or the events it emits, the protocol a host speaks to the runner, a config field, a saved state shape, a module boundary), say what the contract looks like and how it changed before anything else.
Answer routine questions from the evidence. Ask the user only when the answer changes a decision that matters and can't be settled any other way.
Proving a change
Optimize for iteration speed. The measure is the time to feedback you can trust, not the amount of process you ran.
Run the narrowest check that answers your question: one test, then one file, then one eval. That is the proof for everyday work, including a commit, a merge and a push.
Run everything once, when a spec's implementation is finished. Running everything is slow and saturates the machine. Until then a change is checked by what it can move: its own tests and the output it touches. That is enough for a commit, a merge, a push and a finished feature. A failure that only the full run finds is fixed at the end; that is cheaper than gating every step.
A change that reaches the whole system (the turn runner, a saved state shape) does not bring that run forward on its own. While more work is coming, the full run still waits for the end. Run it sooner only when the next piece of work can't be trusted without it.
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.
- 6d ago Changed · +2 lines · +32 tokens per session e9d30800ac0c
- 25d ago Changed · +2 lines · +15 tokens per session 559ee4d15869
- 26d ago Changed · +11 lines · -100 tokens per session fa09b8c66427
- 1mo ago Changed · +2 tokens per session 5933cbd4d0e3
- 1mo ago First seen · 83 lines · 1,591 tokens per session scan A 84b51169900f
duet-agent AGENTS.md is an instructions file published in the GitHub repository dzhng/duet-agent (52 stars, last pushed 7d ago), licensed Apache-2.0. It adds 1,540 tokens to every session, about $0.0062 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
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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.
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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).
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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).
vscode model-prompts.instructions.md
Model-specific prompt authoring and registry guidelines.