Borrowing it
Nothing to install: this file belongs to ariaxhan/agentmailkit. 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/ariaxhan/agentmailkit/main/AGENTS.mdgit clone --depth 1 https://github.com/ariaxhan/agentmailkitWrote 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/ariaxhan/agentmailkit/agents-md)<a href="https://agentmods.dev/instructions/ariaxhan/agentmailkit/agents-md"><img src="https://agentmods.dev/badge/instructions/ariaxhan/agentmailkit/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/ariaxhan/agentmailkit/agents-md"><img src="https://agentmods.dev/badge/instructions/ariaxhan/agentmailkit/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 | $0.02584 | $0.02584 |
| Opus 5.5 | $0.01034 | $0.01034 |
| Sonnet 5.5 | $0.00517 | $0.00517 |
| Haiku 4.5 | $0.00258 | $0.00258 |
Grade A, and why
agentmailkit 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- agentmailkit CLAUDE.md — 97% identical, 6 lines differ
How it starts
The opening of the file, as written. The whole thing — 270 lines — stays where its author put it; the contents beside it link to each section on GitHub.
agentmailkit: setup guide for coding agents
type: note status: active created: 2026-08-27
compression — mandatory
minimum text. zero meaningful loss.
- default: bullets + fragments.
- prose only when structure would lose meaning.
- delete anything removable.
- merge anything redundant.
- shorten anything compressible.
- never narrate work; report results, evidence, blockers, decisions.
- preserve correctness, clarity, decisions, evidence, uncertainty, action.
- length follows information. never pad; never omit.
- between tool calls: silence by default. no preamble, no plan, no progress report.
- one line only if it states a finding that changes what happens next. never intent.
before emitting:
- convert prose → bullets/fragments wherever lossless.
- delete every removable word, sentence, bullet, section, preamble, recap, transition, or explanation.
- repeat until further compression would lose meaning.
do not emit while removable text remains.
verbosity is a defect. omission is also a defect.
You are setting up agentmailkit for the person you are working with. It sends scheduled, LLM-written email digests that run on their machine, read their own files, and send from their own inbox.
Work through this top to bottom. It should take a few minutes and end with a real email in their inbox.
0. What this tool is, so you explain it correctly
A fixed pipeline, not an autonomous agent:
gather sources -> render prompt -> generate -> gate -> render theme -> deliver -> post
One JSON job spec plus one markdown prompt equals one email. The model writes only the words; the engine controls everything else, so the same job produces the same shaped email every run.
Do not describe it as an AI agent that manages their inbox. It does not read incoming mail, decide things, or take actions.
1. Ask these questions first
Do not skip this. Defaults produce a generic email nobody opens. Ask, then build to the answers. Ask them together, in one message, and keep it short.
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 · 270 lines · 2,584 tokens per session scan A 420bda256ef9
agentmailkit AGENTS.md is an instructions file published in the GitHub repository ariaxhan/agentmailkit (1 stars, last pushed 1mo ago), licensed MIT. It adds 2,584 tokens to every session, about $0.0103 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 2026-08-31.
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.
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.
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).