What is Mailbox AGENTS.md?

Repository instructions for Mailbox, a Node.js command-line application for email accounts, storage, and inbox workflows. They cover its package layout, commands, JSON output rules, and tests.

Use them when changing Mailbox's CLI, IMAP or SMTP code, storage, account migration, digest or monitoring workflows, build scripts, or contract tests.

They help an agent work within the existing package boundaries and preserve the command-line interface's JSON contract. They also make the correct build and test commands clear.

How leeguooooo/Mailbox configures Codex and OpenCode

Reuse

Borrowing it

Nothing to install: this file belongs to leeguooooo/Mailbox. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/leeguooooo/Mailbox/main/AGENTS.md

Clone the repo

git clone --depth 1 https://github.com/leeguooooo/Mailbox

Made for: Codex, OpenCode.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/leeguooooo/mailbox/agents-md/github.svg)](https://agentmods.dev/instructions/leeguooooo/mailbox/agents-md)

Your own site

<a href="https://agentmods.dev/instructions/leeguooooo/mailbox/agents-md"><img src="https://agentmods.dev/badge/instructions/leeguooooo/mailbox/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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/leeguooooo/mailbox/agents-md"><img src="https://agentmods.dev/badge/instructions/leeguooooo/mailbox/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 492 This file is loaded in full into every session.

When invoked 492 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

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	$0.00492	$0.00492
Opus 5.5	$0.00197	$0.00197
Sonnet 5.5	$0.00098	$0.00098
Haiku 4.5	$0.00049	$0.00049

Measured 2mo ago against content hash 866a51d63c5b, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

Mailbox 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 2mo 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.

AGENTS.md · 38 lines

How it starts

The opening of the file, as written. The whole thing — 38 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Repository Guidelines

Project Structure & Module Organization

packages/ hosts the Node implementation:
- packages/cli/ CLI entry + command definitions
- packages/core/ IMAP/SMTP + storage + account migration
- packages/shared/ path resolution + JSON contract helpers
- packages/workflows/ digest/monitor/inbox workflows
mailbox-cli/ contains the npm launcher + platform binary packages.
scripts/ contains build helpers (notably scripts/build_binary.js).
docs/ holds CLI contract + release docs; legacy Python/MCP docs remain under docs/archive/.

Build, Test, and Development Commands

Install dependencies: pnpm install
Run tests: pnpm test
Build local pkg binary (and copy into mailbox-cli platform package): pnpm build:binary
Run dev CLI: pnpm -C packages/cli test or node packages/cli/bin/mailbox.js --help

Coding Style & Naming Conventions

Node.js (JavaScript). Keep modules small and side-effect-light.
Prefer explicit error objects in JSON output (success, error).
Avoid breaking JSON contract; add fields in a forward-compatible way.

Testing Guidelines

Contract tests live under packages/cli/test/ (vitest). Use MAILBOX_TEST_MODE=1 to avoid live IMAP/SMTP.
Prefer schema validation (docs/cli_json_schemas/*) to lock minimum stable JSON shapes.

Commit & Pull Request Guidelines

Follow the Conventional Commit style seen in history (feat:, fix:, refactor:); keep subjects ≤72 chars.
Include a brief body noting user-facing changes, risks, and docs updated.
PRs should describe context and testing performed (pnpm test, pnpm build:binary).
Link issues or TODOs and request reviewers for affected areas (operations, services, scripts).

Security & Configuration Tips

Never commit secrets; keep data/ contents (accounts, DBs, logs, attachments) local and gitignored.
Use environment variables or .env for provider credentials; prefer config templates in config_templates/ and examples in examples/.
When debugging, scrub email addresses and tokens from shared logs.

Read the full file on GitHub · 38 lines

Changes

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.

2mo ago First seen · 38 lines · 492 tokens per session scan A 866a51d63c5b

Subscribe to this mod's changes

Mailbox AGENTS.md is an instructions file published in the GitHub repository leeguooooo/Mailbox (42 stars, last pushed 2mo ago), licensed MIT. It adds 492 tokens to every session, about $0.0020 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.

Mailbox AGENTS.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
Mailbox AGENTS.mdleeguooooo/Mailbox	Instructions file	42	2mo ago	MIT	A	492	Codex, OpenCode
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	today	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	yesterday	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

Mailbox: Instructions file for Codex