Agent Mailbox Light
Provides a lightweight, cross-session persistent local mailbox system for multi-agent coordination with low noise.
Install & Use
Copy this prompt and send it to your AI assistant (Claude / Cursor / TRAE / Codex / WorkBuddy etc.) to auto-install:
Help me install this AI Skill: Agent Mailbox Light. It is used for: Provides a lightweight, cross-session persistent local mailbox system for multi-agent coordination with low noise. Full Skill content: https://321skill.com/skills/agent-mailbox-light-x-3/raw/index.md Read that page and install it.
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This Skill addresses the issue where temporary, low-noise coordination messages between multiple AI agents (Agents) in a local workspace can easily get lost or become mixed with long-term memory. In practical development, developers often need different agents (such as coding, testing, or deployment agents) to pass simple contextual prompts or status notifications, but do not want to introduce the burden of complex message queues or guaranteed delivery.
Usage is simple: you only need to create a .agent-mailbox folder in the agent's workspace directory and write mail to the target workspace's inbox directory using the agreed file format (e.g., timestamp--sender--priority--subject.md). You can then retrieve, keep, or archive these coordination messages by reading the local inbox, keep, and archive folders, enabling lightweight cross-session communication.
It is ideal for teams or individuals who need to coordinate multiple local AI agents (like Claude Code Agent) to complete complex tasks. This is especially true for users who have already established multiple independent workspaces and wish to pass temporary, prompt-like information between them without relying on cloud services or complex middleware.
It is recommended to uniformly check the inbox directory under the agent's workspace upon startup or task switching, reading only the latest 1-3 emails to control Token consumption. Note that this is primarily a 'best-effort' local filesystem mailbox; it does not guarantee message delivery, lacks push notifications, and should not be used as a command bus for task execution.
Key Features
Unlike complex message middleware that requires a central registry or guaranteed delivery, it adopts a fully decentralized local filesystem model. Each workspace maintains its own mailbox folders, achieving 'best-effort' fan-out through file scanning, with a design philosophy focused on minimalism and low overhead.
Limitations
This Skill is only applicable to the local filesystem. It does not support remote synchronization, network transmission, or Webhooks, and the sender must have access to the disk path of the recipient's workspace.
FAQ
What if an email is lost?
This is by design. The mailbox operates on a 'best-effort' model; it does not guarantee delivery, does not retry, and skips messages upon send failure. Important information should be transmitted through other reliable channels.
Can it be used across machines or in the cloud?
No. It strictly relies on the local filesystem. The sender's and recipient's workspaces must be on the same machine and within an accessible path.
Installation guide for AI assistants
If your AI coding assistant (Claude Code, Cursor, TRAE etc.) can see this page, send it this message to auto-install:
Visit https://321skill.com/skills/agent-mailbox-light-x-3/raw/index.md to read the original Skill definition (Markdown format) for Agent Mailbox Light, and install it according to the instructions.
Raw Markdown URL for AI: /skills/agent-mailbox-light-x-3/raw/index.md