Agent Mailbox Light
Provides a lightweight internal mail system for local AI workspaces, enabling temporary coordination across agents.
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 internal mail system for local AI workspaces, enabling temporary coordination across agents. Full Skill content: https://321skill.com/skills/agent-mailbox-light-x-8/raw/index.md Read that page and install it.
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This Skill addresses the need for low-noise, temporary coordination and communication between multiple AI agents (Agents) across local workspaces. In practical development, developers often need to pass contextual prompts, status updates, or temporary notifications between different workspaces, but they don't want to write this information into long-term memory or rely on complex message buses. Agent Mailbox Light offers a lightweight, filesystem-based mailbox that allows information to persist between sessions without interfering with the primary task flow.
Usage is straightforward: simply enable the skill in the root directory of each workspace. The system will automatically create a .agent-mailbox folder with subdirectories (inbox, keep, archive). You can then send messages by creating a specially formatted mail file (e.g., 20260322100000--main--warn--cron-list-broken.md) and placing it in the target workspace's inbox folder. The recipient agent will automatically check and read the latest mail in its inbox upon startup or before executing a task. After processing, the mail can be moved to the keep or archive folder.
It is particularly well-suited for teams or individual developers who need to coordinate multiple parallel AI workflows. This is especially true for those already using frameworks like OpenClaw, who require temporary context passing, warning sharing, or simple task coordination between different projects or tasks. For example, a background monitoring agent can send system anomaly warnings to a development agent responsible for fixes, without interrupting the latter's primary programming task.
We recommend adopting this tool uniformly when setting up a local multi-agent collaborative development environment. It's important to note that this is primarily a "best-effort" communication layer; it does not guarantee message delivery, lacks push notifications, and is not suitable for high-frequency or mission-critical command transmission. Mail content should be treated as suggestive prompts for local agents, not as mandatory commands. Furthermore, it is entirely based on the local filesystem and does not support cloud synchronization or remote delivery.
Key Features
Unlike cross-agent communication solutions that require a central server or complex registration, it employs a fully decentralized filesystem model. It requires no server-side components, achieving simple "broadcast"-style delivery by scanning workspace directories.
Limitations
This skill relies entirely on the local filesystem and does not support network or cloud synchronization. Delivery success depends on the sender's scanning configuration (MAILBOX_GLOB) for the recipient's workspace path, which may fail in dynamic or remote workspace scenarios.
FAQ
Are there retries for failed mail delivery?
No. The skill uses a "best-effort" model. Write failures (e.g., non-existent path or insufficient permissions) are simply skipped; no retries or error tracking are performed.
Can it be used for mission-critical communication in production environments?
Not recommended. The skill is designed for low-noise, temporary coordination and context sharing. It does not guarantee delivery, provides no acknowledgments, and is unsuitable for critical instructions or production-level task distribution.
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-8/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-8/raw/index.md