What is agent-messaging?

A plugin for signed messages between artificial-intelligence agents, including agents built by different providers. It defines the Agent Messaging Protocol (AMP) and provides commands for identities, inboxes, sending, replies, and message retrieval.

Use it to initialize an agent identity, register it, check status, send and read messages, reply, delete messages, and fetch or download messages.

It gives agents a defined way to exchange messages and verify who sent them instead of relying on an informal or unauthenticated channel.

agent-messaging — Plugin for Claude Code by agentmessaging

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo

git clone --depth 1 https://github.com/agentmessaging/claude-plugin

Made for: Claude Code.

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/plugins/agentmessaging/claude-plugin/claude-plugin/github.svg)](https://agentmods.dev/plugins/agentmessaging/claude-plugin/claude-plugin)

Your own site

<a href="https://agentmods.dev/plugins/agentmessaging/claude-plugin/claude-plugin"><img src="https://agentmods.dev/badge/plugins/agentmessaging/claude-plugin/claude-plugin/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/plugins/agentmessaging/claude-plugin/claude-plugin"><img src="https://agentmods.dev/badge/plugins/agentmessaging/claude-plugin/claude-plugin.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session not measured What this adds to a session before it is invoked.

When invoked not measured The manifest loads nothing itself; its 1 skill, 13 commands cost 83 tokens a session between them.

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.

Security

Grade A, and why

agent-messaging 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 today.

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.

.claude-plugin/plugin.json · 38 lines

What it actually says

{
  "name": "agent-messaging",
  "version": "0.3.1",
  "description": "Agent Messaging Protocol (AMP) - Secure, cryptographically signed messaging between AI agents across different providers.",
  "homepage": "https://agentmessaging.org",
  "repository": "https://github.com/agentmessaging/claude-plugin",
  "license": "Apache-2.0",
  "author": {
    "name": "23blocks",
    "url": "https://23blocks.com"
  },
  "keywords": [
    "ai-agents",
    "messaging",
    "federation",
    "protocol",
    "inter-agent-communication"
  ],
  "skills": [
    "skills/agent-messaging"
  ],
  "commands": [
    "commands/amp-init.md",
    "commands/amp-identity.md",
    "commands/amp-status.md",
    "commands/amp-send.md",
    "commands/amp-inbox.md",
    "commands/amp-read.md",
    "commands/amp-reply.md",
    "commands/amp-delete.md",
    "commands/amp-prune.md",
    "commands/amp-register.md",
    "commands/amp-fetch.md",
    "commands/amp-download.md"
  ],
  "claude_code_version": ">=1.0.0"
}

Contents

What it installs

The manifest is a name and a version. 1 skill, 13 commands travel with it, and installing the plugin installs all of them — 83 tokens a session between them. Each is measured on its own page, and each can be installed alone.

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.

today Changed a4f96835dc93
7d ago Changed · +1 lines cc1045e6ca29
15d ago Changed a9c5bf71be16
1mo ago First seen · 37 lines scan A 45f8254a3237

Subscribe to this mod's changes

agent-messaging is a plugin published in the GitHub repository agentmessaging/claude-plugin (5 stars, last pushed yesterday), licensed Apache-2.0. Its token cost is not measured: this kind of file is read by the harness, not the model. 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.

Building agents Claude Code ai-agents ai-messaging amp bash cli

agent-messaging

Getting it into your agent

Wrote this? Show the measurements

Grade A, and why

Nothing flagged

What it actually says

What it installs

What this file has done since we first saw it

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