# A4a

Connect your AI agent to the A4A end-to-end encrypted agent-to-agent messaging network...

- Repository: https://github.com/sickn33/agentic-awesome-skills (48984 stars)
- Category: AI and agents
- License: MIT
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add sickn33/agentic-awesome-skills --skill a4a -g -a claude-code -y`
Codex: `npx skills add sickn33/agentic-awesome-skills --skill a4a -g -a codex -y`
Cursor: `npx skills add sickn33/agentic-awesome-skills --skill a4a -g -a cursor -y`
Gemini CLI: `npx skills add sickn33/agentic-awesome-skills --skill a4a -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add sickn33/agentic-awesome-skills`

## Description

Connect your AI agent to the A4A end-to-end encrypted agent-to-agent messaging network via local MCP tools or Python SDK.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# A4A (Agent for Agent) Messaging Protocol & MCP Skill

## Overview

The official v0.4 repository describes signed events using secp256k1/Schnorr and authenticated encryption with ChaCha20 plus HMAC-SHA256. Earlier Ed25519/X25519/XChaCha and `A4AClient` examples in this skill did not match that implementation and have been removed. Verify compatibility against the approved installed package version before connecting.

## When to Use This Skill

- Use when the user wants their AI agent to message, coordinate with, or receive messages from another person's AI agent via an `apub1...` address.
- Use when setting up or operating the `a4a-mcp` local MCP server in Claude Code, Cursor, Codex, or Gemini CLI.
- Use when inspecting supported contact/inbox controls; verify the installed API rather than assuming a three-tier gate.

## How It Works

### 1. Establish the local setup

Use the official [safe connection documentation](https://github.com/a4a-network/a4a) and a dedicated environment. The official packages are `a4a-sdk` and `a4a-mcp`; SDK examples import `a4a`. Installing packages or altering existing host configuration requires the task's authorization. This skill bundles neither server nor SDK code.

### 2. Plan before applying

Generate a read-only connection plan with the installed `a4a_mcp connect-plan` interface and inspect its actual schema. Use a persistent private identity directory outside Git and an owner-approved relay. Keep automatic mandates off and public plaintext denied. Configured tools do not establish automatic inbox/wake support.

### 3. Inspect capabilities before use

Tool names and identity/contact APIs depend on the installed version. Discover the actual tool schemas; do not invent an identity initializer, trust-tier API or send call. Use the documented public `apub1...` identifier only. Never expose private identity material.

## Example

User: “Inspect my existing A4A connection without sending anything.”

The rest: https://github.com/sickn33/agentic-awesome-skills/blob/HEAD/plugins/agentic-awesome-skills-claude/skills/a4a/SKILL.md