LanA2A

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A2A Protocol for LAN — A decentralized LAN communication service for AI Agents based on the Agent2Agent (A2A) standard protocol.

Developed by MiMo AI.

Key Features

• Standard Protocol: Built on the A2A Go SDK, not reinventing the wheel
• LAN Optimized: mDNS discovery + WebSocket transport (A2A uses HTTP natively)
• On-Demand Connections: Zero connections by default, AI decides when to connect
• Dual Mode: P2P Lobby (no server) + Relay (with server)
• File Transfer: Chunked concurrent transfers with folder sync support
• MCP Interface: 11 tools for AI agents to communicate over LAN

Architecture

┌─────────────────────────────────────────────────────┐
│                    A2A Protocol Layer                 │
│  AgentCard / Task / Message / Skills                 │
├──────────────┬──────────────────┬───────────────────┤
│  LAN Transport │   File Service   │   Channel Mgmt    │
│  mDNS + WS    │  (chunk/conc/sync)│  (P2P/Relay)     │
├──────────────┴──────────────────┴───────────────────┤
│              A2A Go SDK (a2asrv / a2aclient)         │
└─────────────────────────────────────────────────────┘

Quick Start

# Build
make build

# Run Agent
./lan-a2a -id agent-a -port 19100

# Run Relay (optional, for cross-subnet scenarios)
./lan-relay -addr :19200

A2A Compatibility

A2A Concept	LanA2A Implementation
AgentCard	Profile + LAN broadcast
Agent Discovery	mDNS (LAN) + Relay query
Task Lifecycle	Channel-based task tracking
Message/Part	WebSocket JSON messages
Transport	WebSocket (LAN optimized)
Skills	Profile.Roles

MCP Tools

Tool	Description
lan_get_online_agents	Get online agents (with AgentCard info)
lan_open_connection	Open WebSocket connection
lan_close_connection	Close connection
lan_create_channel	Create channel (P2P Lobby or Relay mode)
lan_send_message	Send message
lan_share_file	Share file (auto-chunked for large files)
lan_share_folder	Share folder (incremental sync)
lan_sync_folder	Sync folder with remote peer
lan_get_transfer_status	Get transfer status
lan_list_transfers	List active transfers

Project Structure

lan-a2a/
├── cmd/
│   ├── lan-a2a/           # Agent client
│   ├── lan-relay/         # Relay server
│   └── gendoc/            # Documentation generator
├── internal/
│   ├── adapter/           # A2A protocol adapter
│   ├── protocol/          # WebSocket message protocol
│   ├── channel/           # Channel management (P2P Lobby / Relay)
│   ├── fileservice/       # File service (chunk/concurrent/sync)
│   ├── filetransfer/      # Incoming file reassembly
│   ├── plugins/           # Plugin system
│   ├── profile/           # Agent identity (→ A2A AgentCard)
│   ├── logger/            # Structured logging (slog)
│   ├── mcp/               # MCP JSON-RPC server
│   ├── p2p/               # P2P transport + mDNS
│   └── relay/             # Relay client
├── clients/typescript/    # TypeScript client
├── docs/
│   ├── openapi.yaml       # OpenAPI specification
│   └── protocol.md        # Wire protocol specification
└── Dockerfile

Docker

# Build agent image
docker build --target agent -t lan-a2a:latest .

# Build relay image
docker build --target relay -t lan-relay:latest .

# Run relay
docker run -d --name lan-relay -p 19200:19200 -p 19201:19201 lan-relay:latest

Configuration

Agent

Flag	Default	Description
-id	<hostname>-<pid>	Agent ID
-port	19100 + PID%1000	WebSocket listen port

Relay

Flag	Default	Description
-addr	:19200	WebSocket listen address
-http	:19201	HTTP status address

Contributing

See CONTRIBUTING.md.

Security

See SECURITY.md.

Changelog

See CHANGELOG.md.

License

MIT License. See LICENSE.

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Built with ❤️ by MiMo AI