Architecture

┌─────────────┐     ┌──────────────┐     ┌─────────────────┐
│  Platforms   │────▶│   Pipeline   │────▶│    Transport    │
│             │     │              │     │                 │
│ • Telegram  │     │ • Commands   │     │ • CLI (ACP/tmux)│
│ • Discord   │◀────│ • Memory     │◀────│ • API (HTTP)    │
│              │     │ • Streaming  │     │ • Fallback      │
└─────────────┘     └──────────────┘     └─────────────────┘
                           │
                    ┌──────┴──────┐
                    │   abmind    │
                    │  (memory)   │
                    └─────────────┘

┌─────────────────────────────────────────────────────────┐
│                    A2A (Peer-to-Peer)                    │
│                                                         │
│  abTARS instance ◀──── /v1/chat/completions ────▶ abTARS instance  │
│  (Instance A)         JWT + digital signatures     (Instance B)  │
│                       over Tailscale                               │
└─────────────────────────────────────────────────────────┘

Platforms receive messages from users and deliver responses back.

Pipeline processes each message: runs commands, checks permissions, builds prompts with memory context, manages streaming delivery.

Transport communicates with AI models — either by spawning a CLI tool (Kiro, Gemini) or calling an HTTP API (ollama, OpenRouter).

abmind provides persistent memory — recall on every turn, store after every response, sleep cycles for maintenance.

A2A (Agent-to-Agent) enables peer communication between abTARS instances. Agents can ask each other questions, delegate tasks, and share information over an authenticated channel.

A2A Protocol

Two abTARS instances communicate over an authenticated WS peer route over Tailscale:

• Authentication — Ed25519 request signatures on enrolled keys + TLS cert pinning
• Anti-loop — hop counting prevents infinite ping-pong
• Firewall traversal — signed UDP doorbell on port 5353 for NAT/corporate firewalls; either side dials out, route is bidirectional
• Agent tools — peer_session (quick chat, cardless), peer_ask_help (durable delegation), peer_doorbell (request WSS refresh)

Configure peers in ~/.abtars/config/peers.json.

Boot Phases

The bridge starts in ordered phases: config → memory → transport → platforms → capabilities → heartbeat → sleep → dashboard. Each phase is independent — if one fails, the rest continue.

Capabilities

Optional features that load at boot if their requirements are met:

• Browser — external cloak CLI backed by the CloakBrowser stealth runtime
• Skills — markdown-defined agent behaviors
• MCP — external tool servers via mcporter

Heartbeat

A periodic tick (configurable interval) that runs scheduled tasks, checks model health, and triggers sleep cycles during quiet hours.