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Gateway architecture

docs/concepts/architecture.md

2026.5.55.5 KB
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Overview

  • A single long‑lived Gateway owns all messaging surfaces (WhatsApp via Baileys, Telegram via grammY, Slack, Discord, Signal, iMessage, WebChat).
  • Control-plane clients (macOS app, CLI, web UI, automations) connect to the Gateway over WebSocket on the configured bind host (default 127.0.0.1:18789).
  • Nodes (macOS/iOS/Android/headless) also connect over WebSocket, but declare role: node with explicit caps/commands.
  • One Gateway per host; it is the only place that opens a WhatsApp session.
  • The canvas host is served by the Gateway HTTP server under:
    • /__openclaw__/canvas/ (agent-editable HTML/CSS/JS)
    • /__openclaw__/a2ui/ (A2UI host) It uses the same port as the Gateway (default 18789).

Components and flows

Gateway (daemon)

  • Maintains provider connections.
  • Exposes a typed WS API (requests, responses, server‑push events).
  • Validates inbound frames against JSON Schema.
  • Emits events like agent, chat, presence, health, heartbeat, cron.

Clients (mac app / CLI / web admin)

  • One WS connection per client.
  • Send requests (health, status, send, agent, system-presence).
  • Subscribe to events (tick, agent, presence, shutdown).

Nodes (macOS / iOS / Android / headless)

  • Connect to the same WS server with role: node.
  • Provide a device identity in connect; pairing is device‑based (role node) and approval lives in the device pairing store.
  • Expose commands like canvas.*, camera.*, screen.record, location.get.

Protocol details:

WebChat

  • Static UI that uses the Gateway WS API for chat history and sends.
  • In remote setups, connects through the same SSH/Tailscale tunnel as other clients.

Connection lifecycle (single client)

mermaid
sequenceDiagram
    participant Client
    participant Gateway

    Client->>Gateway: req:connect
    Gateway-->>Client: res (ok)
    Note right of Gateway: or res error + close
    Note left of Client: payload=hello-ok
snapshot: presence + health

    Gateway-->>Client: event:presence
    Gateway-->>Client: event:tick

    Client->>Gateway: req:agent
    Gateway-->>Client: res:agent
ack {runId, status:"accepted"}
    Gateway-->>Client: event:agent
(streaming)
    Gateway-->>Client: res:agent
final {runId, status, summary}

Wire protocol (summary)

  • Transport: WebSocket, text frames with JSON payloads.
  • First frame must be connect.
  • After handshake:
    • Requests: {type:"req", id, method, params} → {type:"res", id, ok, payload|error}
    • Events: {type:"event", event, payload, seq?, stateVersion?}
  • hello-ok.features.methods / events are discovery metadata, not a generated dump of every callable helper route.
  • Shared-secret auth uses connect.params.auth.token or connect.params.auth.password, depending on the configured gateway auth mode.
  • Identity-bearing modes such as Tailscale Serve (gateway.auth.allowTailscale: true) or non-loopback gateway.auth.mode: "trusted-proxy" satisfy auth from request headers instead of connect.params.auth.*.
  • Private-ingress gateway.auth.mode: "none" disables shared-secret auth entirely; keep that mode off public/untrusted ingress.
  • Idempotency keys are required for side‑effecting methods (send, agent) to safely retry; the server keeps a short‑lived dedupe cache.
  • Nodes must include role: "node" plus caps/commands/permissions in connect.

Pairing + local trust

  • All WS clients (operators + nodes) include a device identity on connect.
  • New device IDs require pairing approval; the Gateway issues a device token for subsequent connects.
  • Direct local loopback connects can be auto-approved to keep same-host UX smooth.
  • OpenClaw also has a narrow backend/container-local self-connect path for trusted shared-secret helper flows.
  • Tailnet and LAN connects, including same-host tailnet binds, still require explicit pairing approval.
  • All connects must sign the connect.challenge nonce.
  • Signature payload v3 also binds platform + deviceFamily; the gateway pins paired metadata on reconnect and requires repair pairing for metadata changes.
  • Non‑local connects still require explicit approval.
  • Gateway auth (gateway.auth.*) still applies to all connections, local or remote.

Details: Gateway protocol, Pairing, Security.

Protocol typing and codegen

  • TypeBox schemas define the protocol.
  • JSON Schema is generated from those schemas.
  • Swift models are generated from the JSON Schema.

Remote access

  • Preferred: Tailscale or VPN.

  • Alternative: SSH tunnel

    bash
    ssh -N -L 18789:127.0.0.1:18789 user@host

  • The same handshake + auth token apply over the tunnel.

  • TLS + optional pinning can be enabled for WS in remote setups.

Operations snapshot

  • Start: openclaw gateway (foreground, logs to stdout).
  • Health: health over WS (also included in hello-ok).
  • Supervision: launchd/systemd for auto‑restart.

Invariants

  • Exactly one Gateway controls a single Baileys session per host.
  • Handshake is mandatory; any non‑JSON or non‑connect first frame is a hard close.
  • Events are not replayed; clients must refresh on gaps.