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OpenClaw can use Bonjour (mDNS/DNS-SD) to discover an active gateway (WebSocket endpoint). Multicast local. browsing is a LAN-only convenience: the bundled bonjour plugin owns LAN advertising, auto-starting on macOS hosts and opt-in on Linux, Windows, and containerized gateway deployments. The same beacon can also publish through a configured wide-area DNS-SD domain for cross-network discovery. Discovery is best-effort and does not replace SSH or Tailnet-based connectivity.

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Wide-area Bonjour (Unicast DNS-SD) over Tailscale

If the node and gateway are on different networks, multicast mDNS can’t cross the boundary. Keep the same discovery UX by switching to unicast DNS-SD (“Wide-Area Bonjour”) over Tailscale:
  1. Run a DNS server on the gateway host, reachable over the Tailnet.
  2. Publish DNS-SD records for _openclaw-gw._tcp under a dedicated zone (example: openclaw.internal.).
  3. Configure Tailscale split DNS so your chosen domain resolves via that DNS server for clients, including iOS.
openclaw.internal. above is just an example — OpenClaw supports any discovery domain. iOS/Android nodes browse both local. and your configured wide-area domain.

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Gateway config

discovery.wideArea.domain also accepts the OPENCLAW_WIDE_AREA_DOMAIN env var as a fallback when unset.

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One-time DNS server setup (gateway host, macOS only)

This command is macOS-only and requires Homebrew and a running Tailscale connection. It installs CoreDNS (brew install coredns) and configures it to:
  • listen on port 53 only on the gateway’s Tailscale interfaces
  • serve your chosen domain (example: openclaw.internal.) from ~/.openclaw/dns/<domain>.db
Run without --apply first to preview the plan (domain, zone file path, detected Tailnet IP, recommended config) without installing anything. Validate from a Tailnet-connected machine:

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Tailscale DNS settings

In the Tailscale admin console:
  • Add a nameserver pointing at the gateway’s Tailnet IP (UDP/TCP 53).
  • Add split DNS so your discovery domain uses that nameserver.
Once clients accept Tailnet DNS, iOS nodes and CLI discovery can browse _openclaw-gw._tcp in your discovery domain without multicast.

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Gateway listener security

The gateway WS port (default 18789) binds to loopback by default. For LAN/Tailnet access, bind explicitly and keep auth enabled. For Tailnet-only setups, set gateway.bind: "tailnet" in ~/.openclaw/openclaw.json and restart the gateway (or the macOS menubar app).

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What advertises

Only the gateway advertises _openclaw-gw._tcp. LAN multicast advertising comes from the bundled bonjour plugin when enabled; wide-area DNS-SD publishing stays gateway-owned.

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Service types

  • _openclaw-gw._tcp - gateway transport beacon, used by macOS/iOS/Android nodes.

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TXT keys (non-secret hints)

Security notes:
  • Bonjour/mDNS TXT records are unauthenticated. Clients must not treat TXT as authoritative routing.
  • Clients should route using the resolved service endpoint (SRV + A/AAAA). Treat lanHost, tailnetDns, gatewayPort, and gatewayTlsSha256 as hints only.
  • SSH auto-targeting should likewise use the resolved service host, not TXT-only hints.
  • TLS pinning must never let an advertised gatewayTlsSha256 override a previously stored pin.
  • iOS/Android nodes should treat discovery-based direct connects as TLS-only and require explicit user confirmation before trusting a first-time fingerprint.

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Debugging on macOS

Built-in tools:
If browsing works but resolving fails, you’re usually hitting a LAN policy or mDNS resolver issue.

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Debugging in Gateway logs

The gateway writes a rolling log file (printed on startup as gateway log file: ...). Look for bonjour: lines, especially:
  • bonjour: advertise failed ...
  • bonjour: suppressing ciao netmask assertion ...
  • bonjour: ... name conflict resolved / hostname conflict resolved
OpenClaw starts each Bonjour service once and leaves probing, retry, name-conflict resolution, and interface-change republishing to the mDNS responder. This avoids overlapping publish attempts during normal network churn. Repeated internal self-probe messages are suppressed so they cannot flood the gateway log. When multiple OpenClaw gateways advertise from the same host, Bonjour may append suffixes such as (2) or (3) to keep service instance names unique. Those suffixes are normal conflict resolution and do not indicate duplicate OCM supervision. Bonjour uses the system hostname for the advertised .local host when it’s a valid DNS label. If the system hostname contains spaces, underscores, or another invalid DNS-label character, OpenClaw falls back to openclaw.local. Set OPENCLAW_MDNS_HOSTNAME=<name> before starting the gateway when you need an explicit host label.

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Debugging on iOS node

The iOS node uses NWBrowser to discover _openclaw-gw._tcp. To capture logs: Settings -> Gateway -> Advanced -> Discovery Debug Logs, then Settings -> Gateway -> Advanced -> Discovery Logs -> reproduce -> Copy. The log includes browser state transitions and result-set changes.

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When to enable Bonjour

Bonjour auto-starts for empty-config gateway startup on macOS hosts, since the local app and nearby iOS/Android nodes commonly rely on same-LAN discovery. Enable it explicitly when same-LAN auto-discovery is useful on Linux, Windows, or another non-macOS host:
When enabled, Bonjour uses discovery.mdns.mode to decide how much TXT metadata to publish; the same mode controls optional TXT hints in wide-area DNS-SD records. Modes:

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When to disable Bonjour

Leave Bonjour disabled when LAN multicast advertising is unnecessary, unavailable, or harmful — common cases are non-macOS servers, Docker bridge networking, WSL, or a network policy that drops mDNS multicast. The gateway stays reachable through its published URL, SSH, Tailnet, or wide-area DNS-SD; only LAN auto-discovery is unreliable. Use the env override for deployment-scoped problems (safe for Docker images, service files, launch scripts, one-off debugging — it disappears when the environment does):
Use plugin configuration when you intentionally want to turn off the bundled LAN discovery plugin for that OpenClaw config:

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Docker gotchas

The bundled Bonjour plugin auto-disables LAN multicast advertising in detected containers when OPENCLAW_DISABLE_BONJOUR is unset. Docker bridge networks usually don’t forward mDNS multicast (224.0.0.251:5353) between the container and the LAN, so advertising from the container rarely makes discovery work. Gotchas:
  • Bonjour auto-starts on macOS hosts and is opt-in elsewhere. Leaving it disabled doesn’t stop the gateway — it only skips LAN multicast advertising.
  • Disabling Bonjour doesn’t change gateway.bind; Docker still defaults to OPENCLAW_GATEWAY_BIND=lan so the published host port works.
  • Disabling Bonjour doesn’t disable wide-area DNS-SD. Use wide-area discovery or Tailnet when the gateway and node aren’t on the same LAN.
  • Reusing the same OPENCLAW_CONFIG_DIR outside Docker doesn’t persist the container auto-disable policy.
  • Set OPENCLAW_DISABLE_BONJOUR=0 only for host networking, macvlan, or another network where mDNS multicast is known to pass; set it to 1 to force-disable.

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Troubleshooting disabled Bonjour

If a node no longer auto-discovers the gateway after Docker setup:
  1. Confirm whether the gateway is running in auto, forced-on, or forced-off mode:
  2. Confirm the gateway itself is reachable through the published port:
  3. Use a direct target when Bonjour is disabled:
    • Control UI or local tools: http://127.0.0.1:18789
    • LAN clients: http://<gateway-host>:18789
    • Cross-network clients: Tailnet MagicDNS, Tailnet IP, SSH tunnel, or wide-area DNS-SD
  4. If you deliberately enabled the Bonjour plugin in Docker and forced advertising with OPENCLAW_DISABLE_BONJOUR=0, test multicast from the host:
    If browsing is empty, or Gateway logs show repeated ciao probe failures, restore OPENCLAW_DISABLE_BONJOUR=1 and use a direct or Tailnet route.

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Common failure modes

  • Bonjour doesn’t cross networks: use Tailnet or SSH.
  • Multicast blocked: some Wi-Fi networks disable mDNS.
  • Advertiser stuck in probing/announcing: hosts with blocked multicast, container bridges, WSL, or interface churn can leave the responder in a non-announced state. The gateway remains available through direct, SSH, Tailnet, or wide-area DNS-SD routes; disable LAN Bonjour with discovery.mdns.mode: "off" or OPENCLAW_DISABLE_BONJOUR=1 when multicast is unavailable.
  • Docker bridge networking: Bonjour auto-disables in detected containers. Set OPENCLAW_DISABLE_BONJOUR=0 only for host, macvlan, or another mDNS-capable network.
  • Sleep/interface churn: macOS may temporarily drop mDNS results; retry.
  • Browse works but resolve fails: keep machine names simple (avoid emojis or punctuation), then restart the gateway. The service instance name derives from the host name, so overly complex names can confuse some resolvers.

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Escaped instance names (\032)

Bonjour/DNS-SD often escapes bytes in service instance names as decimal \DDD sequences (spaces become \032). This is normal at the protocol level; UIs should decode for display (iOS uses BonjourEscapes.decode).

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Enabling / disabling / configuration

macOS hosts auto-start the bundled LAN discovery plugin by default. When the Bonjour plugin is enabled and OPENCLAW_DISABLE_BONJOUR is unset, Bonjour advertises on normal hosts and auto-disables inside detected containers (Docker, Fly.io machines, and common container runtimes).