--- summary: "Bonjour/mDNS discovery + debugging (Gateway beacons, clients, and common failure modes)" read_when: - Debugging Bonjour discovery issues on macOS/iOS - Changing mDNS service types, TXT records, or discovery UX title: "Bonjour discovery" --- 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. ## 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. ### Gateway config ```json5 { gateway: { bind: "tailnet" }, // tailnet-only (recommended) discovery: { wideArea: { enabled: true, domain: "openclaw.internal" } }, } ``` `discovery.wideArea.domain` also accepts the `OPENCLAW_WIDE_AREA_DOMAIN` env var as a fallback when unset. ### One-time DNS server setup (gateway host, macOS only) ```bash openclaw dns setup --apply ``` 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/.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: ```bash dns-sd -B _openclaw-gw._tcp openclaw.internal. dig @ -p 53 _openclaw-gw._tcp.openclaw.internal PTR +short ``` ### 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. ### 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). ## 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. ## Service types - `_openclaw-gw._tcp` - gateway transport beacon, used by macOS/iOS/Android nodes. ## TXT keys (non-secret hints) | Key | When present | | ----------------------------- | ------------------------------------------------------------------------------ | | `role=gateway` | Always. | | `displayName=` | Always. | | `lanHost=.local` | Always. | | `gatewayPort=` | Always (gateway WS + HTTP). | | `transport=gateway` | Always. | | `gatewayTls=1` | Only when TLS is enabled. | | `gatewayTlsSha256=` | Only when TLS is enabled and a fingerprint is available. | | `gatewayDirectReachable=1` | Only when the gateway is directly reachable (not only via a relay/proxy path). | | `canvasPort=` | Only when the canvas host is enabled; currently the same as `gatewayPort`. | | `tailnetDns=` | mDNS full mode only; optional hint when Tailnet is available. | | `sshPort=` | Full mode only; omitted in minimal and off modes. | | `cliPath=` | Full mode only; omitted in minimal and off modes. | 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. ## Debugging on macOS Built-in tools: ```bash # Browse instances dns-sd -B _openclaw-gw._tcp local. # Resolve one instance (replace ) dns-sd -L "" _openclaw-gw._tcp local. ``` If browsing works but resolving fails, you're usually hitting a LAN policy or mDNS resolver issue. ## 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 cancellation ...` - `bonjour: ... name conflict resolved` / `hostname conflict resolved` - `bonjour: watchdog detected non-announced service ...` - `bonjour: disabling advertiser after ... failed restarts ...` The watchdog treats active `probing`, `announcing`, and fresh conflict-renames as in-progress states. If the service never reaches `announced`, OpenClaw recreates the advertiser and, after repeated failures, disables Bonjour for that gateway process instead of re-advertising forever. 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=` before starting the gateway when you need an explicit host label. ## 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. ## 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: ```bash openclaw plugins enable bonjour ``` 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: | Mode | Behavior | | ------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `minimal` (default) | Core TXT keys only; omits `sshPort`, `cliPath`, `tailnetDns`. | | `full` | Adds `sshPort`, `cliPath`, `tailnetDns` — use when clients need those hints. | | `off` | Suppresses LAN multicast without changing plugin enablement; wide-area DNS-SD can still publish the minimal beacon when `discovery.wideArea.enabled` is true. | ## 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): ```bash OPENCLAW_DISABLE_BONJOUR=1 ``` Use plugin configuration when you intentionally want to turn off the bundled LAN discovery plugin for that OpenClaw config: ```bash openclaw plugins disable bonjour ``` ## 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. ## 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: ```bash docker compose config | grep OPENCLAW_DISABLE_BONJOUR ``` 2. Confirm the gateway itself is reachable through the published port: ```bash curl -fsS http://127.0.0.1:18789/healthz ``` 3. Use a direct target when Bonjour is disabled: - Control UI or local tools: `http://127.0.0.1:18789` - LAN clients: `http://: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: ```bash dns-sd -B _openclaw-gw._tcp local. ``` If browsing is empty, or Gateway logs show repeated ciao watchdog cancellations, restore `OPENCLAW_DISABLE_BONJOUR=1` and use a direct or Tailnet route. ## 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 ciao advertiser in a non-announced state. OpenClaw retries a few times, then disables Bonjour for the current gateway process instead of restarting the advertiser forever. - **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. ## 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`). ## Enabling / disabling / configuration | Setting | Effect | | ---------------------------------------------------- | --------------------------------------------------------------------------------- | | `openclaw plugins enable bonjour` | Enables the bundled LAN discovery plugin on hosts where it isn't default-enabled. | | `openclaw plugins disable bonjour` | Disables LAN multicast advertising by disabling the bundled plugin. | | `OPENCLAW_DISABLE_BONJOUR=1` (or `true`/`yes`/`on`) | Disables LAN multicast advertising without changing plugin config. | | `OPENCLAW_DISABLE_BONJOUR=0` (or `false`/`no`/`off`) | Forces LAN multicast advertising on, including inside detected containers. | | `discovery.mdns.mode` | `off` \| `minimal` (default) \| `full` — see modes above. | | `gateway.bind` | Controls the gateway bind mode in `~/.openclaw/openclaw.json`. | | `OPENCLAW_SSH_PORT` | Overrides the SSH port when `sshPort` is advertised (full mode). | | `OPENCLAW_TAILNET_DNS` | Publishes a MagicDNS hint in TXT when mDNS full mode is enabled. | | `OPENCLAW_CLI_PATH` | Overrides the advertised CLI path (full mode). | 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). ## Related docs - Discovery policy and transport selection: [Discovery](/gateway/discovery) - Node pairing + approvals: [Gateway pairing](/gateway/pairing)