debug: add logging for NodeGatheredInfo event flow

Track when NodeGatheredInfo events are sent and applied to help
diagnose why joining nodes stay as "unknown".

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/EXO/EXO/EXOApp.swift

@@ -45,8 +45,8 @@ struct EXOApp: App {
         let thunderboltBridge = ThunderboltBridgeService(clusterStateService: service)
         _thunderboltBridgeService = StateObject(wrappedValue: thunderboltBridge)
         enableLaunchAtLoginIfNeeded()
-        // Remove old LaunchDaemon components if they exist (from previous versions)
-        cleanupLegacyNetworkSetup()
+        // Install LaunchDaemon to disable Thunderbolt Bridge on startup (prevents network loops)
+        NetworkSetupHelper.promptAndInstallIfNeeded()
         // Check local network access periodically (warning disappears when user grants permission)
         localNetwork.startPeriodicChecking(interval: 10)
         controller.scheduleLaunch(after: 15)
@@ -136,36 +136,6 @@ struct EXOApp: App {
         }
     }
 
-    private func cleanupLegacyNetworkSetup() {
-        guard NetworkSetupHelper.hasInstalledComponents() else { return }
-        // Dispatch async to ensure app is ready before showing alert
-        DispatchQueue.main.async {
-            let alert = NSAlert()
-            alert.messageText = "EXO Network Configuration"
-            alert.informativeText =
-                "EXO needs to configure local network discovery on your device. This requires granting permission once."
-            alert.alertStyle = .informational
-            alert.addButton(withTitle: "Continue")
-            alert.addButton(withTitle: "Later")
-
-            let response = alert.runModal()
-            guard response == .alertFirstButtonReturn else {
-                Logger().info("User deferred legacy network setup cleanup")
-                return
-            }
-
-            do {
-                try NetworkSetupHelper.uninstall()
-                Logger().info("Cleaned up legacy network setup components")
-            } catch {
-                // Non-fatal: user may have cancelled admin prompt or cleanup may have
-                // partially succeeded. The app will continue normally.
-                Logger().warning(
-                    "Could not clean up legacy network setup (non-fatal): \(error.localizedDescription)"
-                )
-            }
-        }
-    }
 }
 
 /// Helper for managing EXO's launch-at-login registration

app/EXO/EXO/Services/NetworkSetupHelper.swift

@@ -11,6 +11,68 @@ enum NetworkSetupHelper {
     private static let legacyScriptDestination =
         "/Library/Application Support/EXO/disable_bridge_enable_dhcp.sh"
     private static let plistDestination = "/Library/LaunchDaemons/io.exo.networksetup.plist"
+    private static let requiredStartInterval: Int = 1786
+
+    private static let setupScript = """
+        #!/usr/bin/env bash
+
+        set -euo pipefail
+
+        PREFS="/Library/Preferences/SystemConfiguration/preferences.plist"
+
+        # Remove bridge0 interface
+        ifconfig bridge0 &>/dev/null && {
+          ifconfig bridge0 | grep -q 'member' && {
+            ifconfig bridge0 | awk '/member/ {print $2}' | xargs -n1 ifconfig bridge0 deletem 2>/dev/null || true
+          }
+          ifconfig bridge0 destroy 2>/dev/null || true
+        }
+
+        # Remove Thunderbolt Bridge from VirtualNetworkInterfaces in preferences.plist
+        /usr/libexec/PlistBuddy -c "Delete :VirtualNetworkInterfaces:Bridge:bridge0" "$PREFS" 2>/dev/null || true
+
+        networksetup -listnetworkservices | grep -q "Thunderbolt Bridge" && {
+          networksetup -setnetworkserviceenabled "Thunderbolt Bridge" off
+        } || true
+        """
+
+    /// Prompts user and installs the LaunchDaemon if not already installed.
+    /// Shows an alert explaining what will be installed before requesting admin privileges.
+    static func promptAndInstallIfNeeded() {
+        // Use .utility priority to match NSAppleScript's internal QoS and avoid priority inversion
+        Task.detached(priority: .utility) {
+            // If already correctly installed, skip
+            if daemonAlreadyInstalled() {
+                return
+            }
+
+            // Show alert on main thread
+            let shouldInstall = await MainActor.run {
+                let alert = NSAlert()
+                alert.messageText = "EXO Network Configuration"
+                alert.informativeText =
+                    "EXO needs to install a system service to automatically disable Thunderbolt Bridge on startup. This prevents network loops when connecting multiple Macs via Thunderbolt.\n\nYou will be prompted for your administrator password."
+                alert.alertStyle = .informational
+                alert.addButton(withTitle: "Install")
+                alert.addButton(withTitle: "Not Now")
+                return alert.runModal() == .alertFirstButtonReturn
+            }
+
+            guard shouldInstall else {
+                logger.info("User deferred network setup daemon installation")
+                return
+            }
+
+            do {
+                try installLaunchDaemon()
+                logger.info("Network setup launch daemon installed and started")
+            } catch {
+                logger.error(
+                    "Network setup launch daemon failed: \(error.localizedDescription, privacy: .public)"
+                )
+            }
+        }
+    }
 
     /// Removes all EXO network setup components from the system.
     /// This includes the LaunchDaemon, scripts, logs, and network location.
@@ -30,6 +92,100 @@ enum NetworkSetupHelper {
         return scriptExists || legacyScriptExists || plistExists
     }
 
+    private static func daemonAlreadyInstalled() -> Bool {
+        let manager = FileManager.default
+        let scriptExists = manager.fileExists(atPath: scriptDestination)
+        let plistExists = manager.fileExists(atPath: plistDestination)
+        guard scriptExists, plistExists else { return false }
+        guard
+            let installedScript = try? String(contentsOfFile: scriptDestination, encoding: .utf8),
+            installedScript.trimmingCharacters(in: .whitespacesAndNewlines)
+                == setupScript.trimmingCharacters(in: .whitespacesAndNewlines)
+        else {
+            return false
+        }
+        guard
+            let data = try? Data(contentsOf: URL(fileURLWithPath: plistDestination)),
+            let plist = try? PropertyListSerialization.propertyList(
+                from: data, options: [], format: nil) as? [String: Any]
+        else {
+            return false
+        }
+        guard
+            let interval = plist["StartInterval"] as? Int,
+            interval == requiredStartInterval
+        else {
+            return false
+        }
+        if let programArgs = plist["ProgramArguments"] as? [String],
+            programArgs.contains(scriptDestination) == false
+        {
+            return false
+        }
+        return true
+    }
+
+    private static func installLaunchDaemon() throws {
+        let installerScript = makeInstallerScript()
+        try runShellAsAdmin(installerScript)
+    }
+
+    private static func makeInstallerScript() -> String {
+        """
+        set -euo pipefail
+
+        LABEL="\(daemonLabel)"
+        SCRIPT_DEST="\(scriptDestination)"
+        LEGACY_SCRIPT_DEST="\(legacyScriptDestination)"
+        PLIST_DEST="\(plistDestination)"
+        LOG_OUT="/var/log/\(daemonLabel).log"
+        LOG_ERR="/var/log/\(daemonLabel).err.log"
+
+        # First, completely remove any existing installation
+        launchctl bootout system/"$LABEL" 2>/dev/null || true
+        rm -f "$PLIST_DEST"
+        rm -f "$SCRIPT_DEST"
+        rm -f "$LEGACY_SCRIPT_DEST"
+        rm -f "$LOG_OUT" "$LOG_ERR"
+
+        # Install fresh
+        mkdir -p "$(dirname "$SCRIPT_DEST")"
+
+        cat > "$SCRIPT_DEST" <<'EOF_SCRIPT'
+        \(setupScript)
+        EOF_SCRIPT
+        chmod 755 "$SCRIPT_DEST"
+
+        cat > "$PLIST_DEST" <<'EOF_PLIST'
+        <?xml version="1.0" encoding="UTF-8"?>
+        <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+        <plist version="1.0">
+        <dict>
+          <key>Label</key>
+          <string>\(daemonLabel)</string>
+          <key>ProgramArguments</key>
+          <array>
+            <string>/bin/bash</string>
+            <string>\(scriptDestination)</string>
+          </array>
+          <key>StartInterval</key>
+          <integer>\(requiredStartInterval)</integer>
+          <key>RunAtLoad</key>
+          <true/>
+          <key>StandardOutPath</key>
+          <string>/var/log/\(daemonLabel).log</string>
+          <key>StandardErrorPath</key>
+          <string>/var/log/\(daemonLabel).err.log</string>
+        </dict>
+        </plist>
+        EOF_PLIST
+
+        launchctl bootstrap system "$PLIST_DEST"
+        launchctl enable system/"$LABEL"
+        launchctl kickstart -k system/"$LABEL"
+        """
+    }
+
     private static func makeUninstallScript() -> String {
         """
         set -euo pipefail

src/exo/main.py

@@ -53,6 +53,7 @@ class Node:
         await router.register_topic(topics.COMMANDS)
         await router.register_topic(topics.ELECTION_MESSAGES)
         await router.register_topic(topics.CONNECTION_MESSAGES)
+        await router.register_topic(topics.STATE_CATCHUP)
         await router.register_topic(topics.DOWNLOAD_COMMANDS)
 
         logger.info(f"Starting node {node_id}")
@@ -82,6 +83,7 @@ class Node:
                 command_sender=router.sender(topics.COMMANDS),
                 download_command_sender=router.sender(topics.DOWNLOAD_COMMANDS),
                 election_receiver=router.receiver(topics.ELECTION_MESSAGES),
+                state_catchup_receiver=router.receiver(topics.STATE_CATCHUP),
             )
         else:
             api = None
@@ -94,6 +96,7 @@ class Node:
                 global_event_receiver=router.receiver(topics.GLOBAL_EVENTS),
                 local_event_sender=router.sender(topics.LOCAL_EVENTS),
                 command_sender=router.sender(topics.COMMANDS),
+                state_catchup_receiver=router.receiver(topics.STATE_CATCHUP),
                 download_command_sender=router.sender(topics.DOWNLOAD_COMMANDS),
                 event_index_counter=event_index_counter,
             )
@@ -107,6 +110,7 @@ class Node:
             global_event_sender=router.sender(topics.GLOBAL_EVENTS),
             local_event_receiver=router.receiver(topics.LOCAL_EVENTS),
             command_receiver=router.receiver(topics.COMMANDS),
+            state_catchup_sender=router.sender(topics.STATE_CATCHUP),
         )
 
         er_send, er_recv = channel[ElectionResult]()
@@ -189,6 +193,7 @@ class Node:
                         global_event_sender=self.router.sender(topics.GLOBAL_EVENTS),
                         local_event_receiver=self.router.receiver(topics.LOCAL_EVENTS),
                         command_receiver=self.router.receiver(topics.COMMANDS),
+                        state_catchup_sender=self.router.sender(topics.STATE_CATCHUP),
                     )
                     self._tg.start_soon(self.master.run)
                 elif (
@@ -235,6 +240,9 @@ class Node:
                             ),
                             local_event_sender=self.router.sender(topics.LOCAL_EVENTS),
                             command_sender=self.router.sender(topics.COMMANDS),
+                            state_catchup_receiver=self.router.receiver(
+                                topics.STATE_CATCHUP
+                            ),
                             download_command_sender=self.router.sender(
                                 topics.DOWNLOAD_COMMANDS
                             ),

src/exo/master/api.py

@@ -166,6 +166,7 @@ class API:
         download_command_sender: Sender[ForwarderDownloadCommand],
         # This lets us pause the API if an election is running
         election_receiver: Receiver[ElectionMessage],
+        state_catchup_receiver: Receiver[State],
     ) -> None:
         self.state = State()
         self._event_log: list[Event] = []
@@ -173,6 +174,7 @@ class API:
         self.download_command_sender = download_command_sender
         self.global_event_receiver = global_event_receiver
         self.election_receiver = election_receiver
+        self.state_catchup_receiver = state_catchup_receiver
         self.event_buffer: OrderedBuffer[Event] = OrderedBuffer[Event]()
         self.node_id: NodeId = node_id
         self.session_id: SessionId = session_id
@@ -1249,6 +1251,7 @@ class API:
             tg.start_soon(self._apply_state)
             tg.start_soon(self._pause_on_new_election)
             tg.start_soon(self._cleanup_expired_images)
+            tg.start_soon(self._state_catchup)
             print_startup_banner(self.port)
             await serve(
                 cast(ASGIFramework, self.app),
@@ -1259,6 +1262,37 @@ class API:
         self.command_sender.close()
         self.global_event_receiver.close()
 
+    async def _state_catchup(self):
+        with self.state_catchup_receiver as states:
+            async for state in states:
+                if (
+                    self.state.last_event_applied_idx == -1
+                    and state.last_event_applied_idx > self.state.last_event_applied_idx
+                ):
+                    # DEBUG: Log buffer state BEFORE clearing
+                    logger.warning(
+                        f"STATE_CATCHUP: About to catch up. "
+                        f"Current buffer indices: {sorted(self.event_buffer.store.keys())}, "
+                        f"next_idx_to_release: {self.event_buffer.next_idx_to_release}, "
+                        f"catching up to idx: {state.last_event_applied_idx}"
+                    )
+
+                    new_idx = state.last_event_applied_idx + 1
+                    self.event_buffer.next_idx_to_release = new_idx
+                    # Preserve events that arrived early but are still valid (idx >= new_idx)
+                    # Remove stale events (idx < new_idx) to prevent memory growth
+                    self.event_buffer.store = {
+                        k: v for k, v in self.event_buffer.store.items() if k >= new_idx
+                    }
+                    self.state = state
+
+                    # DEBUG: Log buffer state AFTER clearing
+                    logger.warning(
+                        f"STATE_CATCHUP: Catchup complete. "
+                        f"Buffer preserved indices: {sorted(self.event_buffer.store.keys())}, "
+                        f"new next_idx_to_release: {self.event_buffer.next_idx_to_release}"
+                    )
+
     async def _apply_state(self):
         with self.global_event_receiver as events:
             async for f_event in events:

src/exo/master/main.py

@@ -68,6 +68,8 @@ class Master:
         # Send events to the forwarder to be indexed (usually from command processing)
         # Ideally these would be MasterForwarderEvents but type system says no :(
         global_event_sender: Sender[ForwarderEvent],
+        # not a fan but - send the entire state to a node so it can catchup without the whole event log.
+        state_catchup_sender: Sender[State],
     ):
         self.state = State()
         self._tg: TaskGroup = anyio.create_task_group()
@@ -77,6 +79,7 @@ class Master:
         self.command_receiver = command_receiver
         self.local_event_receiver = local_event_receiver
         self.global_event_sender = global_event_sender
+        self.state_catchup_sender = state_catchup_sender
         send, recv = channel[Event]()
         self.event_sender: Sender[Event] = send
         self._loopback_event_receiver: Receiver[Event] = recv
@@ -84,7 +87,6 @@ class Master:
             local_event_receiver.clone_sender()
         )
         self._multi_buffer = MultiSourceBuffer[NodeId, Event]()
-        # TODO: not have this
         self._event_log: list[Event] = []
 
     async def run(self):
@@ -291,11 +293,17 @@ class Master:
                                     command.finished_command_id
                                 ]
                         case RequestEventLog():
-                            # We should just be able to send everything, since other buffers will ignore old messages
-                            for i in range(command.since_idx, len(self._event_log)):
-                                await self._send_event(
-                                    IndexedEvent(idx=i, event=self._event_log[i])
+                            if command.since_idx == 0:
+                                # This is an optimization, and should not be relied upon in theory.
+                                logger.info(
+                                    f"Master sending catchup state for index {self.state.last_event_applied_idx}"
                                 )
+                                await self.state_catchup_sender.send(self.state)
+                            else:
+                                for i in range(command.since_idx, len(self._event_log)):
+                                    await self._send_event(
+                                        IndexedEvent(idx=i, event=self._event_log[i])
+                                    )
                     for event in generated_events:
                         await self.event_sender.send(event)
                 except ValueError as e:

src/exo/master/placement_utils.py

@@ -257,7 +257,13 @@ def _find_ip_prioritised(
     ip_to_type = {
         iface.ip_address: iface.interface_type for iface in other_network.interfaces
     }
-    priority = {"ethernet": 0, "wifi": 1, "unknown": 2, "thunderbolt": 3}
+    priority = {
+        "ethernet": 0,
+        "wifi": 1,
+        "unknown": 2,
+        "maybe_ethernet": 3,
+        "thunderbolt": 4,
+    }
     return min(ips, key=lambda ip: priority.get(ip_to_type.get(ip, "unknown"), 2))
 
 

src/exo/master/tests/test_master.py

@@ -27,6 +27,7 @@ from exo.shared.types.memory import Memory
 from exo.shared.types.profiling import (
     MemoryUsage,
 )
+from exo.shared.types.state import State
 from exo.shared.types.tasks import ChatCompletion as ChatCompletionTask
 from exo.shared.types.tasks import TaskStatus
 from exo.shared.types.worker.instances import (
@@ -47,6 +48,7 @@ async def test_master():
     ge_sender, global_event_receiver = channel[ForwarderEvent]()
     command_sender, co_receiver = channel[ForwarderCommand]()
     local_event_sender, le_receiver = channel[ForwarderEvent]()
+    st_s, _st_r = channel[State]()
 
     all_events: list[IndexedEvent] = []
 
@@ -67,6 +69,7 @@ async def test_master():
         global_event_sender=ge_sender,
         local_event_receiver=le_receiver,
         command_receiver=co_receiver,
+        state_catchup_sender=st_s,
     )
     logger.info("run the master")
     async with anyio.create_task_group() as tg:

src/exo/routing/topics.py

@@ -7,6 +7,7 @@ from exo.shared.types.commands import ForwarderCommand, ForwarderDownloadCommand
 from exo.shared.types.events import (
     ForwarderEvent,
 )
+from exo.shared.types.state import State
 from exo.utils.pydantic_ext import CamelCaseModel
 
 
@@ -45,6 +46,7 @@ ELECTION_MESSAGES = TypedTopic(
 CONNECTION_MESSAGES = TypedTopic(
     "connection_messages", PublishPolicy.Never, ConnectionMessage
 )
+STATE_CATCHUP = TypedTopic("state_catchup", PublishPolicy.Always, State)
 DOWNLOAD_COMMANDS = TypedTopic(
     "download_commands", PublishPolicy.Always, ForwarderDownloadCommand
 )

src/exo/shared/types/profiling.py

@@ -48,7 +48,7 @@ class SystemPerformanceProfile(CamelCaseModel):
     ecpu_usage: float = 0.0
 
 
-InterfaceType = Literal["wifi", "ethernet", "thunderbolt", "unknown"]
+InterfaceType = Literal["wifi", "ethernet", "maybe_ethernet", "thunderbolt", "unknown"]
 
 
 class NetworkInterfaceInfo(CamelCaseModel):

src/exo/utils/info_gatherer/info_gatherer.py

@@ -400,7 +400,7 @@ class InfoGatherer:
             return
         old_nics = []
         while True:
-            nics = get_network_interfaces()
+            nics = await get_network_interfaces()
             if nics != old_nics:
                 old_nics = nics
                 await self.info_sender.send(NodeNetworkInterfaces(ifaces=nics))

src/exo/utils/info_gatherer/system_info.py

@@ -1,6 +1,6 @@
 import socket
 import sys
-from subprocess import CalledProcessError, run
+from subprocess import CalledProcessError
 
 import psutil
 from anyio import run_process
@@ -16,8 +16,7 @@ async def get_friendly_name() -> str:
     """
     hostname = socket.gethostname()
 
-    # TODO: better non mac support
-    if sys.platform != "darwin":  # 'darwin' is the platform name for macOS
+    if sys.platform != "darwin":
         return hostname
 
     try:
@@ -28,21 +27,20 @@ async def get_friendly_name() -> str:
     return process.stdout.decode("utf-8", errors="replace").strip() or hostname
 
 
-def _get_interface_types_from_networksetup() -> dict[str, InterfaceType]:
+async def _get_interface_types_from_networksetup() -> dict[str, InterfaceType]:
     """Parse networksetup -listallhardwareports to get interface types."""
     if sys.platform != "darwin":
         return {}
+
     try:
-        result = run(
-            ["networksetup", "-listallhardwareports"], capture_output=True, text=True
-        )
-    except Exception:
+        result = await run_process(["networksetup", "-listallhardwareports"])
+    except CalledProcessError:
         return {}
 
     types: dict[str, InterfaceType] = {}
     current_type: InterfaceType = "unknown"
 
-    for line in result.stdout.splitlines():
+    for line in result.stdout.decode().splitlines():
         if line.startswith("Hardware Port:"):
             port_name = line.split(":", 1)[1].strip()
             if "Wi-Fi" in port_name:
@@ -55,12 +53,15 @@ def _get_interface_types_from_networksetup() -> dict[str, InterfaceType]:
                 current_type = "unknown"
         elif line.startswith("Device:"):
             device = line.split(":", 1)[1].strip()
+            # enX is ethernet adapters or thunderbolt - these must be deprioritised
+            if device.startswith("en") and device not in ["en0", "en1"]:
+                current_type = "maybe_ethernet"
             types[device] = current_type
 
     return types
 
 
-def get_network_interfaces() -> list[NetworkInterfaceInfo]:
+async def get_network_interfaces() -> list[NetworkInterfaceInfo]:
     """
     Retrieves detailed network interface information on macOS.
     Parses output from 'networksetup -listallhardwareports' and 'ifconfig'
@@ -68,7 +69,7 @@ def get_network_interfaces() -> list[NetworkInterfaceInfo]:
     Returns a list of NetworkInterfaceInfo objects.
     """
     interfaces_info: list[NetworkInterfaceInfo] = []
-    interface_types = _get_interface_types_from_networksetup()
+    interface_types = await _get_interface_types_from_networksetup()
 
     for iface, services in psutil.net_if_addrs().items():
         for service in services:

src/exo/worker/main.py

@@ -60,9 +60,8 @@ class Worker:
         connection_message_receiver: Receiver[ConnectionMessage],
         global_event_receiver: Receiver[ForwarderEvent],
         local_event_sender: Sender[ForwarderEvent],
-        # This is for requesting updates. It doesn't need to be a general command sender right now,
-        # but I think it's the correct way to be thinking about commands
         command_sender: Sender[ForwarderCommand],
+        state_catchup_receiver: Receiver[State],
         download_command_sender: Sender[ForwarderDownloadCommand],
         event_index_counter: Iterator[int],
     ):
@@ -71,6 +70,8 @@ class Worker:
 
         self.global_event_receiver = global_event_receiver
         self.local_event_sender = local_event_sender
+        self.state_catchup_receiver = state_catchup_receiver
+        self.local_event_index = 0
         self.event_index_counter = event_index_counter
         self.command_sender = command_sender
         self.download_command_sender = download_command_sender
@@ -110,6 +111,7 @@ class Worker:
             tg.start_soon(self._event_applier)
             tg.start_soon(self._forward_events)
             tg.start_soon(self._poll_connection_updates)
+            tg.start_soon(self._check_catchup_state)
 
         # Actual shutdown code - waits for all tasks to complete before executing.
         self.local_event_sender.close()
@@ -121,13 +123,47 @@ class Worker:
     async def _forward_info(self, recv: Receiver[GatheredInfo]):
         with recv as info_stream:
             async for info in info_stream:
-                await self.event_sender.send(
-                    NodeGatheredInfo(
-                        node_id=self.node_id,
-                        when=str(datetime.now(tz=timezone.utc)),
-                        info=info,
-                    )
+                event = NodeGatheredInfo(
+                    node_id=self.node_id,
+                    when=str(datetime.now(tz=timezone.utc)),
+                    info=info,
                 )
+                logger.warning(
+                    f"NODE_GATHERED_INFO: Sending event for node {self.node_id}, "
+                    f"event_id={event.event_id}"
+                )
+                await self.event_sender.send(event)
+
+    async def _check_catchup_state(self):
+        with self.state_catchup_receiver as states:
+            async for state in states:
+                if (
+                    self.state.last_event_applied_idx == -1
+                    and state.last_event_applied_idx > self.state.last_event_applied_idx
+                ):
+                    # DEBUG: Log buffer state BEFORE clearing
+                    logger.warning(
+                        f"STATE_CATCHUP: About to catch up. "
+                        f"Current buffer indices: {sorted(self.event_buffer.store.keys())}, "
+                        f"next_idx_to_release: {self.event_buffer.next_idx_to_release}, "
+                        f"catching up to idx: {state.last_event_applied_idx}"
+                    )
+
+                    new_idx = state.last_event_applied_idx + 1
+                    self.event_buffer.next_idx_to_release = new_idx
+                    # Preserve events that arrived early but are still valid (idx >= new_idx)
+                    # Remove stale events (idx < new_idx) to prevent memory growth
+                    self.event_buffer.store = {
+                        k: v for k, v in self.event_buffer.store.items() if k >= new_idx
+                    }
+                    self.state = state
+
+                    # DEBUG: Log buffer state AFTER clearing
+                    logger.warning(
+                        f"STATE_CATCHUP: Catchup complete. "
+                        f"Buffer preserved indices: {sorted(self.event_buffer.store.keys())}, "
+                        f"new next_idx_to_release: {self.event_buffer.next_idx_to_release}"
+                    )
 
     async def _event_applier(self):
         with self.global_event_receiver as events:
@@ -139,8 +175,20 @@ class Worker:
                 if event_id in self.out_for_delivery:
                     del self.out_for_delivery[event_id]
 
+                # DEBUG: Log what was ingested
+                logger.warning(
+                    f"EVENT_APPLIER: Ingested event idx={f_event.origin_idx}, "
+                    f"buffer keys now: {sorted(self.event_buffer.store.keys())}"
+                )
+
                 # 2. for each event, apply it to the state
                 indexed_events = self.event_buffer.drain_indexed()
+
+                # DEBUG: Log drain results
+                logger.warning(
+                    f"EVENT_APPLIER: Drained {len(indexed_events)} events, "
+                    f"next_idx_to_release now: {self.event_buffer.next_idx_to_release}"
+                )
                 if indexed_events:
                     self._nack_attempts = 0
 
@@ -157,6 +205,12 @@ class Worker:
                     self._nack_cancel_scope.cancel()
 
                 for idx, event in indexed_events:
+                    # DEBUG: Log NodeGatheredInfo events
+                    if isinstance(event, NodeGatheredInfo):
+                        logger.warning(
+                            f"NODE_GATHERED_INFO: Applying event idx={idx} for node {event.node_id}, "
+                            f"event_id={event.event_id}"
+                        )
                     self.state = apply(self.state, IndexedEvent(idx=idx, event=event))
 
                     # Buffer input image chunks for image editing
@@ -318,10 +372,7 @@ class Worker:
         # We request all events after (and including) the missing index.
         # This function is started whenever we receive an event that is out of sequence.
         # It is cancelled as soon as we receiver an event that is in sequence.
-
-        if since_idx < 0:
-            logger.warning(f"Negative value encountered for nack request {since_idx=}")
-            since_idx = 0
+        assert since_idx >= 0
 
         with CancelScope() as scope:
             self._nack_cancel_scope = scope

src/exo/worker/runner/runner.py

@@ -240,10 +240,6 @@ def main(
                             prompt=prompt,
                         )
 
-                        # GPT-OSS specific parsing to match other model formats.
-                        if isinstance(model, GptOssModel):
-                            mlx_generator = parse_gpt_oss(mlx_generator)
-
                         # For other thinking models (GLM, etc.), check if we need to
                         # prepend the thinking tag that was consumed by the chat template
                         if detect_thinking_prompt_suffix(prompt, tokenizer):
@@ -257,10 +253,16 @@ def main(
                             patch_kimi_tokenizer(tokenizer)
 
                         # GLM models need patched parser (upstream has bug with None regex match)
-                        if "glm" in shard_metadata.model_card.model_id.lower():
+                        elif "glm" in shard_metadata.model_card.model_id.lower():
                             patch_glm_tokenizer(tokenizer)
 
-                        if tokenizer.has_tool_calling:
+                        # GPT-OSS specific parsing to match other model formats.
+                        elif isinstance(model, GptOssModel):
+                            mlx_generator = parse_gpt_oss(mlx_generator)
+
+                        if tokenizer.has_tool_calling and not isinstance(
+                            model, GptOssModel
+                        ):
                             assert tokenizer.tool_call_start
                             assert tokenizer.tool_call_end
                             assert tokenizer.tool_parser  # pyright: ignore[reportAny]
@@ -489,9 +491,10 @@ def get_gpt_oss_encoding():
 
 
 def filter_kimi_tokens(
-    responses: Generator[GenerationResponse],
+    responses: Generator[GenerationResponse | ToolCallResponse],
 ) -> Generator[GenerationResponse]:
     for resp in responses:
+        assert isinstance(resp, GenerationResponse)
         if (
             resp.text == "<|tool_calls_section_begin|>"
             or resp.text == "<|tool_calls_section_end|>"
@@ -501,17 +504,44 @@ def filter_kimi_tokens(
 
 
 def parse_gpt_oss(
-    responses: Generator[GenerationResponse],
-) -> Generator[GenerationResponse]:
+    responses: Generator[GenerationResponse | ToolCallResponse],
+) -> Generator[GenerationResponse | ToolCallResponse]:
     encoding = get_gpt_oss_encoding()
     stream = StreamableParser(encoding, role=Role.ASSISTANT)
     thinking = False
+    current_tool_name: str | None = None
+    tool_arg_parts: list[str] = []
 
     for response in responses:
+        assert isinstance(response, GenerationResponse)
         stream.process(response.token)
 
         delta = stream.last_content_delta
         ch = stream.current_channel
+        recipient = stream.current_recipient
+
+        if recipient != current_tool_name:
+            if current_tool_name is not None:
+                prefix = "functions."
+                if current_tool_name.startswith(prefix):
+                    current_tool_name = current_tool_name[len(prefix) :]
+                yield ToolCallResponse(
+                    tool_calls=[
+                        ToolCallItem(
+                            name=current_tool_name,
+                            arguments="".join(tool_arg_parts).strip(),
+                        )
+                    ]
+                )
+                tool_arg_parts = []
+                break
+            current_tool_name = recipient
+
+        # If inside a tool call, accumulate arguments
+        if current_tool_name is not None:
+            if delta:
+                tool_arg_parts.append(delta)
+            continue
 
         if ch == "analysis" and not thinking:
             thinking = True
@@ -528,13 +558,12 @@ def parse_gpt_oss(
             if thinking:
                 yield response.model_copy(update={"text": "</think>"})
             yield response
-            break
 
 
 def parse_thinking_models(
-    responses: Generator[GenerationResponse],
+    responses: Generator[GenerationResponse | ToolCallResponse],
     tokenizer: TokenizerWrapper,
-) -> Generator[GenerationResponse]:
+) -> Generator[GenerationResponse | ToolCallResponse]:
     """
     For models that inject thinking tags in the prompt (like GLM-4.7),
     prepend the thinking tag to the output stream so the frontend
@@ -542,6 +571,9 @@ def parse_thinking_models(
     """
     first = True
     for response in responses:
+        if isinstance(response, ToolCallResponse):
+            yield response
+            continue
         if first:
             first = False
             yield response.model_copy(
@@ -622,7 +654,7 @@ def _process_image_response(
 
 
 def parse_tool_calls(
-    responses: Generator[GenerationResponse],
+    responses: Generator[GenerationResponse | ToolCallResponse],
     tool_call_start: str,
     tool_call_end: str,
     tool_parser: Callable[[str], dict[str, Any] | list[dict[str, Any]]],
@@ -630,6 +662,7 @@ def parse_tool_calls(
     in_tool_call = False
     tool_call_text_parts: list[str] = []
     for response in responses:
+        assert isinstance(response, GenerationResponse)
         # assumption: the tool call start is one token
         if response.text == tool_call_start:
             in_tool_call = True

src/exo/worker/tests/unittests/test_plan/test_download_and_loading.py

@@ -154,7 +154,7 @@ def test_plan_does_not_request_download_when_shard_already_downloaded():
         tasks={},
     )
 
-    assert result is None
+    assert not isinstance(result, plan_mod.DownloadModel)
 
 
 def test_plan_does_not_load_model_until_all_shards_downloaded_globally():