fix instance type mismatch in /instance/previews endpoint

Derive instance_meta from the actual instance type returned by
place_instance() instead of using the requested instance_meta from
the loop variable. place_instance() overrides single-node placements
to MlxRing, but the preview response was still reporting the original
requested type (e.g., MlxJaccl), causing a mismatch.

Closes #1426

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

dashboard/src/routes/downloads/+page.svelte

@@ -469,11 +469,11 @@
                   <td class="px-4 py-3 text-center align-middle">
                     {#if cell.kind === "completed"}
                       <div
-                        class="flex flex-col items-center gap-1"
+                        class="flex flex-col items-center gap-0.5"
                         title="Completed ({formatBytes(cell.totalBytes)})"
                       >
                         <svg
-                          class="w-7 h-7 text-green-400"
+                          class="w-5 h-5 text-green-400"
                           viewBox="0 0 20 20"
                           fill="currentColor"
                         >
@@ -483,18 +483,18 @@
                             clip-rule="evenodd"
                           ></path>
                         </svg>
-                        <span class="text-xs text-exo-light-gray/70"
+                        <span class="text-[10px] text-exo-light-gray/70"
                           >{formatBytes(cell.totalBytes)}</span
                         >
                         <button
                           type="button"
-                          class="text-exo-light-gray/40 hover:text-red-400 transition-colors mt-0.5 cursor-pointer"
+                          class="text-exo-light-gray/40 hover:text-red-400 transition-colors mt-0.5"
                           onclick={() =>
                             deleteDownload(col.nodeId, row.modelId)}
                           title="Delete from this node"
                         >
                           <svg
-                            class="w-5 h-5"
+                            class="w-3.5 h-3.5"
                             viewBox="0 0 20 20"
                             fill="none"
                             stroke="currentColor"
@@ -517,11 +517,11 @@
                           cell.speed,
                         )} - ETA {formatEta(cell.etaMs)}"
                       >
-                        <span class="text-exo-yellow text-sm font-medium"
+                        <span class="text-exo-yellow text-xs font-medium"
                           >{clampPercent(cell.percentage).toFixed(1)}%</span
                         >
                         <div
-                          class="w-16 h-2 bg-exo-black/60 rounded-sm overflow-hidden"
+                          class="w-14 h-1.5 bg-exo-black/60 rounded-sm overflow-hidden"
                         >
                           <div
                             class="h-full bg-gradient-to-r from-exo-yellow to-exo-yellow/70 transition-all duration-300"
@@ -530,25 +530,25 @@
                             ).toFixed(1)}%"
                           ></div>
                         </div>
-                        <span class="text-[10px] text-exo-light-gray/60"
+                        <span class="text-[9px] text-exo-light-gray/60"
                           >{formatSpeed(cell.speed)}</span
                         >
                       </div>
                     {:else if cell.kind === "pending"}
                       <div
-                        class="flex flex-col items-center gap-1"
+                        class="flex flex-col items-center gap-0.5"
                         title={cell.downloaded > 0
-                          ? `${formatBytes(cell.downloaded)} / ${formatBytes(cell.total)} downloaded (paused)`
+                          ? `${formatBytes(cell.downloaded)} / ${formatBytes(cell.total)} downloaded`
                           : "Download pending"}
                       >
                         {#if cell.downloaded > 0 && cell.total > 0}
-                          <span class="text-exo-light-gray/70 text-xs"
+                          <span class="text-exo-light-gray/70 text-[10px]"
                             >{formatBytes(cell.downloaded)} / {formatBytes(
                               cell.total,
                             )}</span
                           >
                           <div
-                            class="w-full h-1.5 bg-white/10 rounded-full overflow-hidden"
+                            class="w-full h-1 bg-white/10 rounded-full overflow-hidden"
                           >
                             <div
                               class="h-full bg-exo-light-gray/40 rounded-full"
@@ -558,55 +558,9 @@
                               ).toFixed(1)}%"
                             ></div>
                           </div>
-                          {#if row.shardMetadata}
-                            <button
-                              type="button"
-                              class="text-exo-light-gray/50 hover:text-exo-yellow transition-colors cursor-pointer"
-                              onclick={() =>
-                                startDownload(col.nodeId, row.shardMetadata!)}
-                              title="Resume download on this node"
-                            >
-                              <svg
-                                class="w-5 h-5"
-                                viewBox="0 0 20 20"
-                                fill="none"
-                                stroke="currentColor"
-                                stroke-width="2"
-                              >
-                                <path
-                                  d="M10 3v10m0 0l-3-3m3 3l3-3M3 17h14"
-                                  stroke-linecap="round"
-                                  stroke-linejoin="round"
-                                ></path>
-                              </svg>
-                            </button>
-                          {:else}
-                            <span class="text-exo-light-gray/40 text-[10px]"
-                              >paused</span
-                            >
-                          {/if}
-                        {:else if row.shardMetadata}
-                          <button
-                            type="button"
-                            class="text-exo-light-gray/30 hover:text-exo-yellow transition-colors cursor-pointer"
-                            onclick={() =>
-                              startDownload(col.nodeId, row.shardMetadata!)}
-                            title="Start download on this node"
+                          <span class="text-exo-light-gray/40 text-[9px]"
+                            >paused</span
                           >
-                            <svg
-                              class="w-6 h-6"
-                              viewBox="0 0 20 20"
-                              fill="none"
-                              stroke="currentColor"
-                              stroke-width="2"
-                            >
-                              <path
-                                d="M10 3v10m0 0l-3-3m3 3l3-3M3 17h14"
-                                stroke-linecap="round"
-                                stroke-linejoin="round"
-                              ></path>
-                            </svg>
-                          </button>
                         {:else}
                           <span class="text-exo-light-gray/50 text-sm">...</span
                           >
@@ -614,11 +568,11 @@
                       </div>
                     {:else if cell.kind === "failed"}
                       <div
-                        class="flex flex-col items-center gap-1"
+                        class="flex flex-col items-center gap-0.5"
                         title="Download failed"
                       >
                         <svg
-                          class="w-7 h-7 text-red-400"
+                          class="w-5 h-5 text-red-400"
                           viewBox="0 0 20 20"
                           fill="currentColor"
                         >
@@ -631,13 +585,13 @@
                         {#if row.shardMetadata}
                           <button
                             type="button"
-                            class="text-exo-light-gray/40 hover:text-exo-yellow transition-colors cursor-pointer"
+                            class="text-exo-light-gray/40 hover:text-exo-yellow transition-colors"
                             onclick={() =>
                               startDownload(col.nodeId, row.shardMetadata!)}
                             title="Retry download on this node"
                           >
                             <svg
-                              class="w-5 h-5"
+                              class="w-3.5 h-3.5"
                               viewBox="0 0 20 20"
                               fill="none"
                               stroke="currentColor"
@@ -663,13 +617,13 @@
                         {#if row.shardMetadata}
                           <button
                             type="button"
-                            class="text-exo-light-gray/30 hover:text-exo-yellow transition-colors mt-0.5 opacity-0 group-hover:opacity-100 cursor-pointer"
+                            class="text-exo-light-gray/30 hover:text-exo-yellow transition-colors mt-0.5 opacity-0 group-hover:opacity-100"
                             onclick={() =>
                               startDownload(col.nodeId, row.shardMetadata!)}
                             title="Download to this node"
                           >
                             <svg
-                              class="w-5 h-5"
+                              class="w-3.5 h-3.5"
                               viewBox="0 0 20 20"
                               fill="none"
                               stroke="currentColor"

src/exo/download/download_utils.py

@@ -823,7 +823,6 @@ async def download_shard(
 
     for file in filtered_file_list:
         downloaded_bytes = await get_downloaded_size(target_dir / file.path)
-        final_file_exists = await aios.path.exists(target_dir / file.path)
         file_progress[file.path] = RepoFileDownloadProgress(
             repo_id=shard.model_card.model_id,
             repo_revision=revision,
@@ -833,9 +832,7 @@ async def download_shard(
             total=Memory.from_bytes(file.size or 0),
             speed=0,
             eta=timedelta(0),
-            status="complete"
-            if final_file_exists and downloaded_bytes == file.size
-            else "not_started",
+            status="complete" if downloaded_bytes == file.size else "not_started",
             start_time=time.time(),
         )
 

src/exo/main.py

@@ -252,7 +252,7 @@ def main():
     target = min(max(soft, 65535), hard)
     resource.setrlimit(resource.RLIMIT_NOFILE, (target, hard))
 
-    mp.set_start_method("spawn", force=True)
+    mp.set_start_method("spawn")
     # TODO: Refactor the current verbosity system
     logger_setup(EXO_LOG, args.verbosity)
     logger.info("Starting EXO")

src/exo/master/api.py

@@ -168,7 +168,12 @@ from exo.shared.types.openai_responses import (
 )
 from exo.shared.types.state import State
 from exo.shared.types.worker.downloads import DownloadCompleted
-from exo.shared.types.worker.instances import Instance, InstanceId, InstanceMeta
+from exo.shared.types.worker.instances import (
+    Instance,
+    InstanceId,
+    InstanceMeta,
+    MlxJacclInstance,
+)
 from exo.shared.types.worker.shards import Sharding
 from exo.utils.banner import print_startup_banner
 from exo.utils.channels import Receiver, Sender, channel
@@ -513,6 +518,14 @@ class API:
             shard_assignments = instance.shard_assignments
             placement_node_ids = list(shard_assignments.node_to_runner.keys())
 
+            # Derive instance_meta from the actual instance type, since
+            # place_instance() may override it (e.g., single-node → MlxRing)
+            actual_instance_meta = (
+                InstanceMeta.MlxJaccl
+                if isinstance(instance, MlxJacclInstance)
+                else InstanceMeta.MlxRing
+            )
+
             memory_delta_by_node: dict[str, int] = {}
             if placement_node_ids:
                 total_bytes = model_card.storage_size.in_bytes
@@ -525,14 +538,14 @@ class API:
             if (
                 model_card.model_id,
                 sharding,
-                instance_meta,
+                actual_instance_meta,
                 len(placement_node_ids),
             ) not in seen:
                 previews.append(
                     PlacementPreview(
                         model_id=model_card.model_id,
                         sharding=sharding,
-                        instance_meta=instance_meta,
+                        instance_meta=actual_instance_meta,
                         instance=instance,
                         memory_delta_by_node=memory_delta_by_node or None,
                         error=None,
@@ -542,7 +555,7 @@ class API:
                 (
                     model_card.model_id,
                     sharding,
-                    instance_meta,
+                    actual_instance_meta,
                     len(placement_node_ids),
                 )
             )

src/exo/shared/models/model_cards.py

@@ -90,7 +90,6 @@ class ModelCard(CamelCaseModel):
     base_model: str = ""
     capabilities: list[str] = []
     uses_cfg: bool = False
-    trust_remote_code: bool = True
 
     @field_validator("tasks", mode="before")
     @classmethod
@@ -138,7 +137,6 @@ class ModelCard(CamelCaseModel):
             hidden_size=config_data.hidden_size or 0,
             supports_tensor=config_data.supports_tensor,
             tasks=[ModelTask.TextGeneration],
-            trust_remote_code=False,
         )
         await mc.save_to_custom_dir()
         _card_cache[model_id] = mc

src/exo/worker/engines/mlx/utils_mlx.py

@@ -23,7 +23,9 @@ from mlx_lm.models.deepseek_v3 import DeepseekV3Model
 from mlx_lm.tokenizer_utils import TokenizerWrapper
 
 from exo.shared.models.model_cards import ModelId
-from exo.worker.engines.mlx.constants import TRUST_REMOTE_CODE
+from exo.worker.engines.mlx.constants import (
+    TRUST_REMOTE_CODE,
+)
 
 try:
     from mlx_lm.tokenizer_utils import load_tokenizer
@@ -291,11 +293,7 @@ def shard_and_load(
 
 def get_tokenizer(model_path: Path, shard_metadata: ShardMetadata) -> TokenizerWrapper:
     """Load tokenizer for a model shard. Delegates to load_tokenizer_for_model_id."""
-    return load_tokenizer_for_model_id(
-        shard_metadata.model_card.model_id,
-        model_path,
-        trust_remote_code=shard_metadata.model_card.trust_remote_code,
-    )
+    return load_tokenizer_for_model_id(shard_metadata.model_card.model_id, model_path)
 
 
 def get_eos_token_ids_for_model(model_id: ModelId) -> list[int] | None:
@@ -327,7 +325,7 @@ def get_eos_token_ids_for_model(model_id: ModelId) -> list[int] | None:
 
 
 def load_tokenizer_for_model_id(
-    model_id: ModelId, model_path: Path, *, trust_remote_code: bool = TRUST_REMOTE_CODE
+    model_id: ModelId, model_path: Path
 ) -> TokenizerWrapper:
     """
     Load tokenizer for a model given its ID and local path.
@@ -396,7 +394,7 @@ def load_tokenizer_for_model_id(
 
     tokenizer = load_tokenizer(
         model_path,
-        tokenizer_config_extra={"trust_remote_code": trust_remote_code},
+        tokenizer_config_extra={"trust_remote_code": TRUST_REMOTE_CODE},
         eos_token_ids=eos_token_ids,
     )
 

src/exo/worker/runner/runner_supervisor.py

@@ -106,18 +106,13 @@ class RunnerSupervisor:
     def shutdown(self):
         logger.info("Runner supervisor shutting down")
         self._tg.cancel_tasks()
+        self._ev_recv.close()
+        self._task_sender.close()
         if not self._cancel_watch_runner.cancel_called:
             self._cancel_watch_runner.cancel()
-        with contextlib.suppress(ClosedResourceError):
-            self._ev_recv.close()
-        with contextlib.suppress(ClosedResourceError):
-            self._task_sender.close()
-        with contextlib.suppress(ClosedResourceError):
-            self._event_sender.close()
         with contextlib.suppress(ClosedResourceError):
             self._cancel_sender.send(TaskId("CANCEL_CURRENT_TASK"))
-        with contextlib.suppress(ClosedResourceError):
-            self._cancel_sender.close()
+        self._cancel_sender.close()
         self.runner_process.join(5)
         if not self.runner_process.is_alive():
             logger.info("Runner process succesfully terminated")

tests/get_all_models_on_cluster.py

@@ -8,7 +8,7 @@ from urllib.request import urlopen
 
 h = sys.argv[1] if len(sys.argv) > 1 else sys.exit(f"USAGE: {sys.argv[0]} host")
 ts = subprocess.run(
-    ["/Applications/Tailscale.app/Contents/MacOS/Tailscale", "status"], check=True, text=True, capture_output=True
+    ["tailscale", "status"], check=True, text=True, capture_output=True
 ).stdout.splitlines()
 ip = next(
     (sl[0] for line in ts if len(sl := line.split()) >= 2 if sl[1] == h), None

tests/start_distributed_test.py

@@ -15,7 +15,7 @@ if not (args := sys.argv[1:]):
 kind = args[0] if args[0] in ("jaccl", "ring") else "both"
 hosts = args[1:] if kind != "both" else args
 ts = subprocess.run(
-    ["/Applications/Tailscale.app/Contents/MacOS/Tailscale", "status"], check=True, text=True, capture_output=True
+    ["tailscale", "status"], check=True, text=True, capture_output=True
 ).stdout.splitlines()
 ip = {sl[1]: sl[0] for line in ts if len(sl := line.split()) >= 2}
 ips = [ip[h] for h in hosts]

tmp/test_trust_remote_code_attack.sh

@@ -1,125 +0,0 @@
-#!/usr/bin/env bash
-# Test that models added via API get trust_remote_code=false
-# Run this against a running exo instance.
-# Usage: ./test_trust_remote_code_attack.sh [host:port]
-
-set -uo pipefail
-
-HOST="${1:-localhost:52415}"
-MODEL_ID="KevTheHermit/security-testing"
-CUSTOM_CARDS_DIR="$HOME/.exo/custom_model_cards"
-CARD_FILE="$CUSTOM_CARDS_DIR/KevTheHermit--security-testing.toml"
-
-echo "=== Test: trust_remote_code attack via API ==="
-echo "Target: $HOST"
-echo ""
-
-# Clean up RCE proof from previous runs
-rm -f /tmp/exo-rce-proof.txt
-
-# Step 0: Clean up any stale card from previous runs
-if [ -f "$CARD_FILE" ]; then
-  echo "[0] Removing stale card from previous run ..."
-  curl -s -X DELETE \
-    "http://$HOST/models/custom/$(python3 -c 'import urllib.parse; print(urllib.parse.quote("'"$MODEL_ID"'", safe=""))')" >/dev/null
-  rm -f "$CARD_FILE"
-  echo "    Done"
-  echo ""
-fi
-
-# Step 1: Add the malicious model via API
-echo "[1] Adding model via POST /models/add ..."
-ADD_RESPONSE=$(curl -s -w "\n%{http_code}" -X POST "http://$HOST/models/add" \
-  -H "Content-Type: application/json" \
-  -d "{\"model_id\":\"$MODEL_ID\"}")
-HTTP_CODE=$(echo "$ADD_RESPONSE" | tail -1)
-BODY=$(echo "$ADD_RESPONSE" | sed '$d')
-echo "    HTTP $HTTP_CODE"
-
-if [ "$HTTP_CODE" -ge 400 ]; then
-  echo "    Model add failed (HTTP $HTTP_CODE) — that's fine if model doesn't exist on HF."
-  echo "    Response: $BODY"
-  echo ""
-  echo "RESULT: Model was rejected at add time. Attack blocked."
-  exit 0
-fi
-
-# Step 2: Verify the saved TOML has trust_remote_code = false
-echo ""
-echo "[2] Checking saved model card TOML ..."
-if [ ! -f "$CARD_FILE" ]; then
-  echo "    FAIL: Card file not found at $CARD_FILE"
-  exit 1
-fi
-
-if grep -q 'trust_remote_code = false' "$CARD_FILE"; then
-  echo "    SAFE: trust_remote_code = false (fix is active)"
-else
-  echo "    VULNERABLE: trust_remote_code is not false — remote code WILL be trusted"
-fi
-echo "    Contents:"
-cat "$CARD_FILE"
-
-# Step 3: Place the instance
-echo ""
-echo "[3] Attempting POST /place_instance ..."
-PLACE_RESPONSE=$(curl -s -w "\n%{http_code}" -X POST "http://$HOST/place_instance" \
-  -H "Content-Type: application/json" \
-  -d "{\"model_id\":\"$MODEL_ID\"}")
-PLACE_CODE=$(echo "$PLACE_RESPONSE" | tail -1)
-PLACE_BODY=$(echo "$PLACE_RESPONSE" | sed '$d')
-echo "    HTTP $PLACE_CODE"
-echo "    Response: $PLACE_BODY"
-
-# Step 3b: Send a chat completion to actually trigger tokenizer loading
-echo ""
-echo "[3b] Sending chat completion to trigger tokenizer load ..."
-CHAT_RESPONSE=$(curl -s -w "\n%{http_code}" --max-time 30 -X POST "http://$HOST/v1/chat/completions" \
-  -H "Content-Type: application/json" \
-  -d "{\"model\":\"$MODEL_ID\",\"messages\":[{\"role\":\"user\",\"content\":\"hello\"}],\"max_tokens\":1}")
-CHAT_CODE=$(echo "$CHAT_RESPONSE" | tail -1)
-CHAT_BODY=$(echo "$CHAT_RESPONSE" | sed '$d')
-echo "    HTTP $CHAT_CODE"
-echo "    Response: $CHAT_BODY"
-echo ""
-echo "[3c] Checking for RCE proof ..."
-sleep 5
-if [ -f /tmp/exo-rce-proof.txt ]; then
-  echo "    VULNERABLE: Remote code executed!"
-  echo "    Contents:"
-  cat /tmp/exo-rce-proof.txt
-else
-  echo "    SAFE: /tmp/exo-rce-proof.txt does not exist — remote code was NOT executed"
-fi
-
-# Step 4: Clean up — delete instance and custom model
-echo ""
-echo "[4] Cleaning up ..."
-
-# Find and delete any instance for this model
-INSTANCE_ID=$(curl -s "http://$HOST/state" | python3 -c "
-import sys, json
-state = json.load(sys.stdin)
-for iid, wrapper in state.get('instances', {}).items():
-    for tag, inst in wrapper.items():
-        sa = inst.get('shardAssignments', {})
-        if sa.get('modelId', '') == '$MODEL_ID':
-            print(iid)
-            sys.exit(0)
-" 2>/dev/null || true)
-
-if [ -n "$INSTANCE_ID" ]; then
-  echo "    Deleting instance $INSTANCE_ID ..."
-  curl -s -X DELETE "http://$HOST/instance/$INSTANCE_ID" >/dev/null
-  echo "    Done"
-else
-  echo "    No instance found to delete"
-fi
-
-echo "    Deleting custom model card ..."
-curl -s -X DELETE \
-  "http://$HOST/models/custom/$(python3 -c 'import urllib.parse; print(urllib.parse.quote("'"$MODEL_ID"'", safe=""))')" >/dev/null
-echo "    Done"
-
-echo ""
-echo "=== DONE ==="