## Motivation
`reasoning_tokens` is always 0 in usage stats, even when thinking
content streams correctly via `reasoning_content` SSE deltas. The MLX
generators had their own thinking detection comparing individual
detokenized tokens against think tags — this never fires for models
where tags span multiple tokens (e.g. gpt-oss-120b) or are already in
the prompt.
## Changes
- Removed broken per-token thinking detection from `batch_generate.py`
and `generate.py`
- Added `_count_reasoning_tokens` wrapper in `model_output_parsers.py`
that counts `is_thinking=True` responses and patches the total into
Usage on the final response
- Wired it as the outermost stage of `apply_all_parsers`, so it works
regardless of which parser sets `is_thinking`
- Added 3 tests covering `parse_thinking_models` and `parse_gpt_oss`
paths
## Why It Works
The parser pipeline already correctly sets `is_thinking` on each
response. Counting at the output of `apply_all_parsers` means one
counting point that works for all model types, replacing the duplicate
broken logic in two generators.
## Test Plan
### Manual Testing
- 4-node cluster, `mlx-community/gpt-oss-120b-MXFP4-Q8`
- Main branch: `reasoning_tokens: 0` — fix branch: `reasoning_tokens:
25`
### Automated Testing
- 3 new tests: explicit think tags, `starts_in_thinking=True`, and
gpt-oss Harmony analysis channel
## Motivation
When a model instance is deleted (e.g. node disconnect, manual
teardown), any in-flight SSE streaming connections for that instance
hang indefinitely. The API never closes the response stream, so clients
block forever waiting for more chunks.
## Changes
- Listen for `InstanceDeleted` events in the API event loop
- Add `_close_streams_for_instance()` to find and close any active
text/image generation queues tied to tasks on the deleted instance
- Add unit tests covering text gen, image gen, and
unrelated-instance-not-closed scenarios
## Why It Works
When an instance is deleted, we iterate `state.tasks` to find commands
running on that instance, then close and remove their send-side queue
handles. This causes the SSE generator to terminate, unblocking the
client.
## Test Plan
### Manual Testing
- This was causing issues for me on another branch (integration tests).
Including this fix solved the issue
### Automated Testing
- `test_instance_deleted_stream_cleanup.py`: 3 tests covering text gen
cleanup, image gen cleanup, and ensuring unrelated streams are not
affected
While stress-testing inference with rapid client cancels mid-stream, I
hit a reproducible crash where the entire exo process exits.
When a client cancels a streaming chat completion partway through, its
receive stream gets closed cleanly via its context manager. The producer
in `API._apply_state` then calls `queue.send(event.chunk)`, which raises
`anyio.ClosedResourceError` rather than `BrokenResourceError`. The
existing handler only catches `BrokenResourceError`, so the exception
propagates through the API task group, kills the Node task group, and
the process exits with `EXO Shutdown complete`.
Trace from one of the crashes:
```
File "exo/api/main.py", line 1818, in _apply_state
await queue.send(event.chunk)
File "anyio/streams/memory.py", line 212, in send_nowait
raise ClosedResourceError
anyio.ClosedResourceError
```
The fix is to catch `ClosedResourceError` alongside
`BrokenResourceError` in both queue handlers (text and image), so the
dead queue gets dropped and `_apply_state` keeps running for other
in-flight requests.
## Motivation
The exo backend already supports `--fast-synch` / `--no-fast-synch` CLI
flags and the `EXO_FAST_SYNCH` environment variable, but there was no
way to toggle this from the macOS app UI. Users who want fast CPU-to-GPU
synchronization for RDMA with Tensor Parallelism had to use CLI flags.
## Changes
- **ExoProcessController.swift**: Added `fastSynchEnabled`
UserDefaults-backed property and pass `EXO_FAST_SYNCH=on` to the exo
process environment when enabled.
- **SettingsView.swift**: Added a "Performance" section to the Advanced
tab with a "Fast Synch Enabled" toggle, an info icon (ⓘ) tooltip
explaining the feature and trade-offs, and a "Save & Restart" button.
## Why It Works
Follows the exact same pattern as the existing `offlineMode` and
`enableImageModels` settings — UserDefaults persistence, `@Published`
property with `didSet`, environment variable passthrough in
`makeEnvironment()`, and pending state with Save & Restart in the
settings UI. The `EXO_FAST_SYNCH=on` value matches what the Python
backend already reads in `main.py`.
## Test Plan
### Manual Testing
<!-- Hardware: macOS app -->
- Open Settings → Advanced tab → verify "Performance" section with "Fast
Synch Enabled" toggle appears
- Hover the ⓘ icon → verify tooltip explains the feature and GPU lock
trade-off
- Toggle on → click "Save & Restart" → verify process restarts with
`EXO_FAST_SYNCH=on` in env
- Close and reopen Settings → verify the toggle state persists
- Verify "Save & Restart" button is disabled when no changes are pending
### Automated Testing
- Existing settings patterns are well-established; no new automated
tests needed for this UI toggle
---------
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
## Motivation
<!-- Why is this change needed? What problem does it solve? -->
<!-- If it fixes an open issue, please link to the issue here -->
## Changes
<!-- Describe what you changed in detail -->
## Why It Works
<!-- Explain why your approach solves the problem -->
## Test Plan
### Manual Testing
<!-- Hardware: (e.g., MacBook Pro M1 Max 32GB, Mac Mini M2 16GB,
connected via Thunderbolt 4) -->
<!-- What you did: -->
<!-- - -->
### Automated Testing
<!-- Describe changes to automated tests, or how existing tests cover
this change -->
<!-- - -->
## Changes
Mostly chore changes around vscode and jetbrains workspace settings, and
some basedpyright settings tweaks, to allow direnv to work and nixd
autocomplete with flake parts to work
## Motivation
MLX LM has had a massive refactor to their BatchGenerator recently.
Since we'd like new features from MLX LM such as Gemma 4, we need to
update the code to handle this.
Additionally this fixes a significant memory leak in GatedDeltaNet (the
difference is quite substantial, up to 1GB every 1000 tokens, explaining
several memory issues users were facing with Qwen3.5 models)
## Testing
Before
<img width="3146" height="884" alt="image"
src="https://github.com/user-attachments/assets/5af0f55a-393c-4a32-9eed-ae43f1611af4"
/>
After (no memory leak, as one of the changes upstream)
<img width="3190" height="892" alt="image"
src="https://github.com/user-attachments/assets/f0bd128d-fd48-40d4-9bbd-50a564beab14"
/>
When `enable_thinking` is set, chat templates (Qwen3, DeepSeek, etc.)
append `<think>` to the prompt. The model starts generating thinking
content directly without emitting a `<think>` token in the output
stream.
Both generators initialized `in_thinking = False` and only set it to
`True` on seeing a `<think>` token in output. Since that token was part
of the prompt, the flag never flipped and `reasoning_tokens` stayed at 0
in the usage response.
Fix: initialize `in_thinking` from `detect_thinking_prompt_suffix()`,
which already exists and is used by `model_output_parsers` for routing
thinking content correctly.
## Motivation
The timings in the batch generator are a little optimistic; a minor
change is needed to make them more correct.
## Changes
Include the time spent in the API in the generation tps and make sure to
send all requests simultaneously
## Motivation
No way to pause active downloads or delete partial/failed downloads from
the dashboard.
## Changes
- **Backend:** Added `POST /download/cancel` endpoint with
`CancelDownloadParams`/`CancelDownloadResponse` types. Wires into the
existing `CancelDownload` command + coordinator handler.
- **Dashboard store:** Added `cancelDownload(nodeId, modelId)` function.
- **Dashboard UI:**
- Pause + delete buttons on active (downloading) cells
- Delete button on paused/pending and failed cells
- Extracted duplicated SVG icons into `{#snippet}` blocks (`trashIcon`,
`downloadIcon`, `pauseIcon`, `deleteButton`)
- **Tests:** 3 coordinator-level tests for cancel: active download →
pending, nonexistent → no-op, cancel then resume.
## Why It Works
`CancelDownload` command and coordinator handler already existed — just
needed an HTTP endpoint and dashboard wiring. Delete endpoint already
supported all download states.
## Test Plan
### Manual Testing
Started a model download, paused it. Deleted some paused downloads.
Deleted some ongoing downloads.
### Automated Testing
- `test_cancel_active_download_transitions_to_pending` — cancels
in-progress download, asserts `DownloadPending` event and cleanup
- `test_cancel_nonexistent_download_is_noop` — no events emitted
- `test_cancel_then_resume_download` — restart after cancel works
## Motivation
Currently, when a runner fails, the master retries the instance. Most of
the time, this causes a loop over failure. Retries need backoff and a
cap.
## Changes
- src/exo/worker/main.py: Before creating a runner, check an exponential
backoff timer per instance. After EXO_MAX_INSTANCE_RETRIES failures,
send DeleteInstance to permanently remove the instance. Record attempts
on Shutdown; reset on InstanceDeleted.
- src/exo/utils/keyed_backoff.py: Add attempts() method to query retry
count
- src/exo/shared/constants.py: Add EXO_MAX_INSTANCE_RETRIES = 3.
## Why It Works
The worker gates CreateRunner tasks behind a KeyedBackoff, adding
exponential delay (2s base, 30s cap) between retries. After 3 failures
the worker sends DeleteInstance, stopping retries entirely. The backoff
resets when the instance is deleted, so a fresh placement starts clean.
---------
Co-authored-by: Evan <evanev7@gmail.com>
## Motivation
Nemotron Cascade and Nano failing at long decodes.
## Changes
Fixed upstream, just change pyproject and uv lock here.
## Test Plan
### Automated Testing
Tested with a reproduce script upstream
## Motivation
Addresses #1816
## Changes
Update on min prefix cache > min_prefix_hit_length **and** hit ratio >
_MIN_PREFIX_HIT_RATIO_TO_UPDATE
min_prefix_hit_length = max(1000, system prompt length) -> system
prompts must match exactly.
## Test Plan
### Manual Testing
Test on OpenCode and Claude Code
## Motivation
<!-- Why is this change needed? What problem does it solve? -->
<!-- If it fixes an open issue, please link to the issue here -->
## Changes
<!-- Describe what you changed in detail -->
## Why It Works
<!-- Explain why your approach solves the problem -->
## Test Plan
### Manual Testing
<!-- Hardware: (e.g., MacBook Pro M1 Max 32GB, Mac Mini M2 16GB,
connected via Thunderbolt 4) -->
<!-- What you did: -->
<!-- - -->
### Automated Testing
<!-- Describe changes to automated tests, or how existing tests cover
this change -->
<!-- - -->
## Motivation
<!-- Why is this change needed? What problem does it solve? -->
<!-- If it fixes an open issue, please link to the issue here -->
## Changes
<!-- Describe what you changed in detail -->
## Why It Works
<!-- Explain why your approach solves the problem -->
## Test Plan
### Manual Testing
<!-- Hardware: (e.g., MacBook Pro M1 Max 32GB, Mac Mini M2 16GB,
connected via Thunderbolt 4) -->
<!-- What you did: -->
<!-- - -->
### Automated Testing
<!-- Describe changes to automated tests, or how existing tests cover
this change -->
<!-- - -->
adds a path option to the /state endpoint, allowing you to query
subfields of state without grabbing the whole blob
## test plan
poking around in the api
This PR builds on https://github.com/exo-explore/exo/pull/1677 to enable
custom prompts sent from Firefox `browser.ml.chat` to EXO dashboard
using URL parameters in sidebar for summary and other browser
interactions. See "Summarize page" example below.
## Summary
- Parse `?q=<encoded prompt>` URL parameter on page load and auto-submit
it as a chat message
- Clean up the URL with `history.replaceState` to prevent re-submission
on refresh
- Defer auto-send until both cluster state and model list are loaded so
model auto-selection works correctly
## Context
Firefox's built-in AI sidebar (`about:config: browser.ml.chat.enabled`)
integrates with chat providers by appending the user's prompt as
`?q=<URL-encoded prompt>`. Previously the exo dashboard ignored this
parameter. Users can now configure `http://localhost:52415` as a Firefox
AI chatbot provider.
See: https://support.mozilla.org/en-US/kb/ai-chatbot
## Technical notes
- Frontend-only change in `dashboard/src/routes/+page.svelte`
- Uses a Svelte `$effect` that reacts to `pendingFirefoxQuery`, `data`
(cluster state), and `models.length` — fires exactly once when all three
are ready
- If no model is selected, `handleAutoSend` auto-picks the best
available model; if no model fits memory, a toast is shown
- If a model is selected but not running, the message is queued until
the model loads
## Testing
```
http://localhost:52415/?q=Hello+worldhttp://localhost:52415/?q=Summarize+this+page%3A+%5Bpage+title%5D+%5Bpage+url%5D
```
<img width="2056" height="1329" alt="image"
src="https://github.com/user-attachments/assets/74463eb4-ca1a-400d-806a-c19ba93147b9"
/>
## Motivation
Adding a custom model from the Hub tab shows "Added" toast but the model
doesn't appear in the All tab. You have to add it a second time for it
to work. Also, the "All" button in the model picker sidebar is too small
to read comfortably.
## Changes
**Race condition fix (`src/exo/api/main.py`):**
- Call `add_to_card_cache(card)` directly in `add_custom_model()` after
sending the `ForwarderCommand`, before the API response returns
**Sidebar sizing
(`dashboard/src/lib/components/FamilySidebar.svelte`):**
- Increased sidebar min-width from 72/64px to 80/72px
- Increased "All" icon from `w-5 h-5` to `w-6 h-6`
- Increased all sidebar labels from 9px to 11px
## Why It Works
`POST /models/add` sends a `ForwarderCommand(AddCustomModelCard)` and
returns immediately. The frontend then calls `GET /models` which reads
from `_card_cache`. But the cache was only updated by the worker event
handler after the event round-trips through the master — a race the
frontend almost always loses. By updating the cache directly in the API
handler, `GET /models` immediately reflects the new model. The worker's
later `add_to_card_cache` call is idempotent (dict key assignment).
## Test Plan
### Manual Testing
<!-- Hardware: any Mac -->
- Open model picker → Hub tab → add a custom model → verify it appears
in All tab on the first attempt
- Verify sidebar "All" button and other labels are visually larger and
readable
### Automated Testing
- `uv run basedpyright` passes with 0 errors
- `uv run ruff check` passes
---------
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
## Motivation
Replace confusing EXO_MODELS_DIR/EXO_MODELS_PATH with clearer
multi-directory support, enabling automatic download spillover across
volumes.
## Changes
- EXO_MODELS_DIRS: colon-separated writable dirs (default always
prepended, first with enough space wins)
- EXO_MODELS_READ_ONLY_DIRS: colon-separated read-only dirs (protected
from deletion)
- select_download_dir(): picks writable dir by free space
- resolve_existing_model(): unified lookup across all dirs
- is_read_only_model_dir(): path-based read-only detection instead of
hardcoded flag
- Updated coordinator, worker, model cards, tests
## Why It Works
Default dir always included so zero-config behavior is unchanged. Disk
space checked at download time for automatic spillover. Read-only status
derived from path, not hardcoded.
## Test Plan
### Manual Testing
- No env vars set → identical behavior
- EXO_MODELS_DIRS=/Volumes/SSD/models → downloads to external storage
- EXO_MODELS_READ_ONLY_DIRS=/mnt/nfs → models found, deletion blocked
### Automated Testing
- 4 new tests in test_xdg_paths.py (prepend, default-only, overlap,
empty read-only)
- Existing tests updated to patch new constants
## Motivation
During master reelection, `_elect_loop` called `worker.shutdown()` (fire
& forget) then immediately created and started a new Worker.
This caused the old runner subprocess's Metal/GPU teardown to race with
the new worker's startup, resulting in `IOConnectUnmapMemory failed:
kr=0xe00002bc` errors and a full node hang requiring `^C`. Same issue
existed for `DownloadCoordinator`.
## Changes
- Added `anyio.Event`-based `_stopped` signal to `Worker` and
`DownloadCoordinator`, set at the end of their `run()` finally blocks
- Added `wait_stopped()` async method to both classes
- Updated `_elect_loop` to `await wait_stopped()` after calling
`shutdown()` on the old Worker and DownloadCoordinator before creating
replacements
## Why It Works
The old Worker's task group contains the RunnerSupervisor tasks, whose
finally blocks join the runner subprocess (with 5s timeout + SIGTERM +
SIGKILL escalation). By awaiting `wait_stopped()`, we guarantee the old
runner process has fully exited — including GPU memory cleanup — before
a new Worker can start and potentially access the GPU. This eliminates
the race without changing the shutdown mechanics themselves.
## Test Plan
### Manual Testing
Hardware: M4 Pro Mac Mini 24GB + M3 Ultra Mac Studio 96GB, connected via
Thunderbolt
**Repro steps:**
1. Start exo on two nodes with a model sharded across both (e.g.
`Josiefied-Qwen3-14B-abliterated-v3-4bit`)
2. Wait for "runner ready" on both
3. `kill -9` the master node
4. Observe the surviving node's re-election behavior
**Before fix (original crash):**
```
[ 11:02:39.0896AM ] Runner supervisor shutting down
[ 11:02:39.0905AM ] bye from the runner
[ 11:02:39.1052AM ] Stopping Worker
IOConnectUnmapMemory failed: kr=0xe00002bc
IOConnectUnmapMemory failed: kr=0xe00002bc
IOConnectUnmapMemory failed: kr=0xe00002bc
IOConnectUnmapMemory failed: kr=0xe00002bc
^C[ 11:03:45 ] ← hung for over a minute, required manual kill
```
**After fix (clean re-election):**
```
[ 12:15:22.4703PM ] runner loaded
[ 12:15:24.1672PM ] runner ready
[ 12:15:33.5393PM ] Waiting for other campaign to finish
[ 12:15:36.5409PM ] Node elected Master
[ 12:15:36.5413PM ] Unpausing API
```
No `IOConnectUnmapMemory` errors, no hang, no `^C` needed.
### Automated Testing
- No existing tests cover the `_elect_loop` re-election path; this is an
integration-level flow requiring a live router/election/worker stack
- All existing tests pass (307/308, 1 pre-existing Rust binding failure)
- basedpyright: 0 errors, ruff: all checks passed
---------
Co-authored-by: Evan <evanev7@gmail.com>
## Motivation
<!-- Why is this change needed? What problem does it solve? -->
<!-- If it fixes an open issue, please link to the issue here -->
## Changes
<!-- Describe what you changed in detail -->
## Why It Works
<!-- Explain why your approach solves the problem -->
## Test Plan
### Manual Testing
<!-- Hardware: (e.g., MacBook Pro M1 Max 32GB, Mac Mini M2 16GB,
connected via Thunderbolt 4) -->
<!-- What you did: -->
<!-- - -->
### Automated Testing
<!-- Describe changes to automated tests, or how existing tests cover
this change -->
<!-- - -->
missed in #1747, issue #1798.
### the issue
we didn't set the memory poll rate after failling the macmon preflight,
only after failing the followups - as we never ran macmon if preflight
failed, we never hit the followup errors etc.
### testing
requires testing on an m5 pro, but the core issue is solved.
## Motivation
PR #1747 fixed macmon support for M5 Pro/Max by pinning the
`swiftraccoon/macmon` fork in `flake.nix`. This works when running from
source (via Nix) but the distributed macOS `.app` build was still broken
on M5 Pro/Max because it was bundling the wrong macmon.
The error on M5 Pro/Max:
```
macmon preflight failed with return code -6: thread 'main' panicked at src/sources.rs:394:41
```
## Changes
- Removed `macmon` from `brew install` in `build-app.yml` — this was
installing the upstream `vladkens/macmon` which doesn't support M5
Pro/Max
- Added a new step that resolves the pinned macmon fork from the Nix dev
shell (same `swiftraccoon/macmon` at rev `9154d23` already defined in
`flake.nix`) and adds it to `$GITHUB_PATH`
- Added a safety `brew uninstall macmon` to ensure no Homebrew macmon
can shadow the pinned version
## Why It Works
PyInstaller bundles macmon via `shutil.which("macmon")`. Previously this
found the Homebrew (upstream) binary. Now it finds the Nix-overlayed
fork that has M5 Pro/Max support, because `$GITHUB_PATH` prepends the
Nix store path before the PyInstaller step runs.
## Test Plan
### Manual Testing
<!-- Hardware: M5 Pro -->
- Trigger a macOS build and verify the bundled macmon is the pinned fork
- Run the built `.app` on M5 Pro/Max and confirm macmon preflight
succeeds
### Automated Testing
- Existing CI build workflow will validate that the macmon binary is
found and bundled correctly
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
## Motivation
Support cancelling image generation, similar to existing support for
cancelling text generation
## Changes
- Dashboard (app.svelte.ts): Wire up AbortController for both
generateImage and editImage API calls. On abort, show "Cancelled"
instead of an error. Clean up the controller in finally.
- Pipeline runner (pipeline/runner.py): Introduce a cancel_checker
callback and NaN-sentinel cancellation protocol for distributed
diffusion:
- _check_cancellation() - only rank 0 polls the cancel callback
- _send() - replaces data with NaN sentinels when cancelling, so
downstream ranks detect cancellation via _recv_and_check()
- _recv() / _recv_like() wrappers that eval and check for NaN sentinel
- After cancellation, drains any pending ring recv to prevent deadlock
- Skips partial image yields and final decode when cancelled
- Image runner (runner/image_models/runner.py): Deduplicate the
ImageGeneration and ImageEdits match arms into a shared
_run_image_task() method. Thread a cancel_checker closure (backed by the
existing cancel_receiver + cancelled_tasks set) into generate_image().
- Plumbing (distributed_model.py, generate.py): Pass cancel_checker
through the call chain.
## Why It Works
- Rank 0 is the only node that knows about task-level cancellation. When
it detects cancellation, it sends NaN tensors instead of real data.
Higher-order ranks detect the NaN sentinel on recv, set their own
_cancelling flag, and propagate NaN forward
- A drain step after the loop prevents the deadlock case where the last
rank already sent patches that the first would never consume.
- For single-node mode, the loop simply breaks immediately on
cancellation.
## Test Plan
### Automated Testing
New tests in src/exo/worker/tests/unittests/test_image
## Summary
DeepSeek V3.2 (`DeepseekV32ForCausalLM`) is already supported by exo's
inference engine (architecture whitelisted in `model_cards.py`, DSML
encoding added in #1548), but **doesn't work out of the box** due to two
bugs:
### Bug 1: `warmup_inference` passes empty model ID
`warmup_inference()` in `generate.py` accepts `model_id: ModelId` as a
parameter but creates `TextGenerationTaskParams(model=ModelId(""), ...)`
instead of using it. Since `_needs_dsml_encoding()` checks
`"deepseek-v3.2" in task_params.model.lower()`, the empty string never
matches → falls back to `tokenizer.apply_chat_template()` →
**ValueError** because V3.2 has no Jinja chat template.
**Fix:** `model=ModelId("")` → `model=model_id` (one line).
### Bug 2: `_needs_dsml_encoding` limited to tool calling
`_needs_dsml_encoding()` returns `True` only when `task_params.tools` is
present or tool messages exist in `chat_template_messages`. For warmup
and regular chat requests without tools → `return False` → Jinja
fallback → **ValueError**.
Unlike V3.1 (which has a `.jinja` chat template file that transformers
picks up automatically), V3.2 **has no Jinja template at all** — it uses
Python-based DSML encoding for all message types.
**Fix:** For V3.2, always return `True` — DSML encoding handles all
message types.
### Catalog cards
Added inference model cards for:
- `mlx-community/DeepSeek-V3.2-8bit`
- `mlx-community/DeepSeek-V3.2-4bit`
Parameters taken from model `config.json` on HuggingFace, storage sizes
from HF API. Capabilities include `thinking_toggle` (related: #1456).
## Notes
- The model ID string matching approach (`"deepseek-v3.2" in
model.lower()`) is acknowledged tech debt — see #1371 for the planned
architecture-based approach.
## Test plan
- [x] Start exo with DeepSeek V3.2 model → warmup should complete
without crash
- [x] Send a regular chat message (no tools) → should get a response
- [x] Send a chat message with tools → should work as before
- [x] V3.2 cards should appear in the dashboard model catalog
---------
Co-authored-by: user <user@m1.note>
Co-authored-by: Ryuichi Leo Takashige <leo@exolabs.net>
Co-authored-by: Evan <evanev7@gmail.com>
## Motivation
Warmup occasionally had issues; e.g. #1748 and #1793 because we were
using a standard stream_generate, all of which are issues that are
resolved in the wrapper function mlx_generate.
**Enabling peers to be discovered in environments where mDNS is
unavailable (SSH sessions, headless servers, Docker).**
## Motivation
Exo discovers peers exclusively via mDNS, which works great on a local
network but breaks once you move beyond a single L2 broadcast domain:
- SSH sessions on macOS — TCC blocks mDNS multicast from non-GUI
sessions (#1488)
- Headless servers/rack machines — #1682 ("DGX Spark does not find other
nodes")
- Docker Compose — mDNS is often unavailable across container networks;
e.g. #1462 (E2E test framework) needs an alternative
Related works:
#1488 (working implementation made by @AlexCheema and closed because SSH
had a GUI workaround),
#1023 (Headscale WAN then closed due to merge conflicts),
#1656 (discovery cleanup, open).
This PR introduces an optional bootstrap mechanism for peer discovery
while leaving the existing mDNS behavior unchanged.
## Changes
Adds two new CLI flags:
- `--bootstrap-peers` (env: `EXO_BOOTSTRAP_PEERS`) — comma-separated
libp2p multiaddrs to dial on startup and retry periodically
- `--libp2p-port` — fixed TCP port for libp2p to listen on (default:
OS-assigned). Required when bootstrap peers, so other nodes know which
port to dial.
8 files:
- `rust/networking/src/discovery.rs`: Store bootstrap addrs, dial in
existing retry loop
- `rust/networking/src/swarm.rs`: Thread `bootstrap_peers` parameter to
`Behaviour`
- `rust/networking/examples/chatroom.rs`: Updated call site for new
create_swarm signature
- `rust/networking/tests/bootstrap_peers.rs`: Integration tests
- `rust/exo_pyo3_bindings/src/networking.rs`: Accept optional
`bootstrap_peers` in PyO3 constructor
- `rust/exo_pyo3_bindings/exo_pyo3_bindings.pyi` : Update type stub
- `src/exo/routing/router.py`: Pass peers to `NetworkingHandle`
- `src/exo/main.py` : `--bootstrap-peers` CLI arg +
`EXO_BOOTSTRAP_PEERS` env var
## Why It Works
Bootstrap peers are dialed in the existing retry loop — the same path
taken by peers when mDNS-discovered. The swarm handles connection, Noise
handshake, and gossipsub mesh joining from there.
PeerId is intentionally not required in the multiaddr, the Noise
handshake discovers it.
Docker Compose example:
```yaml
services:
exo-1:
environment:
EXO_BOOTSTRAP_PEERS: "/ip4/exo-2/tcp/30000"
exo-2:
environment:
EXO_BOOTSTRAP_PEERS: "/ip4/exo-1/tcp/30000"
```
## Test Plan
### Manual Testing
<details>
<summary>Docker Compose config</summary>
```
services:
exo-node1:
build:
context: .
dockerfile: Dockerfile.bootstrap-test
container_name: exo-bootstrap-node1
hostname: exo-node1
command: ["-q", "--libp2p-port", "30000", "--bootstrap-peers", "/ip4/172.30.20.3/tcp/30000"]
environment:
- EXO_LIBP2P_NAMESPACE=bootstrap-test
ports:
- "52415:52415"
networks:
bootstrap-net:
ipv4_address: 172.30.20.2
deploy:
resources:
limits:
memory: 4g
exo-node2:
build:
context: .
dockerfile: Dockerfile.bootstrap-test
container_name: exo-bootstrap-node2
hostname: exo-node2
command: ["-q", "--libp2p-port", "30000", "--bootstrap-peers", "/ip4/172.30.20.2/tcp/30000"]
environment:
- EXO_LIBP2P_NAMESPACE=bootstrap-test
ports:
- "52416:52415"
networks:
bootstrap-net:
ipv4_address: 172.30.20.3
deploy:
resources:
limits:
memory: 4g
networks:
bootstrap-net:
driver: bridge
ipam:
config:
- subnet: 172.30.20.0/24
```
</details>
Two containers on a bridge network (`172.30.20.0/24`), fixed IPs,
`--libp2p-port 30000`, cross-referencing `--bootstrap-peers`.
Both nodes found each other and established a connection then ran the
election protocol.
### Automated Testing
4 Rust integration tests in `rust/networking/tests/bootstrap_peers.rs`
(`cargo test -p networking`):
| Test | What it verifies | Result |
|------|-----------------|--------|
| `two_nodes_connect_via_bootstrap_peers` | Node B discovers Node A via
bootstrap addr (real TCP connection) | PASS |
| `create_swarm_with_empty_bootstrap_peers` | Backward compatibility —
no bootstrap peers works | PASS |
| `create_swarm_ignores_invalid_bootstrap_addrs` | Invalid multiaddrs
silently filtered | PASS |
| `create_swarm_with_fixed_port` | `listen_port` parameter works | PASS
|
All 4 pass. The connection test takes ~6s
---------
Signed-off-by: DeepZima <deepzima@outlook.com>
Co-authored-by: Evan <evanev7@gmail.com>
## Motivation
The Nemotron model family in the model picker sidebar was displaying as
"Nemotron" with a generic checkmark icon. Since these models are
NVIDIA's Nemotron models, the category should be branded as "NVIDIA"
with the official NVIDIA logo, consistent with how other families are
branded (e.g., "llama" → "Meta", "gpt-oss" → "OpenAI").
## Changes
- **FamilySidebar.svelte**: Added `nemotron: "NVIDIA"` to the
`familyNames` mapping so the sidebar displays "NVIDIA" instead of
"Nemotron"
- **FamilyLogos.svelte**: Added the NVIDIA "eye" logo as an inline SVG
for the `nemotron` family, matching the `viewBox="0 0 24 24"` /
`fill="currentColor"` pattern used by all other brand logos
- **ModelPickerModal.svelte**: Added `"nemotron"` to the `familyOrder`
array so NVIDIA appears in a consistent position in the sidebar
## Why It Works
The model picker derives categories from the `family` field in TOML
model cards. Nemotron models already have `family = "nemotron"`, but the
three UI components (display name, logo, sort order) lacked explicit
entries for it, causing fallback behavior (auto-capitalized name,
checkmark icon, alphabetical sorting). Adding explicit entries for all
three aligns NVIDIA with the existing brand pattern.
## Test Plan
### Manual Testing
<!-- Hardware: N/A - dashboard UI change only -->
- Built dashboard successfully (`npm run build`)
- Verified the NVIDIA logo renders in the sidebar alongside existing
brand logos
### Automated Testing
- No test changes needed — this is a purely cosmetic dashboard change
---------
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
updates macmon to an upstream fork that fixes m5 max issues.
might see if the upstream version gets merged before we release.
---------
Co-authored-by: Alex Cheema <alexcheema123@gmail.com>
## Motivation
Move back to an MLX LM to improve the Qwen 3.5 experience.
## Test Plan
### Manual Testing
Seems to loop less from testing, no speed regressions.
## Motivation
Some users (primarily in China) are unable to access HuggingFace.co. HF
supports the HF_ENDPOINT env variable, and we also support it, but there
is no way to easily do that from the app currently.
## Test Plan
### Manual Testing
hf-mirror works
empty field works
google.com endpoint fails
a fix from pr #1643 which is now stale - should make prefill more
consistent on very slow machines
## testing
qwen-3.5-35b-a3b loads normally
gpt-oss-120b-mxfp4-q8 loads normally
## Motivation
Batch generation reports incorrect statistics, as mlx lm never clears
the original stats, meaning they get polluted over time.
The dashboard also seems considerably slower than bench statistics.
We also have a large discrepancy between B=1 batch generating and
mlx_generate.
Extracting logprobs is massively expensive, causing up to a 25% slowdown
compared to pure batching.
```
[ 12:02:01.1240AM | INFO ] step overhead: 3.49ms (next=12.49ms total=15.99ms)
[ 12:02:02.1600AM | INFO ] step overhead: 3.23ms (next=13.01ms total=16.24ms)
[ 12:02:03.2228AM | INFO ] step overhead: 3.28ms (next=13.38ms total=16.66ms)
[ 12:02:04.2798AM | INFO ] step overhead: 3.25ms (next=12.84ms total=16.10ms)
[ 12:02:05.3152AM | INFO ] step overhead: 3.18ms (next=12.61ms total=15.79ms)
[ 12:02:06.3522AM | INFO ] step overhead: 3.41ms (next=12.83ms total=16.25ms)
[ 12:02:07.3987AM | INFO ] step overhead: 3.38ms (next=13.14ms total=16.52ms)
[ 12:02:08.4537AM | INFO ] step overhead: 1.84ms (next=19.44ms total=21.28ms)
```
## Changes
1. Report stats ourselves instead of using mlx lm's stats for batch
generation (they use perf_counter anyway).
2. Adjust exo bench to match
3. Improve logprobs extraction speed by 10x, improving tps for dashboard
& any requests for logprobs
4. Use an SSE comment to align the speed to the real numbers at the end
of generation
5. Patch mlx for several optimizations given our assumptions and use
cases (e.g. use vllm style RoPE).
6. Switch MLX LM version to latest main, including support for Nemotron
Super and some Qwen3.5 fixes.
## Why It Works
1. Exo bench no longer reports polluted stats
2. Exo bench now handles the reported per-request stats rather than the
aggregate stats
3. The decode speed now jumps back to a real number at the end of the
generation
4. Large batch speedup for rotating KV cache models + 1:1 matching cache
with vllm
## Test Plan
### Manual Testing
Needs testing on OpenCode and CC
Needs eval testing
### Automated Testing
Only going to show the performance optimization difference after the
accurate reporting:
**GPT OSS 20B MXFP4 Q8 (large change)**
Before:
<img width="2466" height="1534" alt="image"
src="https://github.com/user-attachments/assets/88b50637-fca2-4db4-9413-b9eee6e2057e"
/>
<img width="2410" height="1240" alt="image"
src="https://github.com/user-attachments/assets/21e5c76a-2f5f-44d2-8953-121b3ebdbd68"
/>
After:
<img width="2476" height="1472" alt="image"
src="https://github.com/user-attachments/assets/fec5cfbd-fff8-430a-b12e-a329410107a2"
/>
<img width="2454" height="1236" alt="image"
src="https://github.com/user-attachments/assets/0400344b-a4a6-42c0-a9dd-4ee91ade714a"
/>
**Qwen 3.5 35B A3B 8bit (No change)**
Before:
<img width="2414" height="1396" alt="image"
src="https://github.com/user-attachments/assets/e75f0b38-df5d-49fd-ab90-bc1667d981b3"
/>
After:
<img width="2346" height="1234" alt="image"
src="https://github.com/user-attachments/assets/eabfb59c-851f-4d88-b927-e1e699a75cc6"
/>
**Llama 3.2 1B Instruct 4bit (small change)**
Before:
<img width="2516" height="1220" alt="image"
src="https://github.com/user-attachments/assets/c2873655-acff-4536-8263-fb8aea33db80"
/>
After:
<img width="2566" height="1370" alt="image"
src="https://github.com/user-attachments/assets/15f95c75-1c2f-4474-85a2-88c4d0a32543"
/>
## Motivation
Running exo in offline mode on a machine where a model has never been
downloaded causes a crash
## Changes
- `download_shard` now catches `FileNotFoundError` from
`fetch_file_list_with_cache` and returns a `not_started` progress
instead of propagating the exception
## Why It Works
A status query should never crash its caller. By returning
`not_started`, the coordinator's existing offline guard (`if
self.offline:` at line 198) is reached and emits a graceful
`DownloadFailed` event. This also eliminates the warning spam on startup
where the status iterator catches the same exception for every
predefined model.
## Test Plan
### Manual Testing
- Start exo with `--offline` on a machine with no cached models, request
a model via the API — should get a graceful failure instead of a crash
## Motivation
Custom model cards were only saved locally on the node that handled the
API request.
## Changes
- Added AddCustomModelCard and DeleteCustomModelCard commands
- Added CustomModelCardAdded and CustomModelCardDeleted events
- Added custom_model_cards field to cluster State
- Master handles new commands by emitting corresponding events
- Workers persist model cards to disk and update the in-memory cache on
event receipt
- Separated fetch_from_hf (pure fetch) from disk persistence (now
handled by event-sourcing layer)
- Exposed add_to_card_cache() helper for the worker to update the cache
## Why It Works
- Follows the existing event-sourcing pattern: API → Command → Master →
Event → all Workers
- Every node applies the same events, so custom model cards are
consistent across the cluster
## Test Plan
### Manual Testing
Add/delete a custom model via the API on one node, verify it
appears/disappears on all nodes
### Automated Testing
Existing tests cover apply() logic; new event types follow the same
discriminated-union pattern
## Motivation
When placing a model instance across the cluster, the master previously
only considered available RAM. This meant it could pick a node that
hasn't downloaded the model yet, even when another node already has it
(or is further along in downloading it).
## Changes
- Added download_status parameter to place_instance() in placement.py
- Added _get_node_download_fraction() to compute 0.0–1.0 download
progress per node/model
- Added _cycle_download_score() to sum download fractions across a
cycle's nodes
- Cycle selection now uses a (download_score, available_ram) tuple key —
download progress is the primary sort, RAM is the tiebreaker
- Passed self.state.downloads into place_instance() from master/main.py
## Why It Works
Python's tuple comparison gives download progress strict priority over
RAM, so a node with the model already downloaded will always be
preferred over one with more free RAM but no download.
## Test Plan
### Automated Testing
3 new tests cover: completed download preferred, higher partial progress
preferred, failed download not preferred over no-download node
## Summary
- **Add ISO date to verbose stderr format**: when running with `-v`, the
stderr timestamp changes from `HH:mm:ss.SSS` to `YYYY-MM-DD
HH:mm:ss.SSS`, matching the file log format. This makes it possible to
correlate entries across days when stderr is captured by launchd,
systemd, Docker, or file redirection.
- **File log respects verbosity**: `exo.log` now uses DEBUG level when
`-v` is passed, so the persistent log has the same detail as stderr.
Previously it was always INFO regardless of verbosity.
- **Startup banner with PID**: adds a visual separator and process ID to
the startup message, making it easy to identify session boundaries in
long-running logs (e.g. `grep "Starting EXO"`).
The non-verbose (default) stderr format is unchanged — end-user terminal
experience is not affected.
## Motivation
When exo runs as a service (launchd, systemd, Docker), stderr is
typically captured to a file. Without calendar dates in the timestamp,
it is impossible to tell which day a log entry belongs to. This caused
misidentification of log entries during a multi-day RDMA debugging
session on a 4-node cluster.
The file log (`exo.log`) already had dates and rotation, but only
captured INFO level — missing the DEBUG output needed for postmortem
analysis.
## Test plan
- [x] `basedpyright` — 0 errors, 0 warnings, 0 notes
- [x] `ruff check` — all checks passed
- [x] `pytest` — 249 passed, 1 skipped
Co-authored-by: user <user@m1.note>
rltakashige