Audit of asyncio.sleep vs time.sleep and event-loop-blocking calls:
- utils/plugin.py: run pip `install_frontmatter_requirements`
(subprocess.check_call) via asyncio.to_thread in load_tool_module_by_id,
load_function_module_by_id, and install_tool_and_function_dependencies.
- retrieval/utils.py: move the synchronous SSRF-guarded requests probe and
loader.load() in get_content_from_url into a sync helper run via
asyncio.to_thread.
- routers/audio.py: write uploaded audio to disk off the event loop in
transcription().
- routers/pipelines.py: write uploaded pipeline file off the event loop in
upload_pipeline().
The existing time.sleep call sites are all in genuinely synchronous
functions (sync requests/DB drivers/daemon threads) with async
counterparts that already use asyncio.sleep, so no time.sleep -> asyncio.sleep
changes were needed.
Claude-Session: https://claude.ai/code/session_01LXR5bYfsfSS42RGHQZu2Ta
Co-authored-by: Claude <noreply@anthropic.com>
Adds a {{USER_AGENT}} custom-header placeholder that relays the inbound
client's User-Agent to upstream model backends, so providers see the real
client instead of Open WebUI's internal aiohttp UA. This makes upstream
usage/cost attribution and backend telemetry possible, and is opt-in
per-connection (no global flag): admins add {{USER_AGENT}} to a connection's
custom headers in Admin > Settings > Connections.
The placeholder is sourced from the live inbound request (with a metadata
fallback for detached RAG/tool calls), so it resolves on every prompt-sending
path, not just chat completions:
- OpenAI completions, Responses API, and proxy — all route through
get_headers_and_cookies, which now passes the request into get_custom_headers.
- Anthropic Messages API (/api/v1/messages) — already covered, it delegates
to the chat completion handler.
- Ollama (/api/chat, /v1/completions, /v1/chat/completions, /v1/messages,
/v1/responses) — previously had no custom-header support at all; send_request
now applies per-connection custom headers (with templating) for every
Ollama prompt endpoint.
Custom headers are applied after the built-in user-info headers so explicit
admin-configured headers take precedence. The other existing placeholders
({{CHAT_ID}}, {{USER_ID}}, ...) now also work on the newly covered paths.
Frontend: the connection editor's Headers field is now shown for Ollama
connections too (previously gated to non-Ollama), so the placeholder can be
configured there.
Ref: open-webui/open-webui#26159
get_protected_resource_metadata() only attempted RFC 9728 discovery when
the anonymous `initialize` probe returned 401 with a WWW-Authenticate
header. Some remote MCP servers — notably Google's Gmail/Drive/Calendar
MCPs (gmailmcp.googleapis.com, etc.) — answer 200 to an anonymous
initialize, so OAuth scope and authorization-server discovery silently
failed and connections to them could not be established.
Run the discovery regardless of the probe's HTTP status: prefer the
resource_metadata URL from WWW-Authenticate when present, and otherwise
fall back to the RFC 9728 §4.2 well-known URIs. The trade-off is a couple
of extra well-known GETs during MCP connection setup for servers that
expose no PRM document; behavior for 401-responding servers is unchanged.
validate_url() calls socket.getaddrinfo() for SSRF protection, which
blocks the event loop for 100-700ms per DNS lookup. This affects:
- Image generation (get_image_data) — every external image URL
- Image editing (load_url_image) — every external image URL
- OAuth profile pictures (_process_picture_url) — every login
- Webhook delivery (post_webhook) — every notification
- Image base64 conversion (get_image_base64_from_url) — chat images
Wrap all 5 async call sites in asyncio.to_thread() so DNS resolution
runs in the thread pool. The event loop remains free to serve other
requests during the lookup.
Benchmark (3 domains, 3 trials averaged):
- BEFORE: max jitter 479ms, 1 blocked ping per trial
- AFTER: max jitter 1ms, 0 blocked pings (324x improvement)
Co-authored-by: Tim Baek <tim@openwebui.com>
