What causes "The remote service appears unreachable at this time." in Comfy-Org/ComfyUI?

Open the API host directly in a browser or with curl from the same machine to confirm reachability.

Comfy-Org/ComfyUI · error · ApiServerError

The remote service appears unreachable at this time.

Error message

The remote service appears unreachable at this time.

What it means

Companion to 775: the request failed with ClientError/OSError after retries, but connectivity diagnosis shows the local network IS working — so the remote API endpoint itself is unreachable. Raised as ApiServerError pointing at the service, not the user's machine.

Source

Thrown at comfy_api_nodes/util/download_helpers.py:198

            raise ProcessingInterrupted("Task cancelled") from None
        except (ClientError, OSError) as e:
            if attempt <= max_retries:
                request_logger.log_request_response(
                    operation_id=op_id,
                    request_method="GET",
                    request_url=url,
                    error_message=f"{type(e).__name__}: {str(e)} (will retry)",
                )
                await sleep_with_interrupt(delay, cls, None, None, None)
                delay *= retry_backoff
                continue

            diag = await _diagnose_connectivity()
            if not diag["internet_accessible"]:
                raise LocalNetworkError(
                    "Unable to connect to the network. Please check your internet connection and try again."
                ) from e
            raise ApiServerError("The remote service appears unreachable at this time.") from e
        finally:
            if stop_evt is not None:
                stop_evt.set()
            if monitor_task:
                monitor_task.cancel()
                with contextlib.suppress(Exception):
                    await monitor_task
            if req_task and not req_task.done():
                req_task.cancel()
                with contextlib.suppress(Exception):
                    await req_task
            if session:
                with contextlib.suppress(Exception):
                    await session.close()
            if fhandle:
                with contextlib.suppress(Exception):
                    fhandle.flush()
                    fhandle.close()

View on GitHub (pinned to 1c6d8d45b3)

Solutions

Open the API host directly in a browser or with curl from the same machine to confirm reachability.
Check the provider's status page / support channels for an outage.
Update ComfyUI — endpoint hostnames occasionally migrate.
If behind a firewall, allow egress to the API's media domain.

Defensive patterns

Strategy: retry

Validate before calling

import socket

try:
    socket.getaddrinfo(api_host, 443)
except socket.gaierror:
    raise RuntimeError(f'Cannot resolve API host {api_host}; endpoint may have moved')

Try / catch

try:
    await download(url, ...)
except ApiServerError:
    await asyncio.sleep(60)
    return await download(url, ...)  # provider outages are usually transient

Prevention

Watch the provider's status page when ApiServerError appears repeatedly.
Keep ComfyUI updated so API endpoints match current hostnames.
Firewall rules must allow the provider's media domains, not just the main API host.

When it happens

Trigger: The local internet probe succeeds but the specific API host cannot be reached: provider outage, regional CDN issue, host blocked by a firewall rule, stale/hardcoded endpoint, or the service hostname no longer resolving to a live server.

Common situations: Provider-side outage (check status page); DNS entry for the API removed after a shutdown; a firewall allowlist that does not include the media host; asymmetric routing via VPN.

Related errors

AI-assisted analysis of Comfy-Org/ComfyUI@1c6d8d45b3 (2026-08-14). Data as JSON: /api/errors/d9e1e32576239c38. Report an issue: GitHub.