lfnovo/open-notebook · error · ValueError

Invalid URL format. Check server logs for details.

Error message

Invalid URL format. Check server logs for details.

What it means

This is a catch-all ValueError raised by validate_url when URL parsing fails in an unexpected way (anything that isn't already a ValueError, e.g. an exotic malformed URL that breaks urlparse or an IDNA/encoding issue). It signals the input could not be safely interpreted as a URL. The generic message intentionally hides details; the server log holds the underlying exception.

Source

Thrown at open_notebook/utils/url_validation.py:108

                raise
            # Not an IP address, it's a hostname - need to resolve and check
            try:
                # Resolve hostname to IP address. This is a blocking call -
                # run it off the event loop so a slow/hanging DNS lookup
                # doesn't stall every other concurrent request (this is
                # called on the hot path of model provisioning, potentially
                # once per chat message/transformation).
                await _resolve_safe_ips(hostname)
            except socket.gaierror:
                # Could not resolve hostname - allow it since the URL may be
                # valid in the deployment environment (e.g., Azure endpoints,
                # internal DNS names). We only block link-local addresses.
                pass

    except ValueError:
        raise
    except Exception:
        raise ValueError("Invalid URL format. Check server logs for details.")


async def prepare_pinned_http_target(url: str, provider: str) -> PinnedHttpTarget:
    """
    Validate ``url``, resolve DNS once, and pin the outbound target to a vetted IP.

    Unlike ``validate_url`` alone (which still leaves a DNS-rebinding window
    because httpx resolves again at connect time), this rewrites the request
    URL to the vetted address and sets Host / ``sni_hostname`` so routing and
    TLS verification keep the original hostname.

    ``provider`` is accepted for call-site parity with ``validate_url``.

    Raises:
        ValueError: If the URL is invalid, resolves to a blocked address, or
            cannot be resolved for an outbound request.
    """
    if not url or not url.strip():

View on GitHub (pinned to a7de90d38a)

Solutions

  1. Check the server logs for the underlying exception to see what actually failed parsing
  2. Normalize input before saving: url.strip() and reject empty or control-character strings
  3. Fix or remove the malformed URL in the stored credential/config and retry
  4. If it recurs with a seemingly valid URL, add a targeted log of the raw repr(url) to expose hidden characters

Example fix

// before
await create_credential(data={"url": " http://api.example.com\x00 "})
# after
clean = url.strip().split("\x00")[0]
if not clean.startswith(("http://", "https://")):
    raise ValueError("URL must start with http:// or https://")
await create_credential(data={"url": clean})
Defensive patterns

Strategy: try-catch

Validate before calling

from urllib.parse import urlparse

def is_probably_valid_url(url: str) -> bool:
    if not isinstance(url, str) or not url.strip():
        return False
    try:
        p = urlparse(url.strip())
    except Exception:
        return False
    return p.scheme in ("http", "https") and bool(p.hostname)

Try / catch

try:
    validate_url(url)
except ValueError as e:
    logger.warning("URL rejected (%r): %s", url, e)
    # surface a friendly form-field error, keep the raw repr out of logs if it may hold secrets
    raise HTTPException(status_code=422, detail=str(e)) from e

Prevention

When it happens

Trigger: Calling create_credential or update_credential with a malformed base_url; _build_content_state or _revalidate_config_urls running over stored config containing a corrupt URL string (e.g. 'http://exa mple.com', control characters, non-UTF8 bytes, or a port like 'http://host:99999999999').

Common situations: Typo'd provider URL pasted into the credential/config form; DB rows where the URL field contains whitespace, unicode homoglyphs, or was truncated; a URL with an invalid port or unbracketed IPv6.

Related errors

AI-assisted analysis of lfnovo/open-notebook@a7de90d38a (2026-08-27). Data as JSON: /api/errors/8de478b8c0fb11f4. Report an issue: GitHub.