NousResearch/hermes-agent · warning · ValueError

Video at {url} exceeds {max_bytes // (1024 * 1024)}MB cap; r

Error message

Video at {url} exceeds {max_bytes // (1024 * 1024)}MB cap; refusing to cache.

What it means

ValueError from the video caching download loop in agent/video_gen_provider.py:310. The provider streams a generated video to disk in 256KB chunks and enforces a hard byte cap; if the running total exceeds max_bytes the partial file is closed, unlinked, and this error raised. It protects the cache directory from unbounded writes.

Source

Thrown at agent/video_gen_provider.py:310

        extension = "mp4"

    ts = datetime.datetime.now().strftime("%Y%m%d_%H%M%S")
    short = uuid.uuid4().hex[:8]
    path = _videos_cache_dir() / f"{prefix}_{ts}_{short}.{extension}"

    bytes_written = 0
    with path.open("wb") as fh:
        for chunk in response.iter_content(chunk_size=256 * 1024):
            if not chunk:
                continue
            bytes_written += len(chunk)
            if bytes_written > max_bytes:
                fh.close()
                try:
                    path.unlink()
                except OSError:
                    pass
                raise ValueError(
                    f"Video at {url} exceeds {max_bytes // (1024 * 1024)}MB cap; refusing to cache."
                )
            fh.write(chunk)

    if bytes_written == 0:
        try:
            path.unlink()
        except OSError:
            pass
        raise ValueError(f"Video at {url} was empty (0 bytes).")

    return path


def success_response(
    *,
    video: str,
    model: str,

View on GitHub (pinned to c896c09c42)

Solutions

1. Raise the max_bytes cap for the provider if the larger video is expected and disk space allows.
2. Request a smaller output (shorter duration / lower resolution) from the video provider.
3. Check the URL actually points at the intended asset — a wrong URL (e.g. an HTML page behind a redirect) can also inflate size; verify with curl -I.

Example fix

# before
provider._max_cache_bytes = 50 * 1024 * 1024  # 50MB, video is 120MB

# after
provider._max_cache_bytes = 256 * 1024 * 1024  # raise cap to fit expected output

import urllib.request

def video_fits_cap(url: str, max_bytes: int) -> bool:
    try:
        size = int(urllib.request.urlopen(urllib.request.Request(url, method="HEAD")).headers["Content-Length"])
    except (KeyError, OSError):
        return True  # unknown; let the streaming cap decide
    return size <= max_bytes

try:
    path = cache_video(url, max_bytes)
except ValueError as exc:
    if "exceeds" in str(exc):
        raise QuotaError("increase max_bytes or request a smaller video") from exc
    raise

When it happens

Trigger: Downloading a generated video whose size exceeds the configured cap — long-duration / high-resolution generations, a provider returning the wrong (larger) asset, or a misconfigured max_bytes set lower than the provider's typical output.

Common situations: User raises resolution/duration without raising the cap; provider default sizes grow after an API change; the cap is read from config that was never set for this provider.

Related errors

• Image at {url} exceeds {max_bytes // (1024 * 1024)}MB cap; r
• Video at {url} was empty (0 bytes).
• Content too large
• Could not fetch image: ${response.status}
• image too large (max ${mb} MB)

AI-assisted analysis of NousResearch/hermes-agent@c896c09c42 (2026-08-14). Data as JSON: /api/errors/f936c5cb9a221f19. Report an issue: GitHub.