oobabooga/textgen · error · Exception

Could not start cloudflared.

Error message

Could not start cloudflared.

What it means

Raised by _start_cloudflared (modules/api/utils.py:53) after max_attempts (default 3) consecutive failures of _run_cloudflared — the cloudflared binary ran but could not establish a tunnel (no route to Cloudflare edge, invalid/already-bound ports, tunnel_id rejected, missing binary). Each attempt's traceback is printed and the loop sleeps 3s before retrying.

Source

Thrown at modules/api/utils.py:53

        raise Exception(
            'flask_cloudflared not installed. Make sure you installed the requirements.txt for this extension.')

    for _ in range(max_attempts):
        try:
            if tunnel_id is not None:
                public_url = _run_cloudflared(port, port + 1, tunnel_id=tunnel_id)
            else:
                public_url = _run_cloudflared(port, port + 1)

            if on_start:
                on_start(public_url)

            return
        except Exception:
            traceback.print_exc()
            time.sleep(3)

    raise Exception('Could not start cloudflared.')

View on GitHub (pinned to ed888c71f2)

Solutions

1. Check the printed tracebacks of all 3 attempts — they distinguish network failure from binary/port issues.
2. Ensure outbound TCP:7844 (and DNS) to Cloudflare is allowed; on restricted networks try cloudflared's --edge-ip-version or HTTP/2 fallback.
3. Kill stale cloudflared processes (pkill cloudflared) so ports port/port+1 are free, then retry.
4. If tunnels are systematically blocked, drop --public-api and expose via --listen + your own proxy.

Example fix

# before
python server.py --api --public-api   # retries 3x, then: Could not start cloudflared.

# after
pkill -f cloudflared
python server.py --api --listen   # LAN exposure without tunnel

import socket, subprocess

def tunnel_prereqs_ok(port: int) -> bool:
    # local ports free
    for p in (port, port + 1):
        with socket.socket() as s:
            try:
                s.bind(('0.0.0.0', p))
            except OSError:
                return False
    return True

for attempt in range(3):
    if start_server_with_public_api():
        break
    pkill_cloudflared()
    time.sleep(3)
else:
    fall_back_to_lan_listen()  # run without --public-api

When it happens

Trigger: Launching with --public-api (optionally --public-api-id) on a machine with no outbound connectivity to Cloudflare edge (port 7844 blocked), where cloudflared is not installed/downloadable, or the local metrics port (port+1) is already in use by a previous cloudflared instance.

Common situations: Firewalled/containerized environments blocking QUIC/TCP to Cloudflare; stale cloudflared process holding the tunnel or ports; offline machines; repeated starts leaving orphaned tunnel processes.

Related errors

• flask_cloudflared not installed. Make sure you installed the
• you MUST enable IPv6 or IPv4 for the API to work
• Access to non-public address {ip} is blocked
• Could not resolve hostname: {hostname}
• Too many redirects (max {max_redirects})

AI-assisted analysis of oobabooga/textgen@ed888c71f2 (2026-08-15). Data as JSON: /api/errors/07a07c3b4701a71e. Report an issue: GitHub.