TryCloudflare Proxy Verify

Use this skill whenever local content needs to be shared via a public URL.

Rule

Never hand back a trycloudflare URL without verifying it first.

Minimum verification:

1. start the local file server or local web service
2. start the trycloudflare tunnel
3. wait until cloudflared reports a public URL
4. request the final public URL yourself
5. confirm expected HTTP status and, when practical, content type or content length
6. only then return the URL

If verification fails, do not share the URL. Retry or tell the user it is not reachable yet.

Preferred flow

For a single file

1. Put the file in a dedicated temp/export directory.
2. Serve that directory locally, for example with python3 -m http.server.
3. Start cloudflared tunnel --url http://127.0.0.1: --no-autoupdate --protocol http2.
4. Poll logs until a https://*.trycloudflare.com URL appears and the tunnel registers successfully.
5. Verify with curl -I /.
6. Return that verified file URL.

For an existing local web app/service

1. Confirm the local service is reachable on localhost.
2. Start cloudflared against that localhost URL.
3. Verify the externally visible URL with curl before sharing.

Important notes

• Prefer --protocol http2 if QUIC stalls or times out.
• Keep the tunnel process alive after sharing the URL.
• If the first tunnel cannot connect, kill it and create a new one.
• For downloads, verify the exact file path, not just the site root.
• Mention that trycloudflare links are temporary.

Resources

scripts/

• share_local_path.sh: start local server, start tunnel, verify public URL

references/

• verification-checklist.md: checklist for reliable URL validation