Hosting and troubleshooting

Firewalls, HTTPS, caches and the Authorization header.

HTTPS: Claude only connects to public HTTPS addresses. The settings screen warns you when the site isn't on HTTPS.
Cloudflare and firewalls: don't challenge Anthropic's address range 160.79.104.0/21 on /pennerly/* and /.well-known/* (turn off Bot Fight Mode or add a skip rule for those paths).
Page caches: Pennerly marks its responses as not cacheable. If a cache still serves them, exclude /pennerly/*.
CGI hosts: the server must pass the Authorization header to PHP. WordPress's default .htaccess already does.
Bylinely: Pennerly and Bylinely's own connector can be on together; they use different addresses.