internal/

Package graphhook holds the Meta Graph webhook plumbing shared by the Cloud API chat adapters (WhatsApp today, Messenger next): the one-time hub.challenge subscribe handshake and the X-Hub-Signature-256 raw-body HMAC check.

Package runechunk splits platform text at readable rune boundaries.

Package wsclient implements a minimal RFC 6455 WebSocket client on the standard library alone: client role only, no extensions, no compression, no subprotocol negotiation.