arXiv:2611.06034v1 Announce Type: new Abstract: People, companies and software agents often must work on shared records even when they do not trust each other. Today they usually give those records to a central server. The server keeps the canonical copy, authenticates users, and decides who has permissions to act on the record. The CoordX Protocol removes the need for that central server. In the CoordX protocol the author of a record holds full permission over it. Permission for any other party to create, read or update the record is assigned by explicit grants and keys. An invitation only starts contact between two parties. It gives no permission. Each record is a causal tree of signed entries, and each entry is immutable. Each entry names the permission that allowed it. Any party can get the proof of that permission and check it without help from anyone. Two honest parties that check the same bytes, with the same keys and local settings, always get the same answer. The content is encrypted, so the relays that may carry it in transit see only sealed bytes. To exclude a party from future content, the other parties move to new keys. The protocol does not choose a winning version, does not put entries in time order, and does not need global agreement. Applications decide what the entries mean above the level of the protocol.