Bluesky Buys the ATProto Trademark to Fend Off a Legal Threat

Bluesky has purchased the trademark rights to “AT Protocol,” “atproto,” and related variants from a company that had threatened litigation over use of the name. The move is defensive: under U.S. law, an unenforced mark is vulnerable to being claimed by others, so Bluesky acquired and now intends to actively defend it rather than let a bad actor lock the community out of terminology it already relies on.

The company says it won’t charge the ecosystem to use the mark. Ordinary uses—building compatible apps, naming open-source packages, writing documentation, or discussing the protocol—need no license, provided the usage is accurate, doesn’t imply official endorsement, and keeps the developer’s own brand at least as prominent. A license is only required when the name crosses from description into branding: product and company names built around the protocol, paid events, merchandise, domains, certifications, or use of the official logo. Impersonation and passing off an incompatible system as atproto are prohibited.

Ownership sits with Bluesky PBC for now purely as a matter of practicality, since the corporation had the resources to move quickly. Bluesky says it plans to transfer the trademark to an independent protocol governance organization later, and explicitly not to the PLC association, whose charter is limited to running the directory. The company frames the whole arrangement as consistent with how open projects like Rust, Python, Mozilla, Apache, and Linux handle their own marks.