xAI and Anthropic sign access deal for Colossus 1 supercluster
Per xAI's May 14 announcement, the company has agreed to provide Anthropic with access to Colossus 1 — the Memphis-based GPU supercluster Elon Musk's xAI built last year. Unusual rival-buys-from-rival arrangement.
xAI announced on May 14 that it has signed an agreement with Anthropic to provide access to Colossus 1, the supercluster xAI built in Memphis. Terms weren't disclosed in the announcement.
The deal is structurally unusual: Anthropic and xAI compete head-to-head on frontier model capability, with both targeting the same enterprise and developer audience. Anthropic buying compute from xAI's rack suggests either (a) acute capacity pressure on Anthropic's existing supplier mix, (b) attractive economics on the Colossus 1 cluster as xAI rotates toward newer infrastructure, or (c) both.
xAI also shipped Grok Build (a terminal coding agent for SuperGrok Heavy subscribers) on the same day, and is retiring grok-4-1-fast, grok-4-fast, grok-4, grok-code-fast-1, and grok-imagine-image-pro on May 15 in favor of grok-4.3.