A group of tech workers today published an open letter signed by 1,134 signatories from companies building frontier AI models, including Anthropic PBC, OpenAI Group PBC, Google LLC, Meta Platforms Inc., Thinking Machines Inc., and Inherent Laboratories Ltd. The letter focuses on major tech firms' efforts to automate model development programs with AI, warning that "there is a real risk that capability development rapidly accelerates beyond our ability to understand or control the resulting systems." The signatories argue the industry needs a way to "deliberately pace" automated AI development but that the necessary tools are currently unavailable. They request that "the U.S. government support an international effort to develop the technical and governance tools needed to deliberately pace the frontier of automated AI development." The letter follows recent disclosures: in April, OpenAI revealed its GPT-5.5 large language model helped optimize its Nvidia graphics card cluster, increasing token generation speeds up more than 20%, and Anthropic disclosed it is using Claude to speed up its AI safety research.