Explosive Usage: Anthropic revokes ChatGPT-maker OpenAI’s access to Claude; says OpenAI’s technical staff were using our coding tools to…
Anthropic has cut off OpenAI‘s API access to its Claude family of AI models, citing violations of terms of service after discovering the ChatGPT-maker was using Claude’s coding capabilities to develop its upcoming GPT-5 model, according to a Wired report.“Claude Code has become the go-to choice for coders everywhere, and so it was no surprise to learn OpenAI’s own technical staff were also using our coding tools ahead of the launch of GPT-5,” Anthropic spokesperson Christopher Nulty told Wired. “Unfortunately, this is a direct violation of our terms of service.”Sources familiar with the matter revealed that OpenAI was connecting Claude to internal tools through special developer APIs to benchmark Claude’s performance against its own models in coding, writing, and safety categories. The company was also testing how Claude responded to safety-related prompts involving sensitive content like CSAM, self-harm, and defamation.
API access wars heat up among AI giants
OpenAI defended its actions as “industry standard” practice for evaluating AI systems. “While we respect Anthropic’s decision to cut off our API access, it’s disappointing considering our API remains available to them,” OpenAI’s chief communications officer Hannah Wong said in a statement.Anthropic’s commercial terms explicitly prohibit customers from using Claude to “build a competing product or service, including to train competing AI models.” However, the company stated it would continue providing OpenAI access “for the purposes of benchmarking and safety evaluations as is standard practice across the industry.”
Claude Code usage explosion prompts new limits
The access revocation comes amid explosive demand for Claude Code, Anthropic’s AI-powered coding tool. The company recently announced new rate limits, citing unprecedented usage that has strained capacity.“Some of the biggest Claude Code fans are running it continuously in the background, 24/7,” Anthropic tweeted. “For example, one user consumed tens of thousands in model usage on a $200 plan.”This isn’t Anthropic’s first restriction on competitors. Last month, the company cut off AI coding startup Windsurf’s access after rumors of an OpenAI acquisition. Chief Science Officer Jared Kaplan previously said, “I think it would be odd for us to be selling Claude to OpenAI.”The move reflects broader tensions in the AI industry, where companies increasingly restrict competitor access to their APIs—a tactic previously used by Facebook against Twitter-owned Vine and Salesforce against Slack competitors.
