New Delhi, August 4: Anthropic has reportedly blocked OpenAI’s access to its Claude AI models. What exactly did OpenAI do to trigger this sudden move? It is said to be a breach of “terms of service” ahead of the launch of ChatGPT-5 model. Reports suggest that OpenAI may have used Claude in an unusual manner by integrating it into its internal systems. Instead of going through the regular chat interface, it allegedly accessed the model using special developer APIs.

Was it all part of refining the ChatGPT 5 model? Or was it a way to benchmark Claude’s performance? OpenAI’s access to Claude was reportedly revoked at a time when the company is working on GPT-5, an upcoming AI model from OpenAI which is rumored to bring major improvements in coding capabilities. The approach is said to have helped the Sam Altman-run OpenAI to test its internal models behavior under specific conditions to make adjustments as needed. GPT-5 First Look Revealed: OpenAI CEO Sam Altman Shares First Image of Company's Upcoming Model, Says It Recommends ‘Pantheon’ As Best AI Show To Watch.

As per a report of Wired, Anthropic has blocked OpenAI’s access to its API. The decision was allegedly made after Anthropic notified OpenAI that the access was cut off due to "violating the terms of service." Anthropic spokesperson Christopher Nulty reportedly acknowledged the Claude’s rising popularity and noted, “Claude Code has become the go-to choice for coders everywhere.” He added it was not surprising to find out that even "OpenAI's own technical staff were also using our coding tools ahead of the launch of GPT-5."

As per reports, OpenAI allegedly integrated Claude into its internal systems using developer-level APIs rather than the standard chat interface. The approach reportedly helped the company assess Claude’s strengths in areas like coding and writing, while also observing how it handled prompts related to self-harm, defamation, CSAM, and other safety issues.

OpenAI’s chief communications officer Hannah Wong reportedly stated that testing rival AI systems is a common industry practice to track progress and ensure safety. Hannah Wong further said, "While we respect Anthropic’s decision to cut off our API access, it’s disappointing considering our API remains available to them." Truecaller Call Recording Feature To Discontinue for iPhone Users From September 30; Know How To Save Existing Call Recordings.

A day prior of ending OpenAI’s access, Anthropic had reportedly imposed new rate limits on Claude Code, citing unusually high demand and alleged violations of its terms. However, Anthropic spokesperson Christopher Nulty is said to have confirmed that they will "continue to ensure OpenAI has API access for the purposes of benchmarking and safety evaluations as is standard practice across the industry."

(The above story first appeared on LatestLY on Aug 04, 2025 03:27 PM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).