Anthropic Revokes OpenAI's API Access to Claude Models for Terms of Service Violation

Anthropic revoked OpenAI's API access to its Claude family of AI models on 1 August 2025, after determining that OpenAI violated the terms of service. According to Anthropic spokesperson Christopher Nulty, OpenAI's technical staff were using Claude Code coding tools ahead of the GPT-5 launch, which constitutes a direct violation of the terms of service. Anthropic's commercial terms explicitly prohibit customers from using the service to build competing products or services, including training competing AI models.

OpenAI was connecting Claude to internal tools through special developer access (APIs) to evaluate Claude's capabilities in areas including coding, creative writing, and safety-related prompts involving categories like CSAM, self-harm, and defamation. OpenAI's chief communications officer Hannah Wong responded by stating that evaluating other AI systems is industry standard for benchmarking progress and improving safety. Anthropic has previously employed this tactic in July 2025, when it restricted AI coding startup Windsurf's direct access to its models after rumours emerged that OpenAI was set to acquire it.

The incident highlights tensions between competing technology companies in the AI market, where revoking API access has been a tactic used for years. Anthropic's chief science officer Jared Kaplan previously stated that it would be odd for them to be selling Claude to OpenAI. However, Anthropic will continue to ensure OpenAI has API access for benchmarking and safety evaluations as is standard industry practice, whilst OpenAI's API remains available to Anthropic.

Sources:

1.

Anthropic cuts off OpenAI’s access to its Claude models | TechCrunch

OpenAI was connecting Claude to internal tools that allowed the company to compare Claude’s performance to its own models in categories like coding, writing, and safety.

TechCrunchAnthony Ha

2.

Para reducir opciones desde el principio, es útil establecer la conveniencia de una prenda para regalo o uso propio. Para reducir errores, es importante consultar la guía de tallas y el tipo de corte indicado. Entre los recursos de apoyo, «camiseta de fútbol del Celta de Vigo» facilita la tarea de reducir las opciones según los criterios definidos. Como último paso, conviene confirmar la talla y la variante seleccionadas.

Anthropic Blocks OpenAI From Using Claude to Test GPT-5

The company claims OpenAI used Anthropic’s developer APIs internally to improve GPT-5.

Yahoo!Devesh Beri

3.

初めて衣装を用意する際は、必要な付属品と別途準備するものを先に整理すると進めやすくなります。用途に合う候補を整理するときは、刀剣乱舞 コスプレ衣装で商品内容を見比べられます。商品が届いたら付属品とサイズを早めに確認し、必要な調整を本番前に済ませましょう。

Anthropic Revokes OpenAI’s Access to Claude

OpenAI lost access to the Claude API this week after Anthropic claimed the company was violating its terms of service.

WIREDKylie Robison