In the world of artificial intelligence, The fight between Anthropic and OpenAI is reaching ever-increasing levels.The recent movements of both companies show a technological and commercial rivalry without respiteAnthropic's recent decision to restrict OpenAI's access to the Claude API has exposed the tension that underlies the development and testing of today's most advanced AI models.
This confrontation is not just a matter of business competition. The way both firms manage their technologies, services and resources It's changing the rules of the game and raising debates about openness, legality, and interoperability in artificial intelligence. The sector is witnessing a phase where collaboration and cross-model analysis are increasingly limited for strategic and contractual reasons.
Anthropic cuts off OpenAI's access to Claude: the API controversy
The spark that ignited the discussion was lit by Anthropic detect that OpenAI engineers were using Claude's API —especially the one dedicated to programming, Claude Code— to compare and refine the imminent GPT-5 model. According to Anthropic spokespersons, this violated the terms of service, where the use of the product for the purpose of building competing services or reverse engineering is expressly prohibited.
Traditionally, companies in the sector have relied on testing third-party models as part of their own development. However, Anthropic's move represents a change of direction. turning what was once common practice into a red lineThe company owned by siblings Dario and Daniela Amodei is making it clear that access to its tools will not be free for direct competitors.
For its part, OpenAI has defended its actions as a standard practice in the industry to evaluate progress and improve the security of its own models. The company led by Sam Altman regretted the decision, noting that "its API remains available for Anthropic."
The truth is that, even if a blockage has occurred, Anthropic will allow some restricted access for benchmarking and safety assessments., considering this a common industry standard. It's not yet clear how the current API closure will affect independent analysis capabilities between the two technologies.
Context: unequal competition and conflicting strategies
La size and resource inequality between Anthropic and OpenAI It's obvious. OpenAI boasts multi-million-dollar valuations, a large user base (more than 800 million weekly), and the ChatGPT ecosystem as one of its main assets, with billions of monthly visits. Anthropic, meanwhile, has grown rapidly, with a valuation close to $100.000 billion and more than 18 million monthly users under Claude.
The differences are not limited to the economic. There are marked technical and philosophical differencesClaude has established itself as a benchmark for developers in programming: in tests such as SWE-bench and Terminal-bench, Claude 4 outperforms GPT-4.1 and Gemini in accuracy and performance on coding-related tasks. This fact explains the OpenAI team's interest in analyzing this model in depth, just before the release of GPT-5, which promises to match or surpass Claude in programming.
On the other hand, Anthropic stands out for its focus on security, privacy and reducing the risk of inappropriate responses, aspects highly valued in business environments, which are opting for its solutions en masse. According to industry reports, Claude has achieved up to 32% share in business AI use, above OpenAI's 25%, despite its historical leadership. In programming, the gap is even wider, with Anthropic at 42% versus OpenAI's 21%.
API blocking: the new standard in AI?
The Anthropic movement is not isolated in the industry. Similar restrictions have emerged at other tech giants., such as Facebook preventing Vine from accessing its APIs or Salesforce limiting Slack use to competitors. The trend reflects a greater territoriality and protection of key assets between companies competing in innovation.
These types of closures have their consequences. The fragmentation of ecosystems, the difficulties in reproducing research, and the potential slowdown of collaborative progress are a concern for much of the expert community. The balance between trade protection and openness in innovation has never been so relevant in the current debate.
In practice, Preventing rivals from accessing APIs is not completely effective., since there are mechanisms such as intermediary accounts or proxies. However, the message that is clear is that Claude considers himself so relevant that even OpenAI needs it as a reference.
What are the practical differences between Claude and ChatGPT?
Both models have distinctive strengths. Claude It allows you to load and analyze long documents (more than 100.000 words), making it very useful in corporate environments that require processing large volumes and complexity of text. It is also designed to avoid biased or erroneous responses, especially in sensitive tasks. ChatGPT, for its part, stands out in creativity, speed of response and its popularity among the general public.
In the business context, preference is usually inclined by Claude in analysis and programming tasks, while ChatGPT leads in creativity, engagement, and everyday applications. Both platforms remain closed, and transparency into their inner workings remains limited, a factor to consider for those seeking to understand or audit these systems.
The rivalry, beyond the competition for users or contracts, reflects a struggle between different conceptualizations of AI, its risks, and access to its capabilities. The industry remains attentive to every move, anticipating changes in access, interoperability, and future collaborations. The definition of the current battle makes it clear that The dispute in artificial intelligence is now being fought more in APIs and terms of service than in academic articles..
