OpenAI's GPT-5 celebrates its first anniversary, marking a year of significant advancements and the introduction of a new open standard: Agent Plugins. Launched on August 7, 2025, GPT-5 replaced GPT-4o and offered improved reasoning and accuracy. It was integrated into Apple's operating systems, including iOS 26, iPadOS 26, and macOS Tahoe 26, enhancing features like Siri and Writing Tools.

Throughout its first year, GPT-5 saw several iterations, including GPT-5.1 for more natural responses, GPT-5.2 to accelerate professional work, and GPT-5.3 Instant to address tone. GPT-5.4 Thinking introduced a million-token context window and built-in computer use, followed by mini, nano, and specialized versions like GPT-5.4-Cyber. Later updates included GPT-5.5 for autonomous work and the GPT-5.6 Sol, Terra, and Luna models.

OpenAI also launched a dedicated Codex Mac app, which evolved into the new Chat GPT desktop app, integrating chat, work, and coding functionalities. The company is now introducing Agent Plugins, an open, vendor-neutral standard designed for reusable AI-agent extensions to work across compatible products. This new standard aims to standardize the packaging of skills and servers, with a steering committee including Amazon, Microsoft, and OpenAI.