OpenAI Releases GPT-5.5, GPT-5.5 Pro, and Expanded Suite of Models and Tools
Key Takeaways
- ▸GPT-5.5 introduces a 1M token context window with integrated computer use, web search, and multiple advanced capabilities including Skills and MCP support
- ▸New GPT-5.4 mini and nano models provide cost-effective options for high-volume and simple workloads while maintaining strong performance
- ▸Agents SDK now supports controlled sandboxes, memory customization, and open-source harness inspection for greater developer control and flexibility
Summary
OpenAI has unveiled GPT-5.5 and GPT-5.5 Pro, its newest frontier models designed for complex professional work, alongside a comprehensive suite of model and API updates. GPT-5.5 features a 1M token context window, image input, structured outputs, function calling, prompt caching, built-in computer use, Skills support, MCP integration, and web search capabilities, with medium reasoning effort as default. The company also released GPT-5.4 mini and nano variants for cost-effective, high-volume applications, and updated the Agents SDK with sandbox controls, memory management customization, and open-source harness inspection capabilities.
Additionally, OpenAI announced GPT Image 2, a state-of-the-art image generation model with flexible sizing and high-fidelity inputs, and significantly expanded the Sora API with reusable character references, up to 20-second generations, 1080p output on sora-2-pro, and new video editing capabilities. The Responses API now includes tool search for optimized token usage, native compaction support for longer workflows, phase labeling for intermediate commentary, and WebSocket mode support. These announcements represent a comprehensive expansion of OpenAI's platform, emphasizing multi-modal capabilities, performance optimization, and granular developer control.
- Sora API expansion enables longer videos (20 seconds), 1080p output, reusable character references, and Batch API support with video editing capabilities
- Tool search and native compaction features optimize token usage, preserve cache performance, and reduce latency for complex workflows
Editorial Opinion
OpenAI's simultaneous release of frontier-tier (GPT-5.5) and efficiency-tier (GPT-5.4 mini/nano) models signals a maturing platform strategy—democratizing access to advanced capabilities while preserving performance differentiation. The emphasis on developer control through sandbox management, memory customization, and tool search, combined with integrated computer use and web search, positions these models for enterprise automation at scale. This breadth of releases, spanning reasoning-enhanced LLMs, image generation, video generation, and agent infrastructure, demonstrates OpenAI's evolution into a comprehensive AI infrastructure platform.
