GPT-5.5 Brings State-of-the-Art Agentic Coding to Copilot OpenAI's GPT-5.5 is now rolling out on GitHub Copilot for Pro+, Business, and Enterprise users. According to GitHub's early testing, GPT-5.5 "resolves real-world coding challenges previous GPT models couldn't." The headline numbers back that up: 82.7% on Terminal-Bench 2.0 (command-line workflows requiring planning and tool use), 58.6% on SWE-Bench Pro (real-world GitHub issue resolution), and strong gains on Expert-SWE (long-horizon tasks with ~20 hour median human completion times). This is a fully retrained model built specifically for agentic coding—not an incremental improvement on GPT-5.4. OpenAI's release notes emphasize its ability to complete complex, multi-step tasks without human direction, and crucially, it uses fewer tokens to complete the same tasks than GPT-5.4 while matching its per-token latency. More capable and more efficient is a rare combination in LLM releases.…