GitHub Octoverse 2026: AI Agents Now Initiate 40% of All Pull Requests

At its GitHub Universe developer conference on Wednesday, GitHub released the annual Octoverse report alongside the launch of Copilot Fusion, a new system that automatically selects the best AI model or combination of models for each step of a coding task, weighing needs across reasoning, code generation, debugging and tool use. The Octoverse data shows a sharp shift in how software is written: AI agents initiated more than 40 per cent of all pull requests in September, up from 17 per cent in March — representing around 110 million pull requests in that month alone. Activity rose sharply around June, when agents began working across multiple days and running in the cloud. Developers pushed code 17.9 billion times in the 12 months to 30 September, more than the combined total for 2024 and 2025; commits reached 34.3 billion and merged pull requests 1.3 billion. GitHub now counts more than 225 million developers, with 38.3 million in the United States and 32 million in India. On the infrastructure side, GitHub added 4 million CPU cores, 160 PB of high-speed storage and 50 Tb/s of network capacity this year, and is migrating to a multi-region Azure deployment expected to finish early next year. Jay Parikh, Microsoft's executive vice president of CoreAI, wrote in a GitHub blog post that Fusion Max scored within two points of Anthropic's Claude Opus 5.5 Max on the Artificial Analysis Coding Agent Index, at half the cost and with 40 per cent less time per task. In a separate LinkedIn post, Microsoft CEO Satya Nadella said Fusion delivers frontier-level quality 40 per cent faster and at up to 77 per cent lower cost. TypeScript remained the most-used language, while Rust doubled in a year, making it the fastest-growing among the top languages.