GitHub Copilot Fusion multi-model routing
- GitHub Copilot Fusion became generally available October 28 at GitHub Universe, routing coding tasks between Claude and GPT models by developer-selected effort level.
- Fusion Max scored 60 on Artificial Analysis's Coding Agent Index against Claude Code with Opus 5.5's 61.7, at $5.59 versus $11.42 per task and about half the token usage, with HydraFusion's offline evaluations showing 4.9 percentage point quality gains at 67% lower cost on TerminalBench 2.1.
- The event also introduced Foundry and Copilot Projects; the Octoverse 2026 report found pull requests tripled to 220 million per month, attributing most of the growth to agentic engineering.
Fusion offers near-frontier coding agent performance at roughly half the cost per task of Claude Code, with automatic model routing across Claude and GPT models. Separately, the Octoverse data shows that commit and pull request volumes have tripled in under a year, straining GitHub's infrastructure to the point of a multi-hour outage.