GitHub used Copilot to rewrite the shared runtime behind its coding agents from TypeScript into Rust. In its September account of the migration, the company says agents wrote most of more than 800,000 lines of production code while a developer directed the project.
The work landed through 128 pull requests and shipped incrementally. GitHub reports that regressions were found and fixed along the way, while the wider team continued adding capabilities to the runtime.
The runtime supports the Copilot CLI, app and SDK and is shared by multiple products.
GitHub describes work completed primarily by one developer over several months. The article was originally published September 16 and updated September 23.