Collaborating with Anthropic on Claude Sonnet 4.5 to power intelligent coding agents
By Steven Van ·
Vercel adds Claude Sonnet 4.5 to AI Gateway and launches an open-source Coding Agent Platform template built on it.
Claude Sonnet 4.5 is now live on Vercel AI Gateway with full support in the AI SDK. Vercel has been testing the model in v0, in its Next.js build pipelines, and in a new Coding Agent Platform template, and reports gains in design sensibility and code quality when building and linting Next.js applications.
- On Next.js builds, Vercel says the model has higher first-pass success rates and fewer missing dependency errors, correctly inferring which packages to add to package.json before builds run.
- It shows stronger adherence to Next.js and ESLint defaults, and better handling of framework-specific functionality such as using Image from next/image.
- In v0, Vercel reports cleaner component structures, better Tailwind usage, more accessible UI patterns, and better handling of complex prompts and applications like 3D worlds, often in a single attempt.
Alongside the model, Vercel released a Coding Agent Platform template that defaults to Anthropic's Claude Code agent running Claude Sonnet 4.5, alongside support for OpenAI Codex CLI, Cursor CLI, and opencode. After connecting a GitHub organisation, a user picks a repository and defines a task; the agent plans, executes, and commits changes inside an isolated Vercel Sandbox, then opens a pull request for review. The template is open-sourced so teams can fork, audit, and extend it.
