Vercel's CI service, in beta on all plans. It reads your turbo.json, runs only the tasks a change affects, gives each task its own machine and serves unchanged ones from Remote Cache.
The pitch is aimed at agent-heavy repos: coding agents open more PRs than ever, and most CI systems rerun the whole workflow on every push. Vercel CI uses Turborepo's task graph instead. There's no workflow YAML; you tag tasks in turbo.json with "tags": ["ci"], and it works in single-package repos too. Tasks whose inputs haven't changed come from Remote Cache, which is on by default, and the rest each run on their own machine on Hive, Vercel's compute layer, starting as soon as their dependencies finish. Vercel reports 2-6x faster push-to-green on its own repositories.
It posts a GitHub check, so existing branch protection keeps working. Runs can be inspected from the dashboard, the Vercel MCP server or the CLI (vc ci ls, vc ci inspect, vc ci logs --task web#test --level=error, vc ci grep), and setup is itself an agent skill: npx skills use vercel/ci@setup. Launch post.