From the source
Vercel introduced Active CPU pricing for its Fluid compute platform, charging for CPU only when code is actively executing on a vCPU.
The model adds two new metrics—Active CPU and Provisioned Memory—alongside existing invocation billing.
Vercel states the change can bring additional cost savings of up to 90% for workloads with high idle time, such as AI inference, and is enabled by default for Hobby, Pro, and new Enterprise teams.
