Session tracing is now available to all Vercel users, providing end-to-end visibility into the timing of each step in a request's lifecycle, from when it enters Vercel’s infrastructure to execution inside your Vercel Functions.
With session tracing you can:
Start tracing sessions on your deployments directly from the Vercel Toolbar, no setup required.
View spans for Vercel's routing, caching, middleware, and function layers as well as those instrumented in your code.
Share traces with teammates for faster debugging and optimization.
Use tracing alongside logs and metrics to debug, optimize, and improve iteration speed.
Session tracing is free to customers on all plans.
To get started, find Tracing in the Vercel Toolbar, or learn more in the docs.