Bird now connects to Vercel and sets up your API credentials. The integration creates a Bird API key and saves it, with your workspace's regional API endpoint, in the Vercel projects you select. Developers no longer copy either value between dashboards.
During setup, you choose a Bird workspace, your Vercel projects, and a Preview or Production environment. Bird saves BIRD_API_KEY and BIRD_API_BASE_URL as encrypted environment variables.
Finish the installation in Vercel, then redeploy your app so it picks up the variables. The source does not mention plan limits or extra cost.
Source: bird.com