v0

v0 uses the server while it builds: it can check your sending domain, draft templates and send a test. The app it generates sends through the Unitpost SDK with an API key, because v0's MCP tools aren't available to generated code.

1. 1

   Add the server

   In a v0 chat, open the + menu in the prompt form → MCPs → add a custom server with the URL below, and choose OAuth for authentication. No key to copy. Your client opens Unitpost in the browser — pick a workspace, approve the scopes, and you're connected. Tokens refresh automatically.

   Text

   https://mcp.unitpost.com/mcp

2. 2

   Verify

   Ask v0 to list your Unitpost sending domains. It should call email_domains_list; v0 asks before running a tool unless your chat's permission mode allows it.

3. 3

   Send from the app v0 builds

   Create an API key in Unitpost (Settings → API keys, scoped to emails:send), add it to the v0 project as the environment variable UNITPOST_API_KEY, and ask v0 to send email with the unitpost npm package.

   TypeScript

   import { Unitpost } from "unitpost";
   
   const unitpost = new Unitpost(); // reads process.env.UNITPOST_API_KEY
   
   await unitpost.email.send({
     from: "hello@yourdomain.com",
     to: "you@example.com",
     subject: "Hello from v0",
     html: "<p>It works.</p>",
   });

   The from address needs a verified domain. Keep the key in environment variables, never in the code v0 writes.