VercelDeployer

The VercelDeployer bundles your Mastra server and generates output conforming to Vercel's Build Output API. Vercel deploys this output directly as serverless functions.

Installation

To use VercelDeployer, install the @mastra/deployer-vercel package:

npm

npm install @mastra/deployer-vercel@latest

pnpm

pnpm add @mastra/deployer-vercel@latest

Yarn

yarn add @mastra/deployer-vercel@latest

Bun

bun add @mastra/deployer-vercel@latest

Usage example

Import VercelDeployer and set it as the deployer in your Mastra configuration:

src/mastra/index.ts

import { Mastra } from '@mastra/core'
import { VercelDeployer } from '@mastra/deployer-vercel'

export const mastra = new Mastra({
  deployer: new VercelDeployer(),
})

Constructor options

The deployer accepts the following options:

• studio?: boolean: Deploy Studio alongside your API as static assets served from Vercel's Edge CDN. Defaults to false.
• maxDuration?: number: Function execution timeout (in seconds)
• memory?: number: Function memory (in MB)
• regions?: string[]: Regions to deploy the function (e.g. ['sfo1','iad1'])

The maxDuration, memory, and regions options are merged into .vercel/output/functions/index.func/.vc-config.json while preserving default fields (handler, launcherType, runtime, shouldAddHelpers).

Example with overrides

src/mastra/index.ts

import { Mastra } from '@mastra/core'
import { VercelDeployer } from '@mastra/deployer-vercel'

export const mastra = new Mastra({
  deployer: new VercelDeployer({
    studio: true,
    maxDuration: 600,
    memory: 1536,
    regions: ['sfo1', 'iad1'],
  }),
})

Build output

After running mastra build, the deployer generates a .vercel/output directory conforming to Vercel's Build Output API (v3). This directory contains routing configuration and serverless function bundles that Vercel deploys directly, bypassing framework detection.

The output contains:

• config.json: Routing configuration that directs requests to the appropriate handler
• functions/: Your Mastra server bundled as a serverless function
• static/: Studio SPA assets (only when studio: true)

Without studio:

.vercel/
└── output/
    ├── config.json
    └── functions/
        └── index.func/
            ├── .vc-config.json
            ├── index.mjs
            └── node_modules/

With studio: true:

.vercel/
└── output/
    ├── config.json
    ├── static/
    │   ├── index.html
    │   └── assets/
    │       ├── *.js
    │       └── *.css
    └── functions/
        └── index.func/
            ├── .vc-config.json
            ├── index.mjs
            └── node_modules/

When studio is enabled, the routing is configured so that / and the Studio routes listed in the Studio build's route manifest are served from index.html for client-side routing, and static assets (JS, CSS) are served from Vercel's Edge CDN with no function invocations. All other paths, including /api/* and custom routes registered with registerApiRoute(), are handled by the serverless function. Custom routes that fall under a Studio route (for example, /agents/custom) are served from index.html instead, so register custom routes outside Studio's route roots.

This folder is generated during build and shouldn't be committed to version control.