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VercelConfig

The main configuration object for Vercel Build Output API v3.

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Type definition

type VercelConfig = {
  version: 3;
  routes?: Route[];
  images?: ImagesConfig;
  wildcard?: WildcardConfig;
  overrides: OverridesConfig;
  cache?: string[];
}

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Properties

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version
3
required
Build Output API version. Always set to 3.
​
routes
Route[]
Array of routing rules defining how requests are handled. Includes rewrites, redirects, headers, and function mappings.
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images
ImagesConfig
Image optimization configuration from Next.js image config.
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wildcard
WildcardConfig
i18n domain wildcard configuration for locale-specific domains.
​
overrides
OverridesConfig
required
Map of file paths to override configurations for static files.
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cache
string[]
Array of cache control patterns.

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Example

const vercelConfig: VercelConfig = {
  version: 3,
  overrides: {},
  routes: [
    { handle: 'filesystem' },
    { src: '^/api/.*', dest: '/api/handler' },
  ],
  images: {
    sizes: [640, 750, 828, 1080, 1200],
    domains: ['example.com'],
    formats: ['image/avif', 'image/webp'],
  },
};

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ImagesConfig

Configuration for Next.js Image Optimization.

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Type definition

type ImagesConfig = {
  sizes: number[];
  domains: string[];
  remotePatterns?: RemotePattern[];
  localPatterns?: LocalPattern[];
  qualities?: number[];
  minimumCacheTTL?: number;
  formats?: ImageFormat[];
  dangerouslyAllowSVG?: boolean;
  contentSecurityPolicy?: string;
  contentDispositionType?: string;
}

​
Properties

​
sizes
number[]
required
Array of allowed image widths. Combines imageSizes and deviceSizes from Next.js config.
​
domains
string[]
required
Allowed domains for remote images.
​
remotePatterns
RemotePattern[]
Pattern-based remote image configuration with regex support.
​
localPatterns
LocalPattern[]
Pattern-based local image configuration.
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qualities
number[]
Allowed quality values for image optimization.
​
minimumCacheTTL
number
Minimum cache TTL in seconds for optimized images.
​
formats
ImageFormat[]
Allowed image formats for optimization.
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dangerouslyAllowSVG
boolean
Whether to allow SVG image optimization.
​
contentSecurityPolicy
string
Content Security Policy for images.
​
contentDispositionType
string
Content-Disposition header type for images.

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Example

const imagesConfig: ImagesConfig = {
  sizes: [640, 750, 828, 1080, 1200, 1920, 2048, 3840],
  domains: ['example.com', 'cdn.example.com'],
  remotePatterns: [
    {
      protocol: 'https',
      hostname: '**.example.com',
      pathname: '/images/**',
    },
  ],
  formats: ['image/avif', 'image/webp'],
  minimumCacheTTL: 60,
};

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WildcardConfig

Configuration for i18n domain wildcards.

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Type definition

type WildcardConfig = Array<WildCard>

type WildCard = {
  domain: string;
  value: string;
}

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Properties

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domain
string
required
The domain name for this locale.
​
value
string
required
The path prefix for the locale. Empty string for default locale.

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Example

const wildcardConfig: WildcardConfig = [
  {
    domain: 'example.com',
    value: '', // default locale
  },
  {
    domain: 'example.fr',
    value: '/fr',
  },
];

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Notes

Generated from Next.js i18n.domains configuration. The value is:
  • Empty string for the default locale
  • /{locale} for non-default locales

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OverridesConfig

Configuration for static file overrides.

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Type definition

type OverridesConfig = Record<
  string,
  { path?: string; contentType?: string }
>

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Structure

A record mapping file paths to override configurations.
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[key]
string
required
The file path to override (e.g., "./about.html").
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[key].path
string
The URL path to serve the file at (e.g., "./about").
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[key].contentType
string
The Content-Type header to use (e.g., "text/html; charset=utf-8").

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Example

const overrides: OverridesConfig = {
  './about.html': {
    path: './about',
    contentType: 'text/html; charset=utf-8',
  },
  './feed.xml': {
    contentType: 'application/xml',
  },
};

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Use case

Primarily used for:
  • Serving HTML files without .html extension
  • Setting correct content types for static files
  • Path rewriting for static assets

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FuncOutputs

Type representing function outputs from Next.js build.

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Type definition

type FuncOutputs = Array<
  | AdapterOutput['PAGES']
  | AdapterOutput['APP_PAGE']
  | AdapterOutput['APP_ROUTE']
  | AdapterOutput['PAGES_API']
  | AdapterOutput['MIDDLEWARE']
>

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Description

Union type of all possible function output types from the Next.js adapter. Each output includes:
  • pathname: URL pathname
  • id: Unique identifier
  • filePath: Path to function entry
  • assets: Required asset files
  • runtime: “nodejs” or “edge”
  • sourcePage: Original page path
  • config: Function configuration

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Example usage

const nodeOutputs: FuncOutputs = [];
const edgeOutputs: FuncOutputs = [];

for (const output of [
  ...outputs.appPages,
  ...outputs.appRoutes,
  ...outputs.pages,
  ...outputs.pagesApi,
]) {
  if ('runtime' in output) {
    if (output.runtime === 'nodejs') {
      nodeOutputs.push(output);
    } else if (output.runtime === 'edge') {
      edgeOutputs.push(output);
    }
  }
}

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NodeFunctionConfig

Configuration for Node.js serverless functions.

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Type definition

type NodeFunctionConfig = Pick<
  NodejsLambda,
  | 'memory'
  | 'maxDuration'
  | 'experimentalTriggers'
  | 'supportsCancellation'
  | 'handler'
  | 'runtime'
  | 'regions'
  | 'allowQuery'
  | 'framework'
  | 'operationType'
  | 'supportsMultiPayloads'
  | 'supportsResponseStreaming'
  | 'experimentalAllowBundling'
> & {
  filePathMap: Record<string, string>;
  useWebApi?: boolean;
  launcherType: 'Nodejs';
}

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Properties

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filePathMap
Record<string, string>
required
Map of required files (relative to repo root).
​
handler
string
required
Path to the function handler file.
​
runtime
string
required
Node.js runtime version (e.g., “nodejs20.x”).
​
operationType
'PAGE' | 'API'
required
Type of operation this function performs.
​
framework
{ slug: string; version: string }
required
Framework metadata. For Next.js: { slug: 'nextjs', version: '14.1.0' }.
​
maxDuration
number
Maximum execution duration in seconds.
​
supportsMultiPayloads
boolean
Whether the function supports multiple payloads. Always true for Next.js.
​
supportsResponseStreaming
boolean
Whether the function supports streaming responses. Always true for Next.js.
​
experimentalAllowBundling
boolean
Whether to allow bundling. Always true for Next.js.
​
useWebApi
boolean
Whether to use Web API (Request/Response) instead of Node.js API. true for middleware.
​
launcherType
'Nodejs'
required
Launcher type identifier.

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EdgeFunctionConfig

Configuration for Edge Functions.

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Type definition

type EdgeFunctionConfig = {
  runtime: 'edge';
  name: string;
  entrypoint: string;
  environment: Record<string, string>;
  filePathMap: Record<string, string>;
  assets?: Array<{ name: string; path: string }>;
  deploymentTarget: string;
  regions?: 'all' | string | string[];
  framework?: { slug: string; version: string };
}

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Properties

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runtime
'edge'
required
Runtime identifier for Edge Functions.
​
name
string
required
Function name.
​
entrypoint
string
required
Path to the function entrypoint.
​
filePathMap
Record<string, string>
required
Map of JavaScript files required by the function.
​
assets
Array<{ name: string; path: string }>
Non-JavaScript assets (WASM, JSON, etc.).
​
deploymentTarget
string
required
Deployment target. Always "v8-worker" for Edge Functions.
​
environment
Record<string, string>
required
Environment variables for the function.
​
regions
'all' | string | string[]
Deployment regions for the function.
​
framework
{ slug: string; version: string }
Framework metadata.

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Example

const edgeConfig: EdgeFunctionConfig = {
  runtime: 'edge',
  name: 'middleware',
  entrypoint: 'middleware/index.js',
  filePathMap: {
    'middleware.js': 'middleware.js',
  },
  assets: [
    { name: 'data.json', path: 'assets/data.json' },
  ],
  deploymentTarget: 'v8-worker',
  environment: {},
  regions: 'all',
  framework: {
    slug: 'nextjs',
    version: '14.1.0',
  },
};

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