# Module: index ## Table of contents ### Interfaces - [Geo](../interfaces/index.Geo.md) - [Request](../interfaces/index.Request.md) ### Functions - [geolocation](index.md#geolocation) - [getEnv](index.md#getenv) - [ipAddress](index.md#ipaddress) - [next](index.md#next) - [rewrite](index.md#rewrite) - [waitUntil](index.md#waituntil) ## Functions ### geolocation ▸ **geolocation**(`request`): [`Geo`](../interfaces/index.Geo.md) Returns the location information for the incoming request. **`Example`** ```js import { geolocation } from '@vercel/functions'; export function GET(request) { const details = geolocation(request); return Response.json(details); } ``` #### Parameters | Name | Type | Description | | :-------- | :------------------------------------------ | :-------------------------------------------------------------- | | `request` | [`Request`](../interfaces/index.Request.md) | The incoming request object which provides the geolocation data | #### Returns [`Geo`](../interfaces/index.Geo.md) The location information of the request, in this way: ```json { "city": "New York", "country": "US", "flag": "🇺🇸", "countryRegion": "NY", "region": "iad1", "latitude": "40.7128", "longitude": "-74.0060" "postalCode": "10001" } ``` #### Defined in [packages/functions/src/headers.ts:180](https://github.com/vercel/vercel/blob/main/packages/functions/src/headers.ts#L180) --- ### getEnv ▸ **getEnv**(`env?`): `Object` Get System Environment Variables exposed by Vercel. **`See`** https://vercel.com/docs/projects/environment-variables/system-environment-variables#system-environment-variables #### Parameters | Name | Type | Default value | | :---- | :------- | :------------ | | `env` | `Object` | `process.env` | #### Returns `Object` | Name | Type | Description | | :-------------------------------- | :---------------------- | :-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `CI` | `undefined` \| `string` | An indicator that the code is running in a Continuous Integration environment. **`Example`** `ts "1" ` | | `VERCEL` | `undefined` \| `string` | An indicator to show that System Environment Variables have been exposed to your project's Deployments. **`Example`** `ts "1" ` | | `VERCEL_AUTOMATION_BYPASS_SECRET` | `undefined` \| `string` | The Protection Bypass for Automation value, if the secret has been generated in the project's Deployment Protection settings. | | `VERCEL_BRANCH_URL` | `undefined` \| `string` | The domain name of the generated Git branch URL. The value does not include the protocol scheme https://. **`Example`** `ts "*-git-*.vercel.app" ` | | `VERCEL_DEPLOYMENT_ID` | `undefined` \| `string` | The unique identifier for the deployment, which can be used to implement Skew Protection. **`Example`** `ts "dpl_7Gw5ZMBpQA8h9GF832KGp7nwbuh3" ` | | `VERCEL_ENV` | `undefined` \| `string` | The Environment that the app is deployed and running on. **`Example`** `ts "production" ` | | `VERCEL_GIT_COMMIT_AUTHOR_LOGIN` | `undefined` \| `string` | The username attached to the author of the commit that the project was deployed by. **`Example`** `ts "johndoe" ` | | `VERCEL_GIT_COMMIT_AUTHOR_NAME` | `undefined` \| `string` | The name attached to the author of the commit that the project was deployed by. **`Example`** `ts "John Doe" ` | | `VERCEL_GIT_COMMIT_MESSAGE` | `undefined` \| `string` | The message attached to the commit the deployment was triggered by. **`Example`** `ts "Update about page" ` | | `VERCEL_GIT_COMMIT_REF` | `undefined` \| `string` | The git branch of the commit the deployment was triggered by. **`Example`** `ts "improve-about-page" ` | | `VERCEL_GIT_COMMIT_SHA` | `undefined` \| `string` | The git SHA of the commit the deployment was triggered by. **`Example`** `ts "fa1eade47b73733d6312d5abfad33ce9e4068081" ` | | `VERCEL_GIT_PREVIOUS_SHA` | `undefined` \| `string` | The git SHA of the last successful deployment for the project and branch. NOTE: This Variable is only exposed when an Ignored Build Step is provided. **`Example`** `ts "fa1eade47b73733d6312d5abfad33ce9e4068080" ` | | `VERCEL_GIT_PROVIDER` | `undefined` \| `string` | The Git Provider the deployment is triggered from. **`Example`** `ts "github" ` | | `VERCEL_GIT_PULL_REQUEST_ID` | `undefined` \| `string` | The pull request id the deployment was triggered by. If a deployment is created on a branch before a pull request is made, this value will be an empty string. **`Example`** `ts "23" ` | | `VERCEL_GIT_REPO_ID` | `undefined` \| `string` | The ID of the repository the deployment is triggered from. **`Example`** `ts "117716146" ` | | `VERCEL_GIT_REPO_OWNER` | `undefined` \| `string` | The account that owns the repository the deployment is triggered from. **`Example`** `ts "acme" ` | | `VERCEL_GIT_REPO_SLUG` | `undefined` \| `string` | The origin repository the deployment is triggered from. **`Example`** `ts "my-site" ` | | `VERCEL_PROJECT_PRODUCTION_URL` | `undefined` \| `string` | A production domain name of the project. This is useful to reliably generate links that point to production such as OG-image URLs. The value does not include the protocol scheme https://. **`Example`** `ts "myproject.vercel.app" ` | | `VERCEL_REGION` | `undefined` \| `string` | The ID of the Region where the app is running. Possible values: - arn1 (Stockholm, Sweden) - bom1 (Mumbai, India) - cdg1 (Paris, France) - cle1 (Cleveland, USA) - cpt1 (Cape Town, South Africa) - dub1 (Dublin, Ireland) - fra1 (Frankfurt, Germany) - gru1 (São Paulo, Brazil) - hkg1 (Hong Kong) - hnd1 (Tokyo, Japan) - iad1 (Washington, D.C., USA) - icn1 (Seoul, South Korea) - kix1 (Osaka, Japan) - lhr1 (London, United Kingdom) - pdx1 (Portland, USA) - sfo1 (San Francisco, USA) - sin1 (Singapore) - syd1 (Sydney, Australia) - dev1 (Development Region) **`Example`** `ts "iad1" ` | | `VERCEL_SKEW_PROTECTION_ENABLED` | `undefined` \| `string` | When Skew Protection is enabled in Project Settings, this value is set to 1. **`Example`** `ts "1" ` | | `VERCEL_URL` | `undefined` \| `string` | The domain name of the generated deployment URL. The value does not include the protocol scheme https://. NOTE: This Variable cannot be used in conjunction with Standard Deployment Protection. **`Example`** `ts "*.vercel.app" ` | #### Defined in [packages/functions/src/get-env.ts:6](https://github.com/vercel/vercel/blob/main/packages/functions/src/get-env.ts#L6) --- ### ipAddress ▸ **ipAddress**(`input`): `string` \| `undefined` Returns the IP address of the request from the headers. **`Example`** ```js import { ipAddress } from '@vercel/functions'; export function GET(request) { const ip = ipAddress(request); return new Response(`Your IP is ${ip}`); } ``` #### Parameters | Name | Type | Description | | :------ | :------------------------------------------------------- | :-------------------------------------- | | `input` | `Headers` \| [`Request`](../interfaces/index.Request.md) | The incoming request object or headers. | #### Returns `string` \| `undefined` The IP address of the request. #### Defined in [packages/functions/src/headers.ts:131](https://github.com/vercel/vercel/blob/main/packages/functions/src/headers.ts#L131) --- ### next ▸ **next**(`init?`): [`Response`](https://developer.mozilla.org/en-US/docs/Web/API/Response) Returns a Response that instructs the system to continue processing the request. **`Example`** No-op middleware ```ts import { next } from '@vercel/edge'; export default function middleware(_req: Request) { return next(); } ``` **`Example`** Add response headers to all requests ```ts import { next } from '@vercel/edge'; export default function middleware(_req: Request) { return next({ headers: { 'x-from-middleware': 'true' }, }); } ``` #### Parameters | Name | Type | Description | | :------ | :------------------ | :---------------------------------- | | `init?` | `ExtraResponseInit` | Additional options for the response | #### Returns [`Response`](https://developer.mozilla.org/en-US/docs/Web/API/Response) #### Defined in [packages/functions/src/middleware.ts:145](https://github.com/vercel/vercel/blob/main/packages/functions/src/middleware.ts#L145) --- ### rewrite ▸ **rewrite**(`destination`, `init?`): [`Response`](https://developer.mozilla.org/en-US/docs/Web/API/Response) Returns a response that rewrites the request to a different URL. **`Example`** Rewrite all feature-flagged requests from `/:path*` to `/experimental/:path*` ```ts import { rewrite, next } from '@vercel/edge'; export default async function middleware(req: Request) { const flagged = await getFlag(req, 'isExperimental'); if (flagged) { const url = new URL(req.url); url.pathname = `/experimental{url.pathname}`; return rewrite(url); } return next(); } ``` **`Example`** JWT authentication for `/api/:path*` requests ```ts import { rewrite, next } from '@vercel/edge'; export default function middleware(req: Request) { const auth = checkJwt(req.headers.get('Authorization')); if (!checkJwt) { return rewrite(new URL('/api/error-unauthorized', req.url)); } const url = new URL(req.url); url.searchParams.set('_userId', auth.userId); return rewrite(url); } export const config = { matcher: '/api/users/:path*' }; ``` #### Parameters | Name | Type | Description | | :------------ | :------------------------------------------------------------------------ | :---------------------------------- | | `destination` | `string` \| [`URL`](https://developer.mozilla.org/en-US/docs/Web/API/URL) | new URL to rewrite the request to | | `init?` | `ExtraResponseInit` | Additional options for the response | #### Returns [`Response`](https://developer.mozilla.org/en-US/docs/Web/API/Response) #### Defined in [packages/functions/src/middleware.ts:101](https://github.com/vercel/vercel/blob/main/packages/functions/src/middleware.ts#L101) --- ### waitUntil ▸ **waitUntil**(`promise`): `undefined` \| `void` Extends the lifetime of the request handler for the lifetime of the given Promise **`See`** https://developer.mozilla.org/en-US/docs/Web/API/ExtendableEvent/waitUntil **`Example`** ```js import { waitUntil } from '@vercel/functions'; export function GET(request) { waitUntil(fetch('https://vercel.com')); return new Response('OK'); } ``` #### Parameters | Name | Type | Description | | :-------- | :---------------------------------------------------------------------------------------------------------------- | :----------------------- | | `promise` | [`Promise`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise)<`unknown`\> | The promise to wait for. | #### Returns `undefined` \| `void` #### Defined in [packages/functions/src/wait-until.ts:19](https://github.com/vercel/vercel/blob/main/packages/functions/src/wait-until.ts#L19)