Connect Axiom with Vercel to get the deepest observability experience for your Vercel projects. Easily monitor data from requests, functions, and web vitals in one place. 100% live and 100% of your data, no sampling. Axiom’s Vercel app ships with a pre-built dashboard and pre-installed monitors so you can be in complete control of your projects with minimal effort. If you use Axiom Vercel integration, annotations are automatically created for deployments.

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What is Vercel?

Vercel is a platform for frontend frameworks and static sites, built to integrate with your headless content, commerce, or database. Vercel provides a frictionless developer experience to take care of the hard things: deploying instantly, scaling automatically, and serving personalized content around the globe. Vercel makes it easy for frontend teams to develop, preview, and ship delightful user experiences, where performance is the default.

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Send logs to Axiom

Simply install the Axiom Vercel app from here and be streaming logs and web vitals within minutes!

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App Overview

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Request and function logs

For both requests and serverless functions, Axiom automatically installs a log drain in your Vercel account to capture data live. As users interact with your website, various logs will be produced. Axiom captures all these logs and ingests them into the vercel dataset. You can stream and analyze these logs live, or use our pre-build Vercel Dashboard to get an overview of all the important metrics. When you’re ready, you can fork our dashboard and start building your own! For function logs, if you call console.log, console.warn or console.error in your function, the output will also be captured and made available as part of the log. You can use our extended query language, APL, to easily search these logs.

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Web vitals

Axiom supports capturing and analyzing Web Vital data directly from your user’s browser without any sampling and with more data than is available elsewhere. It is perfect to pair with Vercel’s in-built analytics when you want to get really deep into a specific problem or debug issues with a specific audience (user-agent, location, region, etc).
Web Vitals are only currently supported for Next.js websites. Expanded support is coming soon.

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Installation

Perform the following steps to install Web Vitals:
  1. In your Vercel project, run npm install --save next-axiom.
  2. In next.config.js, wrap your NextJS config in withAxiom as follows:
const { withAxiom } = require('next-axiom');

module.exports = withAxiom({
  // ... your existing config
})
This will proxy the Axiom ingest call to improve deliverability.
  1. For Web Vitals, navigate to app/layout.tsx and add the AxiomWebVitals component:
import { AxiomWebVitals } from 'next-axiom';

export default function RootLayout() {
  return (
    <html>
      ...
      <AxiomWebVitals />
      <div>...</div>
    </html>
  );
}
WebVitals are sent only from production deployments.
  1. Deploy your site and watch data coming into your Axiom dashboard.
  • To send logs from different parts of your app, make use of the provided logging functions. For example:
log.info('Payment completed', { userID: '123', amount: '25USD' });

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Client Components

For Client Components, replace the log prop usage with the useLogger hook: 
'use client';
import { useLogger } from 'next-axiom';

export default function ClientComponent() {
  const log = useLogger();
  log.debug('User logged in', { userId: 42 });
  return <h1>Logged in</h1>;
}

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Server Components

For Server Components, create a logger and make sure to call flush before returning: 
import { Logger } from 'next-axiom';

export default async function ServerComponent() {
  const log = new Logger();
  log.info('User logged in', { userId: 42 });

  // ... other operations ...

  await log.flush();
  return <h1>Logged in</h1>;
}

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Route Handlers

For Route Handlers, wrapping your Route Handlers in withAxiom will add a logger to your request and automatically log exceptions: 
import { withAxiom, AxiomRequest } from 'next-axiom';

export const GET = withAxiom((req: AxiomRequest) => {
  req.log.info('Login function called');

  // You can create intermediate loggers
  const log = req.log.with({ scope: 'user' });
  log.info('User logged in', { userId: 42 });

  return NextResponse.json({ hello: 'world' });
});

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Use Next.js 12 for Web Vitals

If you’re using Next.js version 12, follow the instructions below to integrate Axiom for logging and capturing Web Vitals data. In your pages/_app.js or pages/_app.ts and add the following line: 
export { reportWebVitals } from 'next-axiom';

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Upgrade to Next.js 13 from Next.js 12

If you plan on upgrading to Next.js 13, you’ll need to make specific changes to ensure compatibility:
  • Upgrade the next-axiom package to version 1.0.0 or higher:
  • Make sure any exported variables have the NEXT_PUBLIC_ prefix, for example,, NEXT_PUBLIC_AXIOM_TOKEN.
  • In client components, use the useLogger hook instead of the log prop.
  • For server-side components, you need to create an instance of the Logger and flush the logs before the component returns.
  • For Web Vitals tracking, you’ll replace the previous method of capturing data. Remove the reportWebVitals() line and instead integrate the AxiomWebVitals component into your layout.

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Vercel Function logs 4KB limit

The Vercel 4KB log limit refers to a restriction placed by Vercel on the size of log output generated by serverless functions running on their platform. The 4KB log limit means that each log entry produced by your function should be at most 4 Kilobytes in size. If your log output is larger than 4KB, you might experience truncation or missing logs. To log above this limit, you can send your function logs using next-axiom.

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Parse JSON on the message field

If you use a logging library in your Vercel project that prints JSON, your message field will contain a stringified and therefore escaped JSON object.
  • If your Vercel logs are encoded as JSON, they will look like this:
{
  "level": "error",
  "message": "{ \"message\": \"user signed in\", \"metadata\": { \"userId\": 2234, \"signInType\": \"sso-google\" }}",
  "request": {
    "host": "www.axiom.co",
    "id": "iad1:iad1::sgh2r-1655985890301-f7025aa764a9",
    "ip": "199.16.157.13",
    "method": "GET",
    "path": "/sign-in/google",
    "scheme": "https",
    "statusCode": 500,
    "teamName": "AxiomHQ",
  },
  "vercel": {
    "deploymentId": "dpl_7UcdgdgNsdgbcPY3Lg6RoXPfA6xbo8",
    "deploymentURL": "axiom-bdsgvweie6au-axiomhq.vercel.app",
    "projectId": "prj_TxvF2SOZdgdgwJ2OBLnZH2QVw7f1Ih7",
    "projectName": "axiom-co",
    "region": "iad1",
    "route": "/signin/[id]",
    "source": "lambda-log"
  }
}
  • The JSON data in your message would be:
{
  "message": "user signed in",
  "metadata": {
    "userId": 2234,
    "signInType": "sso-google"
   }
}
You can parse the JSON using the parse_json function and run queries against the values in the message field.

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Example

['vercel']
| extend parsed = parse_json(message)
  • You can select the field to insert into new columns using the project operator
['vercel']
| extend parsed = parse_json('{"message":"user signed in", "metadata": { "userId": 2234, "SignInType": "sso-google" }}')
| project parsed["message"]

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More Examples

  • If you have null values in your data you can use the isnotnull() function
['vercel']
| extend parsed = parse_json(message)
| where isnotnull(parsed)
| summarize count() by parsed["message"], parsed["metadata"]["userId"]

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Migrate from Vercel app to next-axiom

In May 2024, Vercel introduced higher costs for using Vercel Log Drains. Because the Axiom Vercel app depends on Log Drains, using the next-axiom library can be the cheaper option to analyze telemetry data for higher volume projects. To migrate from the Axiom Vercel app to the next-axiom library, follow these steps:
  1. Delete the existing log drain from your Vercel project.
  2. Delete NEXT_PUBLIC_AXIOM_INGEST_ENDPOINT from the environment variables of your Vercel project. For more information, see the Vercel documentation.
  3. Create a new dataset in Axiom, and create a new advanced API token with ingest permissions for that dataset.
  4. Add the following environment variables to your Vercel project:
    • NEXT_PUBLIC_AXIOM_DATASET is the name of the Axiom dataset where you want to send data.
    • NEXT_PUBLIC_AXIOM_TOKEN is the Axiom API token you have generated.
  5. In your terminal, go to the root folder of your Next.js app, and then run npm install --save next-axiom to install the latest version of next-axiom.
  6. In the next.config.ts file, wrap your Next.js configuration in withAxiom:
const { withAxiom } = require('next-axiom');

module.exports = withAxiom({
  // Your existing configuration
});
For more configuration options, see the documentation in the next-axiom GitHub repository.

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Send logs from Vercel preview deployments

To send logs from Vercel preview deployments to Axiom, enable preview deployments for the environment variable NEXT_PUBLIC_AXIOM_INGEST_ENDPOINT. For more information, see the Vercel documentation.