Next.js

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1. Install Laminar

npm add @lmnr-ai/lmnr

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2. Initialize Laminar

To instrument your entire Next.js app, place Laminar initialization in instrumentation.{ts,js} file. Learn more about instrumentation.{ts,js} here.

export async function register() {
  // prevent this from running in the edge runtime
  if (process.env.NEXT_RUNTIME === 'nodejs') {

    const { Laminar } = await import('@lmnr-ai/lmnr');
    Laminar.initialize({
      projectApiKey: process.env.LMNR_API_KEY,
    });
  }
}

If you use Next.js < 15, add the following to your next.config.js:

module.exports = {
    experimental: { instrumentationHook: true }
};

The best workaround is to selectively pass instrumentModules to .initialize(). The example below shows how to do this for OpenAI and Anthropic.

const { OpenAI } = await import('openai');
const anthropic = await import('@anthropic-ai/sdk');
const { Laminar } = await import('@lmnr-ai/lmnr');

Laminar.initialize({
  projectApiKey: process.env.LMNR_PROJECT_API_KEY,
  instrumentModules: { openAI: OpenAI, anthropic: anthropic }
});

If you want to try it quickly without manually importing and instrumenting all modules, you can do simple initialization, however, you will need to import and initialize Laminar before importing LLM client libraries. This is because JavaScript binds the imported module to its name at import time, so introducing instrumentation afterwards statically is not possible.

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Next.js traces

Next.js telemetry sends numerous spans, which may seem noisy in Laminar’s dashboard.

By default, Laminar (since @lmnr-ai/lmnr@0.4.29) ignores Next.js spans. If you see many Next.js spans in your traces, it may be that you are using an older version of Laminar. Consider upgrading to the latest version.

If you want to see all Next.js spans, set preserveNextjsSpans to true in Laminar.initialize().

Laminar.initialize({
  projectApiKey: process.env.LMNR_API_KEY,
  preserveNextjsSpans: true
});