Quickstart

Installation & setup

1. 1

   Install the SDK

   Install the Bear Lumen Node.js SDK:

   npm install @bearlumen/node-sdk

2. 2

   Initialize the client

   Set up your API client with your API key:

   import { BearLumen } from '@bearlumen/node-sdk';
   
   const bear = new BearLumen({
     apiKey: process.env.BEAR_LUMEN_API_KEY,
   });

3. 3

   Track an AI call

   Make an AI API call and pass the response to Bear Lumen. It auto-detects the provider and extracts token counts and cost:

   import OpenAI from 'openai';
   
   const openai = new OpenAI();
   
   const response = await openai.chat.completions.create({
     model: 'gpt-4o',
     messages: [{ role: 'user', content: 'Hello!' }],
   });
   
   // Bear Lumen auto-detects the provider and extracts tokens + cost
   const result = await bear.track(response);
   console.log(`Cost: $${result.cost}`);

4. 4

   Add attribution

   Tag calls with a user, feature, or agent to see where your AI spend is going:

   // Add attribution to know who spent what and where
   const result = await bear.track(response, {
     userId: 'user_123',
     feature: 'chat',
     agentId: 'support-bot',
   });
   
   console.log(`User ${result.userId} spent $${result.cost} on ${result.model}`);

5. 5

   Query your costsOptional

   Pull cost breakdowns by model, provider, or user:

   // See costs broken down by model
   const byModel = await bear.costs.byModel({
     startDate: '2025-01-01',
     endDate: '2025-01-31',
   });
   console.log(byModel);
   
   // See costs for a specific user
   const userCosts = await bear.costs.forUser('user_123').summary();
   console.log(userCosts);