Custom Integration - Lumina Documentation

Build custom integrations for any LLM provider.

Using OpenTelemetry Directly

For providers not officially supported, use OpenTelemetry:

import { trace } from '@opentelemetry/api';

const tracer = trace.getTracer('my-custom-provider');

const span = tracer.startSpan('llm_call');

try {
  const response = await customLLM.generate(prompt);

  // Add attributes
  span.setAttribute('model', 'custom-model');
  span.setAttribute('prompt_tokens', response.usage.prompt_tokens);
  span.setAttribute('completion_tokens', response.usage.completion_tokens);
  span.setAttribute('cost_usd', calculateCost(response.usage));

  span.setStatus({ code: 'OK' });
} catch (error) {
  span.setStatus({ code: 'ERROR', message: error.message });
  throw error;
} finally {
  span.end();
}

Custom Cost Calculation

function calculateCost(usage) {
  const promptCost = usage.prompt_tokens * 0.000003; // $0.003 per 1K tokens
  const completionCost = usage.completion_tokens * 0.000015; // $0.015 per 1K tokens
  return promptCost + completionCost;
}

Wrapper Function

Create a reusable wrapper:

async function traceCustomLLM(fn, options) {
  const span = tracer.startSpan(options.name || 'llm_call');

  try {
    const response = await fn();

    span.setAttribute('model', response.model);
    span.setAttribute('prompt_tokens', response.usage.prompt_tokens);
    span.setAttribute('completion_tokens', response.usage.completion_tokens);
    span.setAttribute('cost_usd', calculateCost(response.usage));

    span.setStatus({ code: 'OK' });
    return response;
  } catch (error) {
    span.setStatus({ code: 'ERROR', message: error.message });
    throw error;
  } finally {
    span.end();
  }
}

// Usage
await traceCustomLLM(
  () => customLLM.generate(prompt),
  { name: 'custom-call' }
);