Helicone

Helicone is an LLM observability platform that logs, monitors, and analyzes every LLM API request across your application with a single-line integration. It acts as a transparent proxy that captures all request data without requiring code changes.

Key use cases include:

• Cost tracking — monitor real-time LLM spend across all providers and models
• Latency monitoring — track response times, time-to-first-token, and throughput
• Request logging — capture every prompt and completion for debugging and compliance
• Rate limit management — handle provider rate limits with automatic queuing
• User analytics — track usage patterns per user, feature, or endpoint
• Caching — reduce API costs by caching identical requests

Helicone is used by engineering teams who want production visibility into their LLM usage without instrumenting every API call. The proxy-based architecture means you change a base URL and get instant observability.

Supports OpenAI, Anthropic, Azure OpenAI, Google, and any OpenAI-compatible provider.

1. Sign up at helicone.ai and get your API key.
2. Replace your OpenAI base URL — one line change:

   from openai import OpenAI
   client = OpenAI(
       api_key='sk-...',
       base_url='https://oai.helicone.ai/v1',
       default_headers={
           'Helicone-Auth': 'Bearer your-helicone-key'
       }
   )

3. All requests are now logged. View them in the Helicone dashboard.
4. For Anthropic, use https://anthropic.helicone.ai/v1 as the base URL.

Pricing: Free tier with 100K requests/month. Pro plan at $20/month with higher limits. Enterprise pricing available. See helicone.ai/pricing.