Helicone

Open-source LLM observability via a one-line proxy: log every request, track cost and latency, cache repeats, and debug production prompts without rewriting your app.

Product preview

Overview

Helicone’s trick is installation: point your OpenAI base URL at their gateway and every call is logged, costed, cached and attributable to a user — no SDK rewrite, no tracing instrumentation. That makes it the fastest path from “we have no idea what production spends” to a dashboard.

It is thinner than LangSmith or Langfuse on evals and prompt CMS, and thicker on the gateway features teams actually need on day one: caching, rate limits, key management. Open source and self-hostable, with a cloud that prices on logged requests. If you already have a proxy in front of the model, Helicone is often the first observability layer that sticks.

Pros / Cons

Pros

One-line proxy, no app rewrite
Cost and cache controls from day one
Open source and self-hostable
Works with OpenAI-compatible providers

Cons

Thinner evals than Langfuse or Smith
Gateway is another hop in the request path
Prompt management is not the product

Who it's for

Seeing production LLM spend overnight

Caching repeated prompts

Attributing tokens to users or tenants

Adding observability without an SDK rewrite

Bottom line

The one-line proxy that makes LLM cost and traces visible — start here if you have no instrumentation yet.

Key Features

Drop-in proxy for OpenAI-compatible APIs

Cost, latency and token dashboards

Response caching

User and session tracking

Open-source self-host option

Compare Helicone with alternatives

Helicone vs Hugging Face Helicone vs Replicate Helicone vs Ollama 4 products · AI Platforms

Frequently asked questions

What is Helicone?

Helicone is a AI Platforms tool developed by Helicone. The company was founded in 2022 and is headquartered in San Francisco, USA. Open-source LLM observability via a one-line proxy: log every request, track cost and latency, cache repeats, and debug production prompts without rewriting your app.