Helicone
Open-source AI gateway + LLM observability: 100+ models, one API key.
About
Helicone is an open-source AI gateway and LLM observability platform: point your OpenAI client at their base URL and get access to 100+ models through one API key, with intelligent routing, automatic fallbacks, cost/latency tracking, trace inspection, prompt management, and a playground — all in one dashboard. Integration is literally one line (change baseURL), with first-class hooks for LangChain, Vercel AI SDK, and others. Free tier covers 10k requests/month with no credit card; SOC 2 and GDPR compliant. Apache-2.0, 6.2k stars.
What it can do
- **AI gateway**: 100+ models behind one OpenAI-compatible API key
- **Smart routing**: intelligent routing with automatic provider fallbacks
- **Observability**: traces, sessions, cost/latency/quality analytics
- **Prompt management**: version and deploy prompts without code changes
- **Playground**: iterate on prompts against production traces
- **Enterprise**: SOC 2 + GDPR, self-hostable (open source)
Setup
```ts
import OpenAI from "openai";
const client = new OpenAI({
baseURL: "https://ai-gateway.helicone.ai",
apiKey: process.env.HELICONE_API_KEY,
});
```
Sign up at helicone.ai for a key. Same one-line pattern works for Anthropic, LangChain, Vercel AI SDK. Docs: docs.helicone.ai.
Prerequisites
An existing OpenAI-compatible client setup. A Helicone API key (free tier: 10k requests/mo, no card).
Use cases
Works with
Trust score — 8/10
Scored 8/10 (verified tier, metrics-v1). Evidence: 6,215 GitHub stars (log-scaled vs catalog peers); last push 3d ago; 0 releases/12mo; 168 open issues. Manual review: YC AI gateway + observability; 100+ models one key, routing/fallbacks, 10k free req/mo; 0 GitHub releases/12mo (continuous ship); gateway is a request-path dependency. License: Apache-2.0.
★ 6,215 GitHub stars
How the trust score is built
Full methodology →- Adoption · stars/downloads, log-scaled vs peers
- 7.2/10
- Maintenance · recency, releases, issue load
- 6.8/10
- Openness · license + docs
- 10.0/10
- Manual review · sanity read + red-flag check
- 8.0/10
- · 6,215 GitHub stars (log-scaled vs catalog peers)
- · last push 3d ago; 0 releases/12mo; 168 open issues
- · manual review: YC AI gateway + observability; 100+ models one key, routing/fallbacks, 10k free req/mo; 0 GitHub releases/12mo (continuous ship); gateway is a request-path dependency
Sources
Every fact above was checked against these sources. Where a claim comes from the provider and couldn't be independently verified, the text says so.