Helicone

hybridFree (100k requests)$20/mo GrowthCustom Enterpriseopen source

Best for

Lightweight LLM proxy with cost tracking, caching, and rate limiting — minimal integration effort

Limitations

Proxy-based architecture adds a network hop; less deep tracing than Langfuse; evaluation features are basic

Features

Llm Tracing
Trace LLM calls, tool invocations, and agent reasoning steps end-to-end
Cost Tracking
Track token usage and cost per request, per agent run, and per model
Evaluation
Score agent outputs against test datasets with automated evaluators
Prompt Management
Version, manage, and A/B test prompts in production
Real Time Monitoring
Live dashboards and alerting for agent performance metrics

Frameworks

langchainllamaindexvercel-aiopenai-agents

SDK Languages

pythonjavascripttypescript

Compliance

soc2gdpr

Helicone

Helicone is an open-source LLM observability platform that works as a proxy layer between your application and LLM providers. It logs every request, tracks cost and latency, and provides caching and rate limiting out of the box.

The proxy approach means integration is as simple as changing a base URL — no SDK changes required. For teams that want quick visibility into LLM usage and costs without deep instrumentation, Helicone is a pragmatic starting point.

Last verified: 2026-04-28Verified by: editorial