helicone.ai · Observability
Open source LLM gateway and request logger for tracking cost, latency and usage. Acquired by Mintlify in March 2026; the hosted service now runs in maintenance mode.
Helicone is one of 10 observability tools on TrueIQ. See all observability tools or how we check facts.
// guides
Is LangSmith API free? Yes: API keys and the REST API cost nothing, and the Developer plan covers 5,000 traces a month. See key types, limits and overage costs.
Is Langfuse free for commercial use? Yes: the MIT core can be self hosted in paid products at no cost. See what needs a license key and when the cloud bills.
The best LLM observability tools in 2026 compared: Langfuse, LangSmith, Phoenix, Opik, Weave and more, with licenses, self hosting and who now owns what.
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