Helicone
Open-source LLM observability platform with one-line proxy integration.
Description
Helicone is an open-source LLM observability and AI gateway platform founded in 2023 by Justin Torre and Cole Gottdank through Y Combinator's W23 batch. Mintlify acquired the company in March 2026, and the platform now operates in maintenance mode while customers migrate to alternative tooling. Across three years of operation, Helicone served over 16,000 organizations and processed more than 14.2 trillion tokens.
Key Capabilities:
One-line proxy integration via OpenAI base URL change
LLM tracing and session debugging for agents and chatbots
AI gateway routing across 100+ providers with automatic fallbacks
Response caching, load balancing, and per-user rate limiting
Prompt versioning and prompt management through the gateway
Cost, latency, and quality analytics with PostHog export
Self-hostable deployment with SOC 2 and GDPR compliance
Open source under MIT license
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