Helicone

Helicone is a specialized AI gateway and LLM observability platform designed to help development teams route, debug, and analyze the behavior of large language model (LLM) applications in production. Its primary function is to act as an intermediary layer between an application and multiple LLM providers, enabling centralized request management, performance monitoring, and cost control. The platform supports seamless integration with major providers such as OpenAI, Anthropic, Azure, LiteLLM, Anyscale, Together AI, and OpenRouter, allowing users to switch or load balance between them without modifying application code. One of the core features is request routing. Helicone can intelligently distribute API calls across different providers or models based on custom rules, such as cost thresholds, latency requirements, or fallback logic. This ensures high availability and reduces the risk of single-provider outages. For example, if OpenAI’s API is rate-limited or down, Helicone automatically retries the request on Anthropic or another provider. Observability is another central pillar. Helicone captures detailed metrics for every LLM request, including token usage, latency, response time, error codes, and cost. These metrics are visualized in a dashboard that supports filtering by time range, model, provider, user, or session. Developers can drill down into individual requests to inspect full input/output payloads, see exactly which prompt was sent and what response was received, and identify outliers such as slow responses or repeated failures. Helicone also provides powerful debugging tools. Users can replay past requests with modified parameters or different models to test behavior without incurring extra cost. The platform includes a prompt playground where engineers can