Helicone

Overview

Helicone is an open source observability platform for LLMs. It requires one line of code to integrate and provides monitoring, evaluation, and experimentation capabilities. The project is part of Y Combinator's Winter 2023 batch and is written in TypeScript.

Best for

Best for
LLM developers who need lightweight observability without heavy setup

Use cases

• Monitor LLM API usage and latency
• Evaluate prompt and response quality
• Experiment with different models and prompts

Notes

Helicone is an open source observability platform for LLMs. It requires one line of code to integrate and provides monitoring, evaluation, and experimentation capabilities. The project is part of Y Combinator’s Winter 2023 batch and is written in TypeScript.

5,766 stars on GitHub. Last updated 2026-05-18. Licensed Apache-2.0.

Use cases

• Monitor LLM API usage and latency
• Evaluate prompt and response quality
• Experiment with different models and prompts

Pros

• Quick integration with one line of code
• Open source with community support
• Combines monitoring and evaluation in one tool

Cons

• Limited to TypeScript ecosystem
• May require self-hosting for full control
• Young project with evolving features

Indexed from awesome-llmops and enriched against its public facts.