Langfuse
OSS, self-hostable LLM observability — traces, evals, prompts, and datasets.
- License
- MIT
- Install
- pip package
- Website
- https://langfuse.com
- GitHub
- https://github.com/langfuse/langfuse
pip install langfuse
Helicone
One-line proxy for LLM logging, caching, rate limiting, and cost tracking.
- License
- Apache-2.0
- Install
- env key
- Website
- https://www.helicone.ai
- GitHub
- https://github.com/Helicone/helicone
export HELICONE_API_KEY=...
When to reach for which
Langfuse — OSS, self-hostable LLM observability — traces, evals, prompts, and datasets.
Helicone — One-line proxy for LLM logging, caching, rate limiting, and cost tracking.
Both sit in the Eval & Observability category — they're substitutes, not complements. Pick by your install constraint (MCP-native, license, hosting model) and which tag overlap matters most to your stack.