Langfuse
Open-source (MIT) LLM engineering platform combining tracing, prompt management, evals and datasets, widely used as the default self-hosted observability stack.
| Category | Observability & Tracing |
| Open source | Yes |
| Self-hostable | Yes |
| Pricing model | freemium |
| Pricing notes | Free Hobby tier (50k units/mo); Core $29/mo, Pro $199/mo, unlimited users on paid tiers; MIT core fully self-hostable |
| Framework integrations | langchain, openai-sdk, llamaindex, litellm, opentelemetry, vercel-ai, haystack |
| Funding / ownership | YC W23; $4M seed (Lightspeed, La Famiglia) |
Pricing/feature source: https://langfuse.com/pricing