Library / SDK
Observability & Evaluation
LangWatch
1Monitor, 2evaluate, 3and 4optimize 5LLM 6apps
the six Ws · specification
W1
Who
Maintained by LangWatch.
W2
What
Monitors, evaluates, and optimizes LLM applications.
W3
Where
Self-hosted or LangWatch Cloud, via SDKs.
W4
When
When you need tracing plus evaluation for LLM apps.
W5
Why
Combines observability, evals, and optimization in one place.
W6
With
SDK instrumentation and a datastore.
W7
Watch
Company-maintained; open-source and self-hostable, with a hosted cloud (open-core). Self-hosting keeps traces local; the cloud receives your data.