Library / SDK
Observability & Evaluation
Langtrace
1OpenTelemetry 2tracing 3for 4LLM 5application 6observability
the six Ws · specification
W1
Who
Maintained by Scale3 Labs.
W2
What
An OpenTelemetry-based tool tracing LLM, vector DB, and framework calls with cost and evaluation views.
W3
Where
A self-hostable server plus SDKs, or a managed Langtrace cloud.
W4
When
Reach for it when you want standards-based LLM tracing you can self-host.
W5
Why
Emits open OpenTelemetry traces so data is portable across backends.
W6
With
Instruments OpenAI, Anthropic, LangChain, LlamaIndex, and Pinecone.
W7
Watch
Maintained by Scale3 Labs; open-source (Apache-2.0) SDK and server, with a paid cloud (open-core). Self-hosting keeps traces local.
alternatives