Latency And Performance Monitoring Per Prompt

via “prompt versioning and template management with a/b testing”

Open-source LLM observability — tracing, prompt management, evaluation, cost tracking, self-hosted.

Unique: Prompt versions are linked to traces via foreign key, enabling retrospective analysis of prompt performance without re-running experiments. Chat message compilation logic (in packages/shared/src/server/llm/compileChatMessages.ts) handles role-based message formatting and variable substitution, then stores the compiled prompt in the trace for audit and replay.

vs others: Tighter integration with trace data than Prompt Flow or LangSmith because prompt versions are stored in the same database as traces, enabling instant correlation between prompt changes and metric shifts without external joins or data export.