LLM-native observability & gateways
Best for AI engineers who want request-level tracing, evals, and token-derived cost for the LLM app itself — Helicone, Langfuse, LangSmith, Portkey, LiteLLM, and similar.
Strengths
- Deep per-request instrumentation, prompt management, and evals; several are open-source and self-hostable (Helicone, Langfuse, LiteLLM).
- Broad model coverage with published, developer-friendly pricing (e.g., Helicone Pro $79/mo, Langfuse Core $29/mo, LangSmith Plus $39/seat).
Limitations
- All are AI-only: none ingests AWS/Azure/GCP or Snowflake spend, so they can't reconcile AI cost against the rest of your bill.
- Some report cost as a token-based estimate rather than the provider's billed invoice.