Datadog LLM Observability Pricing in 2026: What It Actually Costs

Two tiers under the new name, Agent Observability: Free at $0/month for up to 40K LLM spans, 15-day retention; and Pro at $160/month annual with 100K LLM spans included and $3.50 per additional 10K. Month-to-month is $200 and $4.20 per 10K; on-demand $240 and $5.00 per 10K. Rates are higher in ap1, ap2 and uk1.

Yes — Datadog renamed it. /product/llm-observability/ 301-redirects to /products/ai/agent-observability/. The docs path and pricing anchor still use the old name, which is why both appear in search.

A single call to an LLM provider. Of the seven span kinds, only LLM bills — workflow, agent, tool, task, embedding and retrieval are free.

No — Datadog states it is standalone. It also does not draw on APM allotments, so every span above your tier is net-new spend. Whether LLM traces are separately billed as APM traces is undocumented; ask your account team.

No. Agent Observability detects prompt injection as an evaluation. Real-time blocking is AI Guard, a separate product billed per million input tokens evaluated including full conversation context, with no published rate.

Use DD_LLMOBS_SAMPLE_RATE — sampling does not affect Agent Observability metrics, which stay based on 100% of instrumented traffic.