Langfuse
Open-source platform for tracing, evaluations, and prompt management. Self-hostable alternative to LangSmith with broad framework support. Acquired by ClickHouse in January 2026; OSS core continues with deeper ClickHouse-backed analytics.
AgentOps
AgentOps provides session replay, cost tracking, and error monitoring designed for AI agents — not just LLM calls. It captures the full agent execution tree including tool calls, decisions, and multi-agent interactions, with a visual session replay for debugging.