Key Takeaway: An AI SRE (AI Site Reliability Engineer) is an autonomous AI agent that triages alerts, investigates incidents, performs root cause analysis, and generates postmortems without step-by-step human direction. Gartner projects that by 2029, 70% of enterprises will deploy agentic AI agents to operate their IT infrastructure, up from less than 5% in 2025. This guide explains what an AI SRE actually does, how it differs from AIOps and traditional SRE, and how to evaluate the commercial and open-source tools available in 2026. An AI SRE is an autonomous software agent that performs site reliability engineering work — alert triage, incident investigation, root cause analysis, postmortem generation, and in some cases guided remediation — using large language models and production tooling to operate with minimal human direction. Unlike chatbots or copilots, an AI SRE decides what to investigate, which systems to query, and how to synthesize findings into actionable outcomes.…