What does fault tolerance mean for AI agent systems?

Fault tolerance in AI agent systems means the agent application can continue or recover when part of the system fails. That failure might be a crashed worker, a timed-out tool call, a temporary API outage, a deployment restart, or a failed handoff between agents. For AI agents, fault tolerance is harder than simple service retry because the execution path can be dynamic and tool calls may have side effects. A production-ready approach combines durable workflows, persisted state, replay, idempotent operations, observability, and policy controls. Diagrid Catalyst is positioned around that production reliability layer.