Durable execution
Also known as: durable workflows, fault-tolerant agent execution, workflow-as-code
The gap between a demo agent and a production agent often comes down to one thing: what happens when something breaks in the middle. A demo runs for thirty seconds on a stable laptop. A production agent might spend hours calling APIs, waiting for human approvals, and coordinating with external services. When a server restarts at 3 AM, a naive agent loses all its state and the work simply disappears. Durable execution is the layer that prevents that.
Tools like Temporal, Inngest Agent Kit, DBOS, Restate, and Cloudflare Workflows implement durable execution by persisting every step of a workflow as an event in a log. If the process dies, a new worker picks up the exact same event history and continues from the last completed step. For AI agents, this means each LLM call and tool invocation becomes independently retryable, with timeouts enforced and results stored before moving on. The agent bills nothing while it waits for a human approval that might arrive the next morning.
Durable execution became a first-tier concern for AI builders in 2026 as agent tasks grew longer and more consequential. Replit's Agent, OpenAI's Codex web agent, and long-running automation in Cursor all use Temporal underneath. The concept pairs naturally with human-in-the-loop design: a durable workflow can pause indefinitely at an approval checkpoint, then resume with full context when the human responds.