Durable Runtime¶

The local in-process loop is good for development. The durable runtime is what you use when the workflow must survive crashes, restarts, and human delays.

What Restate adds¶

• resumable workflows
• exactly-once semantics around completed activity steps
• wait states for HITL without tying up a worker thread
• explicit workflow handlers for start, resolve, query, and cancel operations

Runtime shape¶

• workflow handlers coordinate the long-lived state machine
• activities isolate model calls, tool execution, persistence, and event publishing
• the worker process hosts the Restate app and injected dependencies

When to use it¶

Use the durable runtime when you care about correctness more than simplicity: approvals, long-running jobs, expensive tool calls, or production operations.