Activities

Activities perform the actual work in your application while workflows coordinate them.

An activity is a unit of work that performs actual computations, API calls, or other operations. Key characteristics:

• Must be idempotent (safe to retry)
• Execute in isolated processes
• Have automatic retry mechanisms
• Accept any JSON-serializable types as inputs/outputs (str, int, dict, list, etc.)
• Input/output limited to 2MB

• Basics — defining activities, core features, granularity, and nesting
• Local Activities — run activities directly in the worker process for low-latency operations
• Sticky Worker Sessions — route related activities to the same worker for resource sharing