Separate workflow files

Separate activity files

Sandbox-safe activity import

Sync activities used

Executor for sync activities

References passed, not large data

Activity heartbeating

Heartbeat details recovery

Cancellation cleanup with try/finally

workflow.logger used in workflow

Fairness key on workflow start

Fairness weight set

State initialized in __init__

Update handler returns count

Update validator is read-only

Validator rejects empty items

Validator rejects over-capacity

Query handler is read-only

Fairness explained in comments

Priority import used

Compensation added before activity

Compensations run in reverse

asyncio.shield used for compensations

Patching API used for new step

Descriptive patch ID

workflow.now() for timestamp

workflow.uuid4() or workflow.random() for unique ID

workflow.sleep() for durable delay

CHANGES.md explains patching lifecycle

Compensation activities are idempotent by design