Yes — in Prefect 3.x,

PREFECT_TASKS_DISABLE_CACHING=true

fully disables task caching. That means even if: - your task has a custom

cache_key_fn

, or - your task uses a custom

cache_policy

, and - that key would match an existing persisted result from a prior run ...Prefect will not reuse that cached result. Why: when this setting is enabled, Prefect overrides task caching with

NO_CACHE

, which causes the cache key to be

None

. Since there is no key, Prefect skips the cache lookup entirely, so previously stored results are not read. So the practical behavior is: - no cache key reuse - no cache reads - no cache writes It’s effectively a global caching kill switch for tasks. Relevant source-backed docs/code path: - Prefect settings reference for task settings: Task settings reference - Prefect repository: Prefect source If you want, I can also show the exact source snippets involved (

tasks.py

,

cache_policies.py

, and transaction lookup) in a short annotated example.