# Contents
Prefect Improvement Notices are used to propose, discuss, accept, and memorialize any major architectural decisions for Prefect Core.
# PIN-1: Introduce Prefect Improvement Notices
Introducing PINs for recording Prefect decisions.
Status: Approved
# PIN-2: Implementation of Result Handlers and State Metadata
Adding metadata to States in order to track task results and serialization methods.
Status: Approved
# PIN-3: Agent-Environment Model for Flow Execution
A description of a more complex and executable Environment object.
Status: Approved
# PIN-4: Result Objects for Tracking and Serializing Task Outputs
A new Result object that clarifies the logic introduced by PIN-2.
Status: Approved
# PIN-5: Ability to Combine Tasks
A proposal for automatically combining tasks to ensure data locality; ultimately declined as a general approach.
Status: Declined
# PIN-6: Remove Constant Tasks
A proposal for removing auto-converting non-task objects into Constant Tasks; ultimately declined as the benefits outweigh the costs.
Status: Declined
# PIN-7: Storage and Execution
A proposal for refactoring environments into Storage classes and execution Environment classes with specific, loosely coupled interfaces.
Status: Approved
# PIN-8: Event-Driven / Listener Flows
A proposal for event-driven or long-running flows that run in response to events that arrive in an irregular stream.
Status: Proposed
# PIN-9: Prefect CLI
A proposal for a flexible and live-updating Prefect Cloud command line client.
Status: Approved
# PIN-10: Flexible Schedules
A proposal for a new way of building schedules that captures a wider variety of use cases.
Status: Proposed
# PIN-11: Single-Task Loops
A proposal for a way to loop over single tasks with arbitrary control logic and all Prefect semantics intact
Status: Proposed
# PIN 12: Environment Callbacks
A proposal to introduce user-provided callbacks for Environments which users can use to specify additional behavior before a Flow is run and after a FlowRun has ended.
Status: Accepted
# PIN 13: Universal Cloud Deploys
A proposal to run Flows from Prefect Cloud with local Python resources and packages.
Status: Accepted
# PIN-14: Event-Driven Flow Execution via Listeners
A proposal to enable starting a Flow based on events from user provided sources by leveraging the existing Schedule features.
Status: Proposed; supersedes PIN 8.
# PIN-15: Skip state as Finished + Control Flow Conditional
A proposal to interpret Skip states as Finished instead of Successful while also introducing more conditional control flow constructs.
Status: Proposed