Listener Runnables

Listener metadata currently owns only the event key.
No Listener request or response contract is projected into runnable source.
App Marché does not execute Listener nodes yet.

Current Metadata Boundary

A Listener node stores an event key only. Its source remains part of whole-project validation, but App Marché does not project a listener-specific request binding or Response contract.

Listener metadata	Listener source
Event key	Identifies the intended trigger
Node identity	Keeps the runnable in project validation
No request or response fields	Receives no listener payload contract

Pending Payload Contract

The redesign must define how an emitter declares payload fields, how those fields become typed Nenu bindings, and whether a listener can produce any response. Until then, do not publish a payload-dependent Listener workflow.

Listener Boundaries

Treat the event key as the only stable Listener metadata today.
Do not read request or return Response as a Listener contract.
Defer payload-dependent workflows until the listener contract is redesigned.
Remember that App Marché does not execute Listener nodes yet.
Keep browser UI behavior in Page Script; a listener has no page state, modal, toast, or navigation context.

Common Mistakes

Wrong	Correct
`listener ExpenseCreated { ... }`	Configure the event key in Listener metadata.
Declare `type Request`	Wait for the Listener payload-contract redesign.
Read `request.expense_id`	Do not assume a Listener request binding exists.
Return an invented Response	Do not assume a Listener response contract exists.
Use `toast.success`	Use backend effects such as save, cache, log, or throw.

Continue Learning

API Runnables Compare request-and-response API contracts.Backend Effects Use the effects available to listeners.