# Decision 0005: Selection Source of Truth

Status: Accepted
Date: 2026-05-03

## Context

The composer derives its target from selected nodes. React Flow also has selection behavior, and the workflow store stores nodes with `selected` flags.

If both layers independently own selection, the composer can target the wrong node after canvas actions such as connection-drop creation.

## Decision

The workflow store is the selection source of truth. React Flow selection is a UI mirror.

Implementation direction:

- Add store actions such as `selectSingleNode(nodeId)` and `clearSelection()`.
- Use store actions after `ConnectionDropMenu` creates a new node.
- Composer derives context from store `nodes[].selected`.
- React Flow selection callbacks sync user selection into the store.

## Rationale

The composer already reads workflow data from Zustand. Keeping selection there makes context derivation deterministic and testable.

## Consequences

- New downstream nodes created from connection drop must be selected through the store.
- Tests should cover auto-select after creating image/video generation nodes.
- Avoid local component-only selection fixes that bypass the store.