---
id: EDGE-2
family: GR-EDGE
level: extended
profiles: [storage-api]
posture: normative-target
added: "1.0"
changed: "1.0"
source: https://flowdrop.io/spec/rules/gr-edge/edge-2
specification: FlowDrop Workflow Specification 1.0-draft
licence: CC BY 4.0
---

# EDGE-2 — No edge key is structurally required

*GR-EDGE (Part I) · level: extended · profiles: storage-api · added in 1.0*

## The rule

> **Normative.** This is the rule.
>
> 1. An edge is accepted structurally whatever keys it carries: an absent key takes its empty default: the empty string for an endpoint or a handle, the empty list for a collection.
>
> 2. An edge left without endpoints is not a parse failure; it is refused by validation as an edge missing an endpoint, so an author is told what is wrong with the wire rather than that the document could not be read.

---

Rule identifiers are permanent and are never renumbered. This specification carries
no implementation status: each implementation publishes its own standing against
these rules. Licensed CC BY 4.0.