---
id: R12
family: GR-VAL
level: core
profiles: [storage-api]
posture: normative-target
added: "1.0"
changed: "1.0"
source: https://flowdrop.io/spec/rules/gr-val/r12
specification: FlowDrop Workflow Specification 1.0-draft
licence: CC BY 4.0
---

# R12 — A node may not be wired to itself

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

## The rule

> **Normative.** This is the rule.
>
> 1. An edge whose non-empty `source` equals its `target` is refused with `R12_EDGE_SELF` at `edge.{index}`.
>
> 2. This holds whatever ports the two ends name, so wiring a node's own output into its own input is still refused, and it holds whether or not the named node exists; a self-edge on a node that was deleted also earns R8's two dangling-endpoint errors.
>
> 3. An edge with an empty `source` is never reported as a self-edge, even when its `target` is empty too; R5.c and R8 own that case.

## Why

Recorded under OPEN-7.

## Related rules

- Names: R8.a, R8.b

---

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.