# HARN-ORC-002 — orchestration construct argument has invalid type
**Category:** Orchestration (ORC)
**Variant:** `Code::OrchestrationType` (orchestration type)
## What it means
An orchestration construct — agent / workflow / pipeline / tool definition, or a
`select` block — does not satisfy the structural rules Harn enforces. These
constructs carry runtime semantics that depend on a small set of well-formed
shapes.
Specifically: orchestration construct argument has invalid type.
## How to fix
- Re-read the orchestration construct's spec section and align the arity / type / structure.
## Stability
This code is stable. Its identifier, category, and meaning will not change
without a deprecation cycle. Cross-language tooling and IDE integrations can
dispatch on it directly.