# ONNX003: unsorted-graph-nodes

**Code:** `ONNX003`

**Name:** `unsorted-graph-nodes`

**Severity:** error

**Category:** spec

**Target:** graph

**Fixable:** 🔧 Yes

## Message

Graph nodes are not in topological order.

## Suggestion

Sort the nodes in topological order with `graph.sort()`.

## Details

Nodes within a graph must be in topologically sorted order, meaning
every node's inputs must be produced by a preceding node or be a graph input.

## Example
```python
graph.sort()
```