# Code node

Code node explains how this part of Flowline works and how to use it in a real workflow. This page is dummy content for testing the Cloudairy wiki: structure, navigation, search and rendering.

> **Note:** Flowline is a fictional automation product. Section: **Build › Code**.

## Prerequisites

- A Flowline account (cloud or self-hosted)
- Editor access to the project
- About 15 minutes

## How it works

Every workflow starts with a **trigger**, passes *items* from node to node, and ends when the last node finishes. Code node fits in the middle of that chain: it receives items, does its work, and hands the result to the next node. Use `$json` to read the current item and `$node["Name"]` to reach an earlier node.

![Code node — sample screenshot](https://picsum.photos/seed/code-node/1200/640)

## Step-by-step

1. Open the workflow editor and select **Add node**.
2. Search for **Code node** and add it to the canvas.
3. Fill in the required parameters (see the table below).
4. Select **Test step** to run it with sample data.
5. Check the output panel, then **Save** the workflow.

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| Name | string | Yes | A label shown on the canvas |
| Mode | option | Yes | `run once` or `run per item` |
| Timeout | number | No | Seconds before the step fails (default 80) |
| Retry on fail | boolean | No | Retries up to 3 times with back-off |

## Example

```bash
# Code node
docker run -it --rm \
  -p 5678:5678 \
  -e FLOWLINE_ENCRYPTION_KEY=change-me \
  -v flowline_data:/home/flowline/.flowline \
  flowline/flowline:latest
```

<details><summary>Advanced options</summary><p>Set <code>FLOWLINE_CODE_NODE_LIMIT</code> to cap how many items one execution processes. Leave it unset for no limit.</p></details>

## Troubleshooting

| Symptom | Likely cause | Fix |
| --- | --- | --- |
| Step shows *No output* | The previous node returned zero items | Pin sample data on the previous node |
| `401 Unauthorized` | Expired credential | Reconnect it under **Credentials** |
| Execution times out | Large payload | Split items with **Split Out** |

## Related

- **Build your first workflow**
- **Expressions**
- **Error handling**