---
title: 'Run Code'
description: 'Run a sandboxed JavaScript snippet over wired JSON inputs.'
updated: 2026-07-09
---

# Run Code

**Node type:** `exec:code`  
**Category:** `Data`

## Description

Runs a JavaScript snippet in a locked-down sandbox over your wired inputs. The script runs as an async function body: every resolved input port is available on a frozen `inputs` object keyed by port id, and the script must `return` a JSON-serializable value. Scoring formulas, dedupe checks, contract gates, and alignment logic belong here instead of one-off catalog nodes.

The sandbox has no network, no filesystem, and no access to secrets. Available globals: `inputs`, `console.log` (captured and returned as logs), and the standard JavaScript intrinsics (`JSON`, `Math`, `Date`, `Array`, ...). `require`, `process`, and `fetch` do not exist.

Currently in a limited admin-only beta.

## Canvas ports

These appear as port handles on the left side of the node.

| ID        | Label       | Details |
| --------- | ----------- | ------- |
| `input_1` | **Input 1** | `JSON`  |
| `input_2` | **Input 2** | `JSON`  |

Add as many JSON input ports as you need; each becomes a key on `inputs`.

## Sidebar config

These render as form fields in the right-side config panel when the node is selected.

| ID          | Label            | Details                                                        |
| ----------- | ---------------- | -------------------------------------------------------------- |
| `code`      | **Code**         | `TEXT` _(required)_ · multiline. The script (plain JavaScript) |
| `timeoutMs` | **Timeout (ms)** | `NUMBER` · default `10000`, max `60000`                        |

## Outputs

| ID       | Label      | Type   |
| -------- | ---------- | ------ |
| `output` | **Output** | `JSON` |
| `logs`   | **Logs**   | `TEXT` |

## Limits and failure semantics

- Returned value must be JSON-serializable and at most 1 MB serialized. Exceeding the cap is a failure, not a truncation.
- Captured logs cap at 64 KB.
- A thrown error fails the node with the error message.
- Returning `{ __fail: true, error, failures: [{ id?, rule?, message }] }` fails the node while preserving the structured `failures` list (the hook for future automated retry loops).

## Worked example: score and pick the best item

Wire an LLM or import node emitting a JSON array into `input_1`, then:

```js
// inputs.input_1 = [{ id, views, ageHours }, ...]
const scored = inputs.input_1.map((it) => ({
  ...it,
  score: it.views / Math.max(it.ageHours, 1),
}));
scored.sort((a, b) => b.score - a.score);
console.log('best of', scored.length, 'is', scored[0].id);
return scored[0];
```

The winning item is available downstream on the `output` port; the log line arrives on `logs`.

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_Auto-generated from the Wireflow node registry._

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Documentation index: fetch https://www.wireflow.ai/llms.txt for the full list of Wireflow docs.