# Nodejs Runner (`martin.forejt/nodejs-runner`) Actor

This Actor allows you to quickly run arbitrary JavaScript code in a real Node.js environment, making it ideal for testing, debugging, or executing small scripts without setting up a local Node.js instance. The actor spawns a separate Node.js process to run the provided code and captures the logs.

- **URL**: https://apify.com/martin.forejt/nodejs-runner.md
- **Developed by:** [Martin Forejt](https://apify.com/martin.forejt) (community)
- **Categories:** Developer tools
- **Stats:** 178 total users, 4 monthly users, 100.0% runs succeeded, 7 bookmarks
- **User rating**: No ratings yet

## Pricing

from $0.0005 / actor start

This Actor is paid per event and usage. You are charged both the fixed price for specific events and for Apify platform usage.

Learn more: https://docs.apify.com/actors/running/actors-in-store.md#pay-per-event

## What's an Apify Actor?

Actors are web data automations that power AI and operations. They run on the Apify platform to scrape websites, process data, connect APIs, and automate workflows.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.
Actors are written with capital "A".

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.
The best way to integrate Actors is as follows.

- **AI agents and MCP clients** — the [Apify MCP server](https://docs.apify.com/integrations/mcp.md) at `https://mcp.apify.com` (remote, streamable HTTP, OAuth on first use).
- **Agentic workflows and local Actor development** — [Agent Skills](https://apify.com/.well-known/agent-skills/index.json) with the [Apify CLI](https://docs.apify.com/cli/docs.md): `npm install -g apify-cli`, then `apify login`.
- **JavaScript/TypeScript projects** — the official [JS/TS client](https://docs.apify.com/api/client/js/docs.md): `npm install apify-client`.
- **Python projects** — the official [Python client](https://docs.apify.com/api/client/python/docs.md): `pip install apify-client`.
- **Any other language** — the [REST API](https://docs.apify.com/api/v2.md).

For usage examples, see the [API](#api) section below.

For more details, see Apify documentation as [Markdown index](https://docs.apify.com/llms.txt) and [Markdown full-text](https://docs.apify.com/llms-full.txt).

# README

## Node.js Code Runner

This Apify actor allows you to quickly run arbitrary JavaScript code in a real Node.js environment, making it ideal for testing, debugging, or executing small scripts without setting up a local Node.js instance. The actor spawns a separate Node.js process to run the provided code, captures the logs (stdout and stderr), and saves them to Apify's Key-Value Store for later retrieval.

### Use Case

- **Quick Testing:** Instantly run JavaScript snippets in a Node.js environment.
- **Dynamic Execution:** Dynamically execute and debug code from your workflows.
- **Environment Replication:** Run code in an isolated environment that matches Node.js runtime configurations.

### How It Works

1. The actor receives the JavaScript code to run via its input.
2. It spawns a child Node.js process to execute the code.
3. Captures all logs (stdout and stderr) during execution.
4. Saves the logs to the Apify Key-Value Store for easy access.

***

### Input

The input should be a JSON object with the following structure:

```json
{
  "code": "<your JavaScript code here>"
}
```

#### Input Fields

- **`code`** (string, required): The JavaScript code to execute.

#### Example Input

```json
{
  "code": "console.log('Hello, world!');"
}
```

***

### Output

The output logs from the executed code are saved in the Key-Value Store under the key `LOGS`. The logs include both `stdout` and `stderr` streams, as well as the exit code of the process.

#### Example Logs

```json
[
  "STDOUT: Hello, world!\n",
  "Child process exited with code 0"
]
```

***

### Example Usage

#### Running the Actor

1. Deploy the actor to the Apify platform.
2. Provide the JavaScript code as input.
3. Run the actor.

#### Sample Input

```json
{
  "code": "console.log('The current date is:', new Date().toISOString());"
}
```

#### Sample Output Logs

```json
[
  "STDOUT: The current date is: 2024-12-12T10:00:00.000Z\n",
  "Child process exited with code 0"
]
```

***

### Development Notes

#### Key Features

- **Logs Collection:** Automatically collects and stores all logs for easy retrieval.
- **Error Handling:** Captures errors during execution and stores them for debugging.
- **Environment Replication:** Runs in a real Node.js process, ensuring consistent behavior with a local environment.

#### How to Retrieve Logs

After the actor runs, you can fetch the logs using the Apify SDK or API:

##### In Apify Console:

In the actor run details, navigate to the Key-Value Store section and find the `LOGS` key.

##### Using SDK:

```javascript
const logs = await Actor.getValue('LOGS');
console.log('Retrieved Logs:', logs);
```

##### Using API:

```bash
curl -X GET "https://api.apify.com/v2/key-value-stores/%7BstoreId%7D/records/LOGS"
```

# Actor input Schema

## `code` (type: `string`):

JavaScript code to run in Node.js

## Actor input object example

```json
{
  "code": "console.log('Hello world!');"
}
```

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {
    "code": "console.log('Hello world!');"
};

// Run the Actor and wait for it to finish
const run = await client.actor("martin.forejt/nodejs-runner").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = { "code": "console.log('Hello world!');" }

# Run the Actor and wait for it to finish
run = client.actor("martin.forejt/nodejs-runner").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print(f"💾 Check your data here: https://console.apify.com/storage/datasets/{run.default_dataset_id}")
for item in client.dataset(run.default_dataset_id).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{
  "code": "console.log('\''Hello world!'\'');"
}' |
apify call martin.forejt/nodejs-runner --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,martin.forejt/nodejs-runner"
        }
    }
}

```

The hosted server signs you in with OAuth on first connect, so no API token belongs in this config. Clients without OAuth support can send an `Authorization: Bearer <APIFY_API_TOKEN>` header instead, using a token from API & Integrations in Apify Console (https://console.apify.com/settings/integrations).

## OpenAPI specification

Download the OpenAPI definition: https://api.apify.com/v2/actors/ECFcJkFqhtxYGqqGy/builds/RDkKhRbDSiVKfQCeC/openapi.json