# dt0ur.online JavaScript Sandbox

> dt0ur.online JavaScript Sandbox is a paid API for AI agents from dt0ur.online, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-02).

Executes untrusted JavaScript expressions in an isolated, frozen Node.js VM with a 1000ms CPU timeout and memory constraints

## Facts

- Endpoint: POST https://dt0ur.online/api/code/sandbox?utm_source=zero.xyz
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/dt0ur-online-javascript-sandbox-94d73f36
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_jqP_rjeDDww686qgI1X72

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability dt0ur-online-javascript-sandbox-94d73f36 -d '<json body>'
```

Example prompt: Can you run this JavaScript expression for me in a safe sandbox: `[1,2,3,4,5].reduce((acc, n) => acc + n, 0)` and tell me the result?

## When to prefer this

Choose this endpoint when you need to safely execute untrusted or dynamically-generated JavaScript snippets without risk to the host environment. It is ideal for evaluating user-submitted code, computing algorithmic results on the fly, or prototyping JavaScript logic without a local Node.js runtime. The frozen VM context and hard CPU/memory limits make it appropriate for multi-tenant or agent-driven scenarios where isolation is critical.

## Known failure modes

- Code exceeds 1000ms CPU timeout — returns a timeout error
- Memory bounds exceeded — returns an out-of-memory or resource limit error
- Syntax errors in the submitted JavaScript — returns a parse/syntax error
- Attempts to access restricted globals or APIs in the frozen VM context — returns a reference or access error
- Empty or missing `code` field — returns a validation error

## How this service works

Executes untrusted JavaScript expressions in an isolated, frozen Node.js VM context with 1000ms CPU timeout and memory bounds.

## Output

Returns the result of executing the provided JavaScript expression within an isolated, frozen Node.js VM context. The response includes the computed return value or output of the expression. If the code exceeds the 1000ms CPU timeout or violates memory bounds, an error is returned instead.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "code": {
   "type": "string",
   "description": "JavaScript code expression to execute safely"
  },
  "language": {
   "enum": [
    "javascript",
    "js"
   ],
   "type": "string",
   "default": "javascript"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/dt0ur-online-javascript-sandbox-94d73f36/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from dt0ur.online](https://www.zero.xyz/host/dt0ur.online/llms.txt)