# Agent-Exec Code Execution Sandbox

> Agent-Exec Code Execution Sandbox is a paid API for AI agents from agent-exec.45.67.221.128.sslip.io, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Executes Python 3 or Node.js code in an isolated, network-less sandbox and returns stdout, stderr, and exit code as JSON

## Facts

- Endpoint: POST https://agent-exec.45.67.221.128.sslip.io/execute
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-exec-code-execution-sandbox-f387002f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lbjlNlY6cnn5ak-aKyoq_

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 agent-exec-code-execution-sandbox-f387002f -d '<json body>'
```

Example prompt: Run this Python 3 snippet for me in an isolated sandbox and give me the stdout output: `import math; print(math.factorial(20))`

## When to prefer this

Choose this endpoint when you need to run a small Python 3 or Node.js code snippet in a fully isolated, network-less environment with no account setup required and pay-per-use pricing via x402. Ideal for agents that need on-demand computation, algorithm testing, or data transformation without provisioning any infrastructure. Prefer over cloud function services when you need instant, no-registration, micro-priced execution.

## Known failure modes

- Script syntax error returns non-zero exit code with stderr containing the traceback
- Network calls inside the sandbox fail because it is network-less — any HTTP request or socket use will error
- Execution timeout if script runs too long
- Unsupported language identifier results in error
- Payment failure over x402 returns 402 response before code is run

## How this service works

Accountless, pay-per-use code execution for software agents: submit source code, get stdout, stderr and exit code back from an isolated, network-less sandbox. No account, no API key -- possession of valid payment is sufficient.

## Output

A JSON object containing three fields: stdout (the standard output produced by the script), stderr (any error messages or warnings), and exit code (integer indicating success or failure — 0 for success, non-zero for errors)

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "source",
  "runtime"
 ],
 "properties": {
  "files": {
   "type": "object",
   "description": "Extra files seeded alongside the entry file, as relative-path -> content."
  },
  "stdin": {
   "type": "string",
   "description": "Written to the payload's stdin, then stdin is closed."
  },
  "limits": {
   "type": "object",
   "description": "Per-request resource budget. Every field is optional; an omitted field takes its documented default. A field outside [minimum, maximum] is rejected outright, never clamped."
  },
  "source": {
   "type": "string",
   "description": "Program source, written to the runtime's entry file."
  },
  "runtime": {
   "enum": [
    "python3",
    "node"
   ],
   "type": "string",
   "description": "Must be one of the allowlisted runtimes named here -- this enum (and x-runtimes) is the free way to learn the set. An unsupported value is refused only AFTER a payment attempt, as RUNTIME_UNSUPPORTED, not before."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "outcome",
  "stdout",
  "stderr",
  "exitCode",
  "durationMs",
  "truncated",
  "error",
  "payment",
  "receipt"
 ],
 "properties": {
  "error": {
   "type": [
    "object",
    "null"
   ],
   "properties": {
    "code": {
     "enum": [
      "SANDBOX_INVALID_REQUEST",
      "RUNTIME_RESERVED_FILE_PATH",
      "REQUEST_MALFORMED",
      "PAYMENT_MALFORMED",
      "RUNTIME_UNSUPPORTED",
      "RUNTIME_LIMIT_OUT_OF_RANGE",
      "SANDBOX_TIMEOUT",
      "EXECUTION_MEMORY_LIMIT_EXCEEDED",
      "EXECUTION_OUTPUT_LIMIT_EXCEEDED",
      "SERVICE_BUSY",
      "PAYER_RATE_LIMITED",
      "PAYER_CONCURRENCY_LIMITED",
      "EXECUTE_IP_RATE_LIMITED",
      "EXECUTION_RUNTIME_ERROR",
      "EXECUTION_RUNTIME_ERROR_POSSIBLE_SANDBOX_DENIAL",
      "PAYMENT_INVALID",
      "PAYMENT_AMOUNT_INSUFFICIENT",
      "PAYMENT_REQUIREMENTS_MISMATCH",
      "PAYMENT_REPLAYED",
      "PAYMENT_SETTLEMENT_FAILED",
      "PAYMENT_SETTLEMENT_INDETERMINATE",
      "SANDBOX_UNAVAILABLE",
      "SANDBOX_SETUP_FAILED",
      "SERVICE_INTERNAL_FAILURE",
      "PAYMENT_FACILITATOR_UNAVAILABLE"
     ],
     "type": "string"
    },
    "message": {
     "type": "string"
    },
    "billable": {
     "type": "boolean"
    },
    "category": {
     "type": "string"
    }
   },
   "description": "Null when `outcome` is \"completed\"."
  },
  "stderr": {
   "type": "string"
  },
  "stdout": {
   "type": "string"
  },
  "outcome": {
   "enum": [
    "completed",
    "timeout",
    "error"
   ],
   "type": "string"
  },
  "payment": {
   "type": "object",
   "properties": {
    "asset": {
     "type": "string"
    },
    "payer": {
     "type": "string",
     "description": "The paying wallet's address."
    },
    "amount": {
     "type": "string",
     "description": "Atomic units of the settlement asset that were charged."
    },
    "network": {
     "type": "string"
    },
    "transaction": {
     "type": "string",
     "description": "On-chain settlement transaction hash."
    }
   },
   "description": "The payer is surfaced because it is this service's notion of identity (build.md: the wallet is the account) -- per-payer rate limits and standing are built on it."
  },
  "receipt": {
   "type": "object",
   "required": [
    "requestDigest",
    "payment",
    "priceUsd",
    "price",
    "tier",
    "limits",
    "usage",
    "status",
    "outputDigest"
   ],
   "properties": {
    "tier": {
     "type": "string"
    },
    "price": {
     "type"
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-exec-code-execution-sandbox-f387002f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent-exec.45.67.221.128.sslip.io](https://www.zero.xyz/host/agent-exec.45.67.221.128.sslip.io/llms.txt)