Code Sandbox API
Execute Python, JavaScript, or SQL in a sandbox. Get stdout, execution time, errors. 10s timeout. Pay-per-call via x402 (USDC on Base L2) -- no API key, no signup, no rate-limit wall.
Part of the klymax402 marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.
Quickstart -- MCP
Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):
{
"mcpServers": {
"code-sandbox": {
"url": "https://code-sandbox.api.klymax402.com/mcp"
}
}
}
Quickstart -- HTTP (x402)
curl -X POST "https://code-sandbox.api.klymax402.com/api/execute" \
-H "Content-Type: application/json" \
-d '{"code":"...","language":"..."}'
# -> 402 Payment Required, with an x402 payment challenge in the response body
Any x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.
Tools
| Tool | Method | Path | Price | Description |
|---|---|---|---|---|
code_execute_sandbox | POST | /api/execute | $0.02 | Execute code in a sandboxed environment |
code_execute_sandbox
Use this when you need to execute Python, JavaScript, or SQL code in a sandboxed environment and get the output. Supports Python (subprocess), JavaScript (eval), and SQL (in-memory SQLite).
Parameters
| Name | Type | Required | Description |
|---|---|---|---|
code | string | yes | The code to execute |
language | string | yes | Programming language: python, javascript, or sql |
timeout | number | no | Execution timeout in milliseconds (default: 5000, max: 10000) |
Returns
output-- stdout captured from code execution (max 10KB)language-- the language that was executedexecutionTimeMs-- execution duration in millisecondsexitCode-- process exit code (0 = success)error-- error message if execution failed (null on success)
Example response:
{"output":"Hello World\n42\n","language":"python","executionTimeMs":234,"exitCode":0,"error":null}
When to use: running calculations, data transformations, validating code snippets, or querying in-memory databases. Essential when you need computed results rather than static data.
Example agent prompts
- "Execute Python, JavaScript, or SQL code in a sandboxed environment and get the output"
Payment
- Protocol: x402 -- HTTP-native pay-per-call, no signup, no API key
- Network: Base L2 (
eip155:8453) - Asset: USDC
- Facilitator: Coinbase CDP (primary), PayAI (fallback)
- Also reachable via ATXP (OAuth-wrapped x402, RFC 9728 protected-resource metadata)
Part of klymax402
100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.
- Catalog: https://klymax402.com/llms.txt
- Full API reference: https://klymax402.com/llms-full.txt
- Live stats: https://klymax402.com/stats
License
MIT