Summary
Gives Claude a sandboxed runtime for executing Python, JavaScript, and SQL snippets on demand. The server connects to a remote API at klymax402.com and uses x402 micropayments, meaning you'll incur small charges per execution. Useful when you need to test code fragments, run quick calculations, or validate SQL queries without spinning up local environments. The GitHub repo is sparse on implementation details, but the core value is clear: outsourced code execution with pay-per-use billing. Reach for this when you want Claude to run actual code and return real output rather than just generating examples.
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Public tool metadata for what this MCP can expose to an agent.
1 tools
code_execute_sandboxUse 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). 1. output3 params
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). 1. output
Parameters* required
codestringThe code to execute
languagestringProgramming language: python, javascript, or sqlone of
python · javascript · sqltimeoutnumberExecution timeout in milliseconds (default: 5000, max: 10000)
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
Featured
Keeps your Mac awake while Claude Code, Codex or Cursor works. Lets it sleep when they are done.
Try free for 7 days →Block distracting apps from your iPhone permanently without a 3rd party app. Free and open source.
Block now (100% free) →Notes, actions and memory. Without a meeting bot. First month 100% off.
Download for free →belt cli automatically finds the best tools and skills for your agent. image, video, music, tts...
one prompt install →Free an open-source skills that make AI coding agents easier to understand, verify, and control.
Download for free →Connect your Claude agent to live crypto prices and trading routes via 1inch
Get the MCP →
