Code Sandbox API

io.github.Br0ski777Published by GitHub account Br0ski777v1.1.0Updated Oct 24, 2026

Execute Python, JavaScript, SQL code in a sandbox. x402 micropayment.

VerifiedSSEWeb executableDeveloper Tools Data & Analytics

Server details

Identifier: io.github.Br0ski777/code-sandbox
Transport: SSE
Runtime: Web executable
Trust: Verified
Published: Sep 16, 2026

Security note

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The registry verified the GitHub account Br0ski777 for this listing. That does not show the account is the product's maker.

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Overview

AI-generated overview

Remote MCP server that runs Python, JavaScript or SQL snippets in a sandbox and returns stdout, timing, exit code and errors, paid per call.

What you can do: Execute a code snippet in Python, JavaScript or SQL in a sandboxed environment
Read back captured stdout, execution time, exit code and error message
Set an optional execution timeout in milliseconds, capped at 10 seconds
Use it for calculations, data transformations, snippet validation or in-memory SQLite queries
When to use it: Useful when an assistant needs computed results rather than static data: quick calculations, small data transformations, checking whether a snippet runs, or querying an in-memory SQLite database without a local runtime.
Requirements: A remote MCP endpoint over SSE; nothing to install locally. No API key or signup, but each call is paid through the x402 protocol in USDC on Base L2, so the client must be x402-aware and hold a funded wallet. Network access to the endpoint is required.

Before you install

Every execution costs money (listed at $0.02 per call) in USDC on Base, so an assistant can spend from the connected wallet; set spending limits. Code is sent to a third-party service for execution, so avoid secrets or sensitive data in snippets. The service is a small marketplace offering with no stated data-retention or isolation guarantees.

Installation

In SourceWeft

Open Code Sandbox API in the dashboard and add it to a workspace.
Enable the server for the chats that should use its tools.

Web executable via SSE. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/io.github.Br0ski777%2Fcode-sandbox/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "code-sandbox-api": {
      "type": "sse",
      "url": "https://code-sandbox.api.klymax402.com/mcp"
    }
  }
}

README

Code Sandbox API

[MCP Server] [x402] [License: MIT]

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.):

json

{  "mcpServers": {    "code-sandbox": {      "url": "https://code-sandbox.api.klymax402.com/mcp"    }  }}

{  "mcpServers": {    "code-sandbox": {      "url": "https://code-sandbox.api.klymax402.com/mcp"    }  }}

Quickstart -- HTTP (x402)

bash

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

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

`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 executed
executionTimeMs -- execution duration in milliseconds
exitCode -- process exit code (0 = success)
error -- error message if execution failed (null on success)

Example response:

json

{"output":"Hello World\n42\n","language":"python","executionTimeMs":234,"exitCode":0,"error":null}

{"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

Source: README.md at commit 6449415

Tools

SourceWeft has not read this server's tools yet.

Version history

v1.1.0LatestSep 16, 2026

Score

50% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

Reached in the last 30 daysRequired25 pts
Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.
Auth declaredRequired10 pts
Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.
Tools listed15 pts
Answer tools/list without a credential, or ship a package that starts in a sandbox without one.
DescriptionRequired15 pts
Logo10 pts
Documentation15 pts
License10 pts