The Remix x402 MCP Server

The Remix x402 MCP Server exposes Remix’s Solidity compiler, Slither analysis, contract deployment, and AI security auditing as services that are paid for per call in USDC. It is aimed at AI agents, and at anything else that can pay per call over MCP or plain HTTP.

The server is indexed on the x402 Bazaar with full metadata, so agents can discover the tools rather than being configured with them.

There are two ways to use Remix x402. The first is through any MCP client that can make payments: you describe what you want in plain language, and the client makes the call and pays for it from a wallet. Setting up Claude walks through Claude Desktop and Claude Code, though nothing here is specific to them. The second is to call the HTTP endpoints from your own code.

Available tools

Tool

What it does

Price

compile_solidity

Compiles Solidity sources and returns ABI, bytecode, and metadata

0.01 USDC

analyze_with_slither

Runs Slither static security analysis

0.02 USDC

compile_and_deploy

Compiles and deploys to one network

(Gas cost × 1.3) + 0.05 USDC

compile_and_deploy_multi_network

Compiles once, deploys to several networks

(Total gas × 1.3) + 0.05 USDC, plus a 10% buffer

Two further services, get_audit_checklist and do_audit, run an AI security audit. They are available over HTTP only, and are covered on the AI audit page.

Each tool has its own page in this section, with full parameter and response reference.

HTTP endpoints

Compilation, analysis, and the AI audit services are also reachable as REST endpoints, under https://api.remix.live/mcp/x402-http/:

Method

Endpoint

Price

POST

/compile

0.01 USDC

POST

/analyze

0.02 USDC

POST

/get_audit_checklist

0.05 USDC

POST

/do_audit

0.10 USDC

GET

/info

Free

GET

/health

Free

The split runs both ways: the deployment tools are MCP-only, and the two audit endpoints are HTTP-only. /info reports the server’s name, version, endpoints and prices, and the network it settles on, which makes it a quick way to confirm what you are talking to:

curl https://api.remix.live/mcp/x402-http/info

Or call it from here:

Network

The hosted service settles on Base mainnet, chain ID 8453. Every call therefore spends real USDC, starting at 0.01 for a compile, so treat the prices on this page as money rather than credits.

To work against a testnet instead, you have to run the server yourself on Base Sepolia, chain ID 84532. The HTTP endpoints page covers that. Either way, /info reports the network a given server is on.

Paying for calls

Compilation and analysis are fixed price. The deployment tools are priced dynamically, because the server pays the deployment gas for you: the quote is that gas cost with a multiplier applied, plus a flat fee.

The x402 payment itself is gasless. You sign an authorization rather than sending a transaction, and a facilitator service settles it on chain and pays that transaction’s gas. This covers the payment only. The gas to actually deploy a contract is real, and is what the deployment tools price in.

If your balance does not cover a call, it is rejected before any work is done:

{
  "error": "Insufficient USDC balance. Required: 0.01 USDC, Available: 0.005 USDC"
}

Best practices

  1. Test compilation before you deploy.

  2. Run a Slither analysis before deploying, to catch security issues early, and an AI audit when you want a written review alongside it.

  3. Start with small contracts, to get a feel for the costs.

  4. Use the optimizer for production deployments, to reduce gas costs.

  5. Check constructor arguments carefully before deploying.

  6. Check the network carefully, since testnet tokens have no real value.

  7. Save your deployment addresses. You need them to interact with the contracts afterwards.

  8. Test post-deployment calls on a single network before deploying to several.

Support