X402Engine Mcp — independently scanned and version-tracked by SaferSkills.
SaferSkills independently audited X402Engine Mcp (Agent Skill) and scored it 100/100 (green). The audit ran 55 deterministic rules across Security, Supply Chain, Maintenance, Transparency, and Community; it found 0 high-severity and 0 lower-severity findings. The full rule-by-rule trace and per-finding evidence are below. Free, methodology-open.
Findings & checks · 0 flagged
Every scanned point with the score it earned and what moved between them.
First recorded scan — no prior version to compare against.
The primary manifest — the file an agent reads to learn what this artifact does.
Agent-friendly MCP server for x402engine. It lets agents discover and call pay-per-request APIs through HTTP 402, with automatic USDC payment on Base or Solana.
The live gateway covers LLMs, image and video generation, web search and scraping, code execution, crypto and wallet data, transaction simulation, audio, travel, and IPFS. This MCP exposes a curated tool set and live discovery for the full catalog.
Use a dedicated, low-balance payer wallet. The MCP signs x402 payments locally and never sends the private key to x402engine.
{
"mcpServers": {
"x402engine": {
"command": "npx",
"args": ["-y", "[email protected]"],
"env": {
"X402_EVM_PRIVATE_KEY": "0xYOUR_DEDICATED_PAYER_KEY",
"X402_PAYMENT_NETWORK": "base",
"X402_MAX_PAYMENT_USD": "1.00"
}
}
}
}Fund the wallet with USDC on Base. The x402 facilitator pays transaction gas; the wallet signs an EIP-3009 USDC authorization.
{
"mcpServers": {
"x402engine": {
"command": "npx",
"args": ["-y", "[email protected]"],
"env": {
"X402_SOLANA_PRIVATE_KEY": "YOUR_BASE58_OR_JSON_PRIVATE_KEY",
"X402_PAYMENT_NETWORK": "solana",
"X402_MAX_PAYMENT_USD": "1.00"
}
}
}
}Fund the wallet with USDC on Solana and enough SOL for transaction fees.
The server starts without a wallet, and free tools such as discover_services and service_health still work. Paid tools return their x402 payment requirements until a wallet is configured.
claude mcp add x402engine -- npx -y [email protected]Install the x402engine skill and merge this server into the active Hermes profile's config.yaml:
mcp_servers:
x402engine:
command: npx
args: ["-y", "[email protected]"]
env:
X402_BASE_URL: "https://x402engine.app"
X402_PAYMENT_NETWORK: "auto"
X402_MAX_PAYMENT_USD: "0.10"Start a new session and call discover_services or service_health; both are free. Keep the network on auto until a wallet is configured. For Base payments, store X402_EVM_PRIVATE_KEY in the profile's local .env, add X402_EVM_PRIVATE_KEY: "${X402_EVM_PRIVATE_KEY}" to the server's env, and change the network to base. Never put wallet keys in chat. The cap applies per request; authorize a separate total budget for each task.
Full Hermes setup guide · Installable skill
| Variable | Default | Description |
|---|---|---|
X402_EVM_PRIVATE_KEY | unset | Dedicated payer key for Base USDC |
X402_SOLANA_PRIVATE_KEY | unset | Base58 or JSON payer key for Solana USDC |
X402_PAYMENT_NETWORK | auto | auto, base, or solana |
X402_MAX_PAYMENT_USD | 1.00 | Hard per-request spending limit |
X402_BASE_URL | production gateway | Override the gateway URL |
X402_PAYMENT_HEADER | unset | Legacy pre-signed x402 header |
X402_DEV_BYPASS | unset | Development bypass secret |
In auto mode, Base is preferred when both keys are configured. Automatic payment only accepts the canonical USDC contracts on Base and Solana. It rejects unknown assets, unsupported networks, and amounts above the configured cap before signing.
MegaETH remains available to clients that supply their own compatible payment header.
| Category | Tools |
|---|---|
| Discovery | discover_services, service_health |
| Image and code | generate_image, execute_code |
| Audio | transcribe_audio |
| Crypto | get_crypto_price, get_crypto_markets, get_crypto_history, get_trending_crypto, search_crypto, get_crypto_categories |
| Wallet and token | get_wallet_balances, get_wallet_transactions, get_wallet_pnl, get_token_prices, get_token_metadata |
| IPFS | pin_to_ipfs, get_from_ipfs |
| Travel | search_flights, search_locations, search_hotels, search_cheapest_dates |
Prices are included in each tool description and in live discovery. The gateway catalog can change independently of this package.
npm install
npm test
npm run build~30 seconds. Free. No account. Every finding cites a rule and a line of evidence.