agent-utils-mcp

Six general-purpose utilities for AI agents, exposed as MCP tools and paid $0.01 USDC per call on Base mainnet via x402.

You supply the wallet. This package ships no keys.

The server signs each payment with a key it reads from its own env, which you set in your MCP client's config. Nothing is bundled, and no key is ever sent anywhere except as an EIP-3009 signature to the x402 facilitator.

• Fund a wallet with a few dollars of USDC on Base.

• It needs zero ETH — payments use transferWithAuthorization and the facilitator broadcasts and pays the gas.

• Use a low-balance, disposable wallet. The key sits in your client config in plaintext; any process that can read that file can spend from it.

Related MCP server: MCP Toolbox

Install

{
  "mcpServers": {
    "agent-utils": {
      "command": "npx",
      "args": ["-y", "agent-utils-mcp"],
      "env": {
        "EVM_PRIVATE_KEY": "0xyour_disposable_base_wallet_key"
      }
    }
  }
}

Tools list fine without a key — you can inspect what is on offer before funding anything. The first paid call is where a missing key is reported.

What each call returns

Every tool returns the upstream JSON plus, on a successful payment, the settlement transaction hash:

(paid $0.01 USDC — settle tx 0xb2397b96…)

That is deliberate: you can verify on Basescan that you were charged once, for what you got, rather than taking the server's word for it.

Design notes

These six were not chosen by guesswork. They are the categories that USDC receipts across 1,062 x402 seller wallets showed agents actually pay for — geocoding (56 payers), weather (21), article/PDF→Markdown (7), randomness (6), web search (6).

The upstreams follow two rules worth knowing as a caller:

• A missing value is null with a reason, never a plausible-looking number. Weather reports no reading rather than zero; reverse-geocode says "ocean or unmapped" rather than inventing an address.

• The limits of an answer are stated in the answer. Forecast rows are labelled model output; search says results are unverified and that its ranking is DuckDuckGo's; web_search's count is a maximum, not a promise, because a result whose destination cannot be resolved is dropped rather than guessed at.

url_to_markdown refuses private, loopback, link-local and cloud-metadata addresses, and re-validates every redirect hop — it fetches caller-supplied URLs from inside a private network, so that guard is not optional.

Licence

MIT.